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  • 1.
    Agnihotri, Swarnima
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Yin, D M
    Institute of Urban and Rural Mining, Changzhou University, Changzhou, China.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Sapmaz, Tugba
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Varjani, S
    Gujarat Pollution Control Board, Gandhinagar, India.
    Qiao, W
    Institute of Urban and Rural Mining, Changzhou University, Changzhou, China.
    Koseoglu-Imer, D Y
    Department of Environmental Engineering, Istanbul Technical University, Maslak, Istanbul, Turkey.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    A Glimpse of the World of Volatile Fatty Acids Production and Application: A review2022Inngår i: Bioengineered, ISSN 2165-5979, E-ISSN 2165-5987, Vol. 13, nr 1, s. 1249-1275Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Sustainable provision of chemicals and materials is undoubtedly a defining factor in guaranteeing economic, environmental, and social stability of future societies. Among the most sought-after chemical building blocks are volatile fatty acids (VFAs). VFAs such as acetic, propionic, and butyric acids have numerous industrial applications supporting from food and pharmaceuticals industries to wastewater treatment. The fact that VFAs can be produced synthetically from petrochemical derivatives and also through biological routes, for example, anaerobic digestion of organic mixed waste highlights their provision flexibility and sustainability. In this regard, this review presents a detailed overview of the applications associated with petrochemically and biologically generated VFAs, individually or in mixture, in industrial and laboratory scale, conventional and novel applications.

    Fulltekst (pdf)
    fulltext
  • 2.
    Asadollahzadeh, Mohammadtaghi
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Lennartsson, Patrik R.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Application of Fungal Biomass for the Development of New Polylactic Acid-Based Biocomposites2022Inngår i: Polymers, E-ISSN 2073-4360, Vol. 14, nr 9Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Fungal biomass (FB), a by-product of the fermentation processes produced in large volumes, is a promising biomaterial that can be incorporated into poly(lactic acid) (PLA) to develop enhanced biocomposites that fully comply with the biobased circular economy concept. The PLA/FB composites, with the addition of triethyl citrate (TEC) as a biobased plasticizer, were fabricated by a microcompounder at 150 °C followed by injection molding. The effects of FB (10 and 20 wt %) and TEC (5, 10, and 15 wt %) contents on the mechanical, thermal and surface properties of the biocomposites were analyzed by several techniques. The PLA/FB/TEC composites showed a rough surface in their fracture section. A progressive decrease in tensile strength and Young’s modulus was observed with increasing FB and TEC, while elongation at break and impact strength started to increase. The neat PLA and biocomposite containing 10% FB and 15% TEC exhibited the lowest (3.84%) and highest (224%) elongation at break, respectively. For all blends containing FB, the glass transition, crystallization and melting temperatures were shifted toward lower values compared to the neat PLA. The incorporation of FB to PLA thus offers the possibility to overcome one of the main drawbacks of PLA, which is brittleness.

    Fulltekst (pdf)
    fulltext
  • 3.
    Elyasi, S
    et al.
    Department of Chemical Engineering, Amirkabir University of Technology, 15875-4413, Tehran, Iran.
    Fallah, N
    Department of Chemical Engineering, Amirkabir University of Technology, 15875-4413, Tehran, Iran.
    Bonakdarpour, B
    Department of Chemical Engineering, Amirkabir University of Technology, 15875-4413, Tehran, Iran.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    The effect of temperature and styrene concentration on biogas production and degradation characteristics during anaerobic removal of styrene from wastewater2021Inngår i: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 342Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In the current study, styrene was removed anaerobically from wastewaters at temperatures of 35 degrees C, 25 degrees C, and 15 degrees C and concentration range of 20-150 ppm in the presence of ethanol as a co-substrate and co-solvent. Maximum styrene removal of 93% was achieved at 35 degrees C. The volatilization of styrene was negligible at about 2% at all experimented temperatures. The average special methane yield (SMY) at 35 degrees C was 4.14- and 225-times higher than that of at T = 25 degrees C and T = 15 degrees C, respectively, but no methane was produced in the absence of ethanol. The proteins content of the soluble microbial product (SMP) and extracellular polymeric substance (EPS) was much higher than the carbohydrate content. At styrene concentration > 80 ppm, SMY, SMP, and EPS dropped sharply. The results confirmed the well performance of anaerobic microorganisms in removing styrene from wastewater and biogas production at mesophilic condition.

  • 4.
    Ferreira, Jorge A.
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Lennartsson, Patrik R.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Waste biorefineries using filamentous ascomycetes fungi: Present status and future prospects2016Inngår i: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 215, nr sept, s. 334-345Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Filamentous ascomycetes fungi have had important roles in natural cycles, and are already used industrially for e.g. supplying of citric, gluconic and itaconic acids as well as many enzymes. Faster human activities result in higher consumption of our resources and producing more wastes. Therefore, these fungi can be explored to use their capabilities to convert back wastes to resources. The present paper reviews the capabilities of these fungi in growing on various residuals, producing lignocellulose-degrading enzymes and production of organic acids, ethanol, pigments, etc. Particular attention has been on Aspergillus, Fusarium, Neurospora and Monascus genera. Since various species are used for production of human food, their biomass can be considered for feed applications and so biomass compositional characteristics as well as aspects related to culture in bioreactor are also provided. The review has been further complemented with future research avenues.[on SciFinder (R)]

  • 5.
    Harirchi, Sharareh
    et al.
    Department of Cell and Molecular Biology & Microbiology, Faculty of Biological Science and Technology, University of Isfahan, 8174673441, Isfahan, Iran.
    Etemadifar, Z.
    Department of Cell and Molecular Biology & Microbiology, Faculty of Biological Science and Technology, University of Isfahan, 8174673441, Isfahan, Iran.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Yazdian, Fatemeh
    Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, Tehran, Iran.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    The Effect of Calcium/Magnesium Ratio on the Biomass Production of a Novel Thermoalkaliphilic Aeribacillus pallidus Strain with Highly Heat-Resistant Spores2020Inngår i: Current Microbiology, ISSN 0343-8651, E-ISSN 1432-0991Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Hot springs are fascinating extreme environments for the isolation of polyextremophilic microorganisms with extraordinary characteristics. Since polyextremophilic bacterial growth are not as high as routine bacteria, the objective of this study was to investigate the effect of some environmental factors on biomass and metabolites productions in the newly isolated strain, from Larijan hot spring in Iran. The strain was identified as Aeribacillus pallidus Lhs-10 and deposited as CCUG 72355 and IBRC-M 11202 in Sweden and Iran, respectively. This thermoalkaliphilic strain can grow best at 50 °C, pH 8 and in the presence of 25 g/l NaCl. The physiological characterization of this strain show that [Ca/Mg] ratio affect its growth and biomass production with the best results obtained at the ratio of 2.5. Moreover, lactic and acetic acids production by this strain was affected by pH, aeration, and temperature, where a metabolic shift was detected from lactate to acetate production when the culture was aerated. Besides, its spores could tolerate heating at 80, 85, 90, 95 and 98 °C for 30 min without any reduction in the initial spore population, whereas D-value was defined 50 min at 98 °C. This newly lactic acid-producing strain of A. pallidus can be a promising strain that can be used in the harsh conditions in industrial processes. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.

  • 6.
    Jomnonkhaow, Umarin
    et al.
    Swedish Centre for Resource Recovery, University of Borås, 50190 Borås, Sweden.
    Uwineza, Clarisse
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Wainaina, Steven
    Reungsang, Alissara
    Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002, Thailand.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Membrane bioreactor-assisted volatile fatty acids production and in situ recovery from cow manure2021Inngår i: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Bioresource Technology, Vol. 321, artikkel-id 124456Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Cow manure (CM) generation in large volumes has for long been considered a waste management challenge. However, the organic content of CM signals opportunities for the production of value-added bioproducts such as volatile fatty acids (VFAs) through anaerobic digestion (AD). However, a robust VFAs fermentation process requires effective methane formation inhibition and enhance VFAs recovery. In this study, thermal pretreatment was applied to inhibit methanogens for enhanced VFAs production and an immersed membrane bioreactor (iMBR) for in situ recovery of VFAs in a semi-continuous AD. Maximal VFAs yield of 0.41 g VFAs/g volatile solids (VS) was obtained from thermally-treated CM without inoculum addition. The CM was further fed to the iMBR operating at organic loading rates of 0.8–4.7 gVS/L.d. The VFAs concentration increased to 6.93 g/L by rising substrate loading to 4.7 g VS/L.d. The applied iMBR set-up was successfully used for stable long-term (114 days) VFAs production and recovery.

    Fulltekst (pdf)
    fulltext
  • 7.
    Karimi, Sajjad
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mahboobi Soofiani, Nasrollah
    Fisheries Division, Department of Natural Resources, Isfahan University of Technology.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Use of Organic Wastes and Industrial By-Products to Produce Filamentous Fungi with Potential as Aqua-Feed Ingredients2018Inngår i: Sustainability, E-ISSN 2071-1050, Vol. 10, nr 9Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    Organic-rich waste and industrial by-product streams, generated in enormous amounts on a daily basis, contain substantial amounts of nutrients that are worthy of recovery. Biological conversion of organic-waste streams using filamentous fungi is a promising approach to convert nutrients into value-added bioproducts, such as fungal biomass. High-protein fungal biomass contains different kinds and levels of amino acids, fatty acids, immunostimulants, antioxidants, pigments, etc., which make it a potential choice for application in animal feed supplementation. Considering the challenges long faced by the aquaculture industry in fishmeal production due to the increasing prices and environmental concerns, the aquaculture industry is forced to provide alternative protein-rich sources to replace conventional fishmeal. In this review, the possibilities of utilization of filamentous fungi biomass cultivated on organic-rich waste streams, as an alternative nutrient source in fish feed, were thoroughly reviewed.

  • 8.
    Karimi, Sajjad
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Soofiani, N. M.
    Fisheries Division, Department of Natural Resources, Isfahan University of Technology, Isfahan, 8415683111, Iran.
    Lundh, T.
    Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, Uppsala.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Kiessling, A.
    Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, Uppsala.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Evaluation of filamentous fungal biomass cultivated on vinasse as an alternative nutrient source of fish feed: Protein, lipid, and mineral composition2019Inngår i: Fermentation, ISSN 2311-5637, Vol. 5, nr 4Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The rapid growth of aquaculture and scarcity of conventional fish feed supplements has prompted the introduction of new sustainable supplementation sources. In this study, the potential of five strains of fungal biomass of Ascomycetes and Zygomycetes edible filamentous fungi, Aspergillus oryzae, Neurospora intermedia, Rizhopus oryzae, Monascus purpureus, and Fusarium venenatum, cultivated on vinasse, a by-product of the bioethanol industry, as alternative protein sources for fishmeal in the fish diet was evaluated. It was observed that 5% vinasse with an initial pH of 5-6.5 can support fungal biomass yields of 34.3 +/- 2.4-118.5 +/- 3.9 g DM/L for A. Oryzae, N. intermedia, and R. oryzae. High protein contents of about 44.7%, 57.6%, and 50.9% (w/w), and fat contents of 7.0%, 3.5%, and 5.5% (w/w) were obtained for A. oryzae, N. intermedia, and R. oryzae, respectively. The latter three fungi species contained noticeable amino acid contents, including promising profiles of amino acids that are highly compatible with those of fishmeal. These findings provide evidence that fungal biomasses, with their relatively high protein content, good amino acid profiles, and other essential nutrients, are a promising supplementation alternative that can be produced from low-value by-products and organic-rich waste streams like vinasse to meet the dietary protein requirements in fish feed.

    Fulltekst (pdf)
    fulltext
  • 9.
    Karimi, Sajjad
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Department of Natural Resources, Isfahan University of Technology, Isfahan 8415683111, Iran.
    Soofiani, N. M.
    Department of Natural Resources, Isfahan University of Technology, Isfahan 8415683111, Iran.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Ferreira, Jorge
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Lundh, T.
    Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, 75007 Uppsala, Sweden.
    Kiessling, A.
    Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, 75007 Uppsala, Sweden.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Evaluation of nutritional composition of pure filamentous fungal biomass as a novel ingredient for fish feed2021Inngår i: Fermentation, ISSN 2311-5637, Vol. 7, nr 3, artikkel-id 152Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The rapid growth of aquaculture and the lack of fish meal demand new sustainable ingre-dients. Although fungal biomass is found to be a promising sustainable fish feed supplementation candidate, the characteristics of this protein-rich source are closely influenced by the quality of the applied growth medium. In this work, the nutritional properties of pure filamentous fungal biomass provided from the cultivation of Aspergillus oryzae, Neurospora intermedia and Rhzopus oryzae were evaluated to assess their potential as alternative novel protein sources in fish feed. In this regard, fungal biomass yields of up to 0.19 ± 0.005 (g dry biomass/g substrate glucose) were obtained during submerged cultivation of fungal strains. The pure fungal biomass acquired could contain significant amounts of protein up to 62.2 ± 1.2% (w/w). The obtained protein had a high quality with notable inclusion of essential amino acids such as lysine, arginine, methionine and threonine with comparable concentrations to those of fish meal. Fungal biomass is mainly considered as protein source, however, entitlement of 6.9 ± 0.5, 4.0 ± 0.7 and 17.2 ± 1.1% (w/w) of lipids and ratio of polyunsatu-rated fatty acids (PUFA) to saturated fatty acids (SFA) of 1.37:1, 1.74:1 and 1.47:1 in A. oryzae, N. intermedia and R. oryzae, respectively, signal health benefits for the fish. Considering the results, protein-rich pure fungal biomass with amino acid composition is greatly compatible with fish meal, and contains essential nutrients such as fatty acids and minerals. This pure biomass constitutes a promising sustainable alternative supplement to be introduced in fish feed industry.

  • 10.
    Lukitawesa, Lukitawesa
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Eryildiz, B.
    Istanbul Teknik Üniversitesi, Istanbul, Turkey.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Millati, R.
    Universitas Gadjah Mada, Yogyakarta, Indonesia.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Semi-continuous production of volatile fatty acids from citrus waste using membrane bioreactors2021Inngår i: Innovative Food Science & Emerging Technologies, ISSN 1466-8564, E-ISSN 1878-5522, artikkel-id 102545Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In the production of volatile fatty acids (VFAs) from citrus waste, organic loadings rates (OLR) from 1 to 8 g VS/L·d were applied in semi-continuous anaerobic fermentation using a tubular membrane bioreactor (MBR). Filtration fluxes of the membrane were in the range of 7.9–8.5 L/m2·h. trans-Membrane pressure (TMP) revolved around 24.1–67.5 mbar. No obvious fouling and clogging occurred. The highest yield of VFAs 0.67 g VFA/g VS (volatile solids) was achieved at OLR 4 g VS/L·d. When citrus waste was pretreated to remove D-limonene using an airlift reactor, the highest yield of VFAs 0.84 g VFA/g VS was also obtained at OLR 4 g VS/L·d. A further increase in OLR of up to 8 g VS/L·d caused a sharp decrease in yield for the untreated citrus waste and only marginal changes were observed for the pretreated citrus waste. The main composition of VFAs was acetate, butyrate, caproate, and propionate. © 2020 Elsevier Ltd

  • 11.
    Mahboubi, Amir
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Agnihotri, Swarnima
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Uwineza, Clarisse
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Jomnonkhaow, Umarin
    Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen, Thailand.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Waste-derived volatile fatty acids for sustainable ruminant feed supplementation2022Inngår i: Biomass, Biofuels, Biochemicals, Elsevier, 2022, s. 407-430Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    Linear livestock production practice gives rise to a number of environmental, economic, and social issues including unsustainable feed provision, resource inefficiency, and climate impacts. Provision of dietary supplements in ruminants through bioconversion of organic waste/residues is a promising way to introduce the concept of circular bioeconomy to animal feed production. Volatile fatty acids (VFAs) are natural metabolites mainly generated from the bioconversion of fiber in the rumen of ruminants, and are used as an animal's energy source and precursor for the production of animal products. Considering that VFAs can also be produced from anaerobic digestion (AD) of different organic wastes, this chapter discusses the potentials applications of waste-derived VFAs such as acetic, butyric, and propionic acids as animal feed supplementation. In this regard, first, the effect of VFAs on energy provision, dry matter intake, weight gain, weaning age, ketosis and acidosis, milk yield and composition, hormones, gastrointestinal development, etc., in ruminants are analyzed. Then the potentials of different organic waste sources for the production of VFAs through AD are presented. Finally, the purification and concentration methods such as distillation and membrane separation, whichcan be applied for the production of animal feed grade VFAs solutions, are thoroughly reviewed.

  • 12.
    Mahboubi, Amir
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Cayli, Beray
    Department of Environmental Sciences and Engineering, Graduate School of Science, Engineering and Technology.
    Bulkan, Gülru
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Doyen, Wim
    Flemish Institute for Technological Research.
    De Wever, Heleen
    Flemish Institute for Technological Research.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Removal of Bacterial Contamination from Bioethanol Fermentation System Using Membrane Bioreactor2018Inngår i: Fermentation, Vol. 4, nr 4Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    A major issue hindering efficient industrial ethanol fermentation from sugar-based feedstock is excessive unwanted bacterial contamination. In industrial scale fermentation, reaching complete sterility is costly, laborious, and difficult to sustain in long-term operation. A physical selective separation of a co-culture of Saccharomyces cerevisiae and an Enterobacter cloacae complex from a buffer solution and fermentation media at dilution rates of 0.1–1 1/h were examined using an immersed membrane bioreactor (iMBR). The effect of the presence of yeast, inoculum size, membrane pore size, and surface area, backwashing and dilution rate on bacteria removal were assessed by evaluating changes in the filtration conditions, medium turbidity, and concentration of compounds and cell biomass. The results showed that using the iMBR with dilution rate of 0.5 1/h results in successful removal of 93% of contaminating bacteria in the single culture and nearly complete bacteria decontamination in yeast-bacteria co-culture. During continuous fermentation, application of lower permeate fluxes provided a stable filtration of the mixed culture with enhanced bacteria washout. This physical selective separation of bacteria from yeast can enhance final ethanol quality and yields, process profitability, yeast metabolic activity, and decrease downstream processing costs.

  • 13.
    Mahboubi, Amir
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. The Flemish Institute for Technological Research, VITO NV, Boeretang 200, B-2400, Mol, Belgium.
    Elyasi, S.
    Department of Chemical Engineering, Amirkabir University of Technology, 15875-4413, Tehran, Iran.
    Doyen, W.
    Mixed Matrix Material Innovations BVBA, B-2160, Wommelgem, Belgium.
    De Wever, H.
    The Flemish Institute for Technological Research, VITO NV, Boeretang 200, B-2400, Mol, Belgium.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Concentration-driven reverse membrane bioreactor for the fermentation of highly inhibitory lignocellulosic hydrolysate2020Inngår i: Process Biochemistry, ISSN 1359-5113, E-ISSN 1873-3298, Vol. 92, s. 409-416Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Optimal production of lignocellulosic bioethanol is hindered due to commonly faced issues with the presence of inhibitory compounds and sequentially consumed sugars in the lignocellulosic hydrolysate. Therefore, in order to find a robust fermentation approach, this study aimed at enhancing simultaneous co-assimilation of sugars, and inhibitor tolerance and detoxification. Therefore, fermentation of toxic wheat straw hydrolysate containing up to 20 g/l furfural, using the concentration-driven diffusion-based technique of reverse membrane bioreactor (rMBR) was studied. The rMBR fermentation of the hydrolysate led to complete furfural detoxification and the conversion of 87 % of sugars into ethanol at a yield of 0.48 g/g. Moreover, when the toxicity level of the hydrolysate was increased to 9 g/l of initial furfural, the system responded exceptionally by reducing 89 % of the inhibitor while only experiencing about 25 % drop in the ethanol yield. In addition, using this diffusion-based set-up in extremely inhibitory conditions (16 g/l furfural), cells could detoxify 40 % of the furfural at a high initial furfural to cell ratio of 9.5:1. The rMBR set-up applied proved that by properly synchronizing the medium condition, membrane area, and inhibitor to cell ratio, some of the shortcomings with conventional lignocellulosic fermentation can be tackled, guaranteeing a robust fermentation. 

  • 14.
    Mahboubi, Amir
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Ferreira, Jorge A.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Lennartsson, Patrik R.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Production of Fungal Biomass for Feed, Fatty Acids, and Glycerol by Aspergillus oryzae from Fat-Rich Dairy Substrates2017Inngår i: Fermentation, ISSN 2311-5637, Vol. 3, nr 4Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    Dairy waste is a complex mixture of nutrients requiring an integrated strategy for valorization into various products. The present work adds insights into the conversion of fat-rich dairy products into biomass, glycerol, and fatty acids via submerged cultivation with edible filamentous fungi. The pH influenced fat degradation, where Aspergillus oryzae lipase was more active at neutral than acidic pH (17 g/L vs. 0.5 g/L of released glycerol); the same trend was found during cultivation in crème fraiche (12 g/L vs. 1.7 g/L of released glycerol). In addition to glycerol, as a result of fat degradation, up to 3.6 and 4.5 g/L of myristic and palmitic acid, respectively, were released during A. oryzae growth in cream. The fungus was also able to grow in media containing 16 g/L of lactic acid, a common contaminant of dairy waste, being beneficial to naturally increase the initial acidic pH and trigger fat degradation. Considering that lactose consumption is suppressed in fat-rich media, a two-stage cultivation for conversion of dairy waste is also proposed in this work. Such an approach would provide biomass for possibly feed or human consumption, fatty acids, and an effluent of low organic matter tackling environmental and social problems associated with the dairy sector.

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  • 15.
    Mahboubi, Amir
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Biotechnology.
    Ferreira, Jorge A.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Lennartsson, Patrik R.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Value-added products from dairy waste using edible fungi2017Inngår i: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 59, s. 518-525Artikkel i tidsskrift (Fagfellevurdert)
  • 16.
    Mahboubi, Amir
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Lundin, Magnus
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Doyen, Wim
    The Flemish Institute for Technological Research.
    De Wever, Heleen
    The Flemish Institute for Technological Research.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Diffusion-based reverse membrane bioreactor for simultaneous bioconversion of high-inhibitor xylose-glucose media2018Inngår i: Process Biochemistry, ISSN 1359-5113, E-ISSN 1873-3298, Vol. 72, s. 23-30Artikkel i tidsskrift (Fagfellevurdert)
  • 17.
    Mahboubi, Amir
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Uwineza, C
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Doyen, W
    Mixed Matrix Material Innovations BVBA.
    De Wever, H
    Flemish Institute for Technological Research.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Intensification of lignocellulosic bioethanol production process using continuous double-staged immersed membrane bioreactors2020Inngår i: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 296Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Processing complexities associated with different lignocellulosic bioethanol production stages have hindered reaching full commercial capacity. Therefore, in this study efforts were made to remediate some issues associated with hydrolysis and fermentation, by the integration of immersed membrane bioreactors (iMBRs) into lignocellulosic bioethanol production process. In this regards, double-staged continuous saccharification-filtration and co-fermentation-filtration of wheat straw slurry was conducted using iMBRs at filtration fluxes up to 51.0 l.m-2.h-1 (LMH). The results showed a stable long-term (264 h) continuous hydrolysis-filtration and fermentation-filtration with effective separation of lignin-rich solids (up to 70% lignin) from hydrolyzed sugars, and separation of yeast cells from bioethanol stream at an exceptional filtration performance at 21.9 LMH. Moreover, the effect of factors such as filtration flux, medium quality and backwashing on fouling and cake-layer formation was studied. The results confirmed the process intensification potentials of iMBRs in tackling commonly faced technical obstacles in lignocellulosic bioethanol production.

  • 18.
    Mahboubi, Amir
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Biotechnology.
    Ylitervo, Paeivi
    Doyen, Wim
    De Wever, Heleen
    Molenberghs, Bart
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Continuous bioethanol fermentation from wheat straw hydrolysate with high suspended solid content using an immersed flat sheet membrane bioreactor.2017Inngår i: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 241, s. 296-308Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Finding a technol. approach that eases the prodn. of lignocellulosic bioethanol has long been considered as a great industrial challenge. In the current study a membrane bioreactor (MBR) set-up using integrated permeate channel (IPC) membrane panels was used to simultaneously ferment pentose and hexose sugars to ethanol in continuous fermn. of high suspended solid wheat straw hydrolyzate. The MBR was optimized to flawlessly operated at high SS concns. of up to 20% without any significant changes in the permeate flux and transmembrane pressure. By the help of the retained high cell concn., the yeast cells were capable of tolerating and detoxifying the inhibitory medium and succeeded to co-consume all glucose and up to 83% of xylose in a continuous fermn. mode leading to up to 83% of the theor. ethanol yield. [on SciFinder(R)]

  • 19.
    Mohammadkhani, Ghasem
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Kumar Ramamoorthy, Sunil
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Adolfsson, Karin H.
    Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, 100 44 Stockholm, Sweden.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Hakkarainen, Minna
    Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, 100 44 Stockholm, Sweden.
    Zamani, Akram
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    New Solvent and Coagulating Agent for Development of Chitosan Fibers by Wet Spinning2021Inngår i: Polymers, E-ISSN 2073-4360, Vol. 13, nr 13, artikkel-id 2121Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    Adipic acid was evaluated as a novel solvent for wet spinning of chitosan fibers. A solvent with two carboxyl groups could act as a physical crosslinker between the chitosan chains, resulting in improved properties of the fibers. The performance of adipic acid was compared with conventional solvents, i.e., lactic, citric, and acetic acids. Chitosan solutions were injected into a coagulation bath to form monofilaments. Sodium hydroxide (NaOH) and its mixture with ethanol (EtOH) were used as coagulation agents. Scanning electron microscopy confirmed the formation of uniform chitosan monofilaments with an even surface when using adipic acid as solvent. These monofilaments generally showed higher mechanical strength compared to that of monofilaments produced using conventional solvents. The highest Young’s modulus, 4.45 GPa, was recorded for adipic acid monofilaments coagulated in NaOH-EtOH. This monofilament also had a high tensile strength of 147.9 MPa. Furthermore, taking advantage of chitosan insolubility in sulfuric acid (H2SO4) at room temperature, chitosan fibers were successfully formed upon coagulation in H2SO4-EtOH. The dewatering of fibers using EtOH before drying resulted in a larger fiber diameter and lower mechanical strength. Adipic acid fibers made without dehydration illustrated 18% (for NaOH), 46% (for NaOH-EtOH), and 91% (for H2SO4-EtOH) higher tensile strength compared to those made with dehydration.

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  • 20.
    Mohammadkhani, Ghasem
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Swedish Center for Resource Recovery University of Borås Borås SE Sweden;Department of Chemistry Umeå University Umeå SE Sweden.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Swedish Center for Resource Recovery University of Borås Borås SE Sweden.
    Plöhn, Martin
    Department of Chemistry Umeå University Umeå SE Sweden.
    Funk, Christiane
    Department of Chemistry Umeå University Umeå SE Sweden.
    Ylitervo, Päivi
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Swedish Center for Resource Recovery University of Borås Borås SE Sweden.
    The potential of Nordic microalgae in nutrient removal from anaerobic digestion effluents2024Inngår i: Physiologia Plantarum, ISSN 0031-9317, E-ISSN 1399-3054, Vol. 176, nr 1Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Anaerobic digestion is a promising method for organic waste treatment. While the obtained digestate can function as fertilizer, the liquid fraction produced is rather problematic to discharge due to its high nitrogen and chemical oxygen demand contents. Microalgae have great potential in sustainable nutrient removal from wastewater. This study aimed at evaluating native Swedish microalgae cultivation (batch operation mode, 25°C and continuous light of 80 μmol m−2 s−1) on anaerobic digestion effluent of pulp and paper sludge (PPS) or chicken manure (CKM) to remove ammonium and volatile fatty acids (VFAs). While algal strains, Chlorella vulgaris, Chlorococcum sp., Coelastrella sp., Scotiellopsis reticulata and Desmodesmus sp., could assimilate VFAs as carbon source, acetic acid was the most preferred. Higher algal biomass and cell densities were achieved using PPS compared to CKM. In PPS, Coelastrella sp. and Chlorella vulgaris reached the highest cell densities after 15 days, about 79 × 106 and 43 × 106 cells mL−1, respectively. Although in PPS, ammonium was completely assimilated (195 mg L−1), this was only 46% (172 mg L−1) in CKM. Coelastrella sp. produced the highest biomass concentration independently of the medium (1.84 g L−1 in PPS and 1.99 g L−1 in CKM). This strain is a promising candidate for nutrient removal and biomass production in the aforementioned media, followed by Chlorella vulgaris and Chlorococcum sp. They have great potential to reduce the environmental impact of industrial anaerobic digestion effluents in Nordic countries.

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  • 21. Mousavi, Najmeh
    et al.
    Parchami, Mohsen
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Kumar Ramamoorthy, Sunil
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Hakkarainen, Minna
    Department of Fiber and Polymer Technology, KTH Royal Institute of Technology, 100 44 Stockholm, Sweden.
    Zamani, Akram
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Bioconversion of Carrot Pomace to Value-Added Products: Rhizopus delemar Fungal Biomass and Cellulose2023Inngår i: Fermentation, E-ISSN 2311-5637, Vol. 9, nr 4, artikkel-id 374Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Carrot pomace (CP) which is generated in a large volume in the juice production process, is rich in cellulose, hemicellulose, sugars, pectin, and minerals. However, in many previous investigations, only cellulose was purified and utilized while other components of CP were discarded as waste. Here, CP was valorized into fungal biomass and cellulose with the aim of utilizing all the CP components. Enzymatic pretreatments were applied to solubilize the digestible fraction of CP including hemicellulose, pectin, sucrose, and other sugars for fungal cultivation, while cellulose remained intact in the solid fraction. The dissolved fraction was utilized as a substrate for the cultivation of an edible fungus (Rhizopus delemar). Fungal cultivation was performed in shake flasks and bench-scale bioreactors. The highest fungal biomass concentration was obtained after pretreatment with invertase (5.01 g/L) after 72 h of cultivation (36 and 42% higher than the concentrations obtained after hemicellulase and pectinase treatments, respectively). Invertase pretreatment resulted in the hydrolysis of sucrose, which could then be taken up by the fungus. Carbohydrate analysis showed 28–33% glucan, 4.1–4.9% other polysaccharides, 0.01% lignin, and 2.7–7% ash in the CP residues after enzymatic pretreatment. Fourier transform infrared spectroscopy and thermogravimetric analysis also confirmed the presence of cellulose in this fraction. The obtained fungal biomass has a high potential for food or feed applications, or as a raw material for the development of biomaterials. Cellulose could be purified from the solid fraction and used for applications such as biobased-textiles or membranes for wastewater treatment, where pure cellulose is needed.

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  • 22.
    Mukesh Kumar, Awasthi
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, China.
    Wainaina, Steven
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Zhang, Z Q
    College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, China.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Methanogen and nitrifying genes dynamics in immersed membrane bioreactors during anaerobic co-digestion of different organic loading rates food waste2021Inngår i: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 342, artikkel-id 125920Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This work was aimed to evaluate the distinctive food waste (FW) organic loading rates (OLR) on methanogen and nitrifying genes dynamics and its correlation with identified relative abundance of bacterial dynamics during the anaerobic digestion. This experiment were carried out in the digesters at high OLR of food wastes at (4 to 8 g volatile solids/liter/day reactor R1) and (6 to 10 g volatile solids/liter/day reactor R2). The results shown that the relative abundance of mcrA, mcrB and mcrG genes were richest in the first day of both R1 and R2. In addition, the most of nitrifying genes were greater in after 34 days digestion in R2, while these genes did not show the specific regularity in R1. Finally, the correlation figure shows that Clostridium and Lactobacillus genera were significantly correlated with the different organic acids and methanogen and nitrifying genes dynamics.

  • 23.
    Nazir, Muhammad Tahir
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Ferreira, Jorge
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Sar, Taner
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Swedish Centre for Resource Recovery University of Borås Borås Sweden.
    Production of filamentous fungal biomass with increased oil content using olive oil as a carbon source2022Inngår i: Journal of chemical technology and biotechnology (1986), ISSN 0268-2575, E-ISSN 1097-4660Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    BACKGROUND

    Vegetable oil is more difficult for microorganisms to degrade compared with carbohydrates and protein. Oil-rich waste creates serious environmental and health concerns if it remains untreated. The aim of the work reported here was to evaluate the effects on the nutritional composition of filamentous fungal biomass by growing it in pure olive oil as a carbon source.

    RESULTS

    The growth of different filamentous fungal strains (Aspergillus oryzae, Neurospora intermedia and Rhizopus oryzae) was investigated in pure olive oil. A pre-germination stage of either glucose or yeast extract was necessary for successful fungal growth in olive oil. A. oryzae showed superior performance in comparison with N. intermedia and R. oryzae in terms of biomass growth. The obtained biomass from A. oryzae and N. intermedia was analyzed for protein, fat, ash and alkali-insoluble material, where the presence of olive oil had a steering effect on biomass growth (16 g L−1 with oil versus 4 g L−1 without oil). Nutritional composition of the fungal biomass of A. oryzae contained 0.33% fat and 48% protein when cultivated in medium without olive oil supplementation, while 31% fat and 14% protein contents were observed in the presence of olive oil-containing medium. Similar trends for fat and protein contents were observed for the biomass of N. intermedia. Moreover, microscopy confirmed the presence of oil globules inside the fungal cells.

    CONCLUSIONS

    Fat composition of fungal biomass can be steered through addition of olive oil, which increases the versatility of the produced biomass for various applications, namely in feed, food and biofuel production.

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  • 24.
    Oladzad, S
    et al.
    Amirkabir Univ Technol, Dept Chem Engn, Tehran 158754413, Iran.
    Fallah, N
    Amirkabir Univ Technol, Dept Chem Engn, Tehran 158754413, Iran.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Afsham, N
    Amirkabir Univ Technol, Dept Chem Engn, Tehran 158754413, Iran.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Date fruit processing waste and approaches to its valorization: A review2021Inngår i: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 340, artikkel-id 125625Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    In the Middle East and North Africa, dates are a traditional and economically valuable crop, playing an essential role in people's daily diets. Date fruit production and related processing industry generate a large quantity of waste; for illustration, the date juicing industry produces roughly 17-28% Date press cake (DPC), which is mainly discarded in open lands and drains. Considering the generation volume and the nutrient content of DPC, this organic by-product stream can be valorized through the production of a wide range of products with a great market appeal, such as volatile fatty acids, activated carbon, organic acids, etc. To provide an insight into the feasibility of the application DPC as a green precursor for various chemical and biological processes, the chemical and nutritional composition of dates and DPC, an overview of the date processing industries, and common practices conducted for DPC valorization addressed and thoroughly discussed, in this review.

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  • 25.
    Parchami, Milad
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Swedish Centre for Resource Recovery.
    Rustas, Bengt-Ove
    Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, Box 7024, Uppsala, Sweden.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    An in vitro evaluation of partial energy replacement in a total mixed ration with volatile fatty acids derived from agro-industrial residues2024Inngår i: Systems Microbiology and Biomanufacturing, ISSN 2662-7655Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The scientific interest in volatile fatty acids (VFAs) as an energy source and chemical precursor in ruminant diets has been longstanding, as it has significant implications for animal physiology and well-being. The present study explores the substitution of volatile fatty acids (VFAs) derived from agro-food residues via acidogenic fermentation as an alternative energy source in ruminant feed. Utilizing the gas production method, rumen digestibility assays were conducted, wherein the recovered VFA effluent from the acidogenic fermentation of apple pomace and potato protein liquor was substituted for 10%, 20%, and 30% of the total mixed ration (TMR) energy. Various parameters such as gas, VFA yield and composition, VFA peak intervals, changes in pH, and ammonium nitrogen content were investigated. Based on the results obtained, provision of 20% and 30% of the energy with VFAs did not increase methane production or did not cause significant pH alternations. Nevertheless, such supplementation resulted in increased production and accumulation of VFAs in the rumen media. The bioconversion of agro-food side streams into VFAs opens a new path in sustainable nutrient recovery and feed production from low value agro-industrial residues.

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  • 26.
    Parchami, Milad
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Uwineza, Clarisse
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Ibeabuchi, Onyinyechi H
    Rustas, Bengt-Ove
    Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, Box 7024, Uppsala, Sweden.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Membrane bioreactor assisted volatile fatty acids production from agro-industrial residues for ruminant feed application2023Inngår i: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 170, s. 62-74Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Volatile fatty acids (VFAs) supplementation in ruminants’ diet as a source of energy and chemical precursors and their effect on animal’s physiology and well-being has long been of scientific interest. Production of VFAs through anaerobic digestion of agro-industrial residues not only creates value but also presents an alternative sustainable approach for ruminant feed supplementation. Therefore, this study aimed to investigate the bioconversion of agro-industrial residues produced in large quantities such as apple pomace (AP), thin stillage (Ts), and potato protein liquor (PPL) to VFAs, fully complying to regulations set for ruminant feed supplement production. In this regard, batch acidogenic fermentation assays (pH 6–10) and semi-continuous immersed membrane bioreactor (iMBR) were applied. In batch assays, at pH 10 the co-digestion of Ts and PPL produced the highest VFAs concentration (14.2 g/L), indicating a yield of 0.85 g CODVFAs/g volatile solids (VS)added. The optimum batch condition was then applied in the iMBR for in situ fermentation and recovery of VFAs at different organic loading rates (OLR). With increasing the OLR to 3.7 gVS/L.day, the highest VFAs concentration of 28.6 g/L (1,2 g CODVFAs /gVSadded) was achieved. Successful long-term (114 days) membrane filtration was conducted in a media with a maximum of 40 g/L of total solids (TS), facing irreversible membrane fouling in the final stages. Acidogenic fermentation using an iMBR has the potential to play an important role in the future of feed additive provision through the biorefining of agro-industrial wastes via the carboxylate platform, given the role of VFAs production from organic residues.

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  • 27.
    Parchami, Mohsen
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Agnihotri, Swarnima
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Biovalorization of brewer's spent grain as single-cell protein through coupling organosolv pretreatment and fungal cultivation2023Inngår i: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 169, s. 382-391Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Brewer's spent grain (BSG) is a clean byproduct from the food sector, comprising 85% of the brewing process solid byproducts. BSG is mainly used as low-quality animal feed and often ends up in landfills due to its short shelf life. However, considering its abundant availability and high nutritional content, BSG holds the potential for biorefineries to produce valuable products. The recalcitrant nature of BSG poses a challenge, requiring pretreatment steps. Therefore, this study focused on valorizing BSG obtained from organosolv pretreatment by producing food- and feed-grade single-cell protein (SCP). The BSG was subject to organosolv pretreatment at 180C for 2 h with 50% v/v ethanol as solvent. Filamentous fungi N. intermedia and A. oryzae were cultivated on as-received and different fractions of organosolv-treated BSG to evaluate the effect of factors such as pretreatment, fungal strain, pretreated fraction content, and substrate loading on fungal biomass yield, biomass composition (protein content), and metabolite production. A. oryzae cultivation on all tested substrates yielded 7%-40% more biomass than N. intermedia. Cultivating A. oryzae on organosolv liquor resulted in the highest biomass protein content (44.8% ± 0.7%) with a fungal biomass concentration of 5.1 g/L. A three-fold increase in the substrate loading increased the ethanol-to-substrate yield by 50%, while protein content was decreased by 23%. Finally, a biorefinery concept was proposed to integrate the organosolv pretreatment of BSG with fungal cultivation for maximum yield of SCP while obtaining other products such as lignin and ethanol, providing a sustainable rout for managing BSG.

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  • 28.
    Parchami, Mohsen
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Wainaina, Steven
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    I’Ons, D.
    Gryaab AB, Norra Fågelrovägen, SE 41834 Gothenburg, Sweden.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    MBR-Assisted VFAs production from excess sewage sludge and food waste slurry for sustainable wastewater treatment2020Inngår i: Applied Sciences, E-ISSN 2076-3417, Vol. 10, nr 8Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The significant amount of excess sewage sludge (ESS) generated on a daily basis by wastewater treatment plants (WWTPs) is mainly subjected to biogas production, as for other organic waste streams such as food waste slurry (FWS). However, these organic wastes can be further valorized by production of volatile fatty acids (VFAs) that have various applications such as the application as an external carbon source for the denitrification stage at a WWTP. In this study, an immersed membrane bioreactor set-up was proposed for the stable production and in situ recovery of clarified VFAs from ESS and FWS. The VFAs yields from ESS and FWS reached 0.38 and 0.34 gVFA/gVSadded, respectively, during a three-month operation period without pH control. The average flux during the stable VFAs production phase with the ESS was 5.53 L/m2/h while 16.18 L/m2/h was attained with FWS. Moreover, minimal flux deterioration was observed even during operation at maximum suspended solids concentration of 32 g/L, implying that the membrane bioreactors could potentially guarantee the required volumetric productivities. In addition, the techno-economic assessment of retrofitting the membrane-assisted VFAs production process in an actual WWTP estimated savings of up to 140 €/h for replacing 300 kg/h of methanol with VFAs. © 2020 by the authors.

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  • 29.
    Patel, Alok
    et al.
    Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental, and Natural Resources Engineering, Luleå University of Technology, Luleå, Sweden.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Sárvári Horváth, Ilona
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Rova, Ulrika
    Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental, and Natural Resources Engineering, Luleå University of Technology, Luleå, Sweden.
    Christakopoulos, Paul
    Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental, and Natural Resources Engineering, Luleå University of Technology, Luleå, Sweden.
    Matsakas, Leonidas
    Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental, and Natural Resources Engineering, Luleå University of Technology, Luleå, Sweden.
    Volatile Fatty Acids (VFAs) Generated by Anaerobic Digestion Serve as Feedstock for Freshwater and Marine Oleaginous Microorganisms to Produce Biodiesel and Added-Value Compounds2021Inngår i: Frontiers in Microbiology, E-ISSN 1664-302X, Vol. 12, artikkel-id 614612Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Given an increasing focus on environmental sustainability, microbial oils have been suggested as an alternative to petroleum-based products. However, microbial oil production relies on the use of costly sugar-based feedstocks. Substrate limitation, elevated costs, and risk of contamination have sparked the search for alternatives to sugar-based platforms. Volatile fatty acids are generated during anaerobic digestion of organic waste and are considered a promising substrate for microbial oil production. In the present study, two freshwater and one marine microalga along with two thraustochytrids were evaluated for their potential to produce lipids when cultivated on volatile fatty acids generated from food waste via anaerobic digestion using a membrane bioreactor. Freshwater microalgae Auxenochlorella protothecoides and Chlorella sorokiniana synthesized lipids rich in palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1), and linoleic acid (C18:2). This composition corresponds to that of soybean and jatropha oils, which are used as biodiesel feedstock. Production of added-value polyunsaturated fatty acids (PUFA) mainly omega-3 fatty acids was examined in three different marine strains: Aurantiochytrium sp. T66, Schizochytrium limacinum SR21, and Crypthecodinium cohnii. Only Aurantiochytrium sp. T66 seemed promising, generating 43.19% docosahexaenoic acid (DHA) and 13.56% docosapentaenoic acid (DPA) in total lipids. In summary, we show that A. protothecoides, C. sorokiniana, and Aurantiochytrium sp. T66 can be used for microbial oil production from food waste material.

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  • 30.
    Pervez, M. N.
    et al.
    University of Salerno.
    Bilgiç, B.
    Istanbul Technical University.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Uwineza, Clarisse
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Zarra, T.
    University of Salerno.
    Belgiorno, V.
    University of Salerno.
    Naddeo, V.
    University of Salerno.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Double-stage membrane-assisted anaerobic digestion process intensification for production and recovery of volatile fatty acids from food waste2022Inngår i: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 825, artikkel-id 154084Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The potential of organic waste streams (i.e., food waste) for the sustainable production of precursor chemicals such as volatile fatty acids (VFAs) using anaerobic digestion (AD) has received significant attention in the present days. AD-derived VFAs have great market appeal if the challenges with their recovery and purification from the complex AD effluent is overcome. In this study, a microfiltration immersed membrane bioreactor (MBR) was used for the production of VFAs from food waste and simultaneously in-situ recovery of VFAs. The MBR set-up was applied for 98 days, with a maximum yield of 0.2 gVFA/gVSadded at an organic loading rate (OLR) of 4 g VS/L/d. The recovered permeate was then subjected to further purification using a side stream ultrafiltration unit. It was found that the removal rates of total solids (TS), total suspended solids (TSS), dissolved solids (DS), volatile solids (VS) and volatile suspended solids (VSS) were above 70–80% in both membranes (10 kDa and 50 kDa), and Phosphorus (P), Total Kjeldahl Nitrogen (TKN), chemical oxygen demand (COD), and NH4+-N were also removed partially. Particularly, VFAs concentration (above 6 g/L) was higher for 10 kDa at pH 5.4 in ultrafiltered solution and permeate flux decline was higher for 10 kDa at pH 5.4. These results are also supported by the measurement of UV–Vis spectra of the solution and visual appearance, providing a promising approach towards building a VFAs-based platform. © 2022 Elsevier B.V.

  • 31.
    Pervez, Md. Nahid
    et al.
    Sanitary Environmental Engineering Division (SEED), Department of Civil Engineering, University of Salerno, via Giovanni Paolo II 132, 84084, Fisciano, Salerno, Italy.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Hasan, Shadi Wajih
    Center for Membranes and Advanced Water Technology (CMAT), Department of Chemical Engineering, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, UAE.
    Zarra, Tiziano
    Sanitary Environmental Engineering Division (SEED), Department of Civil Engineering, University of Salerno, via Giovanni Paolo II 132, 84084, Fisciano, Salerno, Italy.
    Belgiorno, Vincenzo
    Sanitary Environmental Engineering Division (SEED), Department of Civil Engineering, University of Salerno, via Giovanni Paolo II 132, 84084, Fisciano, Salerno, Italy.
    Naddeo, Vincenzo
    Sanitary Environmental Engineering Division (SEED), Department of Civil Engineering, University of Salerno, via Giovanni Paolo II 132, 84084, Fisciano, Salerno, Italy.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Microfiltration and Ultrafiltration as Efficient, Sustainable Pretreatment Technologies for Resource Recovery2022Inngår i: Water-Energy-Nexus in the Ecological Transition: Advances in Science, Technology & Innovation / [ed] Naddeo, V., Choo, KH., Ksibi, M, Springer, 2022, s. 279-281Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    This study was carried out with the scope of resource recovery platform from the food waste-based organic materials in the presence of in situ microfiltration immersed anaerobic membrane bioreactor. Afterwards, ultrafiltration technology was adopted. These microfiltration and ultrafiltration processes successfully removed larger particles, i.e., suspended solids from the anaerobically digested effluent. Moreover, ultrafiltration membranes (50 kDa) can also be recovered with a high concentration of volatile fatty acids (VFAs) and nutrients. Among them, acetic acid was the dominant VFAs compound. These results are highly interesting with respect to recovering a higher amount of VFAs by the use of nanofiltration technology in future consortium.

  • 32.
    Pervez, Md. Nahid
    et al.
    Sanitary Environmental Engineering Division (SEED), Department of Civil Engineering, University of Salerno, via Giovanni Paolo II 132, 84084 Fisciano, SA, Italy.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Uwineza, Clarisse
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Sapmaz, Tugba
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Department of Environmental Engineering, Istanbul Technical University, Maslak, 34469 Istanbul, Turkey.
    Zarra, Tiziano
    Department of Environmental Engineering, Istanbul Technical University, Maslak, 34469 Istanbul, Turkey.
    Belgiorno, Vincenzo
    Sanitary Environmental Engineering Division (SEED), Department of Civil Engineering, University of Salerno, via Giovanni Paolo II 132, 84084 Fisciano, SA, Italy.
    Naddeo, Vincenzo
    Sanitary Environmental Engineering Division (SEED), Department of Civil Engineering, University of Salerno, via Giovanni Paolo II 132, 84084 Fisciano, SA, Italy.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Feasibility of nanofiltration process for high efficient recovery and concentrations of food waste-derived volatile fatty acids2022Inngår i: Journal of Water Process Engineering, E-ISSN 2214-7144, Vol. 48, artikkel-id 102933Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Various methods exist for the recovery of volatile fatty acids from organic mixed waste effluents, and among them, the membrane filtration process holds a great promise over other recovery methods due to their simplicity, sustainability and high efficiency. Hence, in this study, nanofiltration experiments were carried out using two commercial nanofiltration membranes of 200–300 Da and 300–500 Da under various pH (4, 5.4, 7 and 9) at constant pressure (15 bar) and temperature of 20-21 °C in order to achieve a higher amount of volatile fatty acids from the real mixed food waste-based effluent. Results showed that solution pH plays an important role in the physicochemical parameters such as total solids removal rate was above 80 % at pH 4, chemical oxygen demand, ammonia and phosphorus removed to some extent at pH 9. Subsequently, the concentration and recovery percentages of volatile fatty acids increased with solution pH 9; in particular, lower molecular weight cut-off membrane, i.e., 200–100 Da, appeared to be more effective with an increased concentration of total volatile fatty acids (16.94 g L−1) and recovery percentage above 90 % at pH 9. Membrane performance was also evaluated and correlated with recovery performance in terms of permeate flux reduction at lower pH. An important finding of this study was the concentration and recovery percentages of volatile fatty acids reached around 96 % after 3rd cycle by conducting a repeated sequencing nanofiltration process, which was identified as a promising option to enhance the recovery percentages of volatile fatty acids.

  • 33.
    Pervez, Md. Nahid
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Uwineza, Clarisse
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Zarra, T
    Sanitary Environmental Engineering Division (SEED), Department of Civil Engineering, University of Salerno, via Giovanni Paolo II 132, 84084 Fisciano, SA, Italy.
    Belgiorno, V
    Sanitary Environmental Engineering Division (SEED), Department of Civil Engineering, University of Salerno, via Giovanni Paolo II 132, 84084 Fisciano, SA, Italy.
    Naddeo, V
    Sanitary Environmental Engineering Division (SEED), Department of Civil Engineering, University of Salerno, via Giovanni Paolo II 132, 84084 Fisciano, SA, Italy.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Factors influencing pressure-driven membrane-assisted volatile fatty acids recovery and purification: A review2022Inngår i: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 817Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Volatile fatty acids (VFAs) are building block chemicals that can be produced through bioconversion of organic waste streams via anaerobic digestion as intermediate products. Purified VFAs are applicable in a wide range of industrial applications such as food, textiles, cosmetics, pharmaceuticals etc. production. The present review focuses on VFAs recovery methods and technologies such as adsorption, distillation, extraction, gas stripping, esterification and membrane based techniques etc., while presenting a discussion of their pros and cons. Moreover, a great attention has been given to the recovery of VFAs through membrane filtration as a promising sustainable clarification, fractionation and concentration approach. In this regard, a thorough overview of factors affecting membrane filtration performance for VFAs recovery has been presented. Filtration techniques such as nanofiltration and reverse osmosis have shown to be capable of recovering over 90% of VFAs content from organic effluent steams, proving the direct effect of membrane materials/surface chemistry, pore size and solution pH in recovery success level. Overall, this review presents a new insight into challenges and potentials of membrane filtration for VFAs recovery based on the effects of factors such as operational parameters, membrane properties and effluent characteristics.

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  • 34.
    Qin, S.
    et al.
    College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, China.
    Wainaina, Steven
    Kumar Asasthi, Sanjeev
    College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, China.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Liu, T.
    College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, China.
    Liu, H.
    College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, China.
    Zhou, Y.
    College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, China.
    Zhang, Z.
    College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, China.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mukesh Kumar, Awasthi
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, China.
    Fungal dynamics during anaerobic digestion of sewage sludge combined with food waste at high organic loading rates in immersed membrane bioreactors2021Inngår i: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 335, artikkel-id 125296Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this study, the influence of distinct hydraulic retention times (HRT) and organic loading rates (OLRs) on fungal dynamics during food waste anaerobic digestion in immersed membrane-based bio-reactors (iMBR) were investigated. The organic loading rate 4–8 g VS/L/d (R1) and 6–10 g VS/L/d (R2) were set in two iMBR. T1 (1d), T2 (15d) and T3 (34d) samples collected from each bioreactor were analyzed fungal community by using 18s rDNA. In R2, T2 had the most abundant Ascomycota, Basidiomycota, Chytridiomycota and Mucoromycota. As for R1, T3 also had the richest Cryptomycota except above four kinds of fungi. Subsequently, the Principal Component Analysis (PCA) and Non-Metric Multi-Dimensional Scaling (NMDS) indicated that fungal diversity was varied among the all three phases (T1, T2, and T3) and each treatment (R1 and R2). Finally, the results showed that different OLRs and HRT have significantly influenced the fungal community. 

  • 35.
    Qin, S.
    et al.
    College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, China.
    Wainaina, Steven
    Liu, H.
    College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, China.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Pandey, A.
    Centre for Innovation and Translational Research, CSIR-Indian Institute of Toxicology Research, Lucknow 226 001, India.
    Zhang, Z.
    College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, China.
    Mukesh Kumar, Awasthi
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, China.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Microbial dynamics during anaerobic digestion of sewage sludge combined with food waste at high organic loading rates in immersed membrane bioreactors2021Inngår i: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 303, artikkel-id 121276Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This study was designed to evaluate the microbial profiling of anaerobic digestion during the processing of sewage sludge and food waste to volatile fatty acids (VFAs) in an immersed membrane bioreactor (iMBR) operating with a distinct organic loading rate (OLR). The results indicated that Firmicutes (0.17–0.38) and Actinobacteria (0.20–0.32) phyla dominated in anaerobic digestion with OLRs of 4 and 8 g VS/L/d, while Firmicutes (0.04–0.08), Actinobacteria (0.03–0.08) and Proteobacteria (0.02) were more abundant with OLR of 6 and 10 g VS/L/d in the bioreactors. Subsequently, the abundance of the Clostridium and Lactobacillus genera were responsible for higher yields of acetate, butyrate, caproate and lactate. The species of Clostridium sp. W14A (0.04–0.06), Bacterium OL-1(0.01–0.30) and Lactobacillus mucosae (0.002–0.01) were rich for both OLR dosages. Additionally, network and redundancy analysis confirmed that Clostridium sp. W14A, Bacterium MS4 and Lactobacillus had significant correlations with the VFAs produced, such as acetate, butyrate, and caproate. Variation analysis also demonstrated an appreciable correlation between environmental factors and the bacterial community. Overall, this bacterial community was dominated by the Firmicutes (0.04–0.38) phylum and Clostridium sp. W14A (0.04–0.60) species, which is a clear indicator of a lower population of acetogenic bacteria associated with greater VFAs generation.

  • 36.
    Sapmaz, Tugba
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Department of Environmental Sciences and Engineering, Istanbul Technical University, Istanbul, Turkey.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Taher, Mustafa N.
    Department of Environmental Sciences and Engineering, Istanbul Technical University, Istanbul, Turkey.
    Beler-Baykal, Bilsen
    Department of Environmental Sciences and Engineering, Istanbul Technical University, Istanbul, Turkey.
    Karagunduz, Ahmet
    Department of Environmental Engineering, Gebze Technical University, Kocaeli, Turkey.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Koseoglu-Imer, Derya Y.
    Department of Environmental Sciences and Engineering, Istanbul Technical University, Istanbul, Turkey.
    Waste-derived volatile fatty acid production and ammonium removal from it by ion exchange process with natural zeolite2022Inngår i: Bioengineered, ISSN 2165-5979, E-ISSN 2165-5987, Vol. 13, nr 6, s. 14751-14769Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Volatile fatty acids (VFAs) produced during anaerobic digestion (AD) of organic waste are a promising alternative carbon source for various biological processes; however, their applications are limited due to the presence of impurities such as ammonium (NH4+). This study investigates the potential for removal of ammonium using a naturally occurring zeolite (clinoptilolite) from chicken manure (CKM) derived VFA effluent recovered from an anaerobic membrane bioreactor (MBR). Experiments were conducted for both synthetic and actual VFA (AD-VFA) solutions, and the effects of different parameters were investigated with batch and continuous studies. It was observed that the Langmuir-type isotherm provided the best fit to the equilibrium data in the isotherm investigations carried out with the AD-VFA solution. The maximum adsorption capacity (qm) was found as 15.7 mg NH4+/g clinoptilolite. The effect of some operational parameters on process performance such as pH, initial NH4+ loading and potassium ion (K+) concentration was investigated. The pH had a negligible effect on ammonium removal for a pH range of 3–7, while the removal efficiency of ammonium decreased with the increase of initial NH4+ loading and K+ concentration. At the optimum conditions determined in batch experiments, the ammonium removal from synthetic and AD-VFA solutions were compared and average ammonium removal efficiencies of 93 and 94% were found in 12 h equilibrium time for synthetic and AD-VFA solutions, respectively. Overall findings indicated that clinoptilolite has excellent potential for ion exchange when combined with biological processes such as acidogenic fermentation of VFAs to purify the solution from high-ammonium content.

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  • 37.
    Sapmaz, Tugba
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Manafi, Reza
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Koseoglu-Imer, Derya Y.
    Department of Environmental Engineering, Istanbul Technical University, Istanbul 34469, Turkey.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    The Effect of Sequential and Simultaneous Supplementation of Waste-Derived Volatile Fatty Acids and Methanol as Alternative Carbon Source Blend for Wastewater Denitrification2023Inngår i: Sustainability, E-ISSN 2071-1050, Vol. 15, nr 8, artikkel-id 6849Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Supplementation of alternative carbon sources is a technological bottleneck, particularly in post-denitrification processes due to stringent effluent nitrogen levels. This study focuses on enhancing the sustainability of wastewater treatment practices by partially replacing conventionally used fossil-derived methanol with organic waste-derived volatile fatty acids (VFAs) in moving bed biofilm reactors (MBBRs). In this regards, results of denitrification batch assays with sequential or simultaneous addition of VFA effluent from acidogenic fermentation of potato starch residue (AD-VFAPPL) and chicken manure (AD-VFACKM), simulated synthetic VFAs solutions (sVFAs), and methanol as carbon source were presented and discussed. Although methanol has proven superior in the conversion of nitrate to nitrite, VFAs are more effective when it comes to reducing nitrite. Although solely added AD-VFAPPL had a slower denitrification capability (0.56 ± 0.13 mgNOx-N removed/m2/day) than methanol (1.04 ± 0.46 mgNOx-N removed/m2/day), up to 50% of the methanol can be replaced by waste-derived AD-VFAPPL and achieve comparable performance (1.08 ± 0.07 mgNOx-N removed/m2/day) with the pure methanol. This proves that the co-addition of VFAs together with methanol can fully compete with pure methanol in performance, providing a promising opportunity for wastewater treatment plants to potentially reduce their carbon footprint and become more sustainable in practice while benefiting from recovered nutrients from waste.

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  • 38.
    Sapmaz, Tugba
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Department of Environmental Engineering, Istanbul Technical University, Maslak, 34469 Istanbul, Turkey.
    Manafi, Reza
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Lorick, Dag
    Gryaab AB, Norra Fagelrovagen, SE 41834 Gothenburg, Sweden.
    Koseoglu-Imer, Derya Y.
    Department of Environmental Engineering, Istanbul Technical University, Maslak, 34469 Istanbul, Turkey.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Potential of food waste-derived volatile fatty acids as alternative carbon source for denitrifying moving bed biofilm reactors2022Inngår i: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 364, artikkel-id 128046Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Fossil-based materials such as methanol are frequently used in the denitrification process of advanced biological wastewater treatment as external carbon source. Volatile fatty acids (VFAs) produced by anaerobic digestion of food waste, are sustainable compounds with the potential to act as carbon sources for denitrification, reducing carbon footprint and material costs. In this study, the effectiveness of food waste-derived VFAs (AD-VFA) was investigated in the post-denitrification process in comparison with synthetic VFA and methanol as carbon sources. Acetic acid had the highest rate of disappearance among single tested VFAs with a denitrification rate of 0.44 g NOx-N removed/m2/day, indicating a preferential utilization pattern. While AD-VFA had a denitrification rate of 0.61 mg NOx-N removed/m2/day, sVFA had a rate of 0.57 mg NOx-N removed/m2/day, indicating that impurities in AD-VFA did not play substantial role in denitrification. AD-VFA proved to be promising carbon source alternative for denitrification in wastewater treatment plants.

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  • 39.
    Sapmaz, Tugba
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Department of Environmental Engineering, Istanbul Technical University, Maslak, 34469 Istanbul, Turkey.
    Uwineza, Clarisse
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    De Wever, Heleen
    Flemish Institute for Technological Research, VITO NV, Boeretang 200, B-2400 Mol, Belgium.
    Koseoglu-Imer, Derya Y.
    Department of Environmental Engineering, Istanbul Technical University, Maslak, 34469 Istanbul, Turkey.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Towards maximum value creation from potato protein liquor: volatile fatty acids production from fungal cultivation effluent2023Inngår i: Biomass Conversion and Biorefinery, ISSN 2190-6815, E-ISSN 2190-6823Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The cornerstones of an efficient circular waste management strategy aiming for enhanced resource efficiency are maximizing organic waste valorization and improving residual conversion to biochemicals. In this regard, this study focuses on the production of volatile fatty acids (VFAs) from the effluent of fungi biomass cultivation on low-grade residues from the potato starch industry with batch and semi-continuous membrane bioreactors (MBRs) containing the effluent of already fermented potato protein liquor (FPPL) inoculated with chicken and cow manure. The effect of pH in the batch experiments on the production and yield of VFAs during acidogenic digestion was evaluated. Rapid generation of VFAs at a concentration of up to 11.8 g/L could be successfully achieved in the MBR. Under the optimal conditions, a high yield of 0.65 g VFAs/g VSfed was obtained for the organic loading rate (OLR) of 1 g VS/L/d using FPPL substrate and chicken manure as inoculum. The results show that the application of sequential multi-step bioconversion of potato starch industry residues has the potential to increase the variety of value-added products generated from a single organic residue while enhancing nutrient recovery capacity. 

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  • 40.
    Sar, Taner
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Rousta, Neda
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Media preparation and sterilization in bioprocesses2022Inngår i: Advances in Bioprocess Engineering, Elsevier , 2022, s. 399-430Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [en]

    Fermentation and bioprocesses in which various metabolites from food to pharmaceutics are produced are constantly evolving. This section is devoted to contamination risks and their eliminations, media preparation, decontamination, and sterilization methods for such processes. For contamination, sources of microbial contaminations and decontamination (physical and chemical) practices are discussed. In addition, sterilization methods (heat, filtration, chemical, and radiation) that are applied for the removal of microorganisms from small-scale to large-scale instruments, gases, and liquids are explained. In the preparation of the media, the batching area, developed equipment, and methods for large-scale reactors are mentioned. In summary, the preparation and sterilization of the media in bioprocesses from laboratory-scale reactors to industrial-scale reactors are evaluated.

  • 41.
    Thunuguntla, Rahul
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Ferreira, Jorge
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Integration of Membrane Bioreactors with Edible Filamentous Fungi for Valorization of Expired Milk2018Annet (Annet vitenskapelig)
    Abstract [en]

    Around 29 million tons of milk end as waste yearly in Europe, representing an environmental issue but also a potential substrate for biological valorization given its nutritional value. Aspergillus oryzae and Neurospora intermedia are edible filamentous fungi with dissimilar metabolism when grown in expired milk. Neurospora intermedia is more devoted to lactose consumption; 68 and 57% of lactose was consumed after cultivation in expired milk and its liquid fraction, respectively. Aspergillus oryzae consumed less lactose in expired milk (14%), but led to better microfiltration characteristics of the final effluent due to fat and protein degradation. A two-stage fed-batch cultivation using membrane bioreactors (MBRs) was developed, bringing together both fungal metabolic characteristics when grown in 70% diluted expired milk. In the first MBR, A.oryzae degraded fat and protein, improved microfiltration, and produced ca 11 g/L of biomass. In the second MBR, N. intermedia consumed the remaining lactose in the permeate and originated ca 7 g/L of biomass. The developed system was successful for valorization of non-sterile milk due to the balance between consumption of bacterial growth-derived acids, consequent pH, and fungal enzymatic activities. Besides, a final clear effluent (83% reduction of COD) was obtained, which is of interest considering wastewater treatment.

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  • 42.
    Toghiani, Javad
    et al.
    Department of Chemical Engineering, Amirkabir University of Technology, 15875-4413, Tehran, Iran.
    Fallah, Narges
    Department of Chemical Engineering, Amirkabir University of Technology, 15875-4413, Tehran, Iran.
    Nasernejad, Bahram
    Department of Chemical Engineering, Amirkabir University of Technology, 15875-4413, Tehran, Iran.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Afsham, Neda
    Department of Chemical Engineering, Amirkabir University of Technology, 15875-4413, Tehran, Iran.
    Sustainable Pistachio Dehulling Waste Management and Its Valorization Approaches: A Review2023Inngår i: Current Pollution Reports, E-ISSN 2198-6592, s. 60-75Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Purpose of Review

    In countries such the USA, Iran, and Turkey, pistachio nut is considered one of the most economically valuable agricultural products. Pistachio production and related dehulling processes generate a large quantity of organic waste, containing green hull, cluster woody part, shells, and leaves. The inadequate conventional management of such wastes calls for sustainable and economical strategies not only to enhance resource efficiency but also to create value.

    Recent Findings

    Pistachio residues have a high content of total extractives and essential oils and a considerable amount of phenolic compounds that explain their good antioxidant activities and other potential human health benefits. Furthermore, considering the generation volume (about 660,000 tons) and lignocellulosic structure, pistachio residues can also be sustainably used to produce value-added products, such as biofuels, phytochemicals, activated carbon, and other potential bioproducts such as filamentous fungi as protein enriched biomass, single-cell protein (SCP), and volatile fatty acids. In general, recent studies have not  comprehensively investigated all value-added potential products.

    Summary

    This review provides a thourough insight into the present pistachio processing industries, and pistachio waste chemical composition and characteristics. Furthermore, the applications of pistachio residues as a renewable source for the production of potential value-added products by various thermochemical (pyrolysis, gasification, and liquefaction), physicochemical (solvent extraction, ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE), and extraction by pressurized liquids (PLE)), and biological (anaerobic digestion (AD) and fermentation (solid-state and submerged)) processes are presented including an analysis of the advantages and disadvantages of such methods. In this regard, production of new products such as edible filamentous fungi and antioxidant, and their market appeal has been briefly considered.

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  • 43.
    Toghiani, Javad
    et al.
    Department of Chemical Engineering, Amirkabir University of Technology, Tehran, 15875-4413, Iran.
    Malekzadeh, Sajjad
    Department of Chemical Engineering, Amirkabir University of Technology, Tehran, 15875-4413, Iran.
    Jamali, Neda
    Department of Chemical Engineering, Amirkabir University of Technology, Tehran, 15875-4413, Iran.
    Afsham, Neda
    Department of Chemical Engineering, Amirkabir University of Technology, Tehran, 15875-4413, Iran.
    Fallah, Narges
    Department of Chemical Engineering, Amirkabir University of Technology, Tehran, 15875-4413, Iran.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Swedish Centre for Resource Recovery.
    Nasernejad, Bahram
    Department of Chemical Engineering, Amirkabir University of Technology, Tehran, 15875-4413, Iran.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Oladzad, Sepideh
    Department of Chemical Engineering, Amirkabir University of Technology, Tehran, 15875-4413, Iran.
    Novel Advanced Oxidation Processes (AOPs) as Lignocellulosic Biomass Pretreatment Approaches and Their Sustainability Assessment: A Review2024Inngår i: Current Pollution Reports, E-ISSN 2198-6592, Vol. 10, s. 207-246Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Purpose of Review

    Lignocellulosic biomass, as a green and sustainable resource, can be used in biorefineries to produce bio-based products. The complex and resistant structure of lignocellulose prevents microorganisms access to carbohydrates in the biorefinery’s main processes, necessitating pretreatment. Different conventional pretreatment methods (physical, physico-chemical, chemical, and biological methods) and also novel advanced oxidation processes (AOPs) and their sustainability, environmental impact, economic viability, energy efficiency and, commercialization state are investigated in this review.

    Recent Findings

    Due to various reviews and studies on conventional pretreatment methods, they are briefly described with proper data. As the mechanisms and principle of operation of AOPs were investigated, during the AOPs pretreatment methods, hydroxyl radicals (·OH) are generated sufficiently to decompose lignocellulosic structure through oxidation. In this paper, we review the different AOPs, i.e., Fenton process, ozonation, photochemical, wet air oxidation, ultrasound, and electrochemical, which are recently used in the pretreatment of lignocellulose. Also, the achievement of different AOPs pretreatment research studies and general trends governing the process operating conditions are presented briefly in tables. Moreover, lignocellulosic biomass pretreatment sustainability assessment approaches such as life cycle assessment (LCA) and economic value and environmental impact (EVEI) are discussed. Although no study compared the sustainability aspects of different AOPs with conventional methods, this review generally addresses them. Further, environmental, energetic, and economic aspects of AOPs methods have been compared as important criteria in selecting a pretreatment method.

    Summary

    This review provides a thorough insight into the biorefinery’s bottleneck, pretreatment, and comprehensively investigated mechanisms, principle of operation, sustainability, environmental, economic, energy, and commercialization state of AOPs methods.

  • 44.
    Uwineza, Clarisse
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Bouzarjomehr, Mohammadali
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Parchami, Milad
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Sar, Taner
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Evaluation of in vitro digestibility of Aspergillus oryzae fungal biomass grown on organic residue derived-VFAs as a promising ruminant feed supplement2023Inngår i: Journal of Animal Science and Biotechnology, E-ISSN 2049-1891, Vol. 14, artikkel-id 120Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background

    As demand for high quality animal feed continues to raise, it becomes increasingly important to minimize the environmental impact of feed production. An appealing sustainable approach to provide feed fractions is to use organic residues from agro-food industry. In this regard, volatile fatty acids (VFAs) such as acetic, propionic and butyric acids, derived from bioconversion of organic residues can be used as precursors for production of microbial protein with ruminant feed inclusion potential. This study aims to investigate the in vitro digestibility of the Aspergillus oryzae edible fungal biomass cultivated on VFAs-derived from anaerobic digestion of residues. The produced fungal protein biomass, along with hay clover silage and rapeseed meal were subjected to various in vitro assays using two-stage Tilley and Terry (TT), gas, and bag methods to evaluate and compare its digestibility for application in ruminant feed.

    Results

    The produced fungal biomass contained a higher crude protein (CP) (41%–49%) and rather similar neutral detergent fiber (NDF) (41%–56%) compared to rapeseed meal. The rumen in vitro dry matter digestibility (IVDMD) of the fungal biomass in the TT method ranged from 82% to 88% (statistically similar to that of the gas method (72% to 85%)). The IVDMD of fungal biomass were up to 26% and 40% greater than that of hay clover silage and rapeseed meal, respectively. The type of substrate and bag method had pronounced effect on the fermentation products (ammonium-N (NH4+-N), total gas and VFAs). Fungal biomass digestion resulted in the highest release of NH4+-N (340–540 mg/L) and the ratio of acetate to propionate ratio (3.5) among subjected substrates.

    Conclusion

    The results indicate that gas method can be used as a reliable predictor for IVDMD as well as fermentation products. Furthermore, the high IVDMD and fermentation product observed for Aspergillus oryzae fungal biomass digestion, suggest that the supplementation of fungal biomass will contribute to improving the rumen digestion by providing necessary nitrogen and energy to the ruminant and microbiota.

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    fulltext
  • 45.
    Uwineza, Clarisse
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Atmowidjojo, A
    Department of Food and Agricultural Product Technology, Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia.
    Ramadhani, A
    Department of Food and Agricultural Product Technology, Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia.
    Wainaina, Steven
    Millati, R
    Department of Food and Agricultural Product Technology, Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia.
    Wikandari, R
    Department of Food and Agricultural Product Technology, Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia.
    Niklasson, C
    Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296 Gothenburg, Sweden.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Cultivation of edible filamentous fungus Aspergillus oryzae on volatile fatty acids derived from anaerobic digestion of food waste and cow manure2021Inngår i: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 337, artikkel-id 125410Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In a circular economy approach, edible filamentous fungi (single cell protein) can be cultivated on volatile fatty acids (VFAs) derived from anaerobic digestion (AD) of organic-rich waste streams. In this study, the effect of pH, concentration/distribution of VFAs, nutrient supplementation, and type of waste on Aspergillus oryzae cultivation on synthetic VFAs, and actual VFAs derived from AD of food waste and cow manure were investigated. The optimal pH for A. oryzae growth on VFAs were 6 and 7 with maximum acetic acid consumption rates of 0.09 g/L. h. The fungus could thrive on high concentrations of acetic (up to 9 g/L) yielding 0.29 g dry biomass/gVFAs(fed). In mixed VFAs cultures, A. oryzae primarily consumed caproic and acetic acids reaching a biomass yield of 0.26 g dry biomass/gVFAs(fed) (containing up to 41% protein). For waste-derived VFAs at pH 6, the fungus successfully consumed 81-100% of caproic, acetic, and butyric acids.

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    fulltext
  • 46.
    Uwineza, Clarisse
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Sar, Taner
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Evaluation of the cultivation of aspergillus oryzae on organic waste-derived vfa effluents and its potential application as alternative sustainable nutrient source for animal feed2021Inngår i: Sustainability, E-ISSN 2071-1050, Vol. 13, nr 22, artikkel-id 12489Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Considering the projected demand for protein supplementation in animal feed, as well as prioritizing plant-based protein provision for the growing human population, great stress is imposed on conventional protein sources, calling for new sustainable alternatives. In this regard, the production and application of single-cell proteins (SCPs) has proven to be a promising alternative. Therefore, in this study, volatile fatty acids (VFAs) effluents recovered from anaerobically digested FW, CKM, CM, and their combinations were applied for the cultivation of edible filamentous fungi Aspergillus oryzae. The biomass was further evaluated considering its protein, fat and alkali insoluble material contents. The maximum fungal biomass yielded of 0.47 ± 0.00 and 0.37 ± 0.00 g dry biomass/g tVFAsCODeq.consumed, with up to 47% protein and 5% fat content successfully cultivated in shake flasks and bench scale reactors, respectively. In addition to the production of protein-rich biomass, significant reductions in medium COD (25–58%) and ammonium (33–48%) were achieved. The results presented in this research work imply that using waste-derived VFAs for the production of animal feed grade SCP is an innovative approach that can contribute to the economy and sustainability of animal feed production process. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

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    fulltext
  • 47.
    Vu, Hoang Danh
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Ferreira, Jorge
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Polyhydroxybutyrate-Natural Fiber Reinforcement Biocomposite Production and Their Biological Recyclability through Anaerobic Digestion2022Inngår i: Energies, E-ISSN 1996-1073, Vol. 15, nr 23Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The existing recycling methods of PHA-based material are ineffective in terms of increasing resource efficiency and the production of high value end-of-life products. Therefore, in this study, a novel approach of acidogenic fermentation was proposed to recycle PHB-based composites reinforced with natural fibers such as cellulose, chitin, chitosan, orange waste, sawdust, soy protein, and starch. The inclusion of cellulose, chitosan, and sawdust improved the impact properties of the composites while other fillers had various effects on the mechanical properties. These three composites and neat PHB were subsequently subjected to biological degradation via acidogenic digestion to determine the possibility of converting PHB-based composites into volatile fatty acids (VFAs). Two different pH levels of 6 and 10 were applied to assess the effect of pH on the bioconversion and inhibition of the methanogenesis. The results showed promising PHB degradation, contributing to considerable VFA production of 2.5 g/L at pH 6 after 47 days. At pH 6, the presence of the natural fibers in the biocomposites promoted the degradation rate. On the contrary, pH 10 proved to be more suitable for the degradation of the fibers. The VFA which is produced can be recirculated into PHB production, fitting with the concept of a circulating bioeconomy.

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  • 48.
    Vu, Hoang Danh
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Root, Andrew
    MagSol, Tuhkanummenkuja 2, 00970 Helsinki, Finland.
    Heinmaa, Ivo
    National Institute of Chemical Physics and Biophysics, 12618 Tallinn, Estonia.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Application of Immersed Membrane Bioreactor for Semi-Continuous Production of Polyhydroxyalkanoates from Organic Waste-Based Volatile Fatty Acids2023Inngår i: Membranes, E-ISSN 2077-0375, Vol. 13, nr 6, artikkel-id 569Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Volatile fatty acids (VFAs) appear to be an economical carbon feedstock for the cost-effective production of polyhydroxyalkanoates (PHAs). The use of VFAs, however, could impose a drawback of substrate inhibition at high concentrations, resulting in low microbial PHA productivity in batch cultivations. In this regard, retaining high cell density using immersed membrane bioreactor (iMBR) in a (semi-) continuous process could enhance production yields. In this study, an iMBR with a flat-sheet membrane was applied for semi-continuous cultivation and recovery of Cupriavidus necator in a bench-scale bioreactor using VFAs as the sole carbon source. The cultivation was prolonged up to 128 h under an interval feed of 5 g/L VFAs at a dilution rate of 0.15 (d−1), yielding a maximum biomass and PHA production of 6.6 and 2.8 g/L, respectively. Potato liquor and apple pomace-based VFAs with a total concentration of 8.8 g/L were also successfully used in the iMBR, rendering the highest PHA content of 1.3 g/L after 128 h of cultivation. The PHAs obtained from both synthetic and real VFA effluents were affirmed to be poly(3-hydroxybutyrate-co-3-hydroxyvalerate) with a crystallinity degree of 23.8 and 9.6%, respectively. The application of iMBR could open an opportunity for semi-continuous production of PHA, increasing the feasibility of upscaling PHA production using waste-based VFAs. 

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    fulltext
  • 49.
    Vu, Hoang Danh
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Root, Andrew
    MagSol, Tuhkanummenkuja 2, 00970 Helsinki, Finland.
    Heinmaa, Ivo
    National Institute of Chemical Physics and Biophysics, 12618 Tallinn, Estonia.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Thorough Investigation of the Effects of Cultivation Factors on Polyhydroalkanoates (PHAs) Production by Cupriavidus necator from Food Waste-Derived Volatile Fatty Acids2022Inngår i: Fermentation, E-ISSN 2311-5637, Vol. 8, nr 11, artikkel-id 605Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Volatile fatty acids (VFAs) have become promising candidates for replacing the conventional expensive carbon sources used to produce polyhydroxyalkanoates (PHAs). Considering the inhibitory effect of VFAs at high concentrations and the influence of VFA mixture composition on bacterial growth and PHA production, a thorough investigation of different cultivation parameters such as VFA concentrations and composition (synthetic and waste-derived VFAs) media, pH, aeration, C/N ratio, and type of nitrogen sources was conducted. Besides common VFAs of acetic, butyric and propionic acids, Cupriavidus necator showed good capability for assimilating longer-chained carboxylate compounds of valeric, isovaleric, isobutyric and caproic acids in feasible concentrations of 2.5–5 g/L. A combination of pH control at 7.0, C/N of 6, and aeration of 1 vvm was found to be the optimal condition for the bacterial growth, yielding a maximum PHA accumulation and PHA yield on biomass of 1.5 g/L and 56%, respectively, regardless of the nitrogen sources. The accumulated PHA was found to be poly(3-hydroxybutyrate-co-3-hydroxyvalerate) with the percentage of hydroxybutyrate in the range 91–96%. Any limitation in the cultivation factors was found to enhance the PHA yield, the promotion of which was a consequence of the reduction in biomass production.

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  • 50.
    Wainaina, Steven
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mohsen, Parchami
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mahboubi, Amir
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Sárvári Horváth, Ilona
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Food waste-derived volatile fatty acids platform using an immersed membrane bioreactor2018Inngår i: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, artikkel-id S0960-8524(18)31650-XArtikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Volatile fatty acids (VFAs) are the key intermediates from anaerobic digestion (AD) process that can be a platform to synthesize products of higher value than biogas. However, some obstacles still exist that prevent large-scale production and application of VFAs, key among them being the difficulty in recovering the acids from the fermentation medium and low product yields. In this study, a novel anaerobic immersed membrane bioreactor (iMBR) with robust cleaning capabilities, which incorporated frequent backwashing to withstand the complex AD medium, was designed and applied for production and in situ recovery of VFAs. The iMBR was fed with food waste and operated without pH control, achieving a high yield of 0.54 g VFA/g VSadded. The continuous VFA recovery process was investigated for 40 days at OLRs of 2 gVS/L/d and 4 gVS/L/d without significant change in the permeate flux at a maximum suspended solids concentration of 31 g/L.

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