Instant active dry baker's yeast is a well-known product widely used for leavening of bread, produced by fermentation, and usually dried by hot air to 94–96% dry matter content. Multi-stage fluidized bed drying process is a commercial effective method for yeast drying. In this work, optimum operating parameters of an industrial continuous fluidized bed dryer for the production of instant active dry yeast were investigated. The dryer contained four zones separated with moving weirs. The operating conditions such as temperature, loading rate of compressed yeast granules, and hot air humidity had direct effects on both yeast activity and viability. The most important factors that affected the quality of the product were loading rate and the operational temperature in each zone on the bed. Optimization was performed for three loading rates of the feed to the dryer, using response surface methodology for the experimental design. The most significant factor was shown to be the loading rate with mean fermentation activity values of 620, 652, and 646 cm3 CO2/h for 300, 350, and 400 kg/h loading rates, respectively. The data analysis resulted in an optimal operating point at a loading rate of 350 kg/h and temperatures of zones 1, 2, 3, and 4 controlled at 33, 31, 31, and 29 °C, respectively. The best activity value was predicted as 668 ± 18 cm3 CO2/h, and confirmation experiments resulted in 660 ± 10 cm3 CO2/h. At the same operating point, the average viability of the cells was predicted as 74.8 ± 3.7% and confirmed as 76.4 ± 0.6%. Compared with the normal operating conditions at the plant, the optimization resulted in more than 12% and 27% improvement in the yeast activity and viability, respectively.

This paper quantifies bread waste throughout the Swedish supply chain and investigates the loss rate of prepackagedbread products at the supplier-retailer interface. The goal is to understand the extent of bread waste inSweden and to identify risk factors for high quantities of waste at the supplier-retailer interface, in order toprovide information supporting waste prevention measures. The study uses primary data, in combination withnational statistics and data from sustainability reports and the literature. Primary data were collected from 380stores of a Swedish retail company and a bakery. Bread waste was calculated to be 80 410 tons/year in Sweden,the equivalent of 8.1 kg per person/year, and was found to be concentrated at households and in retail, specificallyat the supplier-retailer interface. The results provide evidence that take-back agreements between suppliersand retailers, where the retailer only pays for sold products and the supplier bears the cost of the unsoldproducts and their collection and treatment, are risk factors for high waste generation. Current business modelsmay need to be changed to achieve a more sustainable bread supply chain with less waste.

This study was conducted to improve the properties of thin films prepared from orange waste by the solution casting method. The main focus was the elimination of holes in the film structure by establishing better cohesion between the major cellulosic and pectin fractions. For this, a previously developed method was improved first by the addition of sugar to promote pectin gelling, then by the addition of maleic anhydride. Principally, maleic anhydride was introduced to the films to induce cross-linking within the film structure. The effects of concentrations of sugar and glycerol as plasticizers and maleic anhydride as a cross-linking agent on the film characteristics were studied. Maleic anhydride improved the structure, resulting in a uniform film, and morphology studies showed better adhesion between components. However, it did not act as a cross-linking agent, but rather as a compatibilizer. The middle level (0.78%) of maleic anhydride content resulted in the highest tensile strength (26.65 ± 3.20 MPa) at low (7%) glycerol and high (14%) sugar levels and the highest elongation (28.48% ± 4.34%) at high sugar and glycerol levels. To achieve a uniform film surface with no holes present, only the lowest (0.39%) level of maleic anhydride was necessary. 

This study was conducted to improve the properties of thin films prepared from orange waste by the solution casting method. The main focus was the elimination of holes in the film structure by establishing better cohesion between the major cellulosic and pectin fractions. For this, a previously developed method was improved first by the addition of sugar to promote pectin gelling, then by the addition of maleic anhydride. Principally, maleic anhydride was introduced to the films to induce cross-linking within the film structure. The effects of concentrations of sugar and glycerol as plasticizers and maleic anhydride as a cross-linking agent on the film characteristics were studied. Maleic anhydride improved the structure, resulting in a uniform film, and morphology studies showed better adhesion between components. However, it did not act as a cross-linking agent, but rather as a compatibilizer. The middle level (0.78%) of maleic anhydride content resulted in the highest tensile strength (26.65 +/- 3.20 MPa) at low (7%) glycerol and high (14%) sugar levels and the highest elongation (28.48% +/- 4.34%) at high sugar and glycerol levels. To achieve a uniform film surface with no holes present, only the lowest (0.39%) level of maleic anhydride was necessary.

Spent sulphite liquor, the major byproduct from the sulphite pulp production process, was diluted to 50% and used for production of an edible zygomycete Rhizopus sp. The focus was on production, yield, and composition of the fungal biomass composition. The fungus grew well at 20 to 40°C, but 32°C was found to be preferable compared to 20 and 40°C in terms of biomass production and yield (maximum of 0.16 g/g sugars), protein content (0.50-0.60 g/g), alkali-insoluble material (AIM) (ca 0.15 g/g), and glucosamine content (up to 0.30 g/g of AIM). During cultivation in a pilot airlift bioreactor, the yield increased as aeration was raised from 0.15 to 1.0 vvm, indicating a high demand for oxygen. After cultivation at 1.0 vvm for 84 h, high yield and production of biomass (up to 0.34 g/g sugars), protein (0.30-0.50 g/g), lipids (0.02-0.07 g/g), AIM (0.16-0.28 g/g), and glucosamine (0.22-0.32 g/g AIM) were obtained. The fungal biomass produced from spent sulphite liquor is presently being tested as a replacement for fishmeal in feed for fish aquaculture and seems to be a potential source of nutrients and for production of glucosamine.

This study deals with the utilization of chicken feather waste as a substrate for anaerobic digestion and improving biogas production by degradation of the compact structure of the feather keratin. In order to increase the digestibility of the feather, different pretreatments were investigated, including thermal pretreatment at 120 °C for 10 min, enzymatic hydrolysis with an alkaline endopeptidase [0.53–2.66 mL/g volatile solids (VS) feathers] for 0, 2, or 24 h at 55 °C, as well as a combination of these pretreatments. The effects of the treatments were then evaluated by anaerobic batch digestion assays at 55 °C. The enzymatic pretreatment increased the methane yield to 0.40 Nm3/kg VSadded, which is 122 % improvement compared to the yield of the untreated feathers. The other treatment conditions were less effective, increasing the methane yield by 11–50 %. The long-term effects of anaerobic digestion of feathers were examined by co-digestion of the feather with organic fraction of municipal solid waste performed with and without the addition of enzyme. When enzyme was added together with the feed, CH4 yield of 0.485 Nm3/kg VS−1 d−1 was achieved together with a stable reactor performance, while in the control reactor, a decrease in methane production, together with accumulation of undegraded feather, was observed.

The current study aims to assess how a novel fungi product made from the filamentous fungus Neurospora intermedia, cultivated on bread residuals, is perceived using questionnaires. Participants were asked to rate characteristic attributes of a fungi burger patty and state their preference when comparing it to Quorn and hamburger patties. The data were analyzed to assess whether gender or age was statistically associated with preference profiles. Neither age nor gender was associated with the preference profiles regarding the comparison of burger patties. Except for age and bitterness, age and gender were also not associated with the preference profiles regarding the sensory characteristics of the fungi burger patty. Most of the participants liked the characteristics of the fungi burger patty. The results indicate that fungi products from waste can become accepted products when information dissemination targets environmental benefits. Moreover, to be commercially accepted, the chewiness and bitterness of the product should be improved. Other improvements should target the overall taste in order to cater to people who prefer meat-based protein sources.

Providing food security to the growing global population, and the resource depletion associated with current food systems, let to calls for more sustainable food sources. Food that can be produced in a sustainable way (taking all three aspects of sustainable development into consideration) is currently emerging in Western societies. Through tastings, insight can be gathered not only into sensory characteristics but also other aspects that aid innovation and development of food. The current study identified aspects that can affect tastings of emerging food by reviewing relevant literature. General aspects; meat alternatives; ingredients or processing technologies; information, prior knowledge and (un)familiarity; taste and liking; emotional factors; and willingness to engage with emerging food can affect tastings of emerging food. Awareness of the effect that these aspects can have on methodological considerations and results can be constructive in future research that use tastings as a platform to develop new and emerging food. The findings are significant for food science in terms of cornerstones towards potential industrial applications. These include innovating new types of food, assessing most effective technologies in the context of such food, developing new products, and understanding engagement with emerging food products.

The solvent finding step has always been a time-consuming job in chemical-involved processes. The source of difficulty mainly comes from the trial-and-errors, as a repetitive process of chosing solvents and mixing them in different proportions. Computers are good at doing repetitive processes; however, they can only deal with numerical values, rather than qulitative scales. Numerification of qualitative parameters (like solubility) has already been introduced. The most recent one is the Hansen solubility parameters (HSPs). Using the HSPs could provide a solvent or solvent-mixture. In our previous study, we introduced a computer-aided model and a software to find a solvent mixture. In this study, we have used the computer-aided solvent selection model to find some solvent mixtures for polyamide 11, a biobased polymer which has attracted enormous attention recently. Using this numerical model significantly diminished the time of solvent development experimentation by decreasing the possible/necessary trials.

Solvent selection is a crucial step in all solvent-involved processes. Using the Hansen solubility parameters (HSPs)could provide a solvent/solvent-mixture, but there are two main challenges: 1) What solvents should be selected? 2)From each solvent, how much should be added to the mixture? There is no straightforward way to answer the twochallenging questions. This contribution proposes a computer-aided method for selecting solvents (answer to thequestion 1) and finding the adequate amount of each solvent (answer to the question 2) to form a mixture of 2, 3 or4 solvents to dissolve a solute with known HSPs or to replace a solvent. To achieve this, a sophisticated computersoftware package was developed to find the optimized mixture using the mathematical Simplex algorithm based onHSPs values from a database of 234 solvents. To get a list of solvent-mixtures, polyamide66 was tested using itsHSPs. This technique reduces the laboratory effort required in selecting and screening solvent blends while allowinga large number of candidate solvents to be considered for inclusion in a blend. The outcome of this paper significantlydiminished the time of solvent development experimentation by decreasing the possible/necessary trials. Thus, themost suitable solvent/solvent-substitution can be found by the least possible effort; hence, it will save time and costof all solvent-involved processes in the fields of chemistry, polymer and coating industries, chemical engineering, etc.

Anaerobic mono- and co-digestion of two municipal sludge wastes (A and C), grease trap waste (B), and meat processing waste (D) were investigated under mesophilic temperature conditions by biochemical methane potential (BMP) assays and kinetic modeling. Wastes ratios in the mixtures were systematically selected based on Simplex Lattice mixture design, and statistical analyses were performed to elucidate possible synergetic and antagonistic effects of wastes interactions on the kinetics and ultimate methane potentials of wastes co-digestion. The mixture of 1/8A + 1/8B + 1/8C + 5/8D (VS basis) showed the highest COD and VS removals of 35.0% and 33.8%, respectively. Substrates B and D with 980 and 641 mL/g-VS methane yields, respectively, had the highest BMP. However, with reaction rate constants of 0.047 and 0.070 d−1, their methane production was very slow. It was observed that diluting these organic-rich but complex substrates with readily soluble wastes (A and C) enhanced their biogas production rate markedly. Statistical analysis showed that the interactions among the substrates in co-digestion did not have a significant impact on the ultimate cumulative methane yields. Nevertheless, these interactions proved to have synergic and antagonistic effects on the reaction rates, leading to accelerated or hindered methane production rates. As a result, while the methane yield of wastes co-digestion could be predicted by proportional summation of methane yields obtained in mono-digestions of these waste fractions, such linear regressions were unable to provide a good estimation of the rate constants. Quadratic equations, however, were found to estimate the rate constants of the co-digestion process with good accuracy

Small aerosol particles have for a long time been known to be harmful to humans, and are today regarded to cause a larger number of deaths than traffic accidents globally. Energy dispersive x-ray fluorescence (EDXRF) is a well known method that has been used for identification of toxic as well as non-toxic elements in the particles. The combination of elements will together with other information help to identify the sources and predict the effects of particles on environment and human health. The present work was conducted in Kwabenya, a suburb of the capital Accra of Ghana, which is frequently exposed to Harmattan dust from the Sahara-Sahel region. In total 171 filters each of PM2.5 and PM(2.5-10) were collected during 1 year. Levels of elements, black carbon (BC) and mass, were determined for both particle sizes. Principal component analysis (PCA) was performed on the datasets from Harmattan and non-Harmattan periods. The daily average of PM10 was very high, 179 mu g m(-3) and the BC contents were 4 mu g m(-3). The presence of crustal elements was large in PM(2.5-10) as well as in PM2.5, and had a more than tenfold increase in PM(2.5-10) during the Harmattan period. Major characteristic elements for different sources were identified from correlation coefficients and regression analysis of the data. Sahara sand aerosol was the major source in both study periods, but influence from biomass burning, sea-spray and metal industries was also observed. Copyright (C) 2009 John Wiley & Sons, Ltd.

The production of pigments by edible filamentous fungi is gaining attention as a result of the increased interest in natural sources with added functionality in the food, feed, cosmetic, pharmaceutical and textile industries. The filamentous fungus Neurospora intermedia, used for production of the Indonesian food “oncom”, is one potential source of pigments. The objective of the study was to evaluate the fungus’ pigment production. The joint effect from different factors (carbon and nitrogen source, ZnCl2, MgCl2 and MnCl2) on pigment production by N. intermedia is reported for the first time. The scale-up to 4.5 L bubble column bioreactors was also performed to investigate the effect of pH and aeration. Pigment production of the fungus was successfully manipulated by varying several factors. The results showed that the formation of pigments was strongly influenced by light, carbon, pH, the co-factor Zn2+ and first- to fourth-order interactions between factors. The highest pigmentation (1.19 ± 0.08 mg carotenoids/g dry weight biomass) was achieved in a bubble column reactor. This study provides important insights into pigmentation of this biotechnologically important fungus and lays a foundation for future utilizations of N. intermedia for pigment production. 

BACKGROUND : A method is described that uses dil. phosphoric acid for wheat straw pretreatment and subsequent ethanol and fungal biomass prodn. with the edible fungus Neurospora intermedia. Dil. phosphoric acid pretreatment of wheat straw was optimized at a lab. scale, and the results were validated in a biorefinery demonstration plant for the first time. The various conditions for the dil. acid pretreatment include such factors as phosphoric acid concns. (0.5-3.0% w/v), temp. (150-210 °C), and reaction time (5-20 min). RESULTS : The optimal pretreatment conditions were detd. as an acid concn. of 1.75% (w/v) at a temp. of 190 °C for 15 min, based on the max. enzymic digestibility with the min. inhibitor release. The efficiency of enzymic polysaccharide hydrolysis was 36% for untreated straw and 86% for straw pretreated with dil. phosphoric acid. Scale up of the pretreatment at a biorefinery demonstration plant improved the process, with the subsequent efficiency of polysaccharide hydrolysis being 95% of the theor. max. Ethanol fermn. of enzymically hydrolyzed wheat straw using N. intermedia showed an improvement in the ethanol yield from 29% (with untreated straw) to 94% (with dil. phosphoric acid pretreated straw) of the theor. max. CONCLUSION : This study opens up an alternative strategy for the efficient use of wheat straw for the prodn. of ethanol and edible fungal biomass in existing wheat-to-ethanol plants.

The use of an underutilized and abundant lignocellulosic feedstock residue, wheat bran, was studied for ethanol prodn. using dil. phosphoric acid pretreatment followed by fermn. using edible fungi Neurospora intermedia. Wheat bran was subjected to dil. acid pretreatment at varying acid concns. (0.5-3.0% w/v), temp. (150-210 °C), and reaction time (5-20 min). The interaction of multiple factors showed the optimum pretreatment conditions at acid concn. of 1.75% (w/v), at 190 °C for 10 min. The max. total polysaccharide yield of 0.27 ± 0.01 g/g dry biomass loading, corresponding to 66% of the theor. max. was obsd. Subsequent fermn. with N. intermedia showed 85% of the theor. max. ethanol yield from the untreated bran glucose. The effect of the dil. acid pretreatment on the functional groups of the wheat bran cellulose was detd. with 78% redn. in the cellulose crystallinity index. The validation of the dil. phosphoric acid pretreatment in a demo plant is also reported for the first time. Enzymic hydrolysis of pretreated slurry from the demo plant showed 85% total theor. yield of polysaccharides. Compared to the untreated bran biomass, an increase of 51% was obsd. in the ethanol yield following pretreatment, with a total ethanol yield of 95% theor. max. Higher yield of ethanol is also attributed to the xylose fermenting capability of the fungi. [on SciFinder(R)]

Pelleted growth provides many advantages for filamentous fungi, including decreased broth viscosity, improved aeration, stirring, and heat transfer. Thus, the factors influencing the probability of pellet formation of Rhizopus sp. in a defined medium was investigated using a multifactorial experimental design. Temperature, agitation intensity, Ca2+-concentration, pH, and solid cellulose particles, each had a significant effect on pelletization. Tween 80, spore concentration, and liquid volume were not found to have a significant effect. All of the effects were additive; no interactions were significant. The results were used to create a simple defined medium inducing pelletization, which was used for immobilization of a flocculating strain of Saccharomyces cerevisiae in the zygomycetes pellets. A flor-forming S. cerevisiae strain was also immobilized, while a non-flocculating strain colonized the pellets but was not immobilized. No adverse effects were detected as a result of the close proximity between the filamentous fungus and the yeast, which potentially allows for co-fermentation with S. cerevisiae immobilized in pellets of zygomycetes

Collapsible tanks, vessels or bioreactors are finding increasing usage in small/medium scaleprocesses because they offer flexibility and lower cost. However, if they are to be used atlarge scale, they need to be shown capable of handling the physical stress exerted on them.Because of their nonconventional shape and non-uniform pressure distribution, thin shellanalysis cannot be used in calculating their stress. Defining curvature in terms of pressureaddressed these challenges. Using curvature and numerical analysis, the membrane stress incollapsible tanks designed as bioreactors of volumes between 100-1000 m3 were calculated.When the liquid/gas height and static pressure are known, an equation for calculating tensionper length was developed. An equation that could calculate the liquid height from thebioreactor’s volume, dimensions and working capacity was generated. The equation gavevalues of liquid height with a maximum deviation of 3% from that calculated by curvatureanalysis. The stress values from the liquid height and tension equations had a maximumdeviation of 6% from those calculated by curvature analysis. The calculated tensile stress in a1000 m3 collapsible tank was 14.2 MPa. From these calculations, materials that optimize bothcost and safety can be selected when designing collapsible tanks.

BACKGROUND: Several wastes from agro-industrial activities were mixed in different ratios to evaluate the co-digestion process. Methane yield (YCH4), specific methanogenic activity (SMA) and a kinetic parameter (k0) were determined. A second feeding was also performed to examine the recovery of bacterial activity after exhaustion. Mixture ratios of 1:1:1:1 and 1:3:4:0.5 (w/w) showed the best performance, with YCH4 of 664; 582 NmL CH4/gVSsubstrate, as well as SMA of 0.12; 0.13 gCODNmLCH4/gVSinoculum/d, respectively, during the digestion of the first feed. It was possible to relate synergetic effects with enhancement in YCH4 by up to 43%, compared with values calculated from YCH4 of the individual substrates. All batches started up the biogas production after an exhaustion period, when a second feed was added. However, long lag phases (up to 21 days) were observed due to stressed conditions caused by the substrate limitation prior to the second feed.

The use of consecutive feeding was applied to investigate the response of the microbial biomass to a second addition of substrates in terms of biodegradation using batch tests as a promising alternative to predict the behavior of the process. Anaerobic digestion (AD) of the slaughterhouse waste (SB) and its co-digestion with manure (M), various crops (VC), and municipal solid waste were evaluated. The results were then correlated to previous findings obtained by the authors for similar mixtures in batch and semi-continuous operation modes. AD of the SB failed showing total inhibition after a second feeding. Co-digestion of the SB + M showed a significant improvement for all of the response variables investigated after the second feeding, while co-digestion of the SB + VC resulted in a decline in all of these response variables. Similar patterns were previously detected, during both the batch and the semi-continuous modes.

Different mixture ratios of solid cattle slaughterhouse wastes (SB), manure (M), various crops (VC), and municipal solid wastes (MSW) were investigated for biogas production. The objective was to explore possible significant synergistic effects obtained from the combination of these different substrates. The performance of the process was assessed in thermophilic anaerobic batch co-digestion assays, using a four factor mixture design and methane yield (Y-CH4) and specific methane production rate (r(scH4)) as response variables. The highest methane yield, 655 NmL CH4/g VS was obtained when equal parts (ww) of SB, M, VC, and MSW were combined, while the combination of SB, M, and MSW resulted in the highest specific methane production rate (43 NmL CH4/g VS/d). A mixture design model was fitted to data in order to appraise synergistic and antagonistic interactions. Mixing all four substrates resulted in a 31% increase of the expected yield which was calculated from the methane potential of the individual fractions, clearly demonstrating a synergistic effect due to more balanced nutrient composition enhancing the anaerobic digestion process. However, no significant antagonistic effects were observed. In order to maximize both response variables simultaneously, a response surface method was employed to establish the optimal combination of substrate mixtures. The statistical results and analysis of the biological process gave a coherent picture of the results. (C) 2014 Elsevier B.V. All rights reserved.

Dry anaerobic co-digestion of citrus wastes (CW) with chicken feather (CF), wheat straw (WS) and manure bedded with straw (MS) was investigated in batch and continuous processes. Experiments were designed with different mixing ratios considering the inhibitory effect of CW, C/N ratio, and total solid content of individual feedstocks. Best mixing ratio (CF:CW:WS:MS) of 1:1:6:0, enhanced methane yield by 14% compared to the expected yield calculated according to the methane yields obtained from the individual fractions. The process performance of this mixture was then investigated in continuous plug flow reactors at different organic loading rates (OLR) with feedstock total solid contents of 21% TS (RTS21) and 32% TS (RTS32). At OLR of 2 gVS/L/d, a methane yield of 362 NmlCH4/gVSadded was obtained from RTS21, which is 13.5% higher than the yield obtained from RTS32 (319 NmlCH4/gVSadded). However, it was not possible to achieve a stable process when the OLR was further increased to 3.8 gVS/L/d; there were increased total VFAs concentrations and a decline in the biogas production.

Biofuels contribute environment-friendly, renewable energy, minimizing dependence on fossil energy. The pretreatment of biomass is a practical step that accelerates and facilitates the hydrolysis of complex materials. This work aimed to screen, select, and study cocktail formulations for biomass hydrolysis, where the enzymes were provided both from a commercial source (Trichoderma reesei, Novozymes®) and through the cultivation of Aspergillus brasiliensis and Aspergillus tamarii Kita. Experimental mixture designs were used to optimize the enzymatic conversion of substrates into simple sugars. A crude extract rich in amylase (AAB) had a significant favorable influence on cornmeal hydrolysis by maximizing the yield of reducing sugars (RS) (173 μmol mL–1). Celluclast™, rich in cellulase, significantly affected the hydrolysis of banana peel, maximizing the RS yield (175 μmol mL–1). Variable degrees of enzyme synergism were evident from statistical analysis of the biomass hydrolysis.

In this study, a novel process simulation model (PSM) was developed for anaerobic digestion using Aspen Plus® (version 7.3.2). PSM has two parts, one for hydrolysis working based on extent of reaction and the other on kinetics of reactions. A total of 53 reactions were used in the model including inhibitions, rate kinetics, pH, ammonia, volume and HRT. Each reaction set in the kinetic reactor has a FORTRAN program to calculate the kinetics of biogas production. PSM was validated with earlier research studies and industrial experiments in Aspen Plus®. The P-value after statistical analysis was found to be 0.324, which showed there was no significant difference between different validations, even after a change in process conditions, loading rate, HRT and substrate. The sensitivity analysis with a ±10% change in composition and extent of reaction would result in average 4.56% higher value than the experimental value.

A novel process simulation model (PSM) was developed for biogas production in anaerobic digesters using AspenPlus®. The PSM is a library model of anaerobic digestion, which predicts the biogas production from any substrate at any given process condition. A total of 46 reactions were used in the model, which include inhibitions, rate-kinetics, pH, ammonia, volume, loading rate, and retention time. The hydrolysis reactions were based on the extent of the reaction, while the acidogenic, acetogenic, and methanogenic reactions were based on the kinetics. The PSM was validated against a variety of lab and industrial data on anaerobic digestion. The P-value after statistical analysis was found to be 0.701, which showed that there was no significant difference between discrete validations and processing conditions. The sensitivity analysis for a ±10% change in composition of substrate and extent of reaction results in 5.285% higher value than the experimental value. The model is available at http://hdl.handle.net/2320/12358 (Rajendran et al., 2013b).

The present study measures the participation of households in a source separation scheme and, in particular, if the household’s application of the scheme improved after two interventions: (a) shorter distance to the drop-off point and (b) easy access to correct sorting information. The effect of these interventions was quantified and, as far as possible, isolated from other factors that can influence the recycling behaviour. The study was based on households located in an urban residential area in Sweden, where waste composition studies were performed before and after the interventions by manual sorting (pick analysis). Statistical analyses of the results indicated a significant decrease (28%) of packaging and newsprint in the residual waste after establishing a property close collection system (intervention (a)), as well as significant decrease (70%) of the miss-sorted fraction in bags intended for food waste after new information stickers were introduced (intervention (b)). Providing a property close collection system to collect more waste fractions as well as finding new communication channels for information about sorting can be used as tools to increase the source separation ratio. This contribution also highlights the need to evaluate the effects of different types of information and communication concerning sorting instructions in a property close collection system.

Concrete waste as crushed concrete aggregates (CCA) in structural concrete prolongs the technical life of the reference concrete accomplishing closed loop recycling. CCA concrete reaches the reference concrete compressive strength and workability by the densification of CCA and cement paste. Our previous study demonstrates CCA densification by mechanical pre-processing, aggregate quality improvements discerned by increased packing density giving reference concrete strength and workability. This study addresses paste densification with blast furnace slag (GGBS) to replace 30 (wt.%) of Portland cement at reference concrete w/b ratio 0.5 and a lower w/b 0.42. Two CCA replacements are investigated: fine aggregates, CCA50; overall aggregate replacement, CCA100. Compressive strength results show that both CCA50, CCA100 mixes achieve reference values at w/b 0.42, only CCA100 achieves reference value at w/b 0.5 as a climate-optimized concrete. The CCA50 mix-w/b 0.5 reaches reference strength when paste densification by GGBS is combined with CCA densification from mechanical pre-processing of aggregates. The 7-day strength of CCA100 with GGBS increases by 11% by mixing with pre-soaked GGBS. Statistical analysis of CCA100 strength results shows significant improvements with GGBS compared to mechanical pre-processing. Significant improvements are possible in CCA50 mix for a combination of mechanical pre-processed aggregates and GGBS replacement.

In a novel valorization approach for simultaneous pectin extn. and pretreatment (SPEP) of citrus waste (CW) by dil. nitric acid and ethanol, almost all of the CW was converted to bio-derived chems. in a singlestep process at a low/moderate temp. The SPEP was performed at different temps. (70 °C and 80 °C), pH (1.8, 3.0, and 4.3), and extn. times (2 h and 3 h) with a full factorial design. The max. pectin yield of 45.5% was obtained at pH 1.8, 80 °C, and 2 h. The pectin yields at pH 1.8 were much higher than at pH 4.3 and 3. Also, the degree of methyl-esterification at pH 1.8 was higher than 50%, whereas at the higher pH, low methoxyl pectins were extd. The treated CW obtained after the SPEP, free from limonene, was subjected to sep. cellulolytic enzymic hydrolysis and ethanolic fermn. The glucose yields in the enzymic hydrolyzates were higher for the CW treated at pH 1.8. The fermn. of the enzymic hydrolyzates by Mucor indicus resulted in fungal biomass yields in the range of 355 to 687 mg per g of consumed sugars. The optimum conditions for obtaining the max. SPEP yield (glucose + pectin (g) / raw material (g)*100) were pH 1.8, 80 °C, and 2 h, which resulted in a yield of 58.7% (g/g CW). [on SciFinder(R)]

Optimization study of citrus wastes Saccharification by dilute acid hydrolysis