Biowaste is a major source of organic material that can be converted into energy through various processes such as anaerobic digestion, composting, and pyrolysis. However, emerging pollutants, such as pharmaceuticals, pesticides, herbicides, and personal and household products, are a growing concern in wastewater treatment that can be effectively removed by biowaste-to-energy processes. While these contaminants pose significant challenges, the development and implementation of effective monitoring programs and risk assessment tools help to mitigate their impact on human health and the environment. Likewise, monitoring programs, challenges, legislations, and risk assessment tools are essential for understanding and managing the risks associated with emerging pollutants. Biowaste recycling is an important aspect of a biocircular economy perspective as it involves the conversion of organic waste into valuable resources that can be reused sustainably. The review discusses the modern approaches that offer several advantages, including reducing the waste disposal and generating renewable energy while addressing emerging wastewater treatment pollutants. To achieve the goal of a circular economy, modern biotechnological approaches including anaerobic digestion, composting, bioleaching, bioremediation, and microbial fuel cells offer a sustainable and effective way to convert waste into valuable products. These bioproducts alongside energy generation using waste-to-energy technologies can provide economic benefits through revenue generation, reduced waste disposal costs, and improved resource efficiency. To achieve a biocircular economy for biowaste valorization, several stakeholders, including waste collectors, waste management companies, policymakers, and consumers need to be involved. The sustainable conversion of biowaste to energy is an essential and instrumental technology in environmental sustainability.