Bioprocesses for Wastewater Reuse: Closed-Loop System for Energy Options

Wastewater discharged from domestic, agricultural, and commercial industries potentially release significant amounts of toxic and pathogenic contaminants into the environment. Wastewater treatment via bioprocess techniques has received a wide attention due to the benefits of end use, i.e., biochemical compounds with sustainable/eco-friendly bioenergy and bioproduct options. Biological treatment of wastewater is beneficial over physical and chemical treatment technology, as it provides biomass in bulk, which can be used for various purposes. The use of reclaimed water (after biological treatment) is significant in terms of environmental, economic, and social aspects, as it does not harm the ecosystem and produces biomass-based products that generate revenue to maintain economic sustainability and provide job opportunities to maintain social integrity. A central goal of these efforts is identifying the means for closing the loop in production systems that take into account legacy management, waste from fossil fuel industries, and integrated design for advanced renewable energy production systems (biogas from biowaste, bioenergy from crassulacean acid metabolism (CAM) plants) that value five aspects of governance: property rights, policy design, financing, and scale as tools to assist enhanced institutional design for integrative management, technology innovation, and public development. The produced biomass on wastewater can further be used to produce bioenergy (biohydrogen, biogas, bioethanol, and biodiesel) and biobased products that have high market value.