Population growth and industrialization across the globe are leading to the production of larger waste volumes. This will occur even though the current rate of waste production is already exceeding the capacity of existing waste management infrastructure in many parts of the world. The environmental consequences of inadequate waste management are already being realized on both the small and global scale, through, for example, the pollution of local air/water bodies and climate change. While these increases in waste production pose many challenges, they also present many opportunities to develop novel technologies to not only better stabilize these wastes, but also recover valuable resources, such as energy, green chemicals, and nutrients. Therefore, a shift aimed at carbon and resource recovery from waste streams has been implemented as an alternative approach to conventional waste management. For example, biological treatment of wastewaters may be coupled to microalgae-based biofuel production. Also, advanced fermentation processes may be used to recover carbon or produce green chemicals, including methane and/or carboxylic acids. The biorefinery concept is also being increasingly implemented in the industrial sector to recover energy and resources from on-site waste streams. Syngas, for example, a common byproduct in many industrial processes, including steel production, may serve as feedstock for the fermentative production of green chemicals, such as acetic acid and ethanol.

In response to this emerging scientific field, we are organizing a special issue to serve as a platform for novel research that addresses these challenges and specific applications of waste-to-bioenergy or biorefinery concepts. Because it is important for the development of every novel technology to consider the broader environmental impacts and economic feasibility, we of course welcome studies involving life-cycle assessment, technoeconomic analysis, and process safety assessment. Finally, any forms of theoretical papers, methodological studies, empirical research, and clinical studies (or combination thereof) are also welcome.

Potential topics include but are not limited to the following:

• Nutrient recycling/recovery from waste
• Carbon recovery and utilization
• Biomass (i.e., algae) production using waste streams
• Biofuels from biomass
• Biomass to fuels and chemicals
• Bioplastics from biomass
• Advanced technologies for waste reclamation/valorization
• Disposal of residues from waste treatment
• Life-cycle assessment and technoeconomic analysis of renewable energy technologies
• Safety assessment of process and bioproducts involved