Nowadays, it is commonly accepted that a waste stream (solid, liquid, and gaseous alike) is not a waste but a source of invaluable resources, including energy (in different forms, heat, and electricity) and nutrients. Such resource recovery is an efficient way to produce energy by mitigating pollution and improve sustainability in operation. To achieve this goal, a plethora of technologies have been established and integrated into the sustainable waste cycle. Moving toward a new waste cycle will restore the balance between resource scarcity and demand for primary materials reducing energy consumption and thus CO2 emissions. This chapter defines emerging resource recovery technologies across the wastewater treatment cycle. The most important procedures include (1) anaerobic digestion of sludge, (2) co-digestion, incineration, co-incineration, and (3) pyrolysis, gasification, wet-oxidation, all utilized toward construction materials’ fabrication. Processes are further accompanied by energy recovery. The production of biofuels (mainly hydrogen, syngas, and bio-oil) sustained positive prospects of alternative energy sources to current energy mixes.
Low Carbon Energy Technologies in Sustainable Energy Systems, 2021, Pages 3-24,