Autothermal thermophilic aerobic digestion for human excreta treatment

Autothermal thermophilic aerobic digestion (ATAD) is used to treat human excreta hygienically. We previously reported a unique full-scale ATAD, showing distinctive bacterial community transitions and producing high-nitrogen-content liquid fertilizer; nevertheless, the mechanism remains unclear. One hypothesis involves using a gas-inducing (GI) agitator. We designed a lab-scale GI system and compared it with a disk-turbine (DT) agitator system by mimicking the temperature shift of full-scale ATAD. The agitation system and its agitation speed greatly affected physicochemical properties and bacterial community structure.