[Removal of Typical Antibiotics During Aerobic Composting of Human Feces]

Aerobic composting experiments were conducted under three different temperatures (55℃, 35℃, and non-temperature-controlled) with human feces and sawdust as the compost material and bulky matrix respectively. Attention was paid to the effects of temperature on the removal of four typical antibiotics (tetracycline, chlortetracycline, sulfadiazine, and ciprofloxacin) during human feces aerobic composting. Furthermore, three specific experiments were conducted to identify the possible antibiotic degradation mechanisms in aqueous solution and during composting with moist sterile sawdust but without feces and composting with feces and moist sterile sawdust. The most effective removal of the four antibiotics was achieved through thermophilic composting (55℃). At 55℃, more than 90% of all the antibiotics were removed. The degradation of tetracycline and chlortetracycline was more temperature-dependent than that of sulfadiazine and ciprofloxacin. Moreover, tetracycline and chlortetracycline removal was primarily through hydrolysis in moist environments. However, sulfadiazine and ciprofloxacin removal was mainly attributed to adsorption by sawdust particles. The contribution of microbial action to antibiotic degradation was insignificant for all the antibiotics except ciprofloxacin. Up to 20% of this antibiotic was degraded by microbial action.