Acidogenic fermentation pretreatment and detoxification of apramycin process wastewater

A continuous stirred-tank reactor (CSTR) was used to pretreat apramycin process wastewater by acidogenic fermentation. At hydraulic retention time (HRT) of 8 h, with a influent concentration of 5000-8000 mg/L, the average removal rates of COD, suspended solid (SS) and ammoniacal nitrogen were 21.53%, 56.78% and 11.05%, respectively. When the HRT increased to 12 h, the average removal rates of COD, SS and ammoniacal nitrogen decreased to 17.62%, 53.05% and 6.39%, respectively. The ratio of BOD₅/COD for the treated wastewater increased from the original 0.35 to above 0.42, while the specific formation rate of methane by COD removal reached 164 mL/g, indicating that the biodegradability of the wastewater had been enhanced observably and the toxicity to the anaerobic microorganism had been eliminated successfully.