Study on the Pretreatment of Molasses Alcohol Wastewater by the Micro-Aerobic Hydrolysis and Acidification Process

Molasses alcohol wastewater was treated by the micro-aerobic hydrolysis and acidification process as a pretreatment process. The COD removal rate increased quickly at the beginning of the reaction and then very slowly. The COD removal rate and the acidification rate reached the maximum at the aeration rate of 20mL/min. The acidification rates at different pH values increased firstly with the increasing hydraulic retention time and decreased with the time after 8h. The optimal volume loading was determined to be 7.42kgCOD/(m³·d). Under the condition of the hydraulic retention time = 8h, the influent COD concentration <;5000mg/L, the influent pH=6.5 and the aeration rate = 20mL/min (DO=0.56mg/L), the COD removal rate and the acidification rate were 28.9% and 47.6%, respectively.