Treatment of vitamin C wastewater using upflow anaerobic sludge blanket(UASB) reactor

In order to improve the efficiency and evaluate the feasibility of anaerobic digestion for treatment of vitamin C wastewater.A 2.2 L lab-scale mesophilic UASB reactor was investigated over 150 d for the treatment of vitamin C wastewater with optimized running parameters.With inoculation of pre-incubated sludge,successful startup of the reactor was achieved within 65 days at 35 ℃.During the steady-state,undiluted wastewater with a chemical oxygen demand(COD) of 10000 mg/L was fed.The corresponding organic loading rate(OLR) and hydraulic retention time(HRT) were 10.8 kg/(m3·d) and 15 h respectively.Up to 92% of COD was removed and the CH4 production rate of 3.2 m3 /(m3·d) was obtained.The produced biogas contained 72% of CH4.The VSS/TSS ratio of the sludge was improved from 0.41 to 0.82,while the specific methanogenic activity increased from 0.18 to 0.85 L/(gVSS·d) respectively at the beginning of the reactor startup towards the end of the experimental period.