Efficacy Study Of ABR-CSTR Integrated Process On Rice Wine Wastewater Treatment

With the rapid development of rice wine industry, the environmental issues of rice wine wastewater have become increasingly significant. Rice wine wastewater belongs organic wastewater with high concentration, it richs in starch, sugar, protein and other organic matter. Anaerobic biological treatment technology is the best choice for treating high concentration organic wastewater, because of its notable features, such as low consumption, high efficiency, low cost, mild reaction conditions, and no secondary pollution. Anaerobic baffled reactor(ABR) is one of high-rate anaerobic reactors, which based on the theory of multi-phase anaerobic reactor in stages. It has a simple structure, strong retention ability, high stability and other advantages.The performance of ABR-CSTR integrated process on rice wine wastewater treatment was investigated. The operating characteristics of ABR-CSTR integrated process at startup phase and stable phase were studied, including the effect of volume load on the process during the operating phase, and the gas production characteristics of the process. What’s more, HRT, reflux ratio were optimizaed to achieve nitrogen and phosphorus’ s removal. Results of the study indieated:(1)The ABR-CSTR integrated process startup successfully within 100 days. The performance of sludge was well, and the biofacies were separated. Under the operation temperature of 30±2℃, and volume load of 4kgCOD/(m3·d), the effluent concentration of COD was less than 80mg/L, and the removal rates of COD were about 95% to 98%. The average effluent concentration of NH4+-N, TN and TP were 0.6, 20.4 and 0.9mg/L, respectively, the average removal rates were 99%, 56% and 83%.(2)With the volume load increased from 4kgCOD/(m3·d) to 8kgCOD/(m3·d), ABR’s effluent concentration of COD gradually increased and the removal rate decreased from 93% down to 81%. The influent load of CSTR increased, while the removal rates of COD remained above 95%.(3)Under the conditions with volume load of 4kgCOD/(m3·d), 6kgCOD/(m3·d) and 8kgCOD/(m3·d), the biogas output of ABR’s first three compartments were 1.58, 2.48 and 2.88m3/(m3·d). The gas production rate was the highest with volume load of 6kgCOD/(m3·d), and the each compartment’s gas production rates were 0.221, 0.337 and 0.433m3/(kgCOD), respectively.(4)With the volume load of 6kgCOD/(m3·d), HRT of 32 h, R of 150%, SRT of 15 d and DO of 2mg/L, the ABR-CSTR integrated process had stable and efficient effect on nitrogen and phosphorus’ s removal. Under this operating condition, the average effluent concentration of COD, NH4+-N, TN and TP, respectively, were 82.9, 1.4, 12.8 and 1.1mg / L, and the average removal rates were 98%, 97%, 75% and 81%.