Pilot Studies On Combined Process Of ABR-MBBR For Beet Sugar Wastewater And Straw-pulp Wastewater Treatment

Due to its simple configuration and improved biomass retention within reactor and many other advantages over presently well-established reactor systems, anaerobic baffled reactor (ABR) is one of high-rate anaerobic reactors which have been received increasing attention. In addition, moving-bed biofilm reactor (MBBR) is a completely mixed continuously operated biofilm reactor where the biomass is grown on small carrier elements that move along with the water in the reactor. No sludge recycling is necessary for keeping a high level biomass per unit reactor volume. The MBBR has been successfully applied for full-scale treatment of municipal and industrial wastewaters. This paper reported the pilot studies on integrated process of ABR-MBBR for beet sugar effluents and straw-pulp effluents treatment, including the reactor start-up, the methane-producing activity of anaerobic sludge in different compartments, hydraulic and organic shock loads and the development of anaerobic granular sludge. Several key parameters were acquired, which may exhibit important scientific values to the practical application.The following conclusions can be drawn through the study.(1) ABR reactor was effective in treating beet sugar effluents.①When the temperature varied between 19 and 21℃, more than 70% of COD removal was achieved under the condition of the influent COD concentration 4777~6534 mg /L and HRT 96~30 h in the ABR.②ABR may eliminate 86% of SO42-concentration in beet sugar effluents, most degradation was observed in the first two chambers of ABR, the residual SO42- was about 62 mg /L in the effluent.③The ratio of COD / SO42- may effect the removal of COD and SO42- and the biogas production. Along with the ratio increasing, the removal of COD and SO42- improved obviously, as well as the gas production rate. When the ratio of COD/ SO42- exceeded 13, the removal of COD and SO42- remained stable.(2) The combined process of ABR-MBBR was effective in treating straw-pulp effluents.①When the temperature was between 33 and 38℃, about 43 ~ 50 % of COD removal was achieved under the condition of the influent COD concentration 1200~3500 mg /L and HRT 48 ~ 24 h in the ABR.②The effluent from the ABR continued to enter the MBBR. When the HRT of MBBR decreased from 12h to 6 h, the COD removal rate was about 61~70 %.③The coagulation and sedimentation was necessary to polish the ABR-MBBR effluent to demand the latest discharge standards, in which COD and color indices was ordered below 100 mg /L and 40 times, respectively. The dosage of Fe2(SO4)3 was ordered between 1000 to 1250 mg /L.