Research On Treatment Of Pretilachlor And Clomazone Wastewater With Anaerobic Baffled Reactor

As a typical high concentration wastewater with debiodegradation and toxicity, pesticide wastewater would result in a series of adverse effects on the environment if discharged directly without any treatment. In consideration of the anaerobic baffled reactor (ABR) possessing the features of simple structure, high discharge water quality, large shock resistance capacity and being able to actualize the SMPA idea, the study focused on the operation and microorganism characteristics of anaerobic baffled reactor (ABR) treating high concentration organic wastewater, which was produced in the process of Pretilachlor and Clomazone's production, and the feasibility of disposing this kind of pesticide wastewater using ABR was demonstrated by the study.The continuous experiment could be divided to two stages, the start-up and the stable running. The study used low volume loading rate for start-up, original loading was 1.2 kg/(m~3·d), Hydraulic Retention Time (HRT) was 24 h, the temperature was controlled on 35±1℃. With the influent water which was man-made and nourishing, the maximal removal rate of COD reached 95%. During the domestication, the activity of microorganism was restrained. When the system was stable, the removal rate of COD reached 53%. At the stable running stage of ABR when the influent water was pesticide wastewater, the influent COD concentration was increased gradually, the maximal concentration could reach 22000mg/L. But after the domestication, the microorganism could fit the environment, the removal rate of COD reached 55% and maintained stablely. The biodegradability of wastewater was improved by ABR. The numerical value of BOD5/COD was increased from 0.33 to 0.51, and it was in favor of the later treatment.At the stable running stage of ABR, the study discussed the effects of HRT on the removal of COD, which were 12h, 18h and 24h. Under the same influent COD concentration, the average removal rate of COD reached 47.15%, 47.82%, and 51.16% when HRT was 12h, 18h, and 24h, respectively. Therefore, HRT of 24h was choosed in the study.The study also discussed the condition that the influent water was the effluent of Fe-C microelectrolysis. The result showed that if the COD removal rate of Fe-C microelectrolysis was 35%, and the removal rate of COD was 50% after ABR treated, the total removal of COD could reach 67% for pesticide wastewater. It was indicated that this united technics was in favor of increasing the removal rate of COD of pesticide wastewater.