Research On The Treatment Of Synthetic Detergent Wastewater Using The Technology Of Anaerobic Hydrolysis And Activated Sludge Process

LAS in the synthetic detergent wastewater has certain biological toxicity, foaming tendency and emulsifying tendency, so it is not easy for treatment. As for the properties of LAS, investigations had been performed on biodegradability of synthetic detergent firstly, and emphases had been put on experimental analysis on hydrolytic acidification. During the process of hydrolytic acidification, big molecules had been divided into small molecules, and unbiogradable substances were also converted into biodegradable substances in the wastewater, so appropriate condition was provided for subsequent aerobic treatment.On the basis of biodegradability experiment of synthetic detergent wastewater, emphases were put on the research on the technology of coagulating sedimentation, hydrolytic acidification and aerobic treatment the study results showed that, as high concentration LAS pretreatment, the physical-biological treatment had good effect. As LAS concentration is 100mg/L below, FeCl3 input in 20-30mg/L, CaCl2 input in 50-150mg/L, LAS removal reached 50-65% by coagulating sedimentation. COD removal attained 30-50% and the ratio of BOD/COD also increased in the process of hydrolytic acidification. As aerobic treatment technology, activated sludge process of was used for final treatment of anaerobic effluent. When effluent LAS concentration was 80mg/L below and HRT was about 6h, the final effluent with COD=80mg/L,LAS=5mg/L was abtained. So the technology of coagulation-anaerobic hydrolysis-aerobic treatment was adopted for synthetic detergent wastewater treatment.According to the study results, technology design had been made for practical projection. Due to the complexity of influent component and capacity variation, new technologies and measures hah been made accordingly. And the technology present was also improved, e.g. membrane hydrolysis for preventing from hydrolytic sludge outflow, biological contacting oxidation for stability of treatment effect, quartz sand filter and biological carbon reaction for effluent reuse etc. after two months' debugging operation, effluent quality was stable and met national wastewater comprehensive discharge standard (GB8978-1996). The effect of synthetic detergent wastewater treatment by the technology above-mentioned was satisfactory.synthetic detergent wastewater; LAS; coagulating sedimentation;anaerobic hydrolysis; activated sludge process; biological contacting oxidation...