Study On Novel Treatment Process In High Strength AN Wastewater

This paper focuses on the novel process of activated carbon /fresh MnO2+rice-husk biofilm reactor and studied its characteristic in high strength acrylonitrile(AN) wastewater treatment.The effect of applying fresh MnO2 immobilized activated carbon to pretreat high strength acrylonitrile wastewater in different variables such as solution ptK fresh MnO2 mass and reaction time was studied. The results showed that the optimum pH , the amount of fresh MnO2 added and reaction time is <4.0, 500mg/L, 5min, that the rate of AN removal, CODcr is up to 50% in the optium condition , that AN and CODcr is greatly removed for biochemical treatment providing beneficial condition through pretreatment.High-effective acrylonitrile-degrading bacteria biomembrane was cultivated using rice-husk as a carrier .The culture condition of biomembrane were investigated and its microbiological inspection was also made. The experimetal results shows that rice-husk is a good carrier of microbiology and buffer medium of high strength acrylonitrile, that the cultivated acrylonitrile-degrading bacteria can be used to effectively remove AN and tolerate high strength AN, that when the influent AN concentration is 100-800 mg/L, the rate of AN removal is up to 95%, the optimum pH and temperature of cultivated acrylonitrile-degrading bacteria are 6.5 and 20 respectively. In rice-husk biomembrane, the acrylonitrile-degrading bacteria are mainly G+ short bacillus, which have a major action in wastewater treatment.The effect of applying the novel process of activated carbon /fresh MnO2+rice-husk biofilmreactor to treat high strength acrylonitrile wastewater in different operating conditions was studied. The results showed that when the influent AN 500~900mg/L, CODcr700~ 1300 mg/Land pH2.0 ~ 4.0, it can effectively treat high strength acrylonitrile wastewater, and total AN removal rate is up to 99% and total CODcr removal rate is up to 93.5%, the effluent AN , CODcr , NH4+-N can be reduced to below 5, 80 , 15mg/L respectively, meeting the wastewater discharge national standard (GB8978-1996). The novel process provide a new thinking for high-effective, practical and cheap treatment process in high strength acrylonitrile wastewater because of its advantages of high-effective remove AN and CODcr , good effect and low investment and operating cost.