电化学氧化处理丙烯腈废水及对可生化性的提高

以丙烯腈废水为研究对象,进行废水预处理对提高废水的可生化性和后续好氧生物处理效率的研究。实验采用电化学氧化法对难降解丙烯腈废水处理效果进行了单因子试验,分析了电压、电解时间、氯离子质量浓度对废水色度及CODcr的去除效果,以及对废水可生化性的影响。实验结果显示,电化学氧化法在电压5V,pH为3.00,反应时间6h,搅拌速率为250r·min^-1,氯离子质量浓度为5000mg·L^-1的条件下,对CODCr1156mg·L^-1,色度512倍的丙烯腈废水中CODcr去除率达到60%,色度的去除率达到90%,并使废水的可生化性明显提高。CODCr去除率和色度去除率随电解时间、电压增加而增大,电解时间达5h、电压大于5V以后使水电解副反应更容易发生,对有机物的降解速率减小,同时随电解时间延长,能耗逐渐增大,处理成本增大;氯离子质量浓度对电解效果影响较大,适量增大氯离子质量浓度,可以提高CODCr的去除率。

The improvement of acrylonitrile wastewater biodegradability by means of electrochemical oxidation

Acrylonitrile wastewater are pretreated to improve the biodegradability of wastewater and treatment efficiency of subsequent aerobic biochemical process in the paper.The main influence factors of chrome,CODcr removal and biodegradability from acrylonitrile wastewater,which include voltage,electrolysis time,chloride ion concentration,have been examined and analyzed systemically by electrochemical oxidation.Under the analyzed conditions（voltage=5 V,pH=3.00,reaction time=6 h,stirring rate=250 r·min^-1,chloride ion concentration=5 000 mg·L^-1）,the result shows that the removal efficiency of CODCr and chroma for acrylonitrile wastewater（CODCr=1 156 mg·L^-1and chroma=512 times） achieve 60% and 90% respectively.Simutaneously,the biodegradability of the wastewater is obviously improved.The removal rate of CODCr and chrome get better with addition of electrolysis time and electrolysis-voltage,but the removal rate gets slower because of a side reaction during electrolysis process while the voltage is over 5 V and the reaction time is more than 5 h.Additionally,energy consumption and treatment costs increase with the increasing on the electrolysis time.Chloride ion concentration has an obvious influence on electrolysis.Appropriate increase on chloride ion concentration can improve CODCr removal.