水中安乃近高级氧化法去除及其产物的毒性评价

在实验室规模下,利用UV、H2O2、UV/H2O2、Fenton和UV/Fenton等高级氧化技术降解安乃近并对其降解产物进行毒性评价.在对各参数(pH值、H2O2投加量、Fe2+投加量、光照时间)优化的基础上,用TOC去除率和降解率对降解效果进行评价.安乃近及其光催化降解中间产物在水溶液中的毒性通过其对普通小球藻的生长抑制作用评价,并以96h的半数效应浓度(EC50)表示.结果表明,UV/Fenton对安乃近的降解率最大(96%),最佳降解条件为pH3,Fe2+、H2O2浓度分别为2,140mg/L.初期降解产物的生物毒性比母体化合物大,其EC50达到最小值(13.65mg/L),随降解时间的延长,EC50值逐渐增大,在180min为44.07mg/L,小球藻生长状况良好,表明含低浓度安乃近的水溶液经过UV/Fenton法处理后对水中生物已不具有危害作用.

Degradation of dipyrone in water by advanced oxidation processes and evaluation of the toxicity for the degradation products

Dipyrone was depredated by UV, H2O2, UV/H2O2, Fenton, UV/Fenton and other advanced oxidation process in the laboratory scale, and the toxicity of the degradation products was evaluated. On the basis of optimized parameters (pH, H2O2 dosage, Fe2+ dosage, illumination time), the degradation effect was evaluated using removal effect of TOC and degradation of dipyrone. The toxicity of dipyrone and its photocatalytic intermediates in aqueous solution were assessed by the growth inhibition of Chlorella vulgaris and was showed by the 96h half effect of concentration (EC50). The degradation effect of UV/Fenton for dipyrone was most efficient, the optimized parameters were pH 3, Fe2+ 2mg/L and H2O2 140mg/L. Biological test showed that the intermediates were of more toxicity than the matrix compound because the EC50 value was minimum (13.65mg/L) when the reaction time reached 30min. With the reaction time increased the value of EC50 gradually increased, and reached 44.07 mg/L at 180 min, and the chlorella was grew well in good condition, which showing that photo-Fenton reaction was fit for degradation of low concentrations of dipyrone in aqueous solution and the treated water didn¢t have biological toxicity for chlorella.