污水氯化/脱氯消毒副产物的生物毒性

利用发光细菌法考察了氯化／脱氯消毒后污水的生物毒性及余氯形态、氨氮浓度和有机物含量等对消毒后污水生物毒性的影响。研究发现,经氯化／脱氯消毒后污水的生物毒性显著增强;当余氯呈化合态时污水的生物毒性随投氯量的增大而增强,污水对发光细菌的发光抑制率与投氯量的对数有较好的线性关系;当余氯呈游离态时,污水的生物毒性随投氯量的变化出现了峰值,继续增大投氯量后生物毒性有所减小;氨氮有削弱消毒后污水生物毒性的倾向,而有机物则有增强消毒后污水生物毒性的倾向。

Study on Bio-toxicity of Disinfection Byproduct after Chlorination/Dechlorination in Wastewater

Bio-toxicity of disinfected wastewater with chlorination and dechlorination was studied using photobacteria,and the effect of residual chlorine forms,ammonia nitrogen concentration and organic matters content on bio-toxicity in disinfected wastewater was also investigated.The result shows that bio-toxicity in disinfected wastewater increases significantly.When residual chlorine is in combined form,bio-toxicity in wastewater increases along with the increased chlorine dosage,and photobacteria inhibition rate is linear with the logarithm of chlorine dosage;when residual chlorine is in the free form,the peak toxicity occurs with the variation in chlorine dosage,it is followed by the slight reduction of toxicity after increase of chlorine dosage.Ammonia nitrogen shows a tendency to reduce the toxicity in disinfected wastewater,while organic matter shows a tendency to increase the toxicity.