二氧化氯预氧化工艺去除饮用水原水中摇蚊幼虫的试验

目的研究二氧化氯预氧化工艺对原水中摇蚊幼虫的去除效果,解决目前预氯化工艺不能有效控制摇蚊幼虫在给水处理工艺中孳生的难题.方法进行了二氧化氯和液氯灭活第1龄期摇蚊幼虫的对比试验,在此基础上,对不同预氧化工艺下,预氧化与水处理澄清过程对第1龄期摇蚊幼虫的协同去除效果进行了考察,并对其水样的有机浓集物进行了Ames试验,比较了两种饮用水的致突变性.结果二氧化氯与液氯相比对摇蚊幼虫具有更好的灭活作用,投加量1.5 mg/L,接触30 min可以达到100%的灭活率;二氧化氯投加量0.51 mg/L,二氧化氯预氧化与水处理澄清过程的协同作用可以完全去除原水中的第1龄期摇蚊幼虫.Ames试验进一步表明,采用二氧化氯作为预氧化剂可明显降低饮用水的致突变性.结论二氧化氯预氧化工艺是去除饮用水中摇蚊幼虫的有效方法.

Study on Removing Chironomid Larvae from Raw Water Using Chlorine Dioxide Pre-oxidation Process

The excessive propagation of Chironomid larvae in the water treatment system is a difficult problem for the normal operation of waterworks.Since the prechlorination process could not solve effectively this problem,the removal effect of chlorine dioxide pre-oxidation process on the Chironomid larvae was studied.The bench scale experiments were conducted to investigate the inactivation effects of chlorine and chlorine dioxide on the first instar larvae of Chironomid.Furthermore,synergic removal effect of different pre-oxidation processes combined with clarification process on the first instar larvae of Chironomid was evaluated.In order to compare the mutagenic activities of water samples treated with different oxidants pre-oxidation processes,the mutagenicities of organic extracts from the water samples were tested by using Ames test.The results showed that chlorine dioxide possessed better inactivation effect than chlorine.Complete inactivation rate could be reached under the condition of(1.5?mg/L) of chlorine dioxide with(30?min) disposal.The cooperation effect of pre-oxidation and clarification process could increase the removal efficiency of the first instar larvae of Chironomid and entirely remove the first instar larvae of Chironomid at the(0.51?mg/L) of chlorine dioxide.The Ames tests suggested that the mutagenicity of drinking water was considerably reduced by chlorine dioxide preoxidation compared with prechlorination.