生物流化床预处理对饮用水致突变活性的影响

以Ｃ市市区内受污染的Ｎ河水为原水，在实验室内建立起生物流化床预处理－－传统工艺的组合净水工艺。对原水，传统工艺，生物流化床预处理，组合工艺的出水及其相应的氯化出水Ａｍｅｓ试验致突变性研究。以ＲＭ和水样比活性表示，非氯化水样的结果表明：传统工艺和生物预处理都会使原水的致突变性有所提高，后者的增幅大于前者；生物预处理能使两类致突变物尤其是碱基置换型致突变物发生有利于被后续传统工艺去除的变化，使组合工艺

EFFECT OF FLUIDIZED BED BIOREACTOR (FBBR) PRETREATMENT ON MUTAGENIC ACTIVITY OF DRINKING WATER

A drinking water treatment process combining FBBR and conventional process, which took raw water from a polluted river in the urban area of City C, was established in a laboratory scale. The mutagenic activity of the raw water, the effluent of biopretreatment, conventional process, combined process and the four chlorinated counterparts were investigated. Using R M and sample specific activity as indicators, the results from unchlorinated samples showed that both conventional process and biopretreatment could increase the mutagenic activity of the raw water, with the latter increasing more; but biopretreatment could alter the molecular structure of the two kinds of mutagens and made them easier to be removed by the succeeding conventional process, thus the mutagenic activity of the effluent was reduced by the combined process. The results from chlorinated samples showed that both conventional process and biopretreatment could only partly, remove one of the two mutagenic precursors, but increased another. The latter could significantly increase more than the former. Both chlorinated effluents showed strong mutagenic activity. The precursors produced in biopretreatment could be effectively removed by the processes, such as coagulation and filtration. The biofilm could probably change the chemical structures of precursors simultaneous and made them easier to be removed by the succeeding conventional process, so the concentration of the two kinds of mutagens in the effluent of the combined process was much lower than that of raw water. The mutagenic activity of the chlorinated effluent of the combined process was 50.4% (to TA98) and 49.7%(to TA100) lower than that of conventional process, respectively. Since most of the tap water in China was chlorinated, it could be concluded that biopretreatment had a significant effect on reducing the mutagenic activity of drinking water. Biopretreatment could also remove some acute toxicity according to the observation of the background colonies. Tab 5, Ref 21