汉江流域X市供水水体有机提取物致突变性研究

Research on mutagenicity of the organic extracts in supply water in X City of the Hanjiang river

目的明确2019年不同水文期X市汉江水源水及其自来水中有机提取物的致突变性强度水平现状、变化趋势以及常规水处理工艺与管网输送对此趋势的影响。方法应用XAD-2大孔树脂富集汉江流域X城市水源水、出厂水、末梢水中的有机物,经洗脱、浓缩、干燥制得非挥发性有机物(NOCs)干品,运用Ames试验检测并比较各水样中NOCs的致突变性。结果在0.5~4.0 L/皿的测试浓度范围内,枯水期出厂水、末梢水的NOCs对TA98(±S9)的致突变性检测结果为阳性(MR值>2),在加S9后致突变性降低(MR值降低);其余水样的检测结果均为阴性。平水期出厂水、末梢水的NOCs仅对TA98(-S9)的检测结果为阳性,在加S9后致突变性降低;其余水样的检测结果均为阴性。丰水期时,除汉江出厂水外,其他水样对TA98(±S9)的检测结果均为阴性。但各水文期各水样NOCs对TA100(±S9)的检测结果均为阴性。出现阳性结果时的最低水样量为1.0 L/皿。结论2019年X市的汉江供水水体(水源水及其自来水)中的有机提取物具有一定的致突变性。Ames试验呈阳性时的水质属于中度污染。致突变性强度依次为枯水期>平水期>丰水期。水源水经自来水厂消毒处理后,水中有机物致突变性增强,但经过管网后有所降低。水样中非挥发性有机致突变物的作用类型主要为移码突变型。

Objective To clarify the level of current mutagenicity intensity of nonvolatile organic compounds(NOCs)from the source water of the Hanjiang river and its tap water in X city during different hydrological periods in 2019,as well as the influence of conventional water treatment technology and pipe network transportation on this trend.Methods XAD-2 macroporous resin was used to enrich organic matter in urban source water,factory water,and terminal water of the X section of the Hanjiang river.After elution,concentration and drying,dry non-volatile organic compounds(NOCs)were obtained.The mutagenicity of NOCs in various water samples were detected and compared by Ames test.Results Within the test concentration range of 0.5-4 L/dish,NOCs in factory water and terminal water were tested positive for the mutagenicity of TA98(±S9)(MR>2)during the dry season,and mutagenicity decreased after adding S9(MR value decreased).The rest of the water samples were tested negative.NOCs in factory water and terminal water were only positive for TA98(-S9)during the normal flow season,and the mutagenicity was reduced after adding S9.All the other water samples were tested negative.During the wet season,the test results of TA98(±S9)on water samples were negative except for the Hanjiang factory water.However,NOCs in water samples were all negative for TA100(±S9)during hydrological period.The minimum water sample volume for a positive result was 1 L/dish.Conclusion The organic extracts in the water supply(source water and tap water)of Hanjiang river in X city have mutagenicity in a certain degree in 2019.The water quality when Ames test was positive showed moderate pollution.The mutagenicity intensity is in the order of dry season>normal water season>wet season.The mutagenicity enhances after the source water is disinfected by water plant,but it’s reduced after passing through the pipe network.The main mutagenic type of NOCs in water samples is frameshift mutants.