贵阳观山湖区至白云区地下水有机污染现状与防治对策

文章按水文地质条件将全区划分为12个地下水系统，并选择43组控制性水点分丰枯两季进行有机样品采集和测试，在此基础上对研究区地下水中有机污染物的检出、超标、分布及来源均进行了分析。结果显示，参评的86组地下水样品中，有32组检出有机污染物；27种参评有机组分中，10种有机组分存在不同程度的检出，其中，三氯甲烷检出25次，检出率29.07%，其余组分检出率均低于5%；仅有1,2二氯丙烷超标1次，超标率低；区内地下水有机污染物检出浓度较低，超标率低，处于轻度污染阶段；12个系统中，有9个系统发现有机物污染物检出；检出点多分布于工矿企业的下游地段，排污河渠两侧；污染物多来源于中小型工矿企业，以污染物通过落水洞、天窗等进入含水层为主要污染途径；地下水系统排泄区的近源污染多发，危害程度大。针对上述污染特征，提出加强对中小企业污染源的集中管理，加大污水管网建设力度等对策建议。 

Current situation of groundwater organic pollution and control measures in Guanshanhu Lake to Baiyun areas, Guiyang City

The research area is situated in the typical exposed-covered karst area in central Guizhou hilly plain of the Guizhou plateau, where many karst underground rivers and springs have been developed, which is indicative of abundant groundwater resources. In order to clarify the organic pollution status and distribution characteristics in the groundwater, 43 representative sites were selected and water samples were collected both in dry and rainy seasons to analyze organic components, on the basis of the classification of 12 groundwater systems and the potential pollution sources in each groundwater system. The results show that 32 of 86 samples contain organic contaminants. The concentrations of 10 organic pollutants out of 27 organic components analysed are above recommended limits. The pollutant detected ratio of chloroform is the highest with a value of 29.07%, while the ratios of other organic components are lower than 5%, except for one sample with dichloropropane level exceeding the standard. The organic pollutants are detected in 9 groundwater systems, where the contamination sources are mostly located in vicinity of the waste discharges from industries and mines especially from medium-to small-scale enterprises, and some streams and trenchs that divert contaminated substances as well. These pollutants reach groundwater in a concentrated infiltration way through karstic conduits such as sinkholes and karst windows. In overall, the detected ratio of the organic pollutants is relatively high but most of their concentrations are below the national standards; the groundwater in this area is slightly polluted. To prevent the water from further deterioration, it is necessary to implement integrated water management measures via controlling the pollution sources in medium-to small-scale industries, accelerating the construction of pipeline network for industrial and domestic wastewater and improving the pollution monitoring network.