南盘江流域曲靖段土壤及农作物中重金属污染特征与生态风险评价

陈晓鸿 李强 喇优抓

摘 要：通过采集南盘江流域曲靖段内的土壤及农作物样品，分析该段土壤及农作物重金属污染特征和分布规律，通过潜在生态危害指数法和地质累积指数法对流域内土壤重金属污染进行生态风险评价;通过地质积累法反映农作物对重金属的富集状况，并使用内梅罗污染指数法和单因子污染评价指数法来评估农作物中5种重金属的生态风险。结果表明：铅和铬含量超标较为严重，铜、锌、镉均在警戒线上;受重金属污染的地点主要集中在焦煤厂、化肥厂、冶炼厂周边和生活污水排污口处。

关键词：南盘江;农作物;土壤;重金属;生态风险

中图分类号 X53;X825文献标识码 A文章编号 1007-7731（2020）15-0126-07

Abstract： This work collected many soil and crop samples from the Qujing section of the Nanpanriverto reflect the pollution characteristics， fate and transport of the heavy metals. The geological cumulative index method and potential ecological hazard index method were used to illustrate the ecological risk of heavy metals in the soils. Thegeological accumulation method was used to reflect the enrichment of heavy metal in the crops. Furthermore， the mei's pollution index method and single factor pollution method were applied to evaluate the ecological risk of heavy metals in the crops. Pb， Zn， Cu， Cd and Cr in the soils and crops were determined in this paper， The experiment results showed that Pb and Cr contents exceeded the criteria and the others were below the criteria. The location of the polluted soils and crops mainly concentrated in the areas of coking plant， fertilizer plant， smelting plant and sewage drain.

Key words： Nanpan river ; Crops; Soil; Heavy metals; Ecological risk

南盘江为珠江正源，发源于云南省曲靖市沾益县马雄山东麓，流域内拥有抚仙湖、阳宗海、异龙湖、星云湖和杞麓湖五大湖泊。近年来，南盘江流域内水环境污染事件频发，如2008年阳宗海砷污染事件、2011珠江上游饮用水源铬污染事件等。国家水利部、珠江水利局、全国各高等院校及其他机构都投入了大量的资金和精力致力于珠江水系的研究，研究内容包括各个支流、江段、湖泊、流域农田的生态环境和河流污染现状以及生态修复等，但关于珠江源头—南盘江土壤及农作物中重金属污染状况的研究还鲜有报道。

笔者在南盘江流域曲靖段选取18个采样点，测定农作物及土壤样品中Cu、Zn、Pb、Cd和Cr共5种重金属含量，并采用潜在生态危害指数法和地质累积指……