阳宗海水体中砷的形态分布特征及来源研究

采集云南阳宗海湖水和表层沉积物样品,运用地球化学的原理与方法研究了高原湖水环境中砷（As）和其他重金属的含量、存在形态及空间分布,采用原子荧光分光光度法直接分析了样品中As的形态,并在此基础上对其健康危害风险进行了评估。结果表明,该湖泊水体中As的污染已达到较高的水平,对水域周围环境造成较高的环境健康危害风险。湖水中As（Ⅲ）的含量为51.4～350.7μg/L,平均含量为84.0μg/L;As（V）的含量为66.1～988.7μg/L,平均含量为156.1μg/L;总As含量平均值为167.0μg/L。其中该湖泊泉水中As（Ⅲ）的含量为17500.0μg/L,As（V）的含量为12200.0μg/L,具有极高的健康危害。湖水中其他重金属如Fe、Mn、Cu、Zn、Co、Pb的含量均好于国家Ⅱ类水标准,Ni、Cd超国家IV类水标准。结果还表明,该高原湖泊As的存在形态及分布特征与某工厂的排污活动相关。

Study on Source and Speciation Distribution Characteristics of Arsenic in Yangzonghai Lake Waters

The water and sediment samples were collected to study the content,speciation and spatial distribution of As(III)and As(V)in plateau lake(Yangzonghai Lake)using atomic fluorescence spectrometry(AFS)and atomic Absorption spectrometer for heavy metals,with geochemical principle and method.The results showed that Yangzonghai lake was polluted by As in rather high degree and As in the sediments of Yangzonghai caused considerable health risk assessment.The concentration range of As(III)is 51.4~350.7 μg/L,mean content is 84.0 μg/L,and the concentration range of As(V)is 66.1~988.7 μg/L,mean content is 156.1 μg/L.The average concentration of total arsenic in lake waters is 167.0 μg/L.The concentration of As(III)and As(V)is 17 500.0 and 12 200.0 μg/L separately in spring water.The content of iron,manganese,copper,zinc,cobalt,lead et al were much lower than grade II of environmental quality standards for surface water(GB3838-2002).But the content of nickel and cadmium were much higher than Grade IV of environmental quality standards for surface water.The speciation and spatial distribution characteristics of arsenic in surface water and lake was related with the pollution discharge of a factory.