河南某市河水和污泥中重金属污染状况及评价

Situation and assessment of heavy metal pollution in river and mud in one city in Henan Province

目的研究河南省某市郊区河水及其淤泥的重金属污染状况。方法典型性抽样方法选择某市郊区农田灌溉取水河流,利用原子吸收分光光度仪,分别采用石墨炉和火焰法对河水和淤泥中的重金属镉(Cd)、铜(Cu)与铅(Pb)进行了测定。将河水测定结果与《地表水环境质量标准GB3838—2002》及《农田灌溉水质标准GB5084—2005》比较,淤泥样品测定结果与全国土壤背景值进行对比。结果河水样品中铜、镉含量未超过标准,铅含量超标3～6倍。根据单因子污染指数法,河水中Cu、Cd的单因子污染指数均小于0.2,为清洁水平,而Pb则达到6.84,提示河水中Pb污染严重。淤泥中Cu是土壤背景值的4倍多,Cd是土壤背景值的69倍多,Pb是土壤背景值的两倍多,单项污染指数显示淤泥中Pb的污染指数为2.5,属中度污染,淤泥中Cu和Cd的污染指数均大于3,为严重污染,尤以Cd污染突出,其单项污染指数达67.76。河水和淤泥的综合污染指数分别为5.346与84.115,提示二者均属重污染水平,河水的主要污染源于Pb,淤泥的主要污染源于Cd,需要及早处理与控制。

Objective To study the heavy metal contamination status in river water and mud in the suburb of a city in Henan Province.Methods Typical sampling method is used to select a farmland irrigation river of the suburb of a city.Use the atomic absorption spectrophotometry,and measure the heavy metal cadmium（Cd）,copper（Cu）,lead（Pb） in the river water samples and mud samples by graphite furnace method and flame method,respectively.The results of water were compared with GB 3838—2002,Environmental Quality Standards for Surface Water,and GB 5084—2005,Standards for Irrigation Water Quality.The results of mud were compared with national soil background value.The contents of Cu and Cd in the river samples do not exceed the standard,and that of Pb is 3 to 6 times higher than the standard.According to the single factor pollution index method,the single factor pollution indice of Cu,and Cd in the river are less than 0.2 and are of clean level,while that of Pb reaches 6.84,indicating the Pb pollution in river water is severe.Cu in mud is more than 4 times of the soil background value,and that of Cd is more than 69 times of the soil background value,and that of Pb is more than 2 times of the soil background value.The single item pollution index indicates,in mud,the pollution index of Pb is 2.5,medium level pollution.The pollution indice of Cu and Cd in mud are more than 3,is severe pollution,and the Cd pollution is especially heavy,and the single pollution index reaches 67.76.The comprehensive pollution indice of the river and the mud are 5.346 and 84.115,respectively,indicating that both are at heavy pollution level.The main pollution source of the river originates from Pb,and that of the mud is from Cd and it is required to take measure and control as early as possible.