某冶炼厂附近农田镉污染调查与对策

SURVEY AND STRATEGIES OF CADMIUM POLLUTION IN THE FARMLAND NEAR A COPPER SMELTERY

对遭受某铜矿冶炼厂镉污染的湖北省某镇约30km2的农田土壤进行了调查,对土壤耕作层与亚耕层以及污染源(废气、废水和炉渣)中全量Cd和有效态Cd含量的系统测定结果表明:未受Cd污染、受轻度污染及受中度污染的土壤面积分别占3.6%,82.1%,14.3%;土壤中全量Cd及有效态Cd含量的分布规律均表现为西灌区>东灌区>灌间区;土壤耕作层与亚耕层中全量Cd含量的差异不大,而有效态Cd则主要富集于土壤耕作层中;受土壤pH值的影响,Cd在污染区土壤中的活化率低于远离冶炼厂未受污染的农田对照区。该镇农田的Cd污染主要来源于某铜矿冶炼厂的废气和废水,而炉渣的污染相对较小。运用生态方法治理该镇农田的Cd污染具有一定的可行性和适用性,值得研究利用。

A town in Hubei Province has suffered from Cd pollution due to a neighboring copper smeltery.This paper has analyzed 63 soil samples from 35 sampling plots in the study area.The systematic analysis of content of the total and available Cd indicates that the percentage of nonpolluted area,slightpolluted area and mediumpolluted area is 3.6%, 82.1% and 14.3% respectively.While the distribution of total Cd and available Cd shows the same law:west irrigation area>east irrigation area>the area between the wastedraining channels.However,no significant difference of distribution of total Cd is found between the planting soil and subsoil, while available Cd is mainly rich in the planting soil. Because of the relatively high pH, the activity index of Cd in the soils of polluted area is lower than that in compared area. The main sources of Cd pollution in soils are wastewater and exhaust gas of the smeltery. Finally,the paper points out that agroecological regulation strategy is worth studying for it is feasible and suitable to control Cd pollution in the study area.