云南临沧某煤矿区土壤及优势植物中重金属含量特征分析

Analysis on Characteristics of Heavy Metal Content in Soil and DominantPlants in a Coal Mine Area of Lincang,Yunnan

植物修复具有绿色、经济和环境友好等优点而备受关注.累积植物的筛选是植物修复当前研究的重要内容之一.利用微波消解-ICP-OES测定法对临沧某煤矿区土壤样品和9种优势植物中的砷、镉、铬、铜、铅和锌6种重金属元素的含量进行分析.结果表明,土壤中As和Cd的含量分别为50.61 mg/kg和1.68 mg/kg,已超出我国农用土壤污染风险筛选值的阈值,且Cd的含量已超过我国农用土壤污染风险管制的阈值,该区域为典型的As和Cd重金属复合污染场地,应采取一定的管制措施避免重金属污染扩散.9种优势植物中重金属的含量分布表明,蜈蚣蕨的地上、地下部对As和Cd的富集量分别为1798.00,1333.00 mg/kg和39.69,29.55 mg/kg,富集量远高于其他植物.富集系数计算结果显示,蜈蚣蕨的地上和地下组织对As的BCF分别为17.67和13.09倍,对Cd的BCF分别为10.51和7.83倍,表明蜈蚣蕨具有对As和Cd金属复合污染土壤进行植物修复的潜力.

Phytoremediation has attracted much attention because of its green finance and environment-friendly.At present,the screening of cumulative plants is one of the important contents of phytoremediation research.The contents of arsenic,cadmium,Chromium,copper,lead and zinc in soil samples and 9 dominant plants in a coal mine area of Lincang were analyzed by microwave digestion-ICP-OES.The results showed that the contents of As and Cd in the soil of coal mining area were 50.61 mg/kg and 1.68 mg/kg,respectively,which had exceeded the risk screening value threshold of agricultural soil pollution in China,and the content of Cd had exceeded the risk control threshold of agricultural soil pollution in China.This area was a typical site of heavy metal complex pollution of As and Cd.Certain control measures should be taken to avoid the diffusion of heavy metal pollution.The distribution of heavy metal contents in 9 dominant plants showed that the enrichment of As and Cd in the upper and underground parts of Pteris vittata L.was 1798.00 mg/kg and 1333.00 mg/kg,respectively,and 39.69,29.55 mg/kg,which were much higher than other plants.The results of enrichment coefficient calculation showed that the BCF of upper and underground tissues to As was 17.67 and 13.09 times,and that of underground tissues to Cd was 10.51 and 7.83 times,respectively,indicating that Pteris vittata L.has the potential for phytoremediation of As and Cd contaminated soil.