长春市西郊保护地土壤-作物系统铬、汞的形态研究

Form Analysis of Heavy Metals （ Cr, Hg） in Soil - Crop Systems in Western Suburb Areas of Changchun City

本文以长春市西郊保护地土壤-作物系统为研究对象，分析了土壤-作物系统重金属铬、汞的含量及形态分布，并以单因子污染指数法和内梅罗综合污染指数法评价了该地区土壤及农作物的环境质量。结果表明：长春市西郊保护地土壤pH值为7．11，Cr、Hg含量分别为0．4212和54．6625mg·kg-1，未超过土壤环境质量二级标准限值；综合污染指数为0．7144，已经处于警戒水平；该地区土壤重金属形态铬以残渣态为主，可达89．71％左右；汞以氧化物结合态与有机结合态为主。该地区6种农作物样品中cr、Hg含量均未超过国家食品中污染物限量标准，处于安全水平。

Distribution and chemical form analysis of heavy metals （Hg, Cr） were carried out by Tessier sequence extraction in soil- crop system in western suburb areas of Changchun. The environmental quality in the area of the soil and the crops was examined based on a single gene pollution index and comprehensive pollution indexes. Results showed that the pH was 7.11 ; the average contents of Cr and Hg in soil samples were 0. 4212 and 54. 6625mg·kg-1. Both of the two figures did not exceed the secondary standard limits accord- ing to the soil environmental quality standards. The comprehensive pollution index of 0.7144 showed that the soil in western suburb areas in Changchun was clean but at the alert level. The heavy metal Cr in the soil was mainly residue state and reached up to about 89.71%. The heavy metal Hg was in oxide combination state and organic combination state mainly. At the same time contents of Cr and Hg in 6 kinds of crop samples were not more than ＂national food contamination in limited standards＂, which meant crops were all in safe level .