重金属在猪饲料-粪便-土壤-蔬菜中的分布特征研究

Distribution Characteristics of Heavy Metals in Feeds,Pig Manures,Soils and Vegetables

本文调查分析了江西省余江县39个大型养猪场的饲料、猪粪、以及长期施用这些猪粪的菜地土壤及蔬菜的Cu、Zn、Pb、Cd含量,并对饲料、猪粪、土壤和蔬菜重金属含量进行了相关分析。结果表明,大猪和小猪饲料Cu含量超标率分别达81.6%和30.8%,Zn含量超标率分别达89.5%和94.9%,而Pb、Cd未超标。猪粪Cu、Zn含量亦严重超标,且饲料和猪粪中Cu、Zn、Pb、Cd含量呈显著正相关关系。土壤总Zn和总Cd含量分别有7.8%和5.2%的样品超过三级标准,污染较为严重。所有蔬菜样品Cu、Zn、Pb含量均未超过我国食品卫生质量标准,空心菜和芋头Cd含量超标。土壤总Cu、Zn、Cd含量与提取态呈显著正相关。

Serious environmental problems caused by livestock and poultry manures are attracting increasing interests because large amounts of additives are added in feeds during intensive farming.This study investigated the concentrations of Cu,Zn,Pb and Cd in feeds,pig manures,soils and vegetables sampled from 39 intensive farming plants in Yujiang County,Jiangxi Province.The results showed that the rate of exceeding allowable limit of Cu in big pig feed and piglet feed were 81.6% and 30.8%,respectively.Meanwhile,the rate of exceeding allowable limit of Zn in big pig feed and piglet feed were 89.5% and 94.9%,respectively.In addition,Cu and Zn concentrations in some pig manures were also above the Pollutant Emission Standard for Livestock and Breeding Industry（In China）.Furthermore,there were significant positive correlations between the heavy metal concentrations in feeds and pig manures.Total Zn concentration in 7.8% of soil samples and total Cd concentration in 5.2% of soil samples exceeded the Chinese Soil Environmental Quality Standard Ⅲ,which means they have been heavily polluted.The survey also showed that the concentrations of Cu,Zn,and Pb in all vegetable samples were lower than the National Food Hygiene Standard,while Cd concentrations in Ipomoea Aquatica and Colocasia Esculenta exceeded the standard.The significant positive correlations were found between the total Cu,Zn,Cd concentrations and the extractable heavy metal concentrations in soils.