保定市郊养殖场畜禽粪中重金属含量调查分析

Investigation of Heavy Metals in the Excretions of the Livestock and Poultry in the Suburbs of Baoding City

为了解保定市郊畜禽粪污染现状,采用调查问卷和随机取样的方法对保定市郊8个养殖场的基本情况进行了调查,并分析测定了畜禽粪中重金属Cu(铜)、Zn(锌)、Pb(铅)、Cd(镉)、Hg(汞)、As(砷)的含量。调查结果表明8个养殖场规模均较大,饲料以玉米、麦麸、豆粕、豆饼为主,在饲喂过程中均使用了饲料添加剂和兽药。畜禽粪的主要去向是农用,且农用前基本不经过无害化处理。畜禽粪中重金属的含量分析结果表明各养殖场畜禽粪中Cu、Zn含量普遍偏高,其次为As,Pb、Cd和Hg含量均处于较低或很低水平。其中下闸养猪场的Cu含量以及北宋养鸡场的Zn含量明显高于其它养殖场。不同动物粪便中重金属含量也存在一定差异:猪粪和鸡粪中各种重金属含量均较高,而兔粪和牛粪中重金属的含量则相对较低。根据德国的腐熟堆肥标准,畜禽粪中Cu、Zn的超标率分别为83.33%和20.83%;然而根据中国城镇垃圾农用控制标准,在所有样本中有3个As含量超标,超标率为12.5%;其它元素均不超标。

In this study, the basic situations of the stock farms in the suburbs of Baoding city were investigated using the method of questionnaire. And the concentrations of heavy metals in the livestock and poultry excretions were also determined. The results show that the stock farms are all in the middle or large scale, and the animals are mainly feed with corn, wheat bran and bean cake mixed with addictive and animal medicine. The animal excretions are mainly applied in the farmland, garden and orchard without any decomposition. The concentrations of Cu and Zn were much higher than those of other heavy metals in all kinds of excretions. The concentrations of arsenic were in the secondary situations. The contents of Pb, Cd and Hg were very low. The concentrations of Cu in the xiazha hoggery and Zn in the beisong hennery were remarkablely higher than those in the other places. There were differences in the concentrations of the heavy metals among the different kinds of animal manures. In general, the contents of the heavy metals in the excretions of pigs and chooks were higher than those in the excretions of cows and rabbits. According to the permissible level of the heavy metals in compost in German, the exceeding rates of the concentrations of Cu and Zn in excretions were 83.33% and 20.83% respectively. According to the heavy metal limits from municipal solid waste used on agriculture in China, the percentage of As contents exceeding limitation is 12.5% and the contents of other heavy metals in excretions did not exceed this the limitation.