奶牛粪污染条件下土壤重金属的含量与分布

Heavy Metals Content and Distribution in Soil under Cow Manure Pollution Condition

采用野外试验研究了人工模拟降雨条件下,奶牛粪露天堆放还田对土壤重金属含量和分布的影响。结果表明,在第26、40、53和80 d取样时,奶牛粪露天堆放下土壤表层0～10 cm和10～20 cm的铜锌含量均有增加,堆放80 d后0～10 cm土层中全铜、有效铜、全锌和有效锌总增加量最大,分别为1.89、0.54、7.83和1.35 mg·kg-1。土壤重金属的内梅罗综合污染指数≤0.7,尚未形成污染。此外,铜锌在土壤中的最大运移距离未超过20 cm,对地下水污染风险很小。同时,奶牛粪堆放还田对土壤铜锌含量均有明显影响,长期及大面积堆放导致的点源及面源污染风险则应进行进一步研究和评估。

Using field experiment on the condition of artificial precipitation, the paper researched the effect of heaping and returning cow manure to the field in the open air on the content and distribution of heavy metals in soil. The results showed that the contents of copper and zinc in soil layers of 0-10cm and 10-20cm both increased when sampled on the 26th, 40th, 53th and 80th day. After 80 days, the increasing amount of total copper, available-copper, total zinc and availablezinc in the 0-10cm soil layer were the biggest,that were 1.89 mg·kg^-1,0.54 mg·kg^-1, 7.83 mg·kg^-1 and 1.35 mg·kg^-1 respectively.Nemero comprehensive pollution index of heavy metals in soil was ≤ 0.7, so there not yet formed pollution. Besides, the maximum transport distance of copper and zinc in soil don＇t exceed 20cm, the pollution risk of groundwater was little. Meanwhile, the experiment results showed that heaping and returning cow manure to the field had obvious influence to the content of copper and zinc in soil, so the pollution risk of point-source and non-point source caused by long-term and large-area cow manure heaping should be further researched and evaluated.