猪粪堆肥中水分散性胶体的重金属分布研究

Size Distribution of Heavy Metals in Water Dispersible Colloids from Swine Manure Compost

对猪粪有机肥中胶体态重金属的分布进行了定量分析。结果表明,水提取态Cu、Zn、Fe、Mn主要以胶体态存在,Ni、Cr、Cd、As几乎都以可溶态存在。胶体态Cu在0.02~0.2μm胶体中的含量最高,胶体态Zn、Fe、Mn在粒径为1~10μm的大粒径胶体中含量最高。在长期连续施用有机肥引起重金属积累的土壤中,高Cu负荷的小粒径胶体可能会引起深层土壤中重金属积累问题,胶体态有机碳与可溶态有机碳对重金属结合能力的不同可能是导致重金属分布存在差异的重要原因。重金属在不同粒径的分布特征可以为讨论猪粪有机肥中的重金属在环境中的化学行为提供论据。

The research was conducted to study the distribution of heavy metals in water dispersible colloids from swine manure compost.Water extractible Cu,Zn,Fe,and Mn were found mostly in water dispersible colloids,whereas water extractible Ni,Cr,Cd,and As were observed as dissolved.Colloidal Cu largely accumulated in 0.02~0.2 μm colloids.Colloidal Zn,Fe and Mn were largely associated with 1~10 μm colloids.With high load for Cu,fine colloids（0.02~0.2 μm） may constitute an environmental problem in subsurface soil,for area receiving long-term applications of agricultural waste amendment.The higher metal/organic carbon（OC） ratio of colloids than that of dissolved fraction might result in the different distribution of water extractible heavy metals.The results demonstrated the importance of obtaining size fraction data when researching on the chemical behavior of heavy metals of swine manure compost in environment.