猪粪中铜的稳定化研究

Stabilization of Copperin Pig Manure with Amendments

集约化养殖业的发展和饲料添加剂的广泛应用大大提高了畜禽粪便中Cu的含量,增加了农田施用畜禽粪便的环境风险。为降低畜禽粪便中Cu的溶解性,分别选用蒙脱石、粉煤灰、明矾、沸石、硅藻土和磷灰石等6种常见矿物对猪粪进行预处理,采用重金属连续分级方法和淋洗方法,鉴定了猪粪中各形态Cu的变化,考察各稳定剂对猪粪中Cu的钝化效果。结果表明:在添未加稳定剂的情况下,猪粪中Cu主要为有机质结合态和残余态,同时也有较高比例的交换态;蒙脱石、粉煤灰、明矾、沸石、硅藻土和磷灰石对猪粪中Cu均有一定的钝化作用,比对照处理的猪粪中交换态Cu分别降低了45.1%、73.1%、64.6%、38.3%、22.7%和68.3%;同时,添加矿物质明显降低了猪粪中Cu的可淋失性;降低机理是主要是发生了交换态Cu向有机质结合态、氧化物结合态和残余态Cu的转化。

Both development of intensive livestock farming and widely use of feed additive in the livestock and poultry production increase greatly the content of Cu in livestock and poultry manure, which increase the environmental risk of livestock manure applied in farmland. To reduce the solubility of Cu in livestock and poultry manure, six common mineral materials, including montmorillonite, fly ash, alum, zeolite, diatomite and apatite, were selected to test their capacities for stabilization of Cu in pig manure. Sequential fractionation method of heavy metals and leaching experiment were applied to characterize changes in the chemical forms of Cu in pig manure, and evaluate the inactivation of different mineral materials on Cu in pig manure. The results showed that Cu in pig manure without addition of any mineral materials is mainly of organic bound and residual forms with higher percentage of exchangeable copper （5.87%）. All of the mineral materials had significant inactivation on Cu in pig manure. As compared with the control, application of montmorillonite, fly ash, alum, zeolite, diatomite and apatite decreased the exchangeable Cu by 45.1%, 73.1%, 64.6%, 38.3%, 22.7%, and 68.3%, respectively. Addition of the minerals decreased significantly the leaching of Cu from pig manure. The inactivation on Cu in pig manure with application of the mineral materials may be related to the transformation of Cu forms from exchangeable to organic matter bound, oxide bound and residual.