黄淮海地区鸡粪有机肥重金属含量特征及环境风险

本文调查黄淮海地区5省2市120种商品鸡粪有机肥样品,分析测定有机肥中Cu、Cd、Pb、Zn和As含量、形态分布以及浸提毒性.结果表明,有机肥中重金属含量差异较大,表现为ZnCuPbAsCd,与有机肥行业标准相比,Cd、As、Pb存在超标现象,分别为6.7%、47.05%和14.28%,不同省市间重金属含量差异明显.有机肥中Cd、Zn主要以铁锰结合态存在,分别占37.3%和43.79%(质量分数),而残渣态Pb、有机结合态Cu,交换态As比例较高.有机肥中TCLP-Zn、-Cu、-Cd、-Pb和-As含量分别为41.11、3.33、0.07、1.25和0.21 mg·kg~(-1),有机肥中Zn和Pb含量超标数为6和5个,分布在河北省和江苏省.有机肥中Zn、Cu、Cd和As总量与TCLP提取态含量存在显著相关性(P0.05).按鸡粪有机肥年施肥量15t·hm-2推算鸡粪有机肥安全使用年限:河南天津安徽=山东=江苏河北北京.

Characteristics of Heavy Metals in Chicken Manure Organic Fertilizers in the Huang-Huai-Hai Region and related Environmental Risk Assessment

One hundred and twenty types of chicken manure organic fertilizer samples were collected from five provinces and two cities in the Huang-Huai-Hai region, to investigate heavy metal content, fractionation, and environmental risk through toxicity characteristic leaching procedures. Results showed that content of heavy metals in chicken manure organic fertilizer varied greatly, in the order of Zn > Cu > Pb > As > Cd. When compared with the standard for organic manure, ratios of Cd, As, and Pb exceeded the standard by 6.7%, 47.05%, and 14.28%, respectively. Moreover, the content of heavy metals varied significantly in different provinces. Cd and Zn in organic manure fertilizers were mainly Fe and Mn oxide-bound fractions, accounting for 37.3% and 43.79%, respectively. However, the proportion of residual fractions of Pb, organically-bound fractions of Cu, and exchangeable forms of As were higher. Contents of TCLP-Zn,-Cu,-Cd,-Pb and-As in organic manure were 41.11, 33.3, 0.07, 1.25, and 0.21 mg·kg^-1, respectively. The number of samples in which Zn and Pb in organic manure exceeded the standard was 6 and 5, respectively, with these mainly obtained from Hebei and Jiangsu provinces. There was a significant correlation between total content of Zn, Cu, Cd, and As in organic manure and content of TCLP (P<0.05). Based on an annual manure application rate of chicken manure of 15 t·hm^-2, safe application of chicken manure is in the order of Henan > Tianjin > Anhui=Shandong=Jiangsu > Hebei > Beijin.