上海商品有机肥料中重金属含量及影响因素研究

Contents and influencing factors of heavy metals in commercial organic fertilizers in Shanghai

通过调查采样及室内检测的方法,分析上海市商品有机肥料样品331个,就重(类)金属含量情况和影响因素展开研究。结果表明:重(类)金属Cu、As、Cd、Cr、Pb和Hg的含量变化较大,从痕量到1 000 mg/kg均有,平均值分别为262.12、21.00、2.44、38.49、6.22 mg/kg和0.37 mg/kg,超标率依次为55.59%、15.71%、5.14%、0.03%、0和0。物料影响方面,以猪粪作为原料的有机肥料超标情况较多,猪粪有机肥的铜和砷含量偏高,鸡粪有机肥料的砷和镉超标较多。当有机肥料偏碱性时,发生重金属超标几率提高,特别是当8≤pH<9时,Cu、As和Cd分别占总超标个数的54.35%、55.77%和47.06%,Cd在pH<8时,没有发生超标的现象。

The 331 samples from different commercial organic fertilizers in Shanghai were analyzed in terms of heavy metal contents and their influencing factors by sampling investigation and indoor testing.The results showed that the contents of Cu,As,Cd,Cr,Pb and Hg varied relatively large, ranging from trace to 1 000 mg/kg,and averaged 262.12,21.00,2.44,38.49,6.22 and 0.37 mg/kg,respectively, exceeding the set standards by 55.59%,15.71%,5.14%,0.03%,0 and 0.The analysis of raw materials showed that the organic fertilizer whose raw material was pig manure was rather high in Cu and As contents and comparatively large in exceeding the set standards,and the organic fertilizer whose raw material was chicken manure was comparatively large in exceeding the set standards of As and Cd contents.When the pH value of the organic fertilizers was over 7.0,the probability for the heavy metal contents to exceed the set standards increased greatly,and when the pH was greater than or equal to 8 but less than 9,the numbers of samples for Cu,As and Cd contents to exceed the set standards were respectively 54.35%,55.77%and 47.06%of total number of samples to exceed the set standards.When the pH was less than 8,there were no samples whose Cd content exceeded the set standards.