摘要
采用盆栽和田间试验,研究了广州市大坦沙污水处理厂污泥对蔬菜生长发育的影响、污泥中重金属元素在作物体内的累积及在土壤中的残留状况。盆栽结果表明,作物的生长发育和产量与污泥的施用量有一定的关系,施用污泥对于在养分水平较低的砂质土上效果较明显。厂区大田试验还表明,施用污泥对生长周期长的块根类作物的增产效果比茎叶类、果实类作物更显著。作物对Ni的累积量相对为最大,土壤则以Cu、Zn的残留量为最大。在污泥施用量为3×10~4kg ha^(-1)的条件下,作物体内的重金属元素含量均未超过国家食品卫生标准。若污泥施用量为1.5×10~4kg ha^(-1),则其安全施用年限估计为12年。
Pot and field experiments were carried out to study the ecological effect of direct application of municipal sewage sludge on agricultural land. The sewage sludge was from a large sewage treatment plant in Guangzhou. Results showed that. generally, the addition of sludge increased the vegetable yield, especially for those with long period growth and with root harvest. Ni content in the vegetables was significantly increased by the sludge application, but heavy metal contents in the vegetables were not over the national standards at the application rate of 1.5×10~4kg ha^(-1)a^(-1). The sludge application also increased soil heavy metal contents, especially Cu content. The safe term of the application was estimated to be 12 years at the same application rate.
关键词
城市
污泥
肥效
施肥
农田
Sewage sludge, Fertilizer efficiency, Heavy metal content, Ecological effect
