城市污泥及其堆肥对土壤重金属积累的影响

The Effect of Sewage Sludge and its Compost on the Accumulation of Heavy Metals in Soil

与对照相比,在城市污泥及其堆肥的作用下,土壤耕层的重金属含量在一定程度上增加。耕层土壤在试验0的处理(3)、(4),即施城市污泥30 t hm-2和60 t hm-2和试验1的处理(4)即施污泥堆肥60 t hm-2的情况下,根据污染等级,土壤处于重度污染等级,其他处理的土壤耕层处于中等污染等级。在作用后效方面,两个试验中,对于土壤中全量和可吸收态的重金属元素得到下面递减排列:Cd>Zn>Cu>Ni>Pb。比较试验各处理的Zc和土壤污染等级,试验0和试验1的处理4使土壤产生重度污染,其他处理导致试验土壤产生中度污染。

Compared with the control, the contents of heavy metals increased after the application of sewage sludge and its compost. Tilth soils were polluted heavily in treatment 3,4 of experiment 0 and treatment 4 of experiment, and tilth soils were polluted moderately in the other treatments. On aftereffects, the contents of all or absorbable heavy metals declined as the following order： Cd〉Zn〉Cu〉Ni〉Pb. Compared those treated soils in this study with Zc and soil pollution grades, the soils in treatment 0 and treatment 4 of experiment 1 were polluted heavily and soils in the other treatments were polluted moderately.