北京地区重金属在土壤中的纵向分布和迁移

本文讨论了重金属在土壤中的纵向分布和迁移及其对地下水污染的可能性.在典型褐土中,重金属在B层发生淀积,但在冲积性土壤中,重金属的含量随冲积层粘性增高而增多,土柱模拟试验表明,Cd仅在土壤表层聚积.野外研究表明,在旱作农田下,由于灌溉水和雨水不能渗入深层.重金属亦难于下移到深层.但在污泥沉淀池、污水渠或水稻田等长期存纳污水情况下,重金属会向下迁移并可能污染地下水.

VERTICAL DISTRIBUTION AND TRANSFER OF HEAVY METALS IN SOILS OF BEIJING

An investigation on vertical distribution and transfer of heavy metals in soils and its potential harmful effect to ground water have been conducted.Heavy metals have accumulated in B horizon of haplic drab soil, but increase with viscosity of fluviatile horizon in fluviogenic soil. Results of simulation test show that cadmium accumulates only in soil surface. Field study also shows that heavy metals are difficult to go deeper into low level, because irrigation and rain water cannot permeate deep into low level under cultivated soil conditions. Under sewage sludge precipitating tank, sewage water irrigation canal and paddy field, heavy metals can move into low level and thus possibly pollute ground water as well, because soil water can gravitationally permeate into low level.