污水处理厂再生水灌溉对土壤中重金属污染的试验研究

再生水灌溉是解决水资源短缺的潜在途径之一，关于再生水灌溉条件下土壤中重金属的迁移行为及其对表层土壤的污染风险至今仍缺乏研究。通过不同水体浇灌蔬菜的试验研究，相比较污水浇灌和自来水浇灌，再生水灌溉不仅对土壤没有污染，也极大的节约了水资源成本，并为蔬菜提供了大量的生长元素。结果表明，浇灌60天后，再生水中的Cr、Cd、As、Hg、Pb、Ni、Zn和Cu在土壤中有一定的富集，但随着淋溶时间的延长，各种重金属浓度保持不变；再生水浇灌的土壤在垂直迁移上的浓度变化也不大，基本呈水平趋势；与土壤环境质量标准(GB15618—1995)相比，再生水浇灌后的土壤没有额外超标，优于蔬菜种植的土壤标准要求。

Experimental Study of Heavy Metal Pollution in the Soil Irrigated by Sewage Treatment Plant Reclaimed Water

Reclaimed water irrigation is one of the potential ways of solving the shortage of water resources, the pollution risk on migration behavior of heavy metals in the soil which are irrigated by reclaimed water and the related soil surface are still short of research. Through the experimental study of different kinds of water irrigation methods on vegetable, it can be concluded that comparing with sewage irrigation and tap water irrigation, reclaimed water irrigation not only avoids the pollution of the soil but also saves the cost of water resources, and even provides a large number of growth elements for vegetables. The results showed that, after leaching by reclaimed water for 60 days, Cr, Cd, As, Hg, Pb, Ni, Zn and Cu from reclaimed water were enriched in soil to a certain degree, but with the leaching time extending, concentrations of the heavy metal remained stable. The variation of heavy metal content in soil irrigated by reclaimed water was small in vertical depth, basically showed a level trend. According to the soil environment quality standard (GB15618-1995),soil after irrigated by reclaimed water did not exceed the standard, better than soil quality standard of planting vegetables.