Abstract:Reclaimed water irrigation is a potential alternate source of water to help meet water shortages. There are few studies focus on the migration of heavy metals in soil and the topsoil contamination when reclaimed water is used for irrigation. The irrigation on vegetables using reclaimed water from different sources was studied. Reclaimed water irrigation didn't cause soil contamination and conserved fresh water resources comparing with sewage irrigation and tap water irrigation, at the meanwhile, it also could provide large amounts of nutrients for vegetables. The growth of vegetable irrigated by reclaimed water was better than those using tap water or sewage. The heavy metal accumulation in soil was observed after 60 days including Cr, Cd, As, Hg, Pb, Ni, Zn and Cu, which was low in concentration and stayed stable within irrigation duration. The vertical distribution of heavy metals in soil also changed little, with trends staying intact. The heavy metal content in soil was lower than the value in the soil environment quality standard (GB15618-1995), and better than the soil quality standard of vegetable planting. Risk assessment is within the generally acceptable risk range (a).
