Zhangshi wastewater irrigation area is located in the western suburb of Shenyang, Liaoning province. It has utilized untreated wastewater as a source of water and fertilizer for 10-20 years. Because Shenyang Smelter has not built any equipments to treat wastewater before, the quality of inflow raw sewage exceeded the water quality standard of farm irrigated (China). Zhangshi irrigation area has been contaminated with heavy metals seriously. Cadmium and arsenic have been accumulated in the soil and rice. As ...