Research On The Pollution Situation And Spatial Variability Of Heavy Metals In Sewage Irrigated Soil Of Xinjiang

The resolution for economic development of China's western dry territory is a key strategy for China in the 21 st century. Because of its geographic location and natural resources, Xinjiang plays a especial role in China's western-land development plan. However, the water resource of Xinjiang has become a serious concern because of the worsening of the ecological environment, which poses a threat on the area's sustainable economic development. The improvement of the ecological quality depends to a large extent on the availability of water resources. Therefore, reasonable and effective utilization of precious water resources, including the reclaimed urban wastewater, is especially significant for the sustainable development of Xinjiang. While the heavy metal pollution of sewage irrigated soil has been under heated discussion by the scholars. The paper mainly researched the chemical speciation, concentration and spatial variability of heavy metals in sewage irrigated area in Xinjiang.Most of the researches of sewage irrigation have focused on agriculture irrigation , this study was conducted to examine the concentration and chemical fraction of Cu,Zn,Ni,Cr and Pb in seven sewage irrigated areas of Xinjiang. The results showed that the content of heavy metals in 0-20 cm topsoil was much higher than that in middle layer(40-60 cm) and lower layer(80-100 cm). The average contents of Cu,Zn,Ni,Cr and Pb in topsoil in seven sewage irrigated areas is 36.34 mg.kg-1, 82.74mg.kg-1, 39.67mg.kg-1, 44.32mg.kg-1, 14.95mg.kg-1. According to the Standard of Soil Environment Quality (GB15618-1995), the average concentrations of five heavy metals didn't exceed the secondary standard limits. The Nemerow comprehensive pollution indexes of seven sewage irrigated areas lie...