Land utilization is considered as a positive and effective method for sewage sludge disposal. This method takes use of a large number of rich nutrients for soil and crop. The application of sewage sludge in soil incre...Land utilization is considered as a positive and effective method for sewage sludge disposal. This method takes use of a large number of rich nutrients for soil and crop. The application of sewage sludge in soil increases the concentration of heavy metals. Compared with 15-30 cm layer of soil, 0-15 cm layer increased significantly, especially for Cu, Zn and Ni. The concentration of Cd in soil is considered as the main limiting factor, which determines the years of land utilization. If the largest continuous application is 30 t/（hm2.a） to the soil, the largest application period will be 11.53 years. In this paper, set pair analysis model are used in safety evaluation of the soil. After one year application of sewage, the soil can be still safe. Finally, according to the process of the subject put forward some suggestions.展开更多
文摘Land utilization is considered as a positive and effective method for sewage sludge disposal. This method takes use of a large number of rich nutrients for soil and crop. The application of sewage sludge in soil increases the concentration of heavy metals. Compared with 15-30 cm layer of soil, 0-15 cm layer increased significantly, especially for Cu, Zn and Ni. The concentration of Cd in soil is considered as the main limiting factor, which determines the years of land utilization. If the largest continuous application is 30 t/（hm2.a） to the soil, the largest application period will be 11.53 years. In this paper, set pair analysis model are used in safety evaluation of the soil. After one year application of sewage, the soil can be still safe. Finally, according to the process of the subject put forward some suggestions.
