Characteristics of Heavy Metals in Urban Sewage Sludge and its Environmental Capacity for Agricultural Land Use in Guangzhou, China
Urban sewage sludge can be applied to the land to serve as a fertilizer and soil conditioner. But the environmental risks for agricultural usage of urban sludge depends on the contents of pollutants in sludge and the properties of soils. The contents of(Zn、 Cu、 Pb、 Cr、 Mn、 Ni) in seven kinds of sludges were analyzed and the fractionation characteristics of heavy metals in the two sludges were studied. The maximum application and annual application rates of sewage sludge in soil were calculated according to the soil environmental capacity. The results have shown that the contents of Cu, Zn, Mn, Ni were higher and Pb, Cr were lower. Although the contents of heavy metals were higher than the background values of Guangzhou crop soil , they meet the controlled standards of pollutants in sludges for agricultural use (GB18918-2002), except Cu in one sludge. Different heavy metals, as well as the same heavy metal in different sludges, had different forms. The active proportion of Zn, Mn, Ni was large and Cu, Cr existed mainly in reduction forms, but Pb and Fe were in the state of reducible and residual fractions.The main poisonous heavy metals were Cu and Zn according to the calculation of static environment capacity and the dynamic environment capacity of soil. And the maximum application rate of sludge from different sources was discriminative variant .In order to guarantee the safety of urban sludge in agricultural land process, the maximum application and annual application rates of urban sludge in red soil of Guangzhou should be taken into account with the contents of Cu and Zn firstly.
urban sewage sludge heavy metals fractionation agricultural land use
LIU Jingyong SUN Shuiyu XIE Wuming CHEN Minting CHEN Tao
Faculty of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006 Guangdong, China
国际会议
The 6th International Symposium of Asia Institute of Urban Environment(亚洲城市环境学会第六届国际会议)
长春
英文
248-254
2009-09-20（万方平台首次上网日期，不代表论文的发表时间）