施用下水污泥对土壤重金属含量变化与作物生长之影响.doc

施用下水污泥對土壤重金屬含量變化與作物生長之影響 The Influence of Biosolids Application on Heavy Metals and Crop Growth in the Soils 研究生: 黃正介 Cheng-Chieh Huang 指導教授: 許正一 Zeng-Yei Hseu [摘要]Biosolids, that is sewage sludge, is abundant in organic matter, nitrogen, phosphorus and other nutrients for crop growth, but it potentially contains heavy metals. Therefore, it is must to concern the bioavailiabilty and phytotoxicity of heavy metals in the soil applied with sewage sludge. Four municipal sewage sludge from the Ba-Li Wastewater Treatment Plant of Taipei BL , Min-Sen Wastewater Treatment Plant of Taipei MS , Domestic Septage Treatment Plant of Kaohsiung DS , and Wastewater Treatment Plant of the National Pingtung University of Science and Technology NPUST , and an industrial sludge from a paper manufacturing wastewater treatment plant PM were investigated in this study. Deionized water, DTPA, and sequential extractions were used to evaluate the bioavailable concentrations of Cd, Cr, Cu, Ni, Pb, and Zn in the five sludges, respectively. The phytotoxicity of the sludge extract was tested using seed germination of Chinese cabbage Brassica chinensis L. to determine the feasibility of sewage sludge for land application. Three representative arable soils in Taiwan, Lungchung Lt, Ultisol , Chungpin Cp, Mollisol and Chashing Ca, Alfisol soils, were collected and incubated with DS and MS sludge for one year. The heavy metals by sequential extraction and mineralization potential of nitrogen were conducted during the incubation period. After one year incubation, the soils were planted Chinese cabbage by pot experiment in the greenhouse. Results indicated that the pH and electrical conductivity EC values of the PM sludge were much higher than those of the other sludges, but that of the PM sludge contained the lowest amounts of nitrogen and phosphorus. The amount of cadmium was the lowest among the six elements in all the sludges. Zinc is the highest in the BL, MS, DS, and NPUST sludges,