| The composition of municipal sewage sludge and its effects on heavy metals leaching were studied in laboratory. The results showed that the character of sewage sludge from various waste-water treatment plants were great different, but the sludge from the same plant had slight change at various seasons. Except for lower content of organic matter. nitrogen and phosphorus in sludge frOm Nanjing Waste-water Treatment Plant, other sludge from secondary waste-water treatment plants, such as Suzhou Wuxi.. Changzhou and Xuzhou sewage treatment plants, contained 40 to 60% of organic matter.. 3 to 6% of nitrogen.. 1 to 2% of phosphorus.. and other nutrients. Depending on waste water sources, the sewage sludge also contained of Zn., Cu more than 1, 000mg/kg ..300mg/kg~ respectively, and some other heavy metals including Cd.. Cr.. Pb and As. Of the metals Cu.. Zn.. Pb and Cd, the bioavailability of Cd was the greatest. In the light of the regulation of land application of sludge in China(GB4284-84), the most possibility elements exceeding the pollutants limits were Zn and Cu. Land application of sewage sludge is one method of disposal of a waste product while recycling the nutrients contained in the sludge. However, many convincing evidences were found that metals can migrate downwards in sludge-treated soils. To explore these mechanisms, a series of experiments about effects of sludge and dissolved organic matter(DOM) derived from sludge on metal leaching were conducted. The results showed that sewage sludge amended into soil could drastically reduce Cd adsorption by soil, which was due to the DOM from sludge rather than pH decreasing. Herb residues or wood chips could be used as hulking agents through forced aerated static pile model of municipal sewage sludge, but the former had better effects. The temperature of above 550C in 4m3 pile could be observed on the third day after composting and kept 8 to 11 days. Based on the consequent experiments including the effects of bulking agents amended into the sludge and the various ventilation rate on composting~ the optimal technological parameters were proposed: The volume ratio between sludge and agents were 1:1 or 1:3, and the ventilation rate was 0.3 5m3/t mm with frequency of 3 0mm per 3 hours. The cress seed germination index (GI), used as indicators of phytotoxicity and maturation of compost~ exhibited that the sludge compost was stabilized and mature near 40Ih day of composting, when 80% of GI was obtained. The changes of chromatography and spectroscopy characterization of I 27 humic substance~ humic acid (HA) and fulic acid (FA) were investigated by G-75~ fluorescence and FT-IR spectra. The G-75 chromatography showed that the content of high molecular weight (>70, 000Da) fraction increased, with a raise in concentration of Cu, which was more favorably bound to high molecular weigh fraction, and Zn, which was easily associated with fraction of low molecular weight. HA, in the mature composts~ the relative fluorescence intensity decreased, and the maximal intensity shifted to the longer wavelength, but the FA acted in the opposite way. The changes in fluorescing characteristics of HA could be explained by the increasing polycondensation and conjugation of the unsaturated structure and the greater uniformity of fluorophores. The FT-IR spectra showed that during composting, the contents of aniide and polysaccharide in I-IA decreased and the contents of carboxyl...
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