城市污染河道沉积物碳氮赋存对有机质分解的影响

Effect of Carbon and Nitrogen Forms on Decomposition of Organic Matter in Sediments from Urban Polluted River

以城市污染河道沉积物为研究对象，探究城市河道沉积物碳氮赋存特征对有机质分解过程的影响.结果表明，沉积物有机质含量较高是城市河道的显著特征；有机质65％以上以胡敏素类的惰性腐殖质的形式存在；有机氮是氮素的主要赋存形态，约占总氮的57.5％～91.3％；氨氮主要赋存于活性组分中，而惰性有机组分抗分解能力明显高于其他组分；氨氮饱和吸附后的沉积物有机质去除量明显减少，最高达到50％，表明氨氮也是限制有机质分解的重要因素.

To reveal the controlling mechanism of urban polluted river,four trophic level urban river was studied. The change of distribution of organic matter and nitrogen in the sediment was studied while the organic matter was disposed. High level of organic matter is the significant feature of urban city rivers. the humin （HM） was the major fraction of humus, accounting for more than 65%of OM. The most proportion of the total nitrogen （TN） was organic nitrogen which accounted for more than 50% . The amount of organic matter removal increased after the sediment adsorbed the saturated ammonia, which suggested ammonia as the main limited factor for the decomposition of organic matter. The most of Ammonia was adsorbed onto unstable humins. The HM was more stable than other organic matter which was disposed by Hydrogen peroxide （H2 O2 ）.