Effects of organic matter on phosphorus sorption characteristics in sediments of Chinese large eutrophic shallow lakes
有机质对大型富营养化浅水湖泊沉积物磷吸附特征的影响

In this paper, the horizontal distribution of sediment organic matter(OM) content and composition, phosphorus sorption parameters, phosphorus forms and interstitial soluble reactive phosphorus(SRP) concentration from large shallow lakes(Lake Taihu and Lake Chaohu) were described systematically. Comparison equilibrium phosphorus concentration(EPC0) with SRP concentration showed that in the northern of Lake Taihu and the the inlet of Nanfeihe River, where are more serious pollution, sediments still showed the sink function, while other areas sediments had the tendency of phosphorus release. In addition, OM and Olsen-P, P adsorption index, alkaline phosphatase activity(APA) were significantly positively correlated, so the small molecular substance produced by the decomposition of organic matter increased phosphorus adsorption capacity. The indoor simulation experiments of adding small molecular substance further confirmed the above hypothesis. Carbohydrate critically affected the phosphorus sorption energy, and amino acid mainly increased the maximum phosphorus sorption. In short, the organic matter itself and its degradation products affected the sediment phosphorus adsorption capacity in different ways, and accordingly adjusted the process of lake eutrophication.