BEHAVIOR OF DISSOLVED ORGANIC NITROGEN IN SEDIMENT

Substantial amounts of potentially soluble organic nitrogen are released from the sediment as decomposed animal and plant debris from pollution subsides. This paper investigated the behavior of the dissolved organic nitrogen (DON) released from the sediment around Lake Taihu. The initial mass isotherm was used to describe the sorption and desorption of sediment soil to DON. The first-order kinetic equation was suitable for application in the release process. Research on the DON release potential of the sediment soils showed that the pool of potentially soluble organic carbon was estimated to be about 30.575 mu g.g(-1). The characteristics of DON were also investigated in the study. The released DON in the neutral hydrophilic fraction had a molecular weight <3 kDa and was the major component. Ligand exchange was the important mechanism for desorption of DON in Lake Taihu sediment. Both sulfate and phosphate had a significant influence on the release of DON. Therefore, we must pay attention to the importance of DON released from sediment in water environments.