Abstract:The amounts of nitrogen forms in 10surface sediments of Qingyi River in Xuchang City were determined by the sequential extraction technique and 4forms of extractable nitrogen (TTN) including ion exchangeable form (IEF-N), weak acid extractable form (WAEF-N), strong alkali extractable form (SAEF-N), and strong oxidant extractable form (SOEF-N) and non-extractable form (NTN) were found. The distribution characteristics, influence factors and potential risks of nitrogen forms to the river environment were also discussed. The results indicated that the concentration of total nitrogen (TN) was in the range of 2140~9470mg/kg, and had the similar distribution trend with the sediment organic matter (OM) along the mainstream. The dominant form of TTN changed from IEF-N to SAEF-N and then to SOEF-N from upstream to downstream, finally tended to be stable. IEF-N content in the sediment was influenced by sediment OM, pH value, and the amount of ammonia and suspended solid in the overlying water, and was significantly related to TN, which showed that TN can be used as an important indicator for judging the endogenous pollution risk of Qingyi River. In addition, in the overlying water high COD concentration had great effect on the sediment of SAEF-N and NTN, high content of ammonia intensified the release of IEF-N and TN, and TP influenced the activity of NTN. Therefore, the interaction of the overlying water and the sediment must be taken into account during the practical river improvement, and the regulation of water body and sediment. This study could provide important guidance to the water environment comprehensive improvement of Qingyi River and the other similar rivers.
王梅, 刘琰, 郑丙辉, 周娟, 江秋枫. 城市内河表层沉积物氮形态及影响因素[J]. 中国环境科学, 2014, 34(3): 720-726.
WANG Mei, LIU Yan, ZHENG Bing-Hui, ZHOU Juan, JIANG Qiu-Feng. Nitrogen forms in surface sediments of urban river and their influence factors: A case study of Qingyi River in Xuchang City. CHINA ENVIRONMENTAL SCIENCECE, 2014, 34(3): 720-726.