珠江涌表层沉积物中不同形态氮的赋存特征

研究了广州市珠江涌表层沉积物中不同形态氮的赋存特征,并对各形态氮中氨氮含量进行探讨。采用连续分级浸取法将沉积物中的氮分为离子交换态氮(IEF-N)、弱酸可浸取态氮(WAEF-N)、强碱可浸取态氮(SAEF-N)和强氧化剂可浸取态氮(SOEF-N)。结果表明,沉积物中总氮(TN)的质量浓度为3 469.15～8 358.56 mg/kg,各形态氮含量为IEF-N>SOEF-N≈SAEF-N>WAEF-N。IEF-N是4种形态氮中对水体影响最大的,且IEF-N中氨氮含量较高。氮是影响水体水质的重要因素,其中氨氮是判定水体是否黑臭的重要指标。珠江涌沉积物中的氮对水体水质的威胁不可忽视。

Deposit characteristics of different forms of nitrogen in surface sediments of Zhujiang brook

The deposit characteristics of different forms of nitrogen in the surface sediments of Zhujiang brook,Guangzhou were studied,and the contents of ammonia nitrogen in various forms of nitrogen were discussed.The sequential extraction method was employed to determine the nitrogen in surface sediment,which was divided into ion exchange nitrogen(IEF-N),weak acid extractable nitrogen(WAEF-N),strong alkali extractable nitrogen(SAEF-N)and strong oxidizer extractable nitrogen(SOEF-N).The results showed that the total nitrogen(TN)in surface sediment was ranged from 3 469.15 to 8 358.56 mg/kg.The content of different forms of nitrogen was IEF-N >SOEF-N≈SAEF-N >WAEF-N.IEF-N had the most influence of the four forms of nitrogen,and its ammonia nitrogen content was high.Nitrogen was an important factor affecting the water quality of water bodies.Ammonia nitrogen was an important indicator to determine whether water bodies were black and odor.The threat of nitrogen in the sediments of Zhujiang brook to water quality could not be ignored.