太滆南运河入湖河口沉积物氮素分布特征  

Distribution of Nitrogen in the Sediment of Taige South River Estuary

作　　者：马久远[1] 王国祥[1] 李振国[1,2] 张佳[1] 周锋[1] 魏宏农[1] 欧媛[1] 

机构地区：[1]南京师范大学地理科学学院,南京210023 [2]湖南科技大学地理系,湘潭411201

出　　处：《环境科学》2014年第2期577-584,共8页Environmental Science

基　　金：国家自然科学基金项目(41173078);江苏省太湖水环境治理专项(TH2011207);江苏省科技厅科技支撑计划项目(BE2011690)

摘　　要：为研究人湖河口沉积物中氮素的存在形态和空间分布状况，于2012年4月在太涌南运河人湖河口区采集沉积物柱状样品并对沉积物中的氮素进行了测定分析．结果表明，NH＋4-N、TN和Org—N在表层沉积物中的沉积具有一定的同步性．NH＋4-N与Org—N、TN均呈显著正相关（P〈0．05），Org—N和TN呈极显著正相关（P〈0．01）；Org—N是人湖河口表层沉积物氮素的主要成分，平均值为2843．77mg·kg-1，占TN的质量分数为93．38％；氮素的水平分布存在差异：TN和Org—N的含量在入湖河干流延伸方向上，随距离的增加而逐渐降低，在偏离干流延伸方向上，呈“W”型波动变化．NH＋4-N含量在距河口100m内迅速下降，100m后在波动中保持低水平．NO-3-N含量在0～800m内保持平衡，800m后迅速升高；氮素的垂直分布存在差异：在人湖河干流延伸方向，NH＋4-N含量随沉积物深度的增加而升高，NO＋3-N呈现出底层富集向表层富集转变的趋势，TN和Org—N的含量自表层向底层富集．To characterize the distribution of nitrogen in the sediment of Taige south river estuary, column samples of sediments were collected and analyzed in April, 2012. Our results revealed that a synchronized trend existed among the levels of ammonium nitrogen （NH4＋ -N） , organic nitrogen （Org-N） and total nitrogen （TN） in the surface layer of sediment. The NH4＋ -N positively correlated with TN and Org-N significantly （P 〈 0.05） while TN highly significantly correlated with Org-N （P 〈 0. 01 ）. Org-N was the major form of nitrogen, comprising 93.38% of total nitrogen （TN） averagely. Both horizontal and vertical distribution of nitrogen in sediments apparently changed along the distance to stream outlet. In the horizontal dimension in sediments, Org-N and TN decreased progressively as forwarding into the lake in the extending direction of the main stream, while showed a ＂W＂-type fluctuation in the diverged direction away from the main stream. The level of NH4 -N decreased rapidly within 100 m to the stream outlet and remained constantly at a lower level beyond 100 m. However, the level of nitrate nitrogen （NO3--N） stabilized within 0-800 m and increased greatly beyond 800 m. In the vertical dimension in sediments, the level of NH4＋ -N increased with increasing depth. As the distance to the stream outlet increasing, the enrichment of NO3-N was enhanced in surface layers rather than in lower subsurface layers. Ahernativelv. the enrichment of Orz-N and TN were reduced in surface layers but enhanced in subsurface layers.

关 键 词：氮 分布特征 沉积物 入湖河口 太滆南运河 

分 类 号：X522[环境科学与工程—环境工程]