丹江口水库表层沉积物不同形态氮的赋存特征及其生物有效性

发布时间：2018-12-13 11:14

【摘要】：为了揭示丹江口水库沉积物氮空间分布特征及其生物有效性,采用连续分级提取法研究了表层沉积物中可交换态氮(Exchangeable nitrogen,EN)、酸解态氮(Acid hydrolysable nitrogen,HN)及残渣态氮(Residue nitrogen,RN)的赋存特征,同时结合生物可利用态氮的含量,探讨了各形态氮对生物可利用态氮的贡献。结果表明,丹江口水库沉积物中总氮(Total nitrogen,TN)在425~5796 mg/kg之间,平均为1 319.32 mg/kg,其中EN、HN和RN的平均值相对比例为2.15∶1.95∶1,且各形态氮含量的空间分布呈入库河流大于库区开阔区域的特征,尤其在丹江、老灌河以及犟河-堵河入库口的含量较大。潜在矿化氮(Potential mineralized nitrogen,PMN)含量在40.20~1 468.95 mg/kg之间,平均为275.06 mg/kg,其中EN对丹江口水库沉积物PMN的贡献较大,比例在19.85%~90.80%之间,平均为63.47%。各形态氮在不同的水环境条件下发生迁移转化,保持着水-沉积物界面氮的动态平衡。
[Abstract]:In order to reveal the spatial distribution and bioavailability of nitrogen in the sediment of Danjiangkou Reservoir, the exchangeable nitrogen (Exchangeable nitrogen,EN), acidolytic nitrogen (Acid hydrolysable nitrogen,HN) and residual nitrogen (Residue nitrogen,) in surface sediments were studied by continuous fractionation extraction method. The occurrence characteristics of RN) and the contribution of various forms of nitrogen to bioavailable nitrogen were discussed in combination with the content of bioavailable nitrogen. The results show that the total nitrogen (Total nitrogen,TN) in the sediment of Danjiangkou Reservoir is between 425 and 5796 mg/kg, with an average of 1 319.32 mg/kg,. The average ratio of EN,HN to RN is 2.15: 1.95: 1. The spatial distribution of nitrogen content in each form is larger than that in open area of reservoir area, especially in Danjiang River, Laoganhe River and the mouth of stubborn river and plugging river. The potential mineralized nitrogen (Potential mineralized nitrogen,PMN) content ranged from 40.20 mg/kg to 1 468.95 mg/kg, with an average of 275.06 mg/kg,. EN contributed a great deal to PMN in the sediment of Danjiangkou Reservoir, and the proportion of EN was between 19.85% and 90.80%. The average is 63.47. Under different water environment, the nitrogen of different forms of nitrogen transports and transforms, and maintains the dynamic equilibrium of nitrogen at the interface of water and sediment.
【作者单位】：中国环境科学研究院环境基准与风险评估国家重点实验室;南阳市环境保护科学研究所有限公司;
【基金】：中国东部湖泊沉积物底质调查(2014FY110400-01)~~
【分类号】：X524

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