地下水与地表水相互作用下硝态氮的迁移转化实验

发布时间：2019-02-13 05:53

【摘要】：全球水体氮污染形势严峻,且以硝态氮(NO_3~--N)污染为主,研究地下水与地表水(G-S)相互作用模式对NO_3~--N在"潜流带"(HZ)中迁移转化的影响是开展水体氮污染综合防控的关键.开展地表水(S)补给地下水(G)(下降流)、地下水(G)补给地表水(S)(上升流)以及交替作用3种模式的NO_3~--N迁移转化实验,研究表明:3种模式下,出水NO_3~--N浓度可降低95%以上;上升流中反硝化强度大于下降流;异化还原作用(DNRA)对下降流与上升流出水氨氮(NH_4~+-N)浓度的贡献分别约为71%和11%;上升流实验后水-土界面有机氮含量是下降流实验后水-土界面的2.3倍.结果表明,G-S相互作用下NO_3~--N的衰减途径主要包括:合成有机氮、反硝化及DNRA;相互作用模式对各衰减途径的强度存在影响;HZ介质通过吸附NH_4~+-N和微生物作用合成有机氮的方式截留氮素.
[Abstract]:The situation of nitrogen pollution in global water body is severe, and nitrate nitrogen (NO_3~--N) pollution is the main pollution. To study the effect of the interaction model of groundwater and surface water (G-S) on the migration and transformation of NO_3~--N in "subsurface flow zone" (HZ) is the key to carry out comprehensive control of water nitrogen pollution. Surface water (S) recharge groundwater (G) (descending current), groundwater (G) recharge surface water (S) (upwelling) and alternate action three models of NO_3~--N migration and transformation experiments are carried out. The concentration of NO_3~--N in effluent can be reduced by more than 95%. The denitrification intensity in upwelling was higher than that in descending stream, and the contribution of (DNRA) to the concentration of NH_4~ N in downflow and upwelling effluent was about 71% and 11%, respectively. The organic nitrogen content of the water-soil interface is 2.3 times higher than that of the water-soil interface after the upwelling experiment. The results show that the attenuation pathways of NO_3~--N under G-S interaction mainly include: synthesis of organic nitrogen denitrification and DNRA; interaction mode have influence on the intensity of each attenuation pathway; Organic nitrogen was synthesized by adsorption of NH_4~-N with microorganism in HZ medium.
【作者单位】：中国地质大学环境学院;桂林理工大学广西环境污染控制理论与技术重点实验室;
【基金】：国家水体污染控制与治理科技重大专项(No.2012ZX07204-003-04) 中国地质调查局项目(No.DD20160255) 广西矿冶与环境科学实验中心项目(No.KH2012ZD004) 广西高等学校高水平创新团队及卓越学者计划项目(No.002401013001)
【分类号】：X52

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