College of Water Sciences, Beijing Normal University, Beijing, 100875, China.
Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, Beijing, 100875, China.
Environ Sci Pollut Res Int. 2023 Oct;30(46):102281-102294. doi: 10.1007/s11356-023-29386-9. Epub 2023 Sep 4.
Groundwater level recovery has a significant effect on the sources and transformation of nitrogen in groundwater, but there are still few studies on the influences of the water table on the sources and transformation of nitrogen in groundwater using field data. In this study, the changes in groundwater level, geochemical composition, and isotopic signatures of NO and NH during a period of groundwater level recovery at a pilot site were analyzed in detail. The water table underwent progressive recovery of almost 1.6 m in 16 months. At a depth of 5.5 m below the surface, both low NH and high NO appeared in the groundwater, whereas below that depth, both high NH and low NO simultaneously appeared in the groundwater. The main sources of NO were manure and septic waste, and NH fertilizers. The main sources of NH were mineral fertilizers. The main transformation process were nitrification and denitrification at a depth of 5.5 m below the surface; below that depth, the main transformation processes were denitrification and dissimilatory nitrate reduction to ammonium (DNRA). This study provides a theoretical understanding of the relationship between the changing water table and nitrogen in groundwater level recovery areas.
地下水水位恢复对地下水氮素的来源和转化有重要影响，但利用野外数据研究地下水位对氮素来源和转化影响的研究仍然较少。本研究详细分析了一个试点地区地下水水位恢复期间地下水水位、地球化学组成和 NO 和 NH 同位素特征的变化。在 16 个月内，地下水位逐渐恢复了近 1.6 米。在地表以下 5.5 米的深度，地下水同时出现低 NH 和高 NO；而在该深度以下，地下水同时出现高 NH 和低 NO。NO 的主要来源是粪肥和化粪池废物以及 NH 肥料。NH 的主要来源是矿物肥料。在地表以下 5.5 米的深度，主要的转化过程是硝化和反硝化；在该深度以下，主要的转化过程是反硝化和异化硝酸盐还原为铵（DNRA）。本研究为了解变化的地下水位与地下水氮素在恢复区之间的关系提供了理论认识。
