地下水“三氮”污染来源及其识别方法研究进展

地下水"三氮"污染来源的识别研究对污染控制与修复有重要的意义.在阐述地下水"三氮"污染来源(大气氮沉降、土壤天然有机氮矿化、地表径流氮输入、人类活动氮排放等)及其在我国的分布特征的基础上,总结了国际上常用的"三氮"污染来源识别方法,包括水化学方法、统计学相关方法、区域氮平衡法、稳定同位素示踪法及一些新型示踪方法.指出由于"三氮"污染来源的多样性及污染形成机制的复杂性,单一识别方法在应用中均有较明显的局限性,目前主流识别手段为稳定同位素示踪法与多种识别方法相综合.进一步提出要加强新型示踪方法的开拓、定量识别方法的优化,污染源识别与迁移转化机制、地下水补排条件、地下水-地表水转化关系等研究相结合为未来发展的主要趋势.

Research Progress on the Sources of Inorganic Nitrogen Pollution in Groundwater and Identification Methods

The identification of the main inorganic nitrogen (MIN, referring to NH₄⁺-N, NO₃^--N, and NO₂^--N) pollution sources in groundwater is of great significance to its control and repair. A review of the MIN sources in groundwater and the main identification methods was conducted. The main sources of MIN pollution in groundwater (atmospheric nitrogen deposition, soil natural organic nitrogen mineralization, nitrogen from streams, and nitrogen emission from human activity), and its distribution in China were expounded. The common methods for tracing MIN sources include hydrochemical analysis, statistical estimation, regional nitrogen balance evaluation, stable isotopes tracer, and new types of tracers. Because of the variety of nitrogen sources and the complexity of the MIN pollution formation mechanism, the single identification methods shared limitations in application, whereas more comprehensive ones, especially the stable isotope tracer integrated with other methods, were mainstream. Furthermore, future research prospects, including the development of new types of tracing methods, the optimization of quantification methods, the integration of research on pollution source identification, transformation mechanism, groundwater recharge and discharge condition, and groundwater-surface water conversion, have been put forward.