Isotope and dating combined shallow groundwater nitrate source analysis method

Abstract

The invention provides an isotope and dating combined shallow groundwater nitrate source analysis method. The method comprises the following steps: (1) setting a monitoring sampling point and a background value sampling point according to environmental characteristics of a determination area; and (2) monitoring the age of the underground water by using an isotope dating method, and carrying out qualitative identification and quantitative analysis on the nitrate source of the underground water in combination with a nitrogen-oxygen stable double isotope tracing method, research area land utilization and pollution source information. According to the invention, underground water dating and isotope tracing methods are creatively combined. A pollution source can be quickly and accurately identified, the isotope method has the advantage of being slightly influenced by the concentration change of water environment factors, and meanwhile, the average residence time of the underground water ismeasured and compared with the formation time of the pollution source to trace back the industry category which may cause potential pollution, so that the nitrate pollution of the underground water isquickly and accurately traced back.

Description

technical field [0001] The invention belongs to the technical field of environmental pollution prevention and control, and relates to a method for rapidly identifying pollution sources in groundwater, in particular to a method for analyzing nitrate sources in shallow groundwater by combining isotope and dating. Background technique [0002] As an important part of the water cycle, groundwater has the characteristics of stable water quantity and good water quality, and is a precious freshwater resource. The main excessive indicators in groundwater pollution include "three nitrogens", total hardness, manganese, iron, sulfate, fluoride and chloride, among which "three nitrogens" cause more pollution. The "three nitrogens" include nitrite nitrogen, ammonia nitrogen and nitrate nitrogen. [0003] Unlike surface water pollution, groundwater has slow flow, weak alternation, and poor self-purification ability. Once it is polluted, it is difficult to recover, and the repair cost is ...

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Problems solved by technology

The study by Mingzhu L et al. (Tracking sources of groundwater nitrate contamination using nitrogen and oxygen stableisotopes at Beijing area, Environmental Earth Sciences, 2014, 72(3): 707-715) obtained the largest pollution source in the Beijing area through a mass balance mixed model It is feces, but the mass balance model cannot consider the temporal and spatial changes of pollutants in pollution sources and receptors; the influence of isotope fractionation cannot be considered; the identification of the number of pollution sources is affected by the number of isotopes

[0007] my country's groundwater NO 3 - Pollution sources are complicated, and simple water chemical analysis methods or isotopic techniques alone are not enough to accurately reflect the NO 3 - source of pollution

Traditional hydrochemical analysis methods or qualitative judgments based on land use types have large errors and strong uncertainties; while identification based on the isotope characteristic values ​​of different pollution sources is relatively accurate, but the method is single

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