A combined isotopic and dating method for nitrate source apportionment in shallow groundwater

Abstract

The invention provides a shallow groundwater nitrate source analysis method combining isotope and dating, said method comprising the following steps: (1) setting monitoring sampling points and background value sampling points according to the environmental characteristics of the measurement area; (2) ) using the isotope dating method to monitor the age of groundwater, combined with the nitrogen and oxygen stable double isotope traceability method, and the land use and pollution source information in the study area to conduct qualitative identification and quantitative analysis of groundwater nitrate sources. The present invention innovatively combines groundwater dating with isotope traceability methods to realize rapid and accurate identification of pollution sources. The isotope method has the advantage of being less affected by changes in the concentration of water environmental factors. Compared with time, the industry categories that may cause potential pollution can be traced back, and the rapid and accurate traceability of groundwater nitrate pollution can be realized.

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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