Application of Stable Isotope Techniques in Tracing the Sources of Atmospheric NOX and Nitrate

Nitrate is an important component of PM2.5, and its dry deposition and wet deposition can have an impact on ecosystems. Nitrate in the atmosphere is mainly transformed by nitrogen oxides (NOX = NO + NO2) through a number of photochemical processes. For effective management of the atmosphere's environment, it is crucial to understand the sources of atmospheric NOX and the processes that produce atmospheric nitrate. The stable isotope method is an effective analytical method for exploring the sources of NO3- in the atmosphere. This study discusses the range and causes of delta N-15 data from various sources of NOX emissions, provides the concepts of stable isotope techniques applied to NOX traceability, and introduces the use of Bayesian mixture models for the investigation of NOX sources. The combined application of delta N-15 and delta O-18 to determine the pathways of nitrate formation is summarized, and the contribution of Delta O-17 to the atmospheric nitrate formation pathway and the progress of combining Delta O-17 simulations to reveal the atmospheric oxidation characteristics of different regions are discussed, respectively. This paper highlights the application results and development trend of stable isotope techniques in nitrate traceability, discusses the advantages and disadvantages of stable isotope techniques in atmospheric NOX traceability, and looks forward to its future application in atmospheric nitrate pollution. The research results could provide data support for regional air pollution control measures.

Automated summary

Nitrate, an important component of PM2.5, can impact ecosystems through dry and wet deposition. Understanding the sources of atmospheric NOX and the processes of nitrate production are crucial for effective environmental management. Stable isotope techniques provide an effective way to explore NOX sources and atmospheric nitrate pollution, offering a promising tool for traceability in the field of air quality control.