Influence of land use and change in the proportion of electron donors required for denitrification on N2O in groundwater

• Published in: Environmental science and pollution research international 2021-04, Vol.28 (14), p.17684-17696
• Main Authors: Li, Zhao, Li, Fadong, Zhang, Qiuying, Wang, Jianqi, Leng, Peifang, Tian, Chao, Li, Xiaoyan
• Format: Article
• Language: English
• Subjects: Accumulation; Agricultural land; Anions; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Denitrification; Earth and Environmental Science; Ecotoxicology; Electrons; Emission analysis; Emissions; Environment; Environmental Chemistry; Environmental Health; Environmental science; Groundwater; Land use; Nitrates; Nitrous oxide; Research Article; Self organizing maps; Spatial variations; Sulfur; Urban agriculture; Waste Water Technology; Water Management; Water Pollution Control; Water quality
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-020-12258-x

Nitrate (NO 3 − ) and nitrous oxide (N 2 O) accumulate in groundwater in relation to human activities and pose multiple threats to the global environment (harming human health and atmospheric damage). This study focused on the evaluation of groundwater NO 3 − , N 2 O, and its indirect emission factor under different land use types (agricultural land, urban land, and forest) and response mechanism of major anions to dissolved N 2 O within groundwater in Dexing which has the largest copper mine in Asia. Specifically, this work used self-organizing maps (SOMs) to identify which anion conditions (NO 3 − , SO 4 2− , F − , Cl − ) and water quality parameters were suitable for the accumulation of groundwater N 2 O. Finally, we found that the shallow groundwater of agricultural land has a high concentration of NO 3 − and N 2 O and the agricultural activity has a significant effect on the temporal and spatial variation of N 2 O in groundwater. The result of SOMs combined with the positive correlation between N 2 O and NO 3 − /SO 4 2− suggested that the electron donor required for denitrification has a significant effect on N 2 O accumulation. In this respect, when an increased proportion of reduced sulfur is available as an electron donor for autotrophic denitrification, this results in lower concentrations of N 2 O in groundwater. Through the comprehensive evaluation of the anion conditions and N 2 O in groundwater under different land use types, this study case can help to estimate the N 2 O indirect emission from groundwater, so as to constrain the global nitrogen budget.