PMID- 35618121 OWN - NLM STAT- MEDLINE DCOM- 20220623 LR - 20220623 IS - 1879-1026 (Electronic) IS - 0048-9697 (Linking) VI - 839 DP - 2022 Sep 15 TI - Impacts of anthropogenic groundwater recharge (AGR) on nitrate dynamics in a phreatic aquifer revealed by hydrochemical and isotopic technologies. PG - 156187 LID - S0048-9697(22)03284-3 [pii] LID - 10.1016/j.scitotenv.2022.156187 [doi] AB - Although anthropogenic groundwater recharge (AGR) can either elevate or decline the concentration of nitrate in the phreatic aquifer with high hydraulic conductivity, the long-term impact of AGR on nitrate dynamics in the phreatic aquifer and its reason is seldom disclosed. In this study, the hydrogen and oxygen stable isotopes (delta(2)H-H(2)O and delta(18)O-H(2)O) combined with mixing stable isotope analysis in R (MixSIAR) were used to group the study area into the dominant area of AGR by surface water (AGRSW) and the dominant area of natural groundwater recharged by precipitation (NGRP). Hydrochemical parameters and multiple stable isotopes, including delta(2)H-H(2)O, delta(18)O-H(2)O, delta(15)N-NO(3)(-), delta(18)O-NO(3)(-), and delta(13)C-DIC, were applied to explore the impacts of AGR on the concentration, biogeochemical processes, and main sources of nitrate. The results showed that AGR by surface water with low nitrate content can reduce nitrate pollution in groundwater. The characteristic of delta(18)O-NO(3)(-) value revealed that nitrification was the primary biogeochemical process of nitrogen in groundwater. AGR may enhance nitrification as indicated by the delta(18)O-NO(3)(-) value closer to the nitrification theoretical line. Dual nitrate stable isotopes and MixSIAR revealed that chemical fertilizer (CF), soil nitrogen (SN), and surface water (SW) contributed 10.88%, 49.92%, and 27.64% to nitrate in AGRSW groundwater, respectively, which was significantly different from their contributions to NGRP groundwater (p < 0.05). Notably, AGR significantly increased the contribution of SW but decreased the contribution of CF and SN in groundwater. This study provided a basis and guidance for groundwater quality assessment and pollution control in the phreatic aquifer with high hydraulic conductivity. CI - Copyright (c) 2022 Elsevier B.V. All rights reserved. FAU - Cao, Xu AU - Cao X AD - Ministry of Education Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, China. FAU - Shi, Yuanyuan AU - Shi Y AD - Beijing Municipal Research Institute of Eco-Environment Protection, Beijing 100037, China. FAU - He, Wei AU - He W AD - Beijing Municipal Research Institute of Eco-Environment Protection, Beijing 100037, China. FAU - An, Tongyan AU - An T AD - Beijing Municipal Research Institute of Eco-Environment Protection, Beijing 100037, China. FAU - Chen, Xiaorui AU - Chen X AD - Ministry of Education Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, China. FAU - Zhang, Zhanhao AU - Zhang Z AD - Ministry of Education Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, China. FAU - Liu, Fei AU - Liu F AD - Ministry of Education Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, China. FAU - Zhao, Yi AU - Zhao Y AD - Ministry of Education Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, China. FAU - Zhou, Pengpeng AU - Zhou P AD - Ministry of Education Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, China. FAU - Chen, Cuibai AU - Chen C AD - Ministry of Education Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, China. FAU - He, Jiangtao AU - He J AD - Ministry of Education Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, China. FAU - He, Wei AU - He W AD - Ministry of Education Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, China. Electronic address: wei.he@cugb.edu.cn. LA - eng PT - Journal Article DEP - 20220523 PL - Netherlands TA - Sci Total Environ JT - The Science of the total environment JID - 0330500 RN - 0 (Fertilizers) RN - 0 (Nitrates) RN - 0 (Nitrogen Isotopes) RN - 0 (Nitrogen Oxides) RN - 0 (Oxygen Isotopes) RN - 0 (Soil) RN - 0 (Water Pollutants, Chemical) RN - 059QF0KO0R (Water) RN - N762921K75 (Nitrogen) SB - IM MH - Environmental Monitoring/methods MH - Fertilizers/analysis MH - *Groundwater MH - Nitrates/analysis MH - Nitrogen/analysis MH - Nitrogen Isotopes/analysis MH - Nitrogen Oxides/analysis MH - Oxygen Isotopes/analysis MH - Soil/chemistry MH - Water/analysis MH - *Water Pollutants, Chemical/analysis OTO - NOTNLM OT - Anthropogenic groundwater recharge OT - Groundwater nitrate pollution OT - Hydrochemical and isotopic technologies COIS- Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. EDAT- 2022/05/27 06:00 MHDA- 2022/06/24 06:00 CRDT- 2022/05/26 19:25 PHST- 2022/03/30 00:00 [received] PHST- 2022/05/19 00:00 [revised] PHST- 2022/05/19 00:00 [accepted] PHST- 2022/05/27 06:00 [pubmed] PHST- 2022/06/24 06:00 [medline] PHST- 2022/05/26 19:25 [entrez] AID - S0048-9697(22)03284-3 [pii] AID - 10.1016/j.scitotenv.2022.156187 [doi] PST - ppublish SO - Sci Total Environ. 2022 Sep 15;839:156187. doi: 10.1016/j.scitotenv.2022.156187. Epub 2022 May 23.