Nitrogen species and microbial community coevolution along groundwater flowpath in the southwest of Poyang Lake area, China

Xianglong Chen; Guangcai Wang; Yizhi Sheng; Fu Liao; Hairu Mao; Bo Li; Hongyu Zhang; Zhiyuan Qiao; Jiahui He; Yingxue Liu; Yilun Lin; Ying Yang

doi:10.1016/j.chemosphere.2023.138627

Nitrogen species and microbial community coevolution along groundwater flowpath in the southwest of Poyang Lake area, China

Chemosphere. 2023 Jul:329:138627. doi: 10.1016/j.chemosphere.2023.138627. Epub 2023 Apr 7.

Authors

Xianglong Chen¹, Guangcai Wang², Yizhi Sheng³, Fu Liao¹, Hairu Mao¹, Bo Li¹, Hongyu Zhang¹, Zhiyuan Qiao¹, Jiahui He¹, Yingxue Liu¹, Yilun Lin¹, Ying Yang¹

Affiliations

¹ State Key Laboratory of Biogeology and Environmental Geology & MOE Key Laboratory of Groundwater Circulation and Environment Evolution, China University of Geosciences, Beijing, 100083, PR China; School of Water Resources and Environment, China University of Geosciences, Beijing, 100083, PR China.
² State Key Laboratory of Biogeology and Environmental Geology & MOE Key Laboratory of Groundwater Circulation and Environment Evolution, China University of Geosciences, Beijing, 100083, PR China; School of Water Resources and Environment, China University of Geosciences, Beijing, 100083, PR China. Electronic address: wanggc@pku.edu.cn.
³ State Key Laboratory of Biogeology and Environmental Geology & MOE Key Laboratory of Groundwater Circulation and Environment Evolution, China University of Geosciences, Beijing, 100083, PR China. Electronic address: shengyz@cugb.edu.cn.

PMID: 37031839
DOI: 10.1016/j.chemosphere.2023.138627

Abstract

Nitrate and ammonia overload in groundwater can lead to eutrophication of surface water in areas where surface water is recharged by groundwater. However, this process remained elusive due to the complicated groundwater N cycling, which is governed by the co-evolution of hydrogeochemical conditions and N-cycling microbial communities. Herein, this process was studied along a generalized groundwater flowpath in Ganjing Delta, Poyang Lake area, China. From groundwater recharge to the discharge area near the lake, oxidation-reduction potential (ORP), NO₃-N, and NO₂-N decreased progressively, while NH₃-N, total organic carbon (TOC), Fe²⁺, sulfide, and TOC/NO₃^- ratio accumulated in the lakeside samples. The anthropogenic influences such as sewage and agricultural activities drove the nitrate distribution, as observed by Cl^- vs. NO₃^-/Cl^- ratio and isotopic composition of nitrate. The hydrogeochemical evolution was intimately coupled with the changes in microbial communities. Variations in microbial community structures was significantly explained by Fe²⁺, NH₃-N, and sulfide, while TOC/NO₃^- controlled the distribution of predicted N cycling gene. The absence of NH₃-N in groundwater upstream was accompanied by the enrichment in Acinetobacter capable of nitrification and aerobic denitrification. These two processes were also supported by Ca²⁺ + Mg²⁺ vs. HCO₃^- ratio and isotopic composition of NO₃^-. The DNRA process downstream was revealed by both the presence of DNRA-capable microbes such as Arthrobacter and the isotopic composition of NH₄⁺ in environments with high concentrations of NH₃-N, TOC/NO₃^-, Fe²⁺, and sulfide. This coupled evolution of N cycling and microbial community sheds new light on the N biogeochemical cycle in areas where surface water is recharged by groundwater.

Keywords: Ammonium; Groundwater flowpath; Microbial community; Nitrate reduction.

MeSH terms

China
Environmental Monitoring
Groundwater* / chemistry
Nitrates / chemistry
Nitrogen / analysis
Nitrogen Isotopes / analysis
Water Pollutants, Chemical* / analysis

Substances

Nitrogen
Nitrogen Isotopes
Nitrates
Water Pollutants, Chemical