Nitrate attenuation in low-permeability sediments based on isotopic and microbial analyses

Wu, Yuexia1,2; Xu, Ligang1; Wang, Sai3; Wang, Zhenglu4; Shang, Jianying5; Li, Xiqing4; Zheng, Chunmiao6

2018-03-15

10.1016/j.scitotenv.2017.11.039

SCIENCE OF THE TOTAL ENVIRONMENT   影响因子和分区

0048-9697

1879-1026

This study investigated nitrate attenuation in low-permeability sediments (LPS) in a multi-layer aquifer by integrating hydrochemical, isotopic and microbiological molecular techniques in a field site. In the meantime, the overlying high-permeability sediment (HPS) was also examined on the nitrate attenuation for the sake of comparison. Additionally, laboratory flow-through experiments were conducted to assess the overall nitrate reduction rate in the two types of sediment. The delta N-15-NO3- and delta S-34-SO42- values were more enriched by approximately 37 parts per thousand and 15 parts per thousand in the LPS than the overlying HPS associated with substantial reductions of the NO3- and SO42- concentration, indicating the occurrence of strong bio-reductions in nitrate and sulfate. The microbial community diversity analyses showed a higher diversity of the denitrifiers encoding nirS- (Shannon Index SI = 6.3) and nrf-type gene (SI = 2.7), and the sulfate reduction bacteria (SRB) encoding the dsr gene (SI = 6.4) in the LPS than in the HPS. The bacterial community structure was influenced by the groundwater hydrochemistry and the redox conditions. Due to the presence of anoxic groundwater with low levels of nutrients, the LPS featured higher abundances of nitrate reducers belonging to Alphaproteobacteria and SRB belonging to the strictly anaerobic class Clostridia relative to the HPS. Notably, chemolithotrophs were abundant in the LPS and likely coupled the reduction of nitrate with the oxidation of iron. Furthermore, the LPS was demonstrated to attenuate nitrate at a rate two times of the HPS in flow-through experiments, and denitrification accounted for approximately 93% of the nitrate reduction. The high nitrate reduction rate of the LPS was likely attributable to its high functional genes diversity.

Nitrate attenuation Low-permeability sediments Microbial diversity Isotopic analyses Sulfate reduction

SCI ; EI

英语

其他

National Natural Science Foundation of China[41501511] ; National Natural Science Foundation of China[41330632] ; National Natural Science Foundation of China[41371121]

Environmental Sciences & Ecology

Environmental Sciences

WOS:000424130500003

ELSEVIER SCIENCE BV

20174504382570

Aquifers ; Bacteria ; Denitrification ; Encoding (symbols) ; Gene encoding ; Groundwater geochemistry ; Groundwater pollution ; Groundwater resources ; Hydrochemistry ; Hydrogeology ; Isotopes ; Sediments ; Signal encoding ; Sulfur compounds

Groundwater:444.2 ; Biology:461.9 ; Geology:481.1 ; Geochemistry:481.2 ; Soil Mechanics and Foundations:483 ; Information Theory and Signal Processing:716.1 ; Data Processing and Image Processing:723.2 ; Chemical Reactions:802.2 ; Inorganic Compounds:804.2

ENVIRONMENT/ECOLOGY

Web of Science

1.Chinese Acad Sci, Nanjing Inst Geog & Limnol, Key Lab Watershed Geog Sci, 73 East Beijing Rd, Nanjing 210008, Jiangsu, Peoples R China
2.Peking Univ, Coll Engn, Inst Water Sci, 5 Yiheyuan Rd, Beijing 100871, Peoples R China
3.China Geol Survey, Ctr Hydrogeol & Environm Geol, 1305 Qiyi Rd, Baoding, Hebei, Peoples R China
4.Peking Univ, Coll Urban & Environm Sci, Beijing 100871, Peoples R China
5.China Agr Univ, Coll Resources & Environm Sci, Beijing 100193, Peoples R China
6.South Univ Sci & Technol, Sch Environm Sci & Engn, Shenzhen 518025, Peoples R China

Wu, Yuexia,Xu, Ligang,Wang, Sai,et al. Nitrate attenuation in low-permeability sediments based on isotopic and microbial analyses[J]. SCIENCE OF THE TOTAL ENVIRONMENT,2018,618:15-25.

Wu, Yuexia.,Xu, Ligang.,Wang, Sai.,Wang, Zhenglu.,Shang, Jianying.,...&Zheng, Chunmiao.(2018).Nitrate attenuation in low-permeability sediments based on isotopic and microbial analyses.SCIENCE OF THE TOTAL ENVIRONMENT,618,15-25.

Wu, Yuexia,et al."Nitrate attenuation in low-permeability sediments based on isotopic and microbial analyses".SCIENCE OF THE TOTAL ENVIRONMENT 618(2018):15-25.