title: Identification of the microbes mediating Fe reduction in a deep saline aquifer and their influence during managed aquifer recharge.
abstract: In this study, indigenous microbes enabling Fe reduction under saline groundwater conditions were identified, and their potential contribution to Fe release from aquifer sediments during managed aquifer recharge (MAR) was evaluated. Sediment and groundwater samples were collected from a MAR feasibility test site in Korea, where adjacent river water will be injected into the confined aquifer. The residual groundwater had a high salinity over 26.0 psu, as well as strong reducing conditions (dissolved oxygen, DO<2.0mg/L; oxidation-reduction potential, ORP<-100 mV) with high Fe(2+) concentrations. The indigenous microbes that mediate the reduction of Fe-minerals in this deep saline aquifer were found to be Citrobacter sp. However, column experiments to simulate field operation scenarios indicated that additional Fe release would be limited during MAR, as the dominant microbial community in the sediment would shift from Citrobacter sp. to Pseudomonas sp. and Limnohabitans sp. as river water injection alters the pore water chemistry.
authors.affiliation: Center for Water Resource Cycle, Green City Technology Institute, Korea Institute of Science and Technology (KIST), Seoul 136-791, South Korea.
authors.forename: Myoung-Soo
authors.initials: MS
authors.lastname: Ko
authors.affiliation: Center for Water Resource Cycle, Green City Technology Institute, Korea Institute of Science and Technology (KIST), Seoul 136-791, South Korea.
authors.forename: Kyungjin
authors.initials: K
authors.lastname: Cho
authors.affiliation: Center for Water Resource Cycle, Green City Technology Institute, Korea Institute of Science and Technology (KIST), Seoul 136-791, South Korea.
authors.forename: Dawoon
authors.initials: D
authors.lastname: Jeong
authors.affiliation: Center for Water Resource Cycle, Green City Technology Institute, Korea Institute of Science and Technology (KIST), Seoul 136-791, South Korea; Energy Environment Policy and Technology, Green School, Korea University (KU) - Korea Institute of Science and Technology (KIST), Seoul 136-701, South Korea. Electronic address: seunglee@kist.re.kr.
authors.forename: Seunghak
authors.initials: S
authors.lastname: Lee
mesh_terms: D004784:Environmental Monitoring; D052918:Environmental Restoration and Remediation; D060587:Groundwater / Q000737:chemistry* / Q000382:microbiology*; D007501:Iron / Q000378:metabolism*; D056910:Republic of Korea; D054712:Salinity; D014871:Water Microbiology; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D014874:Water Pollutants, Chemical; D007501:Iron
keywords: Deep saline aquifer; Managed aquifer recharge (MAR); Microbe-driven iron reduction; Water quality