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Keithley AE, Gomez-Alvarez V, Williams D, Ryu H, Lytle DA. Depth profiles of biological aerated contactors: Characterizing microbial activity treating reduced contaminants. JOURNAL OF WATER PROCESS ENGINEERING 2023; 56:1-11. [PMID: 38357328 PMCID: PMC10866302 DOI: 10.1016/j.jwpe.2023.104360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2024]
Abstract
The biological treatment process consisting of an aerated contactor and filter is effective for groundwaters containing elevated ammonia and other reduced contaminants, including iron, manganese, arsenic, and methane. Depth profiles characterizing microbial activity across aerated contactors are lacking. A 1-year pilot study comparing gravel- and ceramic-packed contactors was conducted, and media depth profile samples were collected at the conclusion of the study. Media and water samples also were collected from pilot-scale aerated contactors at 4 other water systems. Water quality, media surface metals concentrations, and a suite of biofilm parameters were analyzed. Media surface metals concentrations were greatest at the influent end. ATP concentrations, extracellular polymeric substances, and extracellular enzyme activities tended to be similar across depth. Bacteria and functional genes involved in contaminant oxidation co-occurred and tended to decrease across depth, but were not correlated to the media metals concentration. Microbial community composition changed with depth, and the diversity either decreased or remained similar. The microbial activity profiles through aerated contactors differed from what is typically reported for groundwater biofilters, suggesting that the different reactor flow and dissolved oxygen profiles impacted the microbial community.
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Affiliation(s)
- Asher E. Keithley
- U.S. Environmental Protection Agency, ORD, CESER, WID, Cincinnati, OH 45268, United States
| | - Vicente Gomez-Alvarez
- U.S. Environmental Protection Agency, ORD, CESER, WID, Cincinnati, OH 45268, United States
| | - Daniel Williams
- U.S. Environmental Protection Agency, ORD, CESER, WID, Cincinnati, OH 45268, United States
| | - Hodon Ryu
- U.S. Environmental Protection Agency, ORD, CESER, WID, Cincinnati, OH 45268, United States
| | - Darren A. Lytle
- U.S. Environmental Protection Agency, ORD, CESER, WID, Cincinnati, OH 45268, United States
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Keithley AE, Ryu H, Gomez-Alvarez V, Harmon S, Bennett-Stamper C, Williams D, Lytle DA. Comprehensive characterization of aerobic groundwater biotreatment media. WATER RESEARCH 2023; 230:119587. [PMID: 36638728 PMCID: PMC10119871 DOI: 10.1016/j.watres.2023.119587] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 01/04/2023] [Accepted: 01/05/2023] [Indexed: 06/17/2023]
Abstract
Aerobic biotreatment systems can treat multiple reduced inorganic contaminants in groundwater, including ammonia (NH3), arsenic (As), iron (Fe), and manganese (Mn). While individual systems treating multiple contaminants simultaneously have been characterized and several systems treating one contaminant have been compared, a comparison of systems treating co-occurring contaminants is lacking. This study assessed the treatment performance and microbial communities within 7 pilot- and full-scale groundwater biotreatment systems in the United States that treated waters with pH 5.6-7.8, 0.1-2.0 mg/L dissolved oxygen, 75-376 mg CaCO3/L alkalinity, < 0.03-3.79 mg NH3-N/L, < 4-31 µg As/L, < 0.01-9.37 mg Fe/L, 2-1220 µg Mn/L, and 0.1-5.6 mg/L total organic carbon (TOC). Different reactor configurations and media types were represented, allowing for a broad assessment of linkages between water quality and microbial communities via microscopy, biofilm quantification, and molecular methods. Influent NH3, TOC, and pH contributed to differences in the microbial communities. Mn oxidase gene copy numbers were slightly negatively correlated with the influent Mn concentration, but no significant relationships between gene copy number and influent concentration were observed for the other contaminants. Extracellular enzyme activities, community composition, and carbon transformation pathways suggested heterotrophic bacteria may be important in nitrifying biofilters. Aerobic groundwater biofilters are complex, and improved understanding could lead to engineering enhancements.
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Affiliation(s)
- Asher E Keithley
- ORD, CESER, WID, Drinking Water Management Branch, U.S. Environmental Protection Agency, 26W. Martin Luther King Dr., Cincinnati, OH 45268, United States.
| | - Hodon Ryu
- ORD, CESER, WID, Drinking Water Management Branch, U.S. Environmental Protection Agency, 26W. Martin Luther King Dr., Cincinnati, OH 45268, United States
| | - Vicente Gomez-Alvarez
- ORD, CESER, WID, Drinking Water Management Branch, U.S. Environmental Protection Agency, 26W. Martin Luther King Dr., Cincinnati, OH 45268, United States
| | - Stephen Harmon
- ORD, CESER, WID, Drinking Water Management Branch, U.S. Environmental Protection Agency, 26W. Martin Luther King Dr., Cincinnati, OH 45268, United States
| | - Christina Bennett-Stamper
- ORD, CESER, WID, Drinking Water Management Branch, U.S. Environmental Protection Agency, 26W. Martin Luther King Dr., Cincinnati, OH 45268, United States
| | - Daniel Williams
- ORD, CESER, WID, Drinking Water Management Branch, U.S. Environmental Protection Agency, 26W. Martin Luther King Dr., Cincinnati, OH 45268, United States
| | - Darren A Lytle
- ORD, CESER, WID, Drinking Water Management Branch, U.S. Environmental Protection Agency, 26W. Martin Luther King Dr., Cincinnati, OH 45268, United States
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Ahmad K, Shah HUR, Ashfaq M, Nawaz H. Removal of decidedly lethal metal arsenic from water using metal organic frameworks: a critical review. REV INORG CHEM 2021. [DOI: 10.1515/revic-2021-0005] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Abstract
Water contamination is worldwide issue, undermining whole biosphere, influencing life of a large number of individuals all over the world. Water contamination is one of the chief worldwide danger issues for death, sickness, and constant decrease of accessible drinkable water around the world. Among the others, presence of arsenic, is considered as the most widely recognized lethal contaminant in water bodies and poses a serious threat not exclusively to humans but also towards aquatic lives. Hence, steps must be taken to decrease quantity of arsenic in water to permissible limits. Recently, metal-organic frameworks (MOFs) with outstanding stability, sorption capacities, and ecofriendly performance have empowered enormous improvements in capturing substantial metal particles. MOFs have been affirmed as good performance adsorbents for arsenic removal having extended surface area and displayed remarkable results as reported in literature. In this review we look at MOFs which have been recently produced and considered for potential applications in arsenic metal expulsion. We have delivered a summary of up-to-date abilities as well as significant characteristics of MOFs used for this removal. In this review conventional and advanced materials applied to treat water by adsorptive method are also discussed briefly.
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Affiliation(s)
- Khalil Ahmad
- Institute of Chemistry, Baghdad ul Jadeed Campus, The Islamia University of Bahawalpur , Bahawalpur 63100 , Pakistan
| | - Habib-Ur-Rehman Shah
- Institute of Chemistry, Baghdad ul Jadeed Campus, The Islamia University of Bahawalpur , Bahawalpur 63100 , Pakistan
| | - Muhammad Ashfaq
- Institute of Chemistry, Baghdad ul Jadeed Campus, The Islamia University of Bahawalpur , Bahawalpur 63100 , Pakistan
| | - Haq Nawaz
- CAS Key Laboratory of Engineering Plastics, CAS Research/Education Center for Excellence in Molecular Sciences , Institute of Chemistry, Chinese Academy of Sciences (CAS) , Beijing 100190 , China
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