1
|
Oliveira VH, Fonte BA, Costa F, Sousa AI, Henriques B, Pereira E, Dolbeth M, Díez S, Coelho JP. The effect of Zostera noltei recolonization on the sediment mercury vertical profiles of a recovering coastal lagoon. CHEMOSPHERE 2023; 345:140438. [PMID: 37852379 DOI: 10.1016/j.chemosphere.2023.140438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 09/07/2023] [Accepted: 10/12/2023] [Indexed: 10/20/2023]
Abstract
Mercury's extreme toxicity and persistence in the environment justifies a thorough evaluation of its dynamics in ecosystems. Aveiro Lagoon (Portugal) was for decades subject to mercury effluent discharges. A Nature-based Solution (NbS) involving Zostera noltei re-colonization is being tested as an active ecosystem restoration measure. To study the effect of Zostera noltei on the sediment contaminant biogeochemistry, seasonal (summer/winter) sediment, interstitial water and labile mercury vertical profiles were made in vegetated (Transplanted and Natural seagrass meadows) and non-vegetated sites (Bare-bottom area). While no significant differences (p > 0.05) were observed in the sedimentary phase, Zostera noltei presence reduced the reactive/labile mercury concentrations in the top sediment layers by up to 40% when compared to non-vegetated sediment, regardless of season. No differences were found between vegetated meadows, highlighting the fast recovery of the contaminant regulation ecosystem function provided by the plants after re-colonization and its potential for the rehabilitation of historically contaminated ecosystems.
Collapse
Affiliation(s)
- V H Oliveira
- ECOMARE - Laboratory for Innovation and Sustainability of Marine Biological Resources, CESAM - Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Estrada do Porto de Pesca Costeira, 3830-565, Gafanha da Nazaré, Portugal.
| | - B A Fonte
- ECOMARE - Laboratory for Innovation and Sustainability of Marine Biological Resources, CESAM - Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Estrada do Porto de Pesca Costeira, 3830-565, Gafanha da Nazaré, Portugal
| | - F Costa
- Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456, Coimbra, Portugal
| | - A I Sousa
- ECOMARE - Laboratory for Innovation and Sustainability of Marine Biological Resources, CESAM - Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Estrada do Porto de Pesca Costeira, 3830-565, Gafanha da Nazaré, Portugal
| | - B Henriques
- LAQV-REQUIMTE- Associated Laboratory for Green Chemistry of the Network of Chemistry and Technology, Department of Chemistry, University of Aveiro, 3810-193, Aveiro, Portugal
| | - E Pereira
- LAQV-REQUIMTE- Associated Laboratory for Green Chemistry of the Network of Chemistry and Technology, Department of Chemistry, University of Aveiro, 3810-193, Aveiro, Portugal
| | - M Dolbeth
- CIIMAR - Interdisciplinary Centre of Marine and Environmental Research, Novo Edifício Do Terminal de Cruzeiros Do Porto de Leixões, Avenida General Norton de Matos S/N, 4450-208, Matosinhos, Portugal
| | - S Díez
- Environmental Chemistry Department, Institute of Environmental Assessment and Water Research, IDAEA-CSIC, E-08034, Barcelona, Spain
| | - J P Coelho
- ECOMARE - Laboratory for Innovation and Sustainability of Marine Biological Resources, CESAM - Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Estrada do Porto de Pesca Costeira, 3830-565, Gafanha da Nazaré, Portugal
| |
Collapse
|
2
|
Zhu Q, Li G, Li X, Li C, Li J, Zhao C, Cui J, Du C, Tian Z, Shi Y, Ma Y, Zhang L. Effect of microbial network complexity and stability on nitrogen and sulfur pollutant removal during sediment remediation in rivers affected by combined sewer overflows. CHEMOSPHERE 2023; 331:138832. [PMID: 37150460 DOI: 10.1016/j.chemosphere.2023.138832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 04/23/2023] [Accepted: 04/30/2023] [Indexed: 05/09/2023]
Abstract
Discovering the complexity and improving the stability of microbial networks in urban rivers affected by combined sewer overflows (CSOs) is essential for restoring the ecological functions of urban rivers, especially to improve their ability to resist CSO impacts. In this study, the effects of sediment remediation on the complexity and stability of microbial networks was investigated. The results revealed that the restored microbial community structure using different approaches in the river sediments differed significantly, and random matrix theory showed that sediment remediation significantly affected microbial networks and topological properties; the average path distance, average clustering coefficient, connectedness, and other network topological properties positively correlated with remediation time and weakened the small-world characteristics of the original microbial networks. Compared with other sediment remediation methods, regulating low dissolved oxygen (DO) shifts the microbial network module hubs from Actinobacteria and Bacteroidetes to Chloroflexi and Proteobacteria. This decreases the positive association of networks by 17%-18%, which intensifies the competitiveness among microorganisms, further weakening the influence and transmission of external pressure across the entire microbial network. Compared with that of the original sediment, the vulnerability of the restored network was reduced by more than 36%, while the compositional stability was improved by more than 12%, with reduced fluctuation in natural connectivity. This microbial network succession substantially increased the number of key enzyme-producing genes involved in nitrogen and sulfur metabolism, enhancing nitrification, denitrification, and assimilatory sulfate reduction, thereby increasing the removal rates of ammonia, nitrate, and acid volatile sulfide by 43.42%, 250.68% and 2.66%, respectively. This study comprehensively analyzed the succession patterns of microbial networks in urban rivers affected by CSOs before and after sediment remediation, which may provide a reference for reducing the impact of CSO pollution on urban rivers in the subsequent stages.
Collapse
Affiliation(s)
- Qiuheng Zhu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China; Eco-Environmental Research Department, Nanjing Hydraulic Research Institute, Nanjing, 210098, China
| | - Guowen Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Xiaoguang Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Caole Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Jiaxi Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Chen Zhao
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Jianglong Cui
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Caili Du
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China; College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Zhenjun Tian
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Yuzhu Shi
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Yangyang Ma
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Lieyu Zhang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
| |
Collapse
|
3
|
Millard G, Eckley CS, Luxton TP, Krabbenhoft D, Goetz J, McKernan J, DeWild J. Evaluating the influence of seasonal stratification on mercury methylation rates in the water column and sediment in a contaminated section of a western U.S.A. reservoir. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 316:120485. [PMID: 36279994 PMCID: PMC10259237 DOI: 10.1016/j.envpol.2022.120485] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 10/14/2022] [Accepted: 10/17/2022] [Indexed: 06/14/2023]
Abstract
Mercury methylation frequently occurs at the active oxic/anoxic boundary between the sediment bed and water column of lakes and reservoirs. Previous studies suggest that the predominant mercury methylation zone moves to the water column during periods of stratification and that high potential methylation rates (Km) in sediment require oxygenated overlying water. However, simultaneous measurements of methylmercury (MeHg) production in both the sediment and water column remain limited. Understanding the relative importance of sediment versus water column methylation and the impact of seasonal stratification on these processes has important implications for managing MeHg production. This study measured Km and potential demethylation rates (Kdm) using stable isotope tracers of unfiltered inorganic mercury and MeHg in sediments and water of the littoral and profundal zones of a shallow branch of the Nacimiento Reservoir in California's central coastal range. Field sampling was conducted once during winter (well-mixed/oxygenated conditions) and once during late summer (thermally stratified/anoxic conditions). The results showed very high ambient MeHg concentrations in hypolimnetic waters (up to 7.5 ng L-1; 79% MeHg/total Hg). During late summer, littoral sediments had higher Km (0.024 day-1) compared to profundal sediments (0.013 day-1). Anoxic water column Km were of similar magnitude to Km in the sediment (0.03 day-1). Following turnover, profundal sediment Km did not change significantly, but water column Km became insignificant. Summer and winter sediment Kdm were higher in profundal (2.35, 3.54 day-1, respectively) compared to the littoral sediments (0.52, 2.56 day-1, respectively). When modelled, Km in the water column could account for approximately 40% of the hypolimnetic MeHg. Our modelling results show that the remaining MeHg in the hypolimnion could originate from the profundal sediment. While further study is needed, these results suggest that addressing methylation in the water column and profundal sediment are of equal importance to any remediation strategy.
Collapse
Affiliation(s)
- Geoffrey Millard
- U.S.A. Environmental Protection Agency, Office of Research and Development, 26 W Martin Luther King Dr, Cincinnati, OH, 45220, USA.
| | - Chris S Eckley
- U.S.A. Environmental Protection Agency, Region 10, 1200 Sixth Avenue, Suite 155, Seattle WA, 98101, USA.
| | - Todd P Luxton
- U.S.A. Environmental Protection Agency, Office of Research and Development, 26 W Martin Luther King Dr, Cincinnati, OH, 45220, USA.
| | - David Krabbenhoft
- U.S.A. Geological Survey, Mercury Research Laboratory, 2280 Woodale Drive, Mounds View MN, 55112, USA.
| | - Jennifer Goetz
- U.S.A. Environmental Protection Agency, Office of Research and Development, 26 W Martin Luther King Dr, Cincinnati, OH, 45220, USA.
| | - John McKernan
- U.S.A. Environmental Protection Agency, Office of Research and Development, 26 W Martin Luther King Dr, Cincinnati, OH, 45220, USA.
| | - John DeWild
- U.S.A. Geological Survey, Mercury Research Laboratory, 2280 Woodale Drive, Mounds View MN, 55112, USA.
| |
Collapse
|
4
|
Dai SS, Yang Z, Tong Y, Chen L, Liu SY, Pan R, Li Y, Zhang CJ, Liu YR, Huang Q. Global distribution and environmental drivers of methylmercury production in sediments. JOURNAL OF HAZARDOUS MATERIALS 2021; 407:124700. [PMID: 33333388 DOI: 10.1016/j.jhazmat.2020.124700] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 11/11/2020] [Accepted: 11/25/2020] [Indexed: 06/12/2023]
Abstract
Neurotoxic methylmercury (MeHg) in environments poses substantial risks to human health. Saturated sediments are basic sources of MeHg in food chains; however, distribution patterns and environmental drivers of MeHg at a global scale remain largely unexplored. Here, we characterized global patterns of MeHg distribution and environmental drivers of MeHg production based on 495 sediment samples across five typical ecosystems from the literature (1995-2018) and our own field survey. Our results showed the MeHg concentration ranged from 0.009 to 55.7 μg kg-1 across the different ecosystems, and the highest MeHg concentration and Hg methylation potential were from the sediments of paddy and marine environments, respectively. Further, using combined analysis of random forest and structural equation modeling, we identified temperature and precipitation as important regulators of MeHg production after accounting for the well-known drivers including Hg availability and sediment geochemistry. More importantly, we found increased MeHg production in sediments with elevated mean annual Hg precipitation, and warmer temperature could also accelerate MeHg production by facilitating activities of microbial methylators. Together, this work advances our understanding of global MeHg distribution in sediments and environmental drivers, which are fundamental to the prediction and management of MeHg production and its potential health risk globally.
Collapse
Affiliation(s)
- Shu-Shen Dai
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Ziming Yang
- Department of Chemistry, Oakland University, Rochester, MI 48309, United States
| | - Yindong Tong
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Long Chen
- Key Laboratory of Geographic Information Science (Ministry of Education), School of Geographic Sciences, East China Normal University, Shanghai 200241, China
| | - Si-Yuan Liu
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Rong Pan
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Yanbin Li
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China
| | - Cui-Jing Zhang
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China
| | - Yu-Rong Liu
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China; Hubei Key Laboratory of Soil Environment and Pollution Remediation, Wuhan 430070, China.
| | - Qiaoyun Huang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China; Hubei Key Laboratory of Soil Environment and Pollution Remediation, Wuhan 430070, China
| |
Collapse
|
5
|
Amiri V, Li P, Bhattacharya P, Nakhaei M. Mercury pollution in the coastal Urmia aquifer in northwestern Iran: potential sources, mobility, and toxicity. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:17546-17562. [PMID: 33398765 DOI: 10.1007/s11356-020-11865-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 11/29/2020] [Indexed: 06/12/2023]
Abstract
The concentration of total dissolved mercury (HgT) in surface and groundwater resources in the coastal parts of Urmia aquifer (NW of Iran) was investigated to identify the possible sources and sinks of mercury and the geochemical mechanisms controlling its mobilization. The distribution of water samples on the Piper diagram demonstrates that most samples have the Ca-Mg-HCO3 facies. From 62 water samples collected in this area, one sample contained HgT concentrations exceeding the maximum contaminant level recommended by the WHO (6 μg/L). The principal component analysis (PCA) produced five principal components. The positive moderate correlation of HgT with EC, Cl, K, Mg, and Na indicated that the weathering of geological formations was one of the main sources of mercury in groundwater samples. Position of water samples in Eh-pH regions where microorganisms involved in mercury methylation and mineralization were potentially active demonstrated that the aquifer had undergone sulfate reduction and had reached the final stage of the terminal electron accepting process (TEAP) sequence in the methane production processes which are limited to only 37% of the water samples that have anaerobic conditions. Some Hg-bearing species are in nonequilibrium geochemical conditions. The supersaturation of water samples with magnetite and goethite indicated that these Fe-bearing minerals could act as the strong reducing agents for the reduction of Hg(II) to Hg(0).
Collapse
Affiliation(s)
- Vahab Amiri
- Department of Geology, Faculty of Science, Yazd University, Yazd, Iran.
| | - Peiyue Li
- School of Water and Environment, Chang'an University, No. 126 Yanta Road, Xi'an, 710054, China
- Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of the Ministry of Education, Chang'an University, No. 126 Yanta Road, Xi'an, 710054, China
| | - Prosun Bhattacharya
- KTH-International Groundwater Arsenic Research Group, Department of Sustainable Development, Environmental Science and Engineering, KTH Royal Institute of Technology, Teknikringen 10B, SE-10044, Stockholm, Sweden
- KWR Water Cycle Research Institute, Groningenhaven 7, 3433 PE, Nieuwegein, The Netherlands
| | - Mohammad Nakhaei
- Department of Applied Geology, Faculty of Earth Science, Kharazmi University, Tehran, Iran
| |
Collapse
|
6
|
Fuhrmann BC, Beutel MW, O'Day PA, Tran C, Funk A, Brower S, Pasek J, Seelos M. Effects of mercury, organic carbon, and microbial inhibition on methylmercury cycling at the profundal sediment-water interface of a sulfate-rich hypereutrophic reservoir. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 268:115853. [PMID: 33120160 DOI: 10.1016/j.envpol.2020.115853] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 10/09/2020] [Accepted: 10/12/2020] [Indexed: 06/11/2023]
Abstract
Methylmercury (MeHg) produced by anaerobic bacteria in lakes and reservoirs, poses a threat to ecosystem and human health due to its ability to bioaccumulate in aquatic food webs. This study used 48-hr microcosm incubations of profundal sediment and bottom water from a sulfate-rich, hypereutrophic reservoir to assess seasonal patterns of MeHg cycling under various treatments. Treatments included addition of air, Hg(II), organic carbon, and microbial inhibitors. Both aeration and sodium molybdate, a sulfate-reducing bacteria (SRB) inhibitor, generally decreased MeHg concentration in microcosm water, likely by inhibiting SRB activity. The methanogenic inhibitor bromoethanesulfonate increased MeHg concentration 2- to 4- fold, suggesting that methanogens were potent demethylators. Pyruvate increased MeHg concentration under moderately reduced conditions, likely by stimulating SRB, but decreased it under highly reduced conditions, likely by stimulating methanogens. Acetate increased MeHg concentration, likely due to the stimulation of acetotrophic SRB. Results suggest that iron-reducing bacteria (IRB) were not especially prominent methylators and MeHg production at the sediment-water interface is elevated under moderately reduced conditions corresponding with SRB activity. In contrast, it is suppressed under oxic conditions due to low SRB activity, and under highly reduced conditions (<-100 mV) due to enhanced demethylation by methanogens.
Collapse
Affiliation(s)
- Byran C Fuhrmann
- University of California, Environmental Systems Graduate Program, 5200 North Lake Road, Merced, CA, 95340, USA.
| | - Marc W Beutel
- University of California, Environmental Systems Graduate Program, 5200 North Lake Road, Merced, CA, 95340, USA
| | - Peggy A O'Day
- University of California, Environmental Systems Graduate Program, 5200 North Lake Road, Merced, CA, 95340, USA
| | - Christian Tran
- Environmental Analytical Laboratory, University of California, 5200 North Lake Rd, Merced, CA, 95340, USA
| | - Andrew Funk
- City of San Diego, Public Utilities Department, 9192 Topaz Way, San Diego, CA, 92123, USA
| | - Sarah Brower
- City of San Diego, Public Utilities Department, 9192 Topaz Way, San Diego, CA, 92123, USA
| | - Jeffery Pasek
- City of San Diego, Public Utilities Department, 9192 Topaz Way, San Diego, CA, 92123, USA
| | - Mark Seelos
- University of California, Environmental Systems Graduate Program, 5200 North Lake Road, Merced, CA, 95340, USA
| |
Collapse
|
7
|
Wang AO, Ptacek CJ, Mack EE, Blowes DW. Impact of multiple drying and rewetting events on biochar amendments for Hg stabilization in floodplain soil from South River, VA. CHEMOSPHERE 2021; 262:127794. [PMID: 32771706 DOI: 10.1016/j.chemosphere.2020.127794] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 05/07/2020] [Accepted: 07/21/2020] [Indexed: 06/11/2023]
Abstract
Frequent drying and rewetting due to flooding/precipitation and drainage events in floodplains induces changes in biogeochemical conditions that may influence the effectiveness of in situ Hg stabilization using biochars as soil amendments. This study evaluated two selected biochars anaerobic digestate (DIG) and sulfurized hardwood (MOAK)) as potential amendment materials in moderately reduced floodplain soil under repeated drying and rewetting events using a modified humidity cell protocol. Enhanced release of filter-passing (0.45-μm) total Hg (THg) and MeHg was observed at early times. Elevated concentrations of 0.45-μm THg were associated with DOC and Mn in sediment control and biochar-amended systems. Elevated concentrations of MeHg were associated with Mn in the MOAK-amended system. Thereafter, decreases in 0.45-μm (up to 57%) and unfiltered THg (up to 93%) were observed. As wetting and drying events continued, decreases in pH and alkalinity as well as increases in SO42- (up to 796 mg L-1) and Ca (up to 215 mg L-1) were observed in the MOAK-amended systems with the microbial community shifted towards sulfur-oxidizing bacteria, indicating microbially-driven oxidation of MOAK. Although results of S K-edge X-ray absorption near edge structure (XANES) analysis suggest polysulfur is the predominant S phase in both MOAK- and DIG-amended systems, microbially-driven oxidation of DIG was not observed. Polysulfur in MOAK from the sulfurization process is more bioavailable to sulfur oxidizing communities than in DIG under the repeated drying and wetting conditions. Results of this study suggest biogeochemical conditions as well as biochar properties should be considered when planning full-scale field applications.
Collapse
Affiliation(s)
- Alana O Wang
- Department of Earth and Environmental Sciences, University of Waterloo, 200 University Ave. W., Waterloo, ON, N2L 3G1, Canada
| | - Carol J Ptacek
- Department of Earth and Environmental Sciences, University of Waterloo, 200 University Ave. W., Waterloo, ON, N2L 3G1, Canada.
| | - E Erin Mack
- Formerly at E. I. Du Pont de Nemours and Company, 974 Centre Road, Wilmington, DE, 19805, USA
| | - David W Blowes
- Department of Earth and Environmental Sciences, University of Waterloo, 200 University Ave. W., Waterloo, ON, N2L 3G1, Canada
| |
Collapse
|
8
|
Seelos M, Beutel M, Austin CM, Wilkinson E, Leal C. Effects of hypolimnetic oxygenation on fish tissue mercury in reservoirs near the new Almaden Mining District, California, USA. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 268:115759. [PMID: 33120343 DOI: 10.1016/j.envpol.2020.115759] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 09/23/2020] [Accepted: 09/27/2020] [Indexed: 06/11/2023]
Abstract
Almaden, Calero, and Guadalupe reservoirs (San Jose, CA, USA) are small (<13 million m3) surface water reservoirs polluted by the former New Almaden Mining District, North America's most productive historical mercury (Hg) mine. Stevens Creek Reservoir (Cupertino, CA, USA) also has elevated fish Hg concentrations, but no historical mining source. We report a 15-year dataset to evaluate the effectiveness of line diffuser hypolimnetic oxygenation systems (HOSs) in reducing methylmercury (MeHg) concentrations in reservoir water and fish after four consecutive years of operation. HOSs were installed in each reservoir to increase dissolved oxygen concentrations in bottom water, thereby suppressing the activity of anaerobic bacteria (e.g., sulfate-reducing bacteria) known to produce MeHg. Before HOS operation, MeHg concentrations increased in bottom waters of all four reservoirs during periods of thermal stratification and profundal hypoxia. MeHg concentrations decreased significantly in bottom waters during HOS operation, with mean reductions of 63%-85% below pre-oxygenation concentrations. However, MeHg concentrations were unchanged or increased in surface waters. This could be the result of enhanced mixing between surface and bottom waters as a result of line diffuser oxygenation, or continued Hg methylation occurring in the oxic water column and littoral sediments. Despite little change in whole water column MeHg concentrations, we observed modest but significant declining trends in fish tissue Hg in Guadalupe and Stevens Creek reservoirs. Results suggest that oxygenation, rather than directly lowering MeHg in water, may have mixed nutrients into surface waters, thereby enhancing primary productivity and indirectly affecting Hg bioaccumulation by diluting concentrations in phytoplankton.
Collapse
Affiliation(s)
- Mark Seelos
- Valley Water, San Jose, CA, 95118, USA; Environmental Systems Graduate Program, University of California Merced, Merced, CA, 95343, USA.
| | - Marc Beutel
- Environmental Systems Graduate Program, University of California Merced, Merced, CA, 95343, USA
| | - Carrie M Austin
- San Francisco Bay Regional Water Quality Control Board, Oakland, CA, 94612, USA
| | | | | |
Collapse
|
9
|
Ji X, Liu C, Zhang M, Yin Y, Pan G. Mitigation of methylmercury production in eutrophic waters by interfacial oxygen nanobubbles. WATER RESEARCH 2020; 173:115563. [PMID: 32059129 DOI: 10.1016/j.watres.2020.115563] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 01/17/2020] [Accepted: 01/28/2020] [Indexed: 06/10/2023]
Abstract
In mercury (Hg)-polluted eutrophic waters, algal blooms are likely to aggravate methylmercury (MeHg) production by causing intensified hypoxia and enriching organic matter at the sediment-water interface. The technology of interfacial oxygen (O2) nanobubbles is proven to alleviate hypoxia and may have potential to mitigate the risks of MeHg formation. In this study, incubation column experiments were performed using sediment and overlying water samples collected from the Baihua Reservoir (China), which is currently suffering from co-contamination of Hg and eutrophication. The results indicated that after the application of O2 nanobubbles, the %MeHg (ratio of MeHg to total Hg) in the overlying water and surface sediment decreased by up to 76% and 56% respectively. In addition, the MeHg concentrations decreased from 0.54 ± 0.15 to 0.17 ± 0.01 ng L-1 in the overlying water and from 56.61 ± 9.23 to 25.48 ± 4.08 ng g-1 in the surface sediment. The decline could be attributed to the alleviation of anoxia and the decrease of labile organic matter and bioavailable Hg. In addition, hgcA gene abundances in the overlying water and surface sediment decreased by up to 69% and 44% after the addition of O2 nanobubbles, as is consistent with MeHg occurrence in such areas. Accordingly, this work proposed a promising strategy of using interfacial oxygen nanobubbles to alleviate the potentially enhanced MeHg production during algal bloom outbreaks in Hg-polluted eutrophic waters.
Collapse
Affiliation(s)
- Xiaonan Ji
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Chengbin Liu
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China; State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, PR China
| | - Meiyi Zhang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China.
| | - Yongguang Yin
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China
| | - Gang Pan
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China; Beijing Advanced Science and Innovation Center, Chinese Academy of Sciences, Beijing, 101407, PR China; Center of Integrated Water-Energy-Food Studies (iWEF), School of Animal, Rural, and Environmental Sciences, Nottingham Trent University, Brackenhurst Campus, NG25 0QF, UK.
| |
Collapse
|
10
|
Eckley CS, Gilmour CC, Janssen S, Luxton TP, Randall PM, Whalin L, Austin C. The assessment and remediation of mercury contaminated sites: A review of current approaches. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 707:136031. [PMID: 31869604 PMCID: PMC6980986 DOI: 10.1016/j.scitotenv.2019.136031] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 12/07/2019] [Accepted: 12/07/2019] [Indexed: 04/13/2023]
Abstract
Remediation of mercury (Hg) contaminated sites has long relied on traditional approaches, such as removal and containment/capping. Here we review contemporary practices in the assessment and remediation of industrial-scale Hg contaminated sites and discuss recent advances. Significant improvements have been made in site assessment, including the use of XRF to rapidly identify the spatial extent of contamination, Hg stable isotope fractionation to identify sources and transformation processes, and solid-phase characterization (XAFS) to evaluate Hg forms. The understanding of Hg bioavailability for methylation has been improved by methods such as sequential chemical extractions and porewater measurements, including the use of diffuse gradient in thin-film (DGT) samplers. These approaches have shown varying success in identifying bioavailable Hg fractions and further study and field applications are needed. The downstream accumulation of methylmercury (MeHg) in biota is a concern at many contaminated sites. Identifying the variables limiting/controlling MeHg production-such as bioavailable inorganic Hg, organic carbon, and/or terminal electron acceptors (e.g. sulfate, iron) is critical. Mercury can be released from contaminated sites to the air and water, both of which are influenced by meteorological and hydrological conditions. Mercury mobilized from contaminated sites is predominantly bound to particles, highly correlated with total sediment solids (TSS), and elevated during stormflow. Remediation techniques to address Hg contamination can include the removal or containment of Hg contaminated materials, the application of amendments to reduce mobility and bioavailability, landscape/waterbody manipulations to reduce MeHg production, and food web manipulations through stocking or extirpation to reduce MeHg accumulated in desired species. These approaches often rely on knowledge of the Hg forms/speciation at the site, and utilize physical, chemical, thermal and biological methods to achieve remediation goals. Overall, the complexity of Hg cycling allows many different opportunities to reduce/mitigate impacts, which creates flexibility in determining suitable and logistically feasible remedies.
Collapse
Affiliation(s)
- Chris S Eckley
- U.S. Environmental Protection Agency, Region-10, 1200 6th Ave, Seattle, WA 98101, USA.
| | - Cynthia C Gilmour
- Smithsonian Environmental Research Center, 647 Contees Wharf Rd., Edgewater, MD 21037-0028, USA.
| | - Sarah Janssen
- USGS Upper Midwest Water Science Center, 8505 Research Way, Middleton, WI 53562, USA.
| | - Todd P Luxton
- US Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory, 26 West Martin Luther King Drive, Cincinnati, OH 45268, USA.
| | - Paul M Randall
- US Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, USA.
| | - Lindsay Whalin
- San Francisco Bay Water Board, 1515 Clay St., Ste. 1400, Oakland, CA 94612, USA.
| | - Carrie Austin
- San Francisco Bay Water Board, 1515 Clay St., Ste. 1400, Oakland, CA 94612, USA.
| |
Collapse
|
11
|
Ji X, Liu C, Pan G. Interfacial oxygen nanobubbles reduce methylmercury production ability of sediments in eutrophic waters. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 188:109888. [PMID: 31706242 DOI: 10.1016/j.ecoenv.2019.109888] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 10/23/2019] [Accepted: 10/27/2019] [Indexed: 06/10/2023]
Abstract
Eutrophication can induce hypoxia/anoxia and rich organic matter at the sediment-water interface in surface waters. When eutrophic waters are impacted with mercury (Hg) pollution, methylmercury (MeHg) production ability (MPA) of surface sediment would increase and more MeHg might be produced. To tackle this risk, this study firstly collected samples of surface sediment and overlying water from a typical eutrophic lake-Taihu Lake. Then from a sediment-water simulation system, we demonstrated that eutrophic waters were able to methylate Hg spontaneously, and that sediment is the major Hg sink in the system. After the addition of HgCl2 solution (approximately 1 mg L-1 in the slurry), MeHg concentrations in the sediment increased by 11.7 times after 48 h. The subsequent column experiments proved that O2 nanobubbles could significantly decrease the MPA of surface sediment, by up to 48%. Furthermore, we found that O2 nanobubbles could remediate anoxia mainly by increasing dissolved oxygen (from 0 to 2.1 mg L-1), oxidation-reduction potentials (by 37% on average), and sulfate (by 31% on average) in the overlying water. In addition, O2 nanobubbles could also help decrease organic matter concentration, as was revealed by the decline of dissolved organic carbon in the overlying water (by up to 57%) and total organic carbon in surface sediment (by up to 37%). The remediation of anoxia and reduction of organic matter could contribute to the decrease of hgcA gene abundance (by up to 86%), and thus result in the reduction of MPA after the addition of O2 nanobubbles. This study revealed the risk of MeHg production in case Hg pollution occurs in eutrophic waters and proposed a feasible solution for MeHg remediation.
Collapse
Affiliation(s)
- Xiaonan Ji
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Chengbin Liu
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China; State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, PR China
| | - Gang Pan
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China; Beijing Advanced Science and Innovation Center, Chinese Academy of Sciences, Beijing, 101407, PR China; Center of Integrated Water-Energy-Food Studies (iWEF), School of Animal, Rural, and Environmental Sciences, Nottingham Trent University, Brackenhurst Campus, NG25 0QF, UK.
| |
Collapse
|
12
|
Li W, Zhang S, Zhang L, Li X, Wang F, Li G, Li J, Li W. In-situ remediation of sediment by calcium nitrate combined with composite microorganisms under low-DO regulation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 697:134109. [PMID: 31476511 DOI: 10.1016/j.scitotenv.2019.134109] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Revised: 08/19/2019] [Accepted: 08/24/2019] [Indexed: 06/10/2023]
Abstract
In this work, in-situ remediation of sediment was carried out by combining various methods. The results showed that the treatment effect of Calcium nitrate + composite functional microorganisms + Low-DO (dissolved oxygen) aeration (CN/CFM/LDA) was the best, in which 2.5 g calcium nitrate, 1 g functional bacteria and intermittent aeration (0.1 m3/h, 3 h per day) were utilized for the remediation of 500 g sediments within 40-day experimental period. The DO and oxidation reduction potential (ORP) in overlying water have been improved from 3.23 mg/L to 4.4 mg/L and 25.8 mV to 112.4 mV, respectively. The release fluxes of ammonia nitrogen (NH4+-N), nitrite nitrogen (NO2--N) and nitrate nitrogen (NO3--N) were respectively reduced by 30.51%, 13.11% and 77.45% compared with the control and the removal rate of the acid volatile sulfide (AVS) in sediments was 94.14% compared with the original sample. The results of high-throughput sequencing show that the dominant bacterial community in CN/CFM/LDA was transformed into Proteobacteria (relative abundance of 74.17%) at the phylum level and Thiobacillus (relative abundance of 38.52%) at the genus level. The results of 16S functional prediction indicated that the remediation method can enhance the numbers of microbial key enzymes (92360) in the nitrification and denitrification process, where Low-DO aeration can mediate the growth of denitrifying bacteria and promote the performance of key enzymes. In conclusion, the experimental results show that the use of calcium nitrate and composite functional microorganisms under low-DO regulation has a promising remediation effect on sediments of black-malodorous water.
Collapse
Affiliation(s)
- Weiping Li
- School of Energy and Environment, Inner Mongolia University of Science & Technology, Baotou 014010, China
| | - Shaokang Zhang
- School of Energy and Environment, Inner Mongolia University of Science & Technology, Baotou 014010, China; State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Lieyu Zhang
- Basin Research Center for Water Pollution Control, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
| | - Xiaoguang Li
- State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Fan Wang
- Basin Research Center for Water Pollution Control, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Guowen Li
- State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Jiaxi Li
- State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Wei Li
- State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| |
Collapse
|
13
|
Furey PC, Liess A, Lee S. Substratum-associated microbiota. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2019; 91:1326-1341. [PMID: 31523907 DOI: 10.1002/wer.1226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 08/09/2019] [Accepted: 08/19/2019] [Indexed: 06/10/2023]
Abstract
This survey of 2018 literature on substratum-associated microbiota presents brief highlights on research findings from primarily freshwaters, but includes those from a variety of aquatic ecosystems. Coverage of topics associated with benthic algae and cyanobacteria, though not comprehensive, includes new methods, taxa new to science, nutrient dynamics, trophic interactions, herbicides and other pollutants, metal contaminants, nuisance, bloom-forming and harmful algae, bioassessment, and bioremediation. Coverage of bacteria, also not comprehensive, focused on methylation of mercury, metal contamination, toxins, and other environmental pollutants, including oil, as well as the use of benthic bacteria as bioindicators, in bioassessment tools and in biomonitoring. Additionally, we cover trends in recent and emerging topics on substratum-associated microbiota of relevance to the Water Environment Federation. PRACTITIONER POINTS: This review of literature from 2018 on substratum-associated microbiota presents highlights of findings on algae, cyanobacteria, and bacteria from primarily freshwaters. Topics covered that focus on algae and cyanobacteria include findings on new methods, taxa new to science, nutrient dynamics, trophic interactions, herbicides and other pollutants, metal contaminants, nuisance, bloomforming and harmful algae, bioassessment, and bioremediation. Topics covered that focus on bacteria include findings on methylation of mercury, metal contamination, toxins and other environmental pollutants, including oil, as well as the us e of benthic bacteria as bioindicators, in bioassessment tools and in biomonitoring. A brief presentation of new, noteworthy and emerging topics on substratum-associated microbiota, build on those from 2017, to highlight those of particular relevance to the Water Environment Federation.
Collapse
Affiliation(s)
- Paula C Furey
- Department Biology, St. Catherine University, St. Paul, Minnesota, USA
| | - Antonia Liess
- Rydberg Laboratory, School of Buisness, Engineering and Science, Halmstad University, Halmstad, Sweden
| | - Sylvia Lee
- Office of Research and Development, U.S. Environmental Protection Agency, Washington, District of Columbia, USA
| |
Collapse
|
14
|
Du S, Wang X, Zhang T, Ding C. Kinetic characteristics and predictive models of methylmercury production in paddy soils. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 253:424-428. [PMID: 31325887 DOI: 10.1016/j.envpol.2019.07.050] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 06/25/2019] [Accepted: 07/10/2019] [Indexed: 06/10/2023]
Abstract
Understanding the mercury (Hg) methylation process is important for the management of paddy soils contaminated by Hg. In this work, samples of eighteen paddy soils with varying soil properties were spiked with inorganic Hg and subjected to a 90 d flooding period. Soil pH and redox potential (Eh) were measured in situ at intervals, and soils were sampled for the analysis of methylmercury (MeHg). The Hg methylation efficiency increased with flooding time and reached a relatively steady state at 30 d of incubation, ranging from 0.08% to 2.52%, and was significantly correlated with the in situ soil pH and Eh. The Elovich equation could adequately describe the kinetic production of MeHg. MeHg production was well predicted by the in situ soil pH and Eh of flooded soils, in addition to the organic matter content of air-dried soil samples and flooding time. The two predictive models explained 78% and 68% of the variability of the Hg methylation efficiency. The results suggested that the methylation of inorganic Hg in paddy soils after flooding can be predicted as a function of routinely measured soil properties and flooding time, a correlation that can be utilized to improve understanding of the extent of Hg methylation and the management of Hg-contaminated paddy soils.
Collapse
Affiliation(s)
- Shuyang Du
- CAS Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xingxiang Wang
- CAS Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; Ecological Experimental Station of Red Soil, Chinese Academy of Sciences, Yingtan 335211, China
| | - Taolin Zhang
- CAS Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Changfeng Ding
- CAS Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
| |
Collapse
|