1
|
He Z, Shen J, Zhao Y, Ru Y, Zhang D, Pan X. Microbial antagonistic mechanisms of Hg(II) and Se(IV) in efficient wastewater treatment using granular sludge. Water Res 2024; 253:121311. [PMID: 38367382 DOI: 10.1016/j.watres.2024.121311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 01/02/2024] [Accepted: 02/12/2024] [Indexed: 02/19/2024]
Abstract
The antagonistic effects of mercury (Hg) and selenium (Se) have been extensively studied in higher animals and plants. In this study, the microbial antagonistic effects of Hg and Se were utilized for wastewater treatment. We developed and optimized a new granular sludge approach to efficiently remove Hg(II) and Se(IV) from wastewater. Under anaerobic-oxic-anaerobic (AOA) conditions, the removal rates of Hg(II) and Se(IV) reached up to 99.91±0.07 % and 97.7 ± 0.8 %, respectively. The wastewater Hg(II) was mostly (97.43±0.01 %) converted to an inert mineral called tiemannite (HgSe) in the sludge, and no methylmercury (MeHg) was detected. The HgSe in sludge is less toxic, with almost no risk of secondary release, and it can be recovered with high purity. An inhibition experiment of mercury reduction and the high expression of the mer operon indicated that most Hg(II) (∼71 %) was first reduced to Hg0, and then Hg0 reacted with Se0 to synthesize HgSe. Metagenomic results showed that the final sludge (day 182) was dominated by two unclassified bacteria in the orders Rhodospirillales (27.7 %) and Xanthomonadales (6.3 %). Their metagenome-assembled genomes (MAGs) were recovered, suggesting that both of them can reduce Hg(II) and Se(IV). Metatranscriptomic analyses indicate that they can independently and cooperatively synthesize HgSe. In summary, granular sludge under AOA conditions is an efficient method for removing and recovering Hg from wastewater. The microbial transformation of Hg2+to Hg0 to HgSe may occur widely in both engineering and natural ecosystems.
Collapse
Affiliation(s)
- Zhanfei He
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, China
| | - Jiaquan Shen
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, China
| | - Yuanhai Zhao
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, China
| | - Yulong Ru
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, China
| | - Daoyong Zhang
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, China
| | - Xiangliang Pan
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, China.
| |
Collapse
|
2
|
Wu Q, Wang B, Hu H, Bravo AG, Bishop K, Bertilsson S, Meng B, Zhang H, Feng X. Sulfate-reduction and methanogenesis are coupled to Hg(II) and MeHg reduction in rice paddies. J Hazard Mater 2023; 460:132486. [PMID: 37690197 DOI: 10.1016/j.jhazmat.2023.132486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 08/17/2023] [Accepted: 09/03/2023] [Indexed: 09/12/2023]
Abstract
Methylmercury (MeHg) produced in rice paddies is the main source of MeHg accumulation in rice, resulting in high risk of MeHg exposure to humans and wildlife. Net MeHg production is affected by Hg(II) reduction and MeHg demethylation, but it remains unclear to what extent these processes influence net MeHg production, as well as the role of the microbial guilds involved. We used isotopically labeled Hg species and specific microbial inhibitors in microcosm experiments to simultaneously investigate the rates of Hg(II) and MeHg transformations, as well as the key microbial guilds controlling these processes. Results showed that Hg(II) and MeHg reduction rate constants significantly decreased with addition of molybdate or BES, which inhibit sulfate-reduction and methanogenesis, respectively. This suggests that both sulfate-reduction and methanogenesis are important processes controlling Hg(II) and MeHg reduction in rice paddies. Meanwhile, up to 99% of MeHg demethylation was oxidative demethylation (OD) under the incubation conditions, suggesting that OD was the main MeHg degradative pathway in rice paddies. In addition, [202Hg(0)/Me202Hg] from the added 202Hg(NO3)2 was up to 13.9%, suggesting that Hg(II) reduction may constrain Hg(II) methylation in rice paddies at the abandoned Hg mining site. This study improves our understanding of Hg cycling pathways in rice paddies, and more specifically how reduction processes affect net MeHg production and related microbial metabolisms.
Collapse
Affiliation(s)
- Qingqing Wu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Baolin Wang
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Haiyan Hu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China.
| | - Andrea G Bravo
- Department of Marine Biology and Oceanography, Institut de Ciencies del Mar (ICM-CSIC), Barcelona E08003, Catalunya, Spain
| | - Kevin Bishop
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala SE-75007, Sweden
| | - Stefan Bertilsson
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala SE-75007, Sweden
| | - Bo Meng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Hua Zhang
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China.
| | - Xinbin Feng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China; University of Chinese Academy of Sciences, Beijing 100049, China
| |
Collapse
|
3
|
Jinadasa BKKK, Jayasinghe GDTM, Pohl P, Fowler SW. Mitigating the impact of mercury contaminants in fish and other seafood-A review. Mar Pollut Bull 2021; 171:112710. [PMID: 34252733 DOI: 10.1016/j.marpolbul.2021.112710] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 06/23/2021] [Accepted: 07/05/2021] [Indexed: 06/13/2023]
Abstract
Mercury (Hg) is a well-known toxicant which enters the marine environment by both natural and anthropogenic sources. Consumption of fish and other seafood that contain methylmercury (MeHg) is a leading source of Hg exposure in humans. Considerable efforts have been made to mitigate the Hg presence and reduce its risks to humans. In this review the acknowledged methods of mitigation are summarized such as regulation and maximum allowable limits, and culinary treatments. In addition, selected industrial level trials are reviewed, and studies on Hg intoxication and the protective effects of the essential trace element, selenium (Se), are discussed. In view of the available literature, Hg reduction in fish and other seafood on a large industrial scale still is largely unsuccessful. Hence, more research and further attempts are necessary in order to better mitigate the Hg problem in fish and other seafood products.
Collapse
Affiliation(s)
- B K K K Jinadasa
- Analytical Chemistry Laboratory (ACL), National Aquatic Resources Research & Development Agency (NARA), Colombo-15, Sri Lanka; Department of Food Science & Technology, Faculty of Livestock, Fisheries & Nutrition, Wayamba University of Sri Lanka, Makandura, Gonawila (NWP), Sri Lanka.
| | - G D T M Jayasinghe
- Analytical Chemistry Laboratory (ACL), National Aquatic Resources Research & Development Agency (NARA), Colombo-15, Sri Lanka
| | - Pawel Pohl
- Department of Analytical Chemistry and Chemical Metallurgy, Faculty of Chemistry, Wroclaw University of Science and Technology, Wybrzeze St. Wyspianskiego 27, 50-370 Wrocław, Poland
| | - Scott W Fowler
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794-5000, USA
| |
Collapse
|
4
|
Lu Z, Yuan W, Luo K, Wang X. Litterfall mercury reduction on a subtropical evergreen broadleaf forest floor revealed by multi-element isotopes. Environ Pollut 2021; 268:115867. [PMID: 33160734 DOI: 10.1016/j.envpol.2020.115867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 10/12/2020] [Accepted: 10/13/2020] [Indexed: 06/11/2023]
Abstract
Litterfall mercury (Hg) deposition is the dominant source of soil Hg in forests. Identifying reduction processes and tracking the fate of legacy Hg on forest floor are challenging tasks. Interplays between isotopes of carbon (C) and nitrogen (N) may shed some lights on Hg biogeochemical processes because their biogeochemical cycling closely links with organic matters. Isotope measurements at the evergreen broadleaf forest floor at Mt. Ailao (Mountain Ailao) display that δ202Hg and Δ199Hg both significantly correlate with δ13C and δ15N in soil profiles. Data analysis results show that microbial reduction is the dominant process for the distinct δ202Hg shift (up to ∼1.0‰) between Oi and 0-10 cm surface mineral soil, and dark abiotic organic matter reduction is the main cause for the Δ199Hg shift (∼-0.18‰). Higher N in foliage leads to greater Hg concentration, and Hg0 re-emission via microbial reduction on forest floor is likely linked to N release and immobilization on forest floor. We thus suggest that the enhanced N deposition in global forest ecosystems can potentially influence Hg uptake by vegetation and litter Hg sequestration on forest floor.
Collapse
Affiliation(s)
- Zhiyun Lu
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Xishuangbanna, Yunnan, 666303, China; Ailaoshan Station for Subtropical Forest Ecosystem Studies, Chinese Academy of Sciences, Jingdong, Yunnan, 676200, China
| | - Wei Yuan
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China
| | - Kang Luo
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Xishuangbanna, Yunnan, 666303, China; Ailaoshan Station for Subtropical Forest Ecosystem Studies, Chinese Academy of Sciences, Jingdong, Yunnan, 676200, China
| | - Xun Wang
- College of Resources and Environment, Southwest University, Chongqing, 400715, China.
| |
Collapse
|
5
|
Grigoropoulos CJ, Doulos LT, Zerefos SC, Tsangrassoulis A, Bhusal P. Estimating the benefits of increasing the recycling rate of lamps from the domestic sector: Methodology, opportunities and case study. Waste Manag 2020; 101:188-199. [PMID: 31622864 DOI: 10.1016/j.wasman.2019.10.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 09/17/2019] [Accepted: 10/03/2019] [Indexed: 06/10/2023]
Abstract
The scope of this paper is to identify the benefits of lamp recycling from the domestic sector. Data related to the recycled lamps was obtained from two recycling companies and were compared to those related to the waste lamps from the domestic sector. This was achieved by a new methodology which uses two alternative approaches. The first one is dependent on previous research data in relation to the number of active lamps while the second one elaborates on electricity consumption and sales data, in order to define the corresponding number of active lamps., The wasted amount of glass, metal and plastic is calculated along with the energy savings, the annual emissions of CO2-eq, the economic benefit from their sale and the potential reduction of hazardous waste, such as mercury to solid waste landfills under various scenarios. The amount of recovered materials collected by the Hellenic recycling companies contributes to a reduction of CO2-eq by 1298 tonnes, which falls significantly short of the CO2-eq that could have been saved 3108-5463tonnes if all the lamps were recycled. Furthermore, the recycling companies have an annual economic benefit of €32,251 which could be increased by €122,725 if all lamps were recycled together with the proper recycling of 3.4 kg of mercury, which was disposed in the environment. Finally, a future scenario was examined, in which all lamps in the domestic sector were assumed to be LEDs, an issue that can affect the viability of the recycling factories and it was proved that these might be affected.
Collapse
Affiliation(s)
- C J Grigoropoulos
- School of Applied Arts, Hellenic Open University, Patra, Greece; Department of Pharmacy, University of Patras, Greece
| | - L T Doulos
- School of Applied Arts, Hellenic Open University, Patra, Greece; Lighting Laboratory, National Technical University of Athens, Athens, Greece.
| | - S C Zerefos
- School of Applied Arts, Hellenic Open University, Patra, Greece
| | - A Tsangrassoulis
- Department of Architecture, University of Thessaly, Pedion Areos, 38334 Volos, Greece
| | - P Bhusal
- Department of Electrical Engineering and Automation, Aalto University, Finland
| |
Collapse
|
6
|
Padalkar PP, Chakraborty P, Chennuri K, Jayachandran S, Sitlhou L, Nanajkar M, Tilvi S, Singh K. Molecular characteristics of sedimentary organic matter in controlling mercury (Hg) and elemental mercury (Hg 0) distribution in tropical estuarine sediments. Sci Total Environ 2019; 668:592-601. [PMID: 30856569 DOI: 10.1016/j.scitotenv.2019.02.353] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 02/20/2019] [Accepted: 02/22/2019] [Indexed: 06/09/2023]
Abstract
Sedimentary organic matter (SOM) plays an important role in hosting and reducing HgII in marine/estuarine sediment. This study provides a better understanding on the influence of nature of SOM, in regulating sedimentary mercury (Hg) and elemental mercury (Hg0) distribution, and speciation in the Zuari and Mandovi Estuaries that are representative of monsoon fed tropical estuaries, located in the central west coast of India. Salinity of the overlying water column controlled the physical and chemical characteristics of SOM in the estuarine systems. The high molecular weight (MW) SOM dominated at the mid and upstream (low salinity region) of the estuaries, whereas, the low MW SOM prevailed at the downstream (high salinity region). Sediment Hg showed more affinity towards the SOM of high MW. Increasing MW of SOM increased total sedimentary HgT in both the estuaries. SOM with low MW in the estuarine sediment displayed a negative relationship with the sediment Hg concentration. Distribution of Hg0 concentration in the estuarine sediment suggests that reduction of HgII in presence low MW SOM was a dominant process. It was also found that distribution and speciation of Hg0 in the estuarine sediment depends on the quantity, quality of the SOM, and the total sediment Hg loading. This study demonstrated that the competition between Hg-SOM complexation and HgII reduction by SOM controls HgII/Hg0 distribution in tropical estuarine sediment systems.
Collapse
Affiliation(s)
- Prasad P Padalkar
- Geological Oceanography Division, CSIR-National Institute of Oceanography, Dona Paula, Goa 403004, India
| | - Parthasarathi Chakraborty
- Geological Oceanography Division, CSIR-National Institute of Oceanography, Dona Paula, Goa 403004, India; Centre for Oceans, Rivers, Atmosphere and Land Sciences, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India.
| | - Kartheek Chennuri
- Geological Oceanography Division, CSIR-National Institute of Oceanography, Dona Paula, Goa 403004, India
| | - Saranya Jayachandran
- Geological Oceanography Division, CSIR-National Institute of Oceanography, Dona Paula, Goa 403004, India
| | - Lamjahao Sitlhou
- Geological Oceanography Division, CSIR-National Institute of Oceanography, Dona Paula, Goa 403004, India
| | - Mandar Nanajkar
- Business Development Group, CSIR-National Institute of Oceanography, Dona Paula, Goa 403004, India
| | - Supriya Tilvi
- Chemical Oceanography Division, CSIR-National Institute of Oceanography, Dona Paula, Goa 403004, India
| | - Keisham Singh
- Chemical Oceanography Division, CSIR-National Institute of Oceanography, Dona Paula, Goa 403004, India
| |
Collapse
|
7
|
Pannu R, Siciliano SD, O'Driscoll NJ. Quantifying the effects of soil temperature, moisture and sterilization on elemental mercury formation in boreal soils. Environ Pollut 2014; 193:138-146. [PMID: 25016467 DOI: 10.1016/j.envpol.2014.06.023] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 06/19/2014] [Accepted: 06/24/2014] [Indexed: 06/03/2023]
Abstract
Soils are a source of elemental mercury (Hg(0)) to the atmosphere, however the effects of soil temperature and moisture on Hg(0) formation is not well defined. This research quantifies the effect of varying soil temperature (278-303 K), moisture (15-80% water filled pore space (WFPS)) and sterilization on the kinetics of Hg(0) formation in forested soils of Nova Scotia, Canada. Both, the logarithm of cumulative mass of Hg(0) formed in soils and the reduction rate constants (k values) increased with temperature and moisture respectively. Sterilizing soils significantly (p < 0.05, n = 10) decreased the percent of total Hg reduced to Hg(0). We describe the fundamentals of Hg(0) formation in soils and our results highlight two key processes: (i) a fast abiotic process that peaks at 45% WFPS and depletes a small pool of Hg(0) and; (ii) a slower, rate limiting biotic process that generates a large pool of reducible Hg(II).
Collapse
Affiliation(s)
- Ravinder Pannu
- Department of Soil Science, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK S7N 5A8, Canada; Department of Earth and Environmental Science, Acadia University, K. C. Irving Environmental Science Center, Wolfville, NS B4P 2R6, Canada
| | - Steven D Siciliano
- Department of Soil Science, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK S7N 5A8, Canada
| | - Nelson J O'Driscoll
- Department of Earth and Environmental Science, Acadia University, K. C. Irving Environmental Science Center, Wolfville, NS B4P 2R6, Canada.
| |
Collapse
|