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Cantu MA, Durham JA, McClymont EL, Vogel AH, Gobas FAPC. Low Dietary Uptake Efficiencies and Biotransformation Prevent Biomagnification of Octamethylcyclotetrasiloxane (D4) and Decamethylcyclopentasiloxane (D5) in Rainbow Trout. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:10252-10261. [PMID: 38811014 PMCID: PMC11171459 DOI: 10.1021/acs.est.4c00457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 04/26/2024] [Accepted: 04/29/2024] [Indexed: 05/31/2024]
Abstract
With octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5) being considered for evaluation under the UN Stockholm Convention on Persistent Organic Pollutants, which specifically acknowledges risks of biomagnification of persistent organic pollutants in traditional foods, a study into the mechanism of the biomagnification process of D4 and D5 in Rainbow trout was conducted by combining the absorption-distribution-metabolism-excretion for bioaccumulation (ADME-B) approach to determine intestinal and somatic biotransformation rates and radiochemical analyses to identify metabolite formation. High rates of intestinal biotransformation of D4 and D5 (i.e., 2.1 (0.70 SE) and 0.88 (0.67 SE) day-1, respectively) and metabolite formation [i.e., 52.0 (17 SD)% of D4 and 56.5% (8.2 SD)% of D5 were metabolized] were observed that caused low dietary uptake efficiencies of D4 and D5 in fish of 15.5 (2.9 SE)% and 21.0 (6.5 SE)% and biomagnification factors of 0.44 (0.08 SE) for D4 and 0.78 (0.24 SE) kg-lipid·kg-lipid-1 for D5. Bioaccumulation profiles indicated little effect of growth dilution on the bioaccumulation of D4 and D5 in fish and were substantially different from those of PCB153. The study highlights the importance of intestinal biotransformation in negating biomagnification of substances in organisms and explains differences between laboratory tests and field observations of bioaccumulation of D4 and D5.
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Affiliation(s)
- Mark A. Cantu
- School
of Resource and Environmental Management, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Jeremy A. Durham
- Toxicology
and Environmental Research and Consulting, The Dow Chemical Company, Midland, Michigan 48674, United States
| | - E. Lynn McClymont
- Toxicology
and Environmental Research and Consulting, The Dow Chemical Company, Midland, Michigan 48674, United States
| | - Annette H. Vogel
- Toxicology
and Environmental Research and Consulting, The Dow Chemical Company, Midland, Michigan 48674, United States
| | - Frank A. P. C. Gobas
- School
of Resource and Environmental Management, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
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2
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Xing Y, Ge Y, Lu S, Yang T, Peng X. Dimethylcyclosiloxanes in Mobile Smart Terminal Devices: Concentrations, Distributions, Profiles, and Environmental Emissions. TOXICS 2024; 12:287. [PMID: 38668510 PMCID: PMC11053745 DOI: 10.3390/toxics12040287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 04/10/2024] [Accepted: 04/11/2024] [Indexed: 04/29/2024]
Abstract
Dimethylcyclosiloxanes (DMCs) are utilized as vital monomers in the synthesis of organosilicon compounds, integral to the manufacture of mobile smart terminal devices. Toxicological studies have revealed potential endocrine-disrupting activity, reproductive toxicity, neurotoxicity, and other toxicities of the DMCs. This study investigated the concentrations and composition profiles of seven DMCs, including hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6), and tetradecamethylcycloheptasiloxane (D7), hexadecamethylcyclooctasiloxane (D8), and octadecamethylcyclononasiloxane (D9) in three types of mobile smart terminal device components (silicone rubber, adhesive, and plastics). Environmental emissions of DMCs from silicone rubber materials were also estimated to improve the recognition of their potential fate within the environment. D5-D9 were widely present in silicone rubber and adhesives with detection rates ranging from 91-95.5% and 50-100%, respectively, while D3 and D4 were more frequently detected in plastics, both showing a detection rate of 61.1%. Silicone rubber had the highest total DMCs (∑7DMCs) and a concentration of 802.2 mg/kg, which were dominated by D7, D8, and D9. DMCs detected in adhesives were dominated by D4, D5, and D6. The estimated emission of ∑DMCs released into the environment in China from silicone rubber used in mobile smart terminal devices exceeds 5000 tons per year. Further studies are needed on the presence of DMCs in various commodities and environmental media to assess their ecological and human health impacts, as well as the toxicological effects of D7-D9 for the appropriate regulation of these chemicals.
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Affiliation(s)
- Yuanna Xing
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; (Y.X.); (T.Y.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yiming Ge
- School of Public Health (Shenzhen), Shenzhen Campus of SunYat-sen University, Shenzhen 518107, China; (Y.G.); (S.L.)
| | - Shaoyou Lu
- School of Public Health (Shenzhen), Shenzhen Campus of SunYat-sen University, Shenzhen 518107, China; (Y.G.); (S.L.)
| | - Tao Yang
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; (Y.X.); (T.Y.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xianzhi Peng
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; (Y.X.); (T.Y.)
- University of Chinese Academy of Sciences, Beijing 100049, China
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3
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Chen W, Lee S, Moon HB. Cyclic and linear siloxane contamination in sediment and invertebrates around a thermal power plant in Korea: Source impact, distribution, seasonal variation, and potential for bioaccumulation. CHEMOSPHERE 2024; 349:140779. [PMID: 38008296 DOI: 10.1016/j.chemosphere.2023.140779] [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: 09/06/2023] [Revised: 11/19/2023] [Accepted: 11/20/2023] [Indexed: 11/28/2023]
Abstract
Siloxanes have been commonly used as additives in a variety of industrial and consumer products. Media and government investigations have revealed that defoamers containing siloxanes are used in the effluent of thermal power plants in Korea. However, investigations of the source impact of siloxane contamination from the discharge of thermal power plants into coastal environments are scarce. In this study, sediment and invertebrates were collected around a thermal power plant to assess source impact, seasonal variation, and a potential for bioaccumulation. Although siloxanes were detectable in sediment and invertebrates, the spatial distribution and composition (which differed between the siloxanes found in sediment and invertebrates and those in defoamer used in the plant) suggest they were likely transported by long-distance migration as well as the discharge of thermal power plant. Seasonal differences might affect sedimentary contamination and the bioaccumulation potential of siloxanes. Specifically, octamethylcyclotetrasiloxane (D4) may have limited adsorption capacity and potential for long-distance migration, as its contribution in sediment far from the coastline was greater than that of decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6). However, higher D5 accumulation in invertebrates, and D5 has a potential bioaccumulation. A molecular docking analysis showed that the binding affinity between D5 and the cytochrome enzyme in invertebrates was weaker than that with other siloxanes, which could lead to higher D5 accumulation in invertebrates.
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Affiliation(s)
- Wenming Chen
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou, Hainan, 571158, China.
| | - Sunggyu Lee
- Department of Marine Science and Convergence Engineering, College of Science and Convergence Technology, Hanyang University, Ansan, 15588, Republic of Korea
| | - Hyo-Bang Moon
- Department of Marine Science and Convergence Engineering, College of Science and Convergence Technology, Hanyang University, Ansan, 15588, Republic of Korea.
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Kang Y, Lee S, Chen W, Moon HB. Factors determining contamination and time trends in cyclic and linear siloxanes in sediments from an industrialized lake in Korea. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 269:115817. [PMID: 38103470 DOI: 10.1016/j.ecoenv.2023.115817] [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: 07/10/2023] [Revised: 12/08/2023] [Accepted: 12/09/2023] [Indexed: 12/19/2023]
Abstract
Siloxanes, widely used in various consumer and industrial products, are emerging concerns of contaminants. Despite this, limited studies have been conducted on contamination and time trends on siloxanes in coastal environments. In the present study, four cyclic and 15 linear siloxanes were measured in sediments collected from an artificial saltwater lake in Korea during 2001-2016 to investigate contamination, time trends, and ecotoxicological concerns. Cyclic siloxanes were detected in all sediment samples, whereas linear siloxanes were not frequently detected. The highest siloxane concentrations were observed in creeks passing through various industrial complexes, indicating that industrial activities predominantly contributed to siloxane contamination in coastal environments. Decamethylcyclopentasiloxane (D5) and dodecylcyclohexasiloxane (D6) were predominant siloxanes in sediments over the last two decades. Siloxane concentrations significantly increased in creek sediments from 2008 to 2016, whereas those in inshore and offshore regions significantly decreased due to a strong dilution effect by the operation of tidal power plant. This suggests that consumption patterns and coastal development activities are crucial factors determining the contamination and time trends in the sedimentary siloxanes. The sedimentary concentrations of octamethylcyclotetrasiloxane (D4) and D5 exceeded several thresholds, raising the potentials for ecological risks to aquatic organisms.
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Affiliation(s)
- Yujin Kang
- Department of Marine Science and Convergence Engineering, College of Science and Convergence Technology, Hanyang University, Ansan 15588, Republic of Korea
| | - Sunggyu Lee
- Department of Marine Science and Convergence Engineering, College of Science and Convergence Technology, Hanyang University, Ansan 15588, Republic of Korea
| | - Wenming Chen
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou, Hainan 571158, China
| | - Hyo-Bang Moon
- Department of Marine Science and Convergence Engineering, College of Science and Convergence Technology, Hanyang University, Ansan 15588, Republic of Korea.
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5
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Liu N, Zhang J, He X, Xu L, Cai Y. Occurrence and fate of chlorinated methylsiloxanes in surrounding aqueous systems of Shengli oilfield, China. J Environ Sci (China) 2023; 125:332-339. [PMID: 36375918 DOI: 10.1016/j.jes.2021.11.033] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 11/22/2021] [Accepted: 11/22/2021] [Indexed: 06/16/2023]
Abstract
Mono-chlorinated products of cyclic volatile methylsiloxanes (cVMS), i.e., Monochlormet-hylheptamethylcyclotetrasiloxane [D3D(CH2Cl)], monochlormethylnonamethylcyclopenta-siloxane [D4D(CH2Cl)], and monochlormethylundemethylcyclohexasiloxane [D5D(CH2Cl)], were detected in water [<LOQ (Limit of quantitation) -86.3 ng/L, df (detection frequency) = 23%-38%, n=112] and sediment samples [<LOQ-504 ng/g dw (dry weight), df = 33%-38%, n=112] from 16 lakes located in Shengli oilfield of China, and had apparent increasing trends (31%-34% per annum) in sediments during Year 2014-2020. Simulated experiments showed that chloro-cVMS in sediment-water system had approximately 1.7-2.0 times slower elimination rates than parent cVMS. More specifically, compared with those of parent cVMS, volatilization (86-2558 days) and hydrolysis (135-549 days) half-lives of chloro-cVMS were respectively 1.3-2.0 and 1.8-2.1 times longer. In two species of freshwater mussels (n=1050) collected from six lakes, concentrations of chloro-cVMS ranged from 9.8-998 ng/g dw in Anodonta woodiana and 8.4-970 ng/g dw in Corbicula fluminea. Compared with parent cVMS, chloro-cVMS had 1.1-1.5 times larger biota-sediment accumulation factors (2.1-3.0) and 1.1-1.7 times longer half-lives (13-42 days). Their stronger persistence in sediment and bioaccumulation in freshwater mussels suggested that environmental emission, distribution and risks of chloro-cVMS deserve further attention.
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Affiliation(s)
- Nannan Liu
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin 300384, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China.
| | - Jie Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China
| | - Xudan He
- Institute of Resources and Environment, Beijing Academy of Science and Technology, Beijing 100089, China
| | - Lin Xu
- School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 330106, China.
| | - Yaqi Cai
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China; School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 330106, China; University of Chinese Academy of Sciences, Beijing 100049, China
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6
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Kumari K, Singh A, Marathe D. Cyclic volatile methyl siloxanes (D4, D5, and D6) as the emerging pollutants in environment: environmental distribution, fate, and toxicological assessments. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023:10.1007/s11356-023-25568-7. [PMID: 36809612 DOI: 10.1007/s11356-023-25568-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 01/18/2023] [Indexed: 06/18/2023]
Abstract
Cyclic volatile methyl siloxanes (cVMS) have now become a subject of environmental contamination and risk assessment due to their widespread use and occurrence in different environmental matrices. Due to their exceptional physio-chemical properties, these compounds are diversely used for formulations of consumer products and others implying their continuous and significant release to environmental compartments. This has captured the major attention of the concerned communities on the grounds of potential health hazards to human and biota. The present study aims at comprehensively reviewing its occurrence in air, water, soil, sediments, sludge, dusts, biogas, biosolids, and biota and their environmental behavior as well. Concentrations of cVMS in indoor air and biosolids were higher; however, no significant concentrations were observed in water, soil, and sediments except for wastewaters. No threat to the aquatic organisms has been identified as their concentrations do not exceed the NOEC (maximum no observed effect concentration) thresholds. Mammalian (rodents) toxicity hazards were not very evident except for the occurrence of uterine tumors in very rare cases under long-term chronic and repeated dose exposures in laboratory conditions. Human relevancy to rodents were also not strongly enough established. Therefore, more careful examinations are required to develop stringent weight of evidences in scientific domain and ease the policy making with respect to their production and use so as to combat any environmental consequences.
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Affiliation(s)
- Kanchan Kumari
- CSIR-National Environmental Engineering Research Institute (NEERI), Kolkata Zonal Centre, 700 107, Kolkata, West Bengal, India.
- Academy of Scientific and Innovative Research (AcSIR), Uttar Pradesh, Ghaziabad, 201 002, India.
| | - Anshika Singh
- Academy of Scientific and Innovative Research (AcSIR), Uttar Pradesh, Ghaziabad, 201 002, India
- CSIR-National Environmental Engineering Research Institute (NEERI), Nagpur, 440020, Maharashtra, India
| | - Deepak Marathe
- Academy of Scientific and Innovative Research (AcSIR), Uttar Pradesh, Ghaziabad, 201 002, India
- CSIR-National Environmental Engineering Research Institute (NEERI), Nagpur, 440020, Maharashtra, India
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7
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Chen W, Kang YJ, Lee HK, Lee M, Moon HB. Nationwide monitoring of cyclic and linear siloxanes in sediment and bivalves from Korean coastal waters: Occurrence, geographical distribution, and bioaccumulation potential. MARINE POLLUTION BULLETIN 2022; 185:114201. [PMID: 36257246 DOI: 10.1016/j.marpolbul.2022.114201] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 09/27/2022] [Accepted: 09/28/2022] [Indexed: 06/16/2023]
Abstract
Contamination of coastal environments by siloxanes is of growing concern. Sediment and bivalves were collected from 50 locations along the Korean coast to assess the geographical distribution, sources, and bioaccumulation potential of siloxanes. Cyclic and linear siloxanes were detectable in all sediment and bivalve samples. The highest siloxane concentrations were detected in sediment (656 ng/g dw) and bivalves (3273 ng/g dw) from highly industrialized bays and harbor-zones, suggesting that industrial and shipping activities are major sources of siloxanes in coastal environment. The geographical distribution of siloxanes was similar in sediment and bivalves. Sedimentary siloxanes were dominated by cyclic siloxanes, while linear siloxanes were predominant in bivalves. Bioaccumulation of linear siloxanes in bivalves originated mainly from the sedimentary environment. Mean biota-sediment accumulation factors (BSAFs) of seven siloxanes ranged from 1.26 to 6.03, indicating potential for bioaccumulation. This is the first report on the nationwide survey on siloxanes in Korean coastal waters.
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Affiliation(s)
- Wenming Chen
- Department of Marine Science and Convergence Engineering, College of Science and Convergence Technology, Hanyang University, Ansan 15588, Republic of Korea; College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, PR China
| | - Yu-Jin Kang
- Department of Marine Science and Convergence Engineering, College of Science and Convergence Technology, Hanyang University, Ansan 15588, Republic of Korea
| | - Hyun-Kyung Lee
- Department of Marine Science and Convergence Engineering, College of Science and Convergence Technology, Hanyang University, Ansan 15588, Republic of Korea
| | - Moonjin Lee
- Maritime Safety and Environmental Research Division, Korea Research Institute of Ships and Ocean Engineering, Daejeon 34103, Republic of Korea
| | - Hyo-Bang Moon
- Department of Marine Science and Convergence Engineering, College of Science and Convergence Technology, Hanyang University, Ansan 15588, Republic of Korea.
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8
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Bernardo F, Alves A, Homem V. A review of bioaccumulation of volatile methylsiloxanes in aquatic ecosystems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 824:153821. [PMID: 35167889 DOI: 10.1016/j.scitotenv.2022.153821] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 02/07/2022] [Accepted: 02/08/2022] [Indexed: 06/14/2023]
Abstract
Volatile methylsiloxanes (VMSs) are found in a broad range of industrial and consumer products. They are categorized as "high production volume chemicals" by the U.S. Environmental Protection Agency and listed as candidates of substances of very high concern in 2018, by the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH). Industrial wastewater and treated effluents may contain VMSs in different amounts, which can be discharged in the receptor media and may lead to environmental contamination. This can result in direct exposure to aquatic receptors in the water column or to benthic invertebrates from contact and/or ingestion of sediments, and indirect exposures through the aquatic food chain. The possible toxicological effects of VMSs for the aquatic biota and human ecology are not very well known since published information regarding this topic is scarce. VMSs have been subjected to regulatory scrutiny for environmental concerns and have already been screened to determine their environmental risk and ecological harm. This paper aims to assess VMSs bioaccumulation and potential biomagnification on food webs, using several bioaccumulation metrics. The result is a high-level overview of all the collected data, comparing the findings and the experimental conditions applied during the assessments. Several studies present conflicting results regarding the bioaccumulation categorization. Some aquatic organisms demonstrated a high bioconcentration and bioaccumulation of these contaminants. Trophic magnification factors (TMFs) have been suggested as the most reliable tool to assess a chemical behaviour in food webs. However, bioaccumulation studies in food webs provided mixed information, with some studies indicating trophic dilution and others presenting a potential of trophic biomagnification of VMSs. Efforts should be directed to obtain field-based levels of VMSs at different trophic levels and a wider range of linear VMSs should be analysed, since most studies focused on D4, D5 and D6.
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Affiliation(s)
- Fábio Bernardo
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; ALiCE-Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Arminda Alves
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; ALiCE-Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Vera Homem
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; ALiCE-Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal.
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Tang J, Zhang C, Wang L, Hu Y, Su P, Wang W, He X. Photo-electrocatalytic degradation of cyclic volatile methyl siloxane by ZnO-coated aluminum anode: Optimal parameters, kinetics, and reaction pathways. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 733:139246. [PMID: 32422461 DOI: 10.1016/j.scitotenv.2020.139246] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 04/09/2020] [Accepted: 05/04/2020] [Indexed: 06/11/2023]
Abstract
Cyclic volatile methylsiloxanes (cVMSs) are widely used in industrial processes and consumer products, which have been reported to be potentially toxic to human health due to their persistence and bioaccumulation. In this study, a novel photo-catalytic zinc oxide (ZnO)-coated aluminum (ZnO@Al) anode was prepared by a facile hydrothermal epitaxial process for the purpose of degrading cVMSs in practical wastewater. Morphological data and compositional analysis showed a compact coating layer that had the characteristic peaks of ZnO. To optimize the degradation process, central composite design combined with response surface methodology was applied to acquire the optimum parameters of cVMSs removal, and results indicated the cVMSs removal efficiency was approximately 63.3% at the conditions of current density = 17.3 mA/cm2, initial pH of electrolyte = 7.8, plate distance = 18 mm, UV intensity = 90 W, and reaction time = 80 min. Furthermore, the photo-electrocatalytic degradation of cVMSs obeys the pseudo-first order kinetic reaction, and the anode exhibited high durability as the attenuation of cVMSs removal efficiency was <6% after four times reuse. It was also observed that with the application period of the anode was extended, the electroflocculation reaction gradually occurred. The FT-IR of the generated flocs and the total ion gas chromatograms mass spectrometer analysis unraveled the methyl groups in Si-CH3 could be easily attacked by hydroxyl radicals to form the intermediates of monohydroxy substituted products (m/z = 298, 372, and 446) and eventually short-chain carboxylic acids, alkyl radical and silicate. The effective removal of cVMSs by photo-electrocatalytic process using ZnO@Al anode provide significant implication in treatment of practical wastewater.
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Affiliation(s)
- Jiawei Tang
- School of Chemical & Environmental Engineering, China University of Mining & Technology (Beijing), Beijing 100083, China
| | - Chunhui Zhang
- School of Chemical & Environmental Engineering, China University of Mining & Technology (Beijing), Beijing 100083, China.
| | - Liangliang Wang
- Environmental Protection Research Institute of Light Industry, Beijing 100095, China
| | - Yufeng Hu
- School of Chemical & Environmental Engineering, China University of Mining & Technology (Beijing), Beijing 100083, China
| | - Peidong Su
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China; Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Wenqian Wang
- School of Chemical & Environmental Engineering, China University of Mining & Technology (Beijing), Beijing 100083, China
| | - Xuwen He
- School of Chemical & Environmental Engineering, China University of Mining & Technology (Beijing), Beijing 100083, China
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10
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Xue X, Jia H, Xue J. Reply to Comment on "Bioaccumulation of Methyl Siloxanes in Common Carp (Cyprinus carpio) and in an Estuarine Food Web in Northeastern China". ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2020; 78:174-181. [PMID: 31927657 DOI: 10.1007/s00244-019-00705-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Affiliation(s)
- Xiaohong Xue
- College of Science, Dalian Maritime University, 1 Linghai Road, Dalian, 116026, Liaoning, China
| | - Hongliang Jia
- International Joint Research Centre for Persistent Toxic Substances (IJRC-PTS), College of Environmental Science and Engineering, Dalian Maritime University, Dalian, 116026, China
| | - Jingchuan Xue
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27519, USA.
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11
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Kim J, Woodburn K, Coady K, Xu S, Durham J, Seston R. Comment on "Bioaccumulation of Methyl Siloxanes in Common Carp (Cyprinus carpio) and in an Estuarine Food Web in Northeastern China". ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2020; 78:163-173. [PMID: 31838554 PMCID: PMC6987058 DOI: 10.1007/s00244-019-00681-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Accepted: 10/16/2019] [Indexed: 06/10/2023]
Abstract
We have reviewed a paper titled "Bioaccumulation of Methyl Siloxanes in Common Carp (Cyprinus carpio) and in an Estuarine Food Web in Northeastern China" by Xue et al., which was published in the Archives of Environmental Contamination and Toxicology in 2019. In the paper, the authors presented and discussed the measured bioconcentration factors (BCFs), biomagnification factors (BMFs), and trophic magnification factors (TMFs) of selected volatile methylsiloxanes in Shuangtaizi estuary in China. Although we appreciate their efforts for sample collection and data analysis, we have identified significant errors in calculations of BCFs, TMFs, and BMFs, as well as animal welfare issues and food web trophic level assumptions. Based on the data, we have attempted to correct some of the analysis and offered a more complete and robust interpretation of the related data, when possible. Collectively, these errors would likely lead to very different conclusions than yours in the paper.
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Affiliation(s)
- Jaeshin Kim
- Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI USA
| | - Kent Woodburn
- Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI USA
| | - Katie Coady
- Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI USA
| | - Shihe Xu
- Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI USA
| | - Jeremy Durham
- Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI USA
| | - Rita Seston
- Hyla Environmental Consulting, LLC, Midland, MI USA
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