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Asadi Zeidabadi F, Banayan Esfahani E, Moreira R, McBeath ST, Foster J, Mohseni M. Structural dependence of PFAS oxidation in a boron doped diamond-electrochemical system. ENVIRONMENTAL RESEARCH 2024; 246:118103. [PMID: 38181849 DOI: 10.1016/j.envres.2024.118103] [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: 10/04/2023] [Revised: 12/11/2023] [Accepted: 01/02/2024] [Indexed: 01/07/2024]
Abstract
Driven by long-term persistence and adverse health impacts of legacy perfluorooctanoic acid (PFOA), production has shifted towards shorter chain analogs (C4, perfluorobutanoic acid (PFBA)) or fluorinated alternatives such as hexafluoropropylene oxide dimer acid (HFPO-DA, known as GenX) and 6:2 fluorotelomer carboxylic acid (6:2 FTCA). Yet, a thorough understanding of treatment processes for these alternatives is limited. Herein, we conducted a comprehensive study using an electrochemical approach with a boron doped diamond anode in Na2SO4 electrolyte for the remediation of PFOA common alternatives, i.e., PFBA, GenX, and 6:2 FTCA. The degradability, fluorine recovery, transformation pathway, and contributions from electro-synthesized radicals were investigated. The results indicated the significance of chain length and structure, with shorter chains being harder to break down (PFBA (65.6 ± 5.0%) < GenX (84.9 ± 3.3%) < PFOA (97.9 ± 0.1%) < 6:2 FTCA (99.4 ± 0.0%) within 120 min of electrolysis). The same by-products were observed during the oxidation of both low and high concentrations of parent PFAS (2 and 20 mg L-1), indicating that the fundamental mechanism of PFAS degradation remained consistent. Nevertheless, the ratio of these by-products to the parent PFAS concentration varied which primarily arises from the more rapid PFAS decomposition at lower dosages. For all experiments, the main mechanism of PFAS oxidation was initiated by direct electron transfer at the anode surface. Sulfate radical (SO4•-) also contributed to the oxidation of all PFAS, while hydroxyl radical (•OH) only played a role in the decomposition of 6:2 FTCA. Total fluorine recovery of PFBA, GenX, and 6:2 FTCA were 96.5%, 94.0%, and 76.4% within 240 min. The more complex transformation pathway of 6:2 FTCA could explain its lower fluorine recovery. Detailed decomposition pathways for each PFAS were also proposed through identifying the generated intermediates and fluorine recovery. The proposed pathways were also assessed using 19F Nuclear Magnetic Resonance (NMR) spectroscopy.
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Affiliation(s)
- Fatemeh Asadi Zeidabadi
- Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, Canada
| | - Ehsan Banayan Esfahani
- Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, Canada
| | - Raphaell Moreira
- Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, Canada
| | - Sean T McBeath
- Department of Civil and Environmental Engineering, University of Massachusetts Amherst, Amherst, MA, 01002, United States
| | - Johan Foster
- Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, Canada
| | - Madjid Mohseni
- Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, Canada.
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Mojiri A, Vishkaei MN, Zhou JL, Trzcinski AP, Lou Z, Kasmuri N, Rezania S, Gholami A, Vakili M, Kazeroon RA. Impact of polystyrene microplastics on the growth and photosynthetic efficiency of diatom Chaetoceros neogracile. MARINE ENVIRONMENTAL RESEARCH 2024; 194:106343. [PMID: 38215624 DOI: 10.1016/j.marenvres.2024.106343] [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: 07/01/2023] [Revised: 12/17/2023] [Accepted: 01/07/2024] [Indexed: 01/14/2024]
Abstract
The increasing prevalence of microplastic pollution in aquatic environments has raised concerns about its impact on marine life. Among the different types of microplastics, polystyrene microplastics (PSMPs) are one of the most commonly detected in aquatic systems. Chaetoceros neogracile (diatom) is an essential part of the marine food web and plays a critical role in nutrient cycling. This study aimed to monitor the ecotoxicological impact of PSMPs on diatoms and observe enzymatic interactions through molecular docking simulations. Results showed that diatom growth decreased with increasing concentrations and exposure time to PSMPs, and the lowest photosynthetic efficiency (Fv/Fm) value was observed after 72 and 96 h of exposure to 200 mg L-1 of PSMPs. High concentrations of PSMPs led to a decrease in chlorophyll a content (up to 64.4%) and protein content (up to 35.5%). Molecular docking simulations revealed potential interactions between PSMPs and the extrinsic protein in photosystem II protein of diatoms, suggesting a strong affinity between the two. These findings indicate a detrimental effect of PSMPs on the growth and photosynthetic efficiency of diatoms and highlight the need for further research on the impact of microplastics on marine microbial processes.
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Affiliation(s)
- Amin Mojiri
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | | | - John L Zhou
- School of Civil and Environmental Engineering, University of Technology Sydney, NSW 2007, Australia
| | - Antoine P Trzcinski
- School of Agriculture and Environmental Science, University of Southern Queensland, West Street, Toowoomba, QLD, 4350, Australia
| | - Ziyang Lou
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Norhafezah Kasmuri
- School of Civil Engineering, College of Engineering, Universiti Teknologi MARA (UiTM), Shah Alam, 40450, Selangor, Malaysia
| | - Shahabaldin Rezania
- Department of Environment and Energy, Sejong University, Seoul, 05006, South Korea
| | - Ali Gholami
- Department of Agriculture, Shahin Shahr Branch, Islamic Azad University, Shahin Shahr, Iran
| | | | - Reza Andasht Kazeroon
- School of Civil Engineering, Xi'an University of Architecture and Technology, 710055, Shaanxi, China
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Zhang YH, Ding TT, Huang ZY, Liang HY, Du SL, Zhang J, Li HX. Environmental exposure and ecological risk of perfluorinated substances (PFASs) in the Shaying River Basin, China. CHEMOSPHERE 2023; 339:139537. [PMID: 37478992 DOI: 10.1016/j.chemosphere.2023.139537] [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: 04/03/2023] [Revised: 07/09/2023] [Accepted: 07/15/2023] [Indexed: 07/23/2023]
Abstract
There have been concerns raised about the environmental effects of perfluoroalkyl substances (PFASs) because of their toxicity, widespread distribution, and persistence. Understanding the occurrences and ecological risk posed by PFASs is essential, especially for the short-chain replacements perfluorobutanoic acid (PFBA) and perfluorobutane sulfonic acid (PFBS), which are now becoming predominant PFASs. The lack of aquatic life criteria (ALC), however, prevents an accurate assessment of the ecological risks of PFBA and PFBS. This study thus investigated the occurrence of 15 PFASs at 29 sampling sites in Shaying River Basin (in China) systematically, conducted the toxicity tests of PFBA and PFBS on eight resident aquatic organisms in China, and derived the predicted non-effect concentration (PNEC) values for PFBA and PFBS for two environmental media in China. The results showed that the total PFASs concentrations (ΣPFASs) ranged from 5.07 to 20.32 ng/L (average of 10.95 ng/L) in surface water, whereas in sediment, ΣPFASs ranged from 6.46 to 20.05 ng/g (dw) (average of 11.51 ng/g). The presence of PFBS was the most prominent PFASs in both water (0.372-8.194 ng/L) and sediment (4.54-15.72 ng/g), demonstrating that short-chain substitution effects can be observed in watersheds. The PNEC values for freshwater and sediment were 6.60 mg/L and 8.30 mg/kg (ww), respectively, for PFBA, and 14.04 mg/L, 37.08 mg/kg (ww), respectively, for PFBS. Ecological risk assessment of two long-chain PFASs, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), and two short-chain PFASs, PFBA and PFBS, using the hazard quotient method revealed that Shaying River and other major River Basins in China were at risk of PFOS contamination. This study contributes to a better understanding of the presence and risk of PFASs in the Shaying River and first proposes the ALCs for PFBA and PFBS in China, which could provide important reference information for water quality standards.
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Affiliation(s)
- Ya-Hui Zhang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, PR China; Environmental Analysis and Testing Laboratory, Chinese Research Academy of Environmental Sciences, Beijing, 100012, PR China.
| | - Ting-Ting Ding
- Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, PR China
| | - Zi-Yan Huang
- Environmental Analysis and Testing Laboratory, Chinese Research Academy of Environmental Sciences, Beijing, 100012, PR China; Hangzhou Yanqu Information Technology Co., Ltd, Hangzhou, 310005, PR China; Key Laboratory of Water Pollution Control and Waste Water Resource of Anhui Province, College of Environment and Energy Engineering, Anhui Jianzhu University, Hefei, 230601, PR China
| | - Hong-Yi Liang
- Environmental Analysis and Testing Laboratory, Chinese Research Academy of Environmental Sciences, Beijing, 100012, PR China; School of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao, 066004, China
| | - Shi-Lin Du
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, PR China; Environmental Analysis and Testing Laboratory, Chinese Research Academy of Environmental Sciences, Beijing, 100012, PR China
| | - Jin Zhang
- Key Laboratory of Water Pollution Control and Waste Water Resource of Anhui Province, College of Environment and Energy Engineering, Anhui Jianzhu University, Hefei, 230601, PR China
| | - Hui-Xian Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, PR China.
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