1
|
Huang J, Song G, Hao M, He Y, Hao H, Li R, Shi B, Huang X. Efficient removal of per- and polyfluoroalkyl substances (PFASs) from stored rainwater by composite metal salt /polydimethyldiallylammonium chloride coagulants. CHEMOSPHERE 2024; 366:143494. [PMID: 39374667 DOI: 10.1016/j.chemosphere.2024.143494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2024] [Revised: 10/02/2024] [Accepted: 10/05/2024] [Indexed: 10/09/2024]
Abstract
Stored rainwater, the primary source of drinking water in the villages and towns of the Loess Plateau in northwest China, has been found to contain per- and polyfluoroalkyl substances (PFASs) and lacks necessary treatment measures. Coagulation is a common water treatment process, and enhancing its efficacy in removing PFASs can significantly improve treatment efficiency, reduce costs, and minimize the environmental and health risks associated with perfluorinated compounds. This study investigated the removal efficiency of perfluorobutanoic acid (PFBA), perfluorobutanesulfonic acid (PFBS), perfluorooctanoic acid (PFOA), and perfluorooctanesulfonic acid (PFOS) using inorganic salt coagulants alone and in combination with polydimethyldiallylammonium chloride (PDMDAAC). The results indicated that the removal efficiencies of the four PFASs by polyferric chloride (PFCl) and polyaluminum chloride (PACl) increased with alkalinity. PDMDAAC significantly enhanced the coagulation removal efficiency of the four PFASs. The removal efficiency of the four PFASs was highest when the raw water pH was near 7. Within the molecular weight range of 0-500,000 for PDMDAAC, the removal efficiency of the four PFASs increased with increasing molecular weight. Charge neutralization is the primary coagulation mechanism for the removal of anionic PFASs. Therefore, this study provides guidance for selecting coagulants to remove PFASs from stored rainwater.
Collapse
Affiliation(s)
- Junhao Huang
- School of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou, 450000, Henan, China; Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Gangfu Song
- School of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou, 450000, Henan, China
| | - Mingming Hao
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yitian He
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Haotian Hao
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Ruihua Li
- School of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou, 450000, Henan, China
| | - Baoyou Shi
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xin Huang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
| |
Collapse
|
2
|
Ren Z, Zhang R, Xu X, Li Y, Wang N, Leiviskä T. Sorption/desorption and degradation of long- and short-chain PFAS by anion exchange resin and UV/sulfite system. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 361:124847. [PMID: 39216671 DOI: 10.1016/j.envpol.2024.124847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2024] [Revised: 08/26/2024] [Accepted: 08/27/2024] [Indexed: 09/04/2024]
Abstract
A combined sorption/desorption and UV/sulfite degradation process was investigated for achieving efficient elimination of PFAS from water. Two gel-type resins, Purolite A532E and A600, and one macroporous resin, Purolite A860, were firstly tested for the sorption of individual PFPrA, PFHxA, PFOA, PFOS, and GenX at different concentrations. Sorption data and density functional theory (DFT) calculations revealed that electrostatic interactions predominated for short-chain PFAS sorption and hydrophobic interactions played a more significant role for long-chain PFAS than for short-chain PFAS. A600 and A860 were selected for desorption tests with 0.025% NaOH, 5% NaCl, and 5% NH4Cl solution with or without 20% ethanol (EtOH) due to their high sorption capacity for all target PFAS. The mixture of 5% NH4Cl and 20% EtOH as the desorption solution typically showed the highest desorption efficiency. PFOS was the most resistant for desorption but its desorption could be enhanced by stronger mixing conditions (in 5% NaCl + 20% EtOH). Direct degradation of studied PFAS in the desorption solution (0.025% NaOH, 5% NaCl, and 5% NH4Cl) by UV/sulfite achieved 97.6-100% degradation and 46.6-86.1% defluorination. EtOH hindered degradation and thus should be separated from the water before UV/sulfite degradation.
Collapse
Affiliation(s)
- Zhongfei Ren
- Chemical Process Engineering, University of Oulu, P.O. Box 4300, FIN-90014, Oulu, Finland
| | - Ruichi Zhang
- Chemical Process Engineering, University of Oulu, P.O. Box 4300, FIN-90014, Oulu, Finland
| | - Xing Xu
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, PR China
| | - Yanwei Li
- Environment Research Institute, Shandong University, Qingdao, 266237, PR China
| | - Ningru Wang
- Environment Research Institute, Shandong University, Qingdao, 266237, PR China
| | - Tiina Leiviskä
- Chemical Process Engineering, University of Oulu, P.O. Box 4300, FIN-90014, Oulu, Finland.
| |
Collapse
|
3
|
Liu M, Liu X, Graham NJD, Yu W. Uncovering the neglected role of anions in trivalent cation-based coagulation processes. WATER RESEARCH 2024; 254:121352. [PMID: 38401286 DOI: 10.1016/j.watres.2024.121352] [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: 11/09/2023] [Revised: 01/08/2024] [Accepted: 02/20/2024] [Indexed: 02/26/2024]
Abstract
Coagulation efficiency is heavily contingent upon a profound comprehension of the underlying mechanisms, facilitated by the evolution of coagulation theory. However, the role of anions, prevalent components in raw and wastewaters, has been relatively overlooked in this context. To address this gap, this study has investigated the impact of three common anions (i.e., chloride, sulfate, and phosphate) on Al-based coagulation. The results have shown that the influence of anions on coagulation depends predominantly on their ability to compete with hydroxyl groups throughout the entire coagulation process, encompassing hydrolysis, aggregation, and the growth of large flocs. Moreover, this competition is subject to the dual influence of both anion concentration and hydroxyl concentration (i.e., pH). The results have revealed the intricate interplay between anions and coagulants, their impact on floc structure, and their importance in optimizing coagulation efficiency and ensuring the production of high-quality water.
Collapse
Affiliation(s)
- Mengjie Liu
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Xun Liu
- School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Nigel J D Graham
- Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Wenzheng Yu
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| |
Collapse
|
4
|
Zhang M, Wang W, Gong T, Wu Y, Chen G. Cutting-edge technologies and relevant reaction mechanism difference in treatment of long- and short-chain per- and polyfluoroalkyl substances: A review. CHEMOSPHERE 2024; 354:141692. [PMID: 38490606 DOI: 10.1016/j.chemosphere.2024.141692] [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: 02/06/2024] [Revised: 03/10/2024] [Accepted: 03/11/2024] [Indexed: 03/17/2024]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are emerging contaminants. Compared with short-chain PFAS, long-chain PFAS are more hazardous. Currently, little attention has been paid to the differences in reaction mechanisms between long-chain and short-chain PFAS. This pressing concern has prompted studies about eliminating PFAS and revealing the mechanism difference. The reaction rate and reaction mechanism of each technology was focused on, including (1) adsorption, (2) ion exchange (IX), (3) membrane filtration, (4) advanced oxidation, (5) biotransformation, (6) novel functional material, and (7) other technologies (e.g. ecological remediation, hydrothermal treatment (HT), mechanochemical (MC) technology, micro/nanobubbles enhanced technology, and integrated technologies). The greatest reaction rate k of photocatalysis for long- and short-chain PFAS high up to 63.0 h-1 and 19.7 h-1, respectively. However, adsorption, membrane filtration, and novel functional material remediation were found less suitable or need higher operation demand for treating short-chain PFAS. Ecological remediation is more suitable for treating natural waterbody for its environmentally friendly and fair reaction rate. The other technologies all showed good application potential for both short- and long-chain PFAS, and it was more excellent for long-chain PFAS. The long-chain PFAS can be cleavaged into short-chain PFAS by C-chain broken, -CF2 elimination, nucleophilic substitution of F-, and HF elimination. Furthermore, the application of each type of technology was novelly designed; and suggestions for the future development of PFAS remediation technologies were proposed.
Collapse
Affiliation(s)
- Meng Zhang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China
| | - Wenbing Wang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China.
| | - Tiantian Gong
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China
| | - Yulin Wu
- Shanghai Geotechnical Investigations and Design Institute Engineering Consulting (Group) Co. Ltd., China
| | - Guangyao Chen
- School of Material Science and Engineering, Shanghai University, Shanghai, 200444, China
| |
Collapse
|
5
|
Hubert M, Meyn T, Hansen MC, Hale SE, Arp HPH. Per- and polyfluoroalkyl substance (PFAS) removal from soil washing water by coagulation and flocculation. WATER RESEARCH 2024; 249:120888. [PMID: 38039821 DOI: 10.1016/j.watres.2023.120888] [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: 09/08/2023] [Revised: 11/09/2023] [Accepted: 11/15/2023] [Indexed: 12/03/2023]
Abstract
Soil washing is currently attracting attention as a promising remediation strategy for land contaminated with per- and polyfluoroalkyl substances (PFAS). In the soil washing process, the contaminant is transferred from the soil into the liquid phase, producing a PFAS contaminated process water. One way to treat such process water is to use coagulation and flocculation; however, few studies are available on the performance of coagulation and flocculation for removing PFAS from such process water. This study evaluated 6 coagulants and flocculants (polyaluminium chloride (PACl), zirconium oxychloride octahydrate, cationic and anionic polyacrylamide, Polyclay 685 and Perfluor Ad®), for the treatment of a proxy PFAS contaminated washing water, spiked with PFAS concentrations found at typical Aqueous Film Forming Foam (AFFF) contaminated sites. PFAS removal efficiencies (at constant pH) varied greatly depending on the coagulants and flocculants, as well as the dosage used and the targeted PFAS. All tested coagulants and flocculants reduced the turbidity by >95%, depending on the dosage. Perfluor Ad®, a specially designed coagulant, showed the highest removal efficiency for all longer chain (>99%) and shorter chain PFAS (>68%). The cationic polyacrylamide polymer removed longer chain PFAS up to an average of 80%, whereas average shorter chain PFAS removal was lower (<30%). The two metal-based coagulants tested, PACl and zirconium, removed longer chain PFAS by up to an average of 61% and shorter chain PFAS up to 48%. Polyclay 685, a mixture of powdered activated carbon (PAC) and aluminium sulphate, removed longer chain PFAS by 90% and shorter chain PFAS on average by 76%, when very high dosages of the coagulant were used (2,000 mg/L). PFAS removal efficiencies correlated with chain length and headgroup. Shorter chain PFAS removal was dependent on electrostatic interaction with the precipitating flocs, whereas for longer chain PFAS, hydrophobic interactions between apolar functional groups and flocs created by the coagulant/flocculant, dissolved organic matter and suspended solids played a major role. The results of this study showed that by selecting the most efficient coagulant and aqueous conditions, a greater amount of PFAS can be removed from process waters in soil washing facilities, and thus included as part of various treatment trains.
Collapse
Affiliation(s)
- Michel Hubert
- Norwegian Geotechnical Institute (NGI), NO-0806 Oslo, Norway; Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim, Norway.
| | - Thomas Meyn
- Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim, Norway
| | | | - Sarah E Hale
- Norwegian Geotechnical Institute (NGI), NO-0806 Oslo, Norway; DVGW-Technologiezentrum Wasser, 76139 Karsruhe, Germany
| | - Hans Peter H Arp
- Norwegian Geotechnical Institute (NGI), NO-0806 Oslo, Norway; Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim, Norway
| |
Collapse
|
6
|
Zhou L, Li W, Zhang J, Mao H. Removal of perfluorooctanoic acid (PFOA) in the liquid culture of Phanerochaete chrysosporium. CHEMOSPHERE 2023; 345:140427. [PMID: 37844703 DOI: 10.1016/j.chemosphere.2023.140427] [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: 03/29/2023] [Revised: 09/19/2023] [Accepted: 10/10/2023] [Indexed: 10/18/2023]
Abstract
Perfluorooctanoic acid (PFOA) is becoming a concern due to its persistence, bioaccumulation, and potential harmful effects on humans and the environment. In this study, the fungus Phanerochaete chrysosporium (P. chrysosporium) was used to remove the PFOA in liquid culture system. The results showed that the average activities of laccase (Lac), lignin peroxidase (LiP), and manganese peroxidase (MnP) enzymes secreted by P. chrysosporium were 0.0003 U/mL, 0.013 U/mL, and 0.0059 U/mL, respectively, during the incubation times of 0-75 days. The pH of 3 and incubation time of 45-55 days were the optimum parameters for the three enzymes activities. The enzyme activities in P. chrysosporium incubation system were firstly inhibited by adding PFOA and then they were enhanced after 14 days. The maximum removal efficiency of PFOA (69.23%) was achieved after 35 days in P. chrysosporium incubation system with an initial PFOA concentration of 0.002 mM and no veratryl alcohol (VA). Adsorption was not a main pathway for PFOA removal and the PFOA adsorbed in fungi mycelial mat accounted for merely 1.91%. The possible products of PFOA contained partially fluorinated aldehyde, alcohol, and aromatic ring. These partially fluorinated compounds might result from PFOA degradation via a combination of cross-coupling and rearrangement of free radicals.
Collapse
Affiliation(s)
- Lina Zhou
- Xi'an International University, Xi'an, Shaanxi 710077, PR China
| | - Wanting Li
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, PR China
| | - Jin Zhang
- Xi'an International University, Xi'an, Shaanxi 710077, PR China
| | - Hui Mao
- Xi'an International University, Xi'an, Shaanxi 710077, PR China.
| |
Collapse
|
7
|
Zhuang Y, Qin X, Shi B. Interface hydrogen bonding dominated perfluorooctanoic acid (PFOA) accumulation by iron particles in drinking water pipes. CHEMOSPHERE 2023; 312:137211. [PMID: 36368546 DOI: 10.1016/j.chemosphere.2022.137211] [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: 08/12/2022] [Revised: 10/10/2022] [Accepted: 11/08/2022] [Indexed: 06/16/2023]
Abstract
Iron particle is one of the key factors inducing discoloration in drinking water distribution system (DWDS), but the mechanism of iron particles on the accumulation of trace organic pollutants in DWDS is not clear. Here, iron-based pipes from real DWDS were used to investigate the perfluorooctanoic acid (PFOA) accumulation mechanisms in DWDS. Results showed that old unlined pipes had a much higher accumulation capacity for PFOA than new pipes. Among the corrosion products in old pipes, Fe2O3 and Fe3O4 did not have obvious accumulation for PFOA, while FeOOH exhibited a strong accumulation effect for PFOA. Furthermore, the in-situ formed iron particles contributed more to PFOA accumulation than pre-formed iron particles. Interestingly, PFOA caused an increase in turbidity and particle size of in-situ formed iron particles. Mulliken charge of F-bonded Fe increased from +1.28 e to +1.30 e, which indicated that the oxidation state of Fe-center was strengthened by PFOA. When dissolved oxygen existed, a PFOA-FeOOH-O2 linkage could form through COO-Fe coordination and O2 interface adsorption, which enhanced cytotoxicity due to the generation of •OH radicals. These findings implied that interface hydrogen bonding dominated PFOA accumulation by iron particles in DWDS, which would increase the risks of discoloration.
Collapse
Affiliation(s)
- Yuan Zhuang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Xinyi Qin
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Baoyou Shi
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
| |
Collapse
|
8
|
Wang M, Cai Y, Zhou B, Yuan R, Chen Z, Chen H. Removal of PFASs from water by carbon-based composite photocatalysis with adsorption and catalytic properties: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 836:155652. [PMID: 35508243 DOI: 10.1016/j.scitotenv.2022.155652] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 04/24/2022] [Accepted: 04/28/2022] [Indexed: 05/27/2023]
Abstract
Per- and polyfluoroalkyl substances (PFASs) are a class of persistent organic pollutants widely distributed in aquatic environments. The adsorption and photocatalytic methods have been widely used to remove PFASs in water because of their respective advantages. Still, they have apparent defects when used alone. Therefore, the adsorption and photocatalytic technologies are combined through suitable preparation methods, and the excellent properties of the two are used to synergize the treatment of organic pollutants. This strategy of "concentrating" pollutants and then degrading them in a centralized manner plays an essential role in removing trace PFASs. Nevertheless, a review focusing on this kind of adsorption photocatalyst system is lacking. This review will fill this gap and provide a reference for developing a carbon-based composite photocatalyst. Firstly, different carbon-based composite photocatalysts are reviewed in detail, focusing on the differences in various composite materials' excellent adsorption and catalytic properties. Secondly, the factors influencing the removal effect of carbon-based composite photocatalysts are discussed. Thirdly, the removal mechanism of carbon-based composite photocatalysts is summarized in detail. The removal process involves two steps: adsorption and photodegradation. The adsorption process involves multiple cooperative adsorption mechanisms, and photocatalytic degradation includes oxidative and reductive degradation. Fourthly, the comparison of adsorption-photocatalysis with common treatment techniques (including removal rate, range of adaptation, cost, and the possibility of expanding application) is summarized. Finally, the prospects of carbon-based composite photocatalysts for repairing PFASs are given by evaluating the performance of different composites.
Collapse
Affiliation(s)
- Mingran Wang
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Yanping Cai
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Beihai Zhou
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Rongfang Yuan
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Zhongbing Chen
- Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, 16500 Prague, Czech Republic
| | - Huilun Chen
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China.
| |
Collapse
|
9
|
A Review of Treatment Techniques for Short-Chain Perfluoroalkyl Substances. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12041941] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In recent years, an increasing amount of short-chain perfluoroalkyl substance (PFAS) alternatives has been used in industrial and commercial products. However, short-chain PFASs remain persistent, potentially toxic, and extremely mobile, posing potential threats to human health because of their widespread pollution and accumulation in the water cycle. This study systematically summarized the removal effect, operation conditions, treating time, and removal mechanism of various low carbon treatment techniques for short-chain PFASs, involving adsorption, advanced oxidation, and other practices. By the comparison of applicability, pros, and cons, as well as bottlenecks and development trends, the most widely used and effective method was adsorption, which could eliminate short-chain PFASs with a broad range of concentrations and meet the low-carbon policy, although the adsorbent regeneration was undesirable. In addition, advanced oxidation techniques could degrade short-chain PFASs with low energy consumption but unsatisfied mineralization rates. Therefore, combined with the actual situation, it is urgent to enhance and upgrade the water treatment techniques to improve the treatment efficiency of short-chain PFASs, for providing a scientific basis for the effective treatment of PFASs pollution in water bodies globally.
Collapse
|
10
|
Li YF, Hu CY, Lee YC, Lo SL. Effects of zinc salt addition on perfluorooctanoic acid (PFOA) removal by electrocoagulation with aluminum electrodes. CHEMOSPHERE 2022; 288:132665. [PMID: 34710459 DOI: 10.1016/j.chemosphere.2021.132665] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 10/22/2021] [Accepted: 10/23/2021] [Indexed: 06/13/2023]
Abstract
In this study, the electrocoagulation (EC) of perfluorooctanoic acid (PFOA) by an aluminum electrode with the addition of zinc salt was investigated. Adding ZnCl2 successfully prevented a rise in pH during EC and increased the efficiency from 73.7% to over 99%. In addition, the longer the carbon chain of a PFA was, the better the removal of that PFA by electrocoagulation. The main functions of ZnCl2 were to prevent the rise in pH and improve flotation because the flocs with added ZnCl2 were easy to gather together and had a faster floating speed. The XPS results demonstrated the occurrence of bonding between aluminum and fluoride. This finding indicates that complexation between aluminum and fluoride may be the main mechanism for removal when aluminum electrodes are used to remove perfluoroalkyl (PFA) compounds.
Collapse
Affiliation(s)
- Yueh-Feng Li
- Graduate Institute of Environmental Engineering, National Taiwan University, 71 Chou-Shan Rd., Taipei, 10673, Taiwan, ROC
| | - Ching-Yao Hu
- School of Public Health, Taipei Medical University, 250 Wu-Xing Street, Taipei, 11031, Taiwan, ROC
| | - Yu-Chi Lee
- Graduate Institute of Environmental Engineering, National Taiwan University, 71 Chou-Shan Rd., Taipei, 10673, Taiwan, ROC
| | - Shang-Lien Lo
- Graduate Institute of Environmental Engineering, National Taiwan University, 71 Chou-Shan Rd., Taipei, 10673, Taiwan, ROC; Water Innovation, Low Carbon and Environmental Sustainability Research Center, National Taiwan University, Taipei, 10617, Taiwan, ROC.
| |
Collapse
|
11
|
Wang Y, Lin C, Liu X, Ren W, Huang X, He M, Ouyang W. Efficient removal of acetochlor pesticide from water using magnetic activated carbon: Adsorption performance, mechanism, and regeneration exploration. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 778:146353. [PMID: 33725597 DOI: 10.1016/j.scitotenv.2021.146353] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 02/18/2021] [Accepted: 03/03/2021] [Indexed: 05/28/2023]
Abstract
In this study, MnFe2O4 supported activated carbon magnetic adsorbent (MnFe2O4@AC) was successfully prepared by a simple one-pot solvothermal method and used for the adsorption and removal of acetochlor from aqueous media. Results showed that MnFe2O4@AC with a MnFe2O4/AC mass ratio of 1:2 was characterized by good magnetism and high acetochlor adsorption capacity over a wide ranging pH, ionic strength, and humic acid concentration in an aqueous solution. Acetochlor was adsorbed on MnFe2O4@AC mainly by hydrogen bonding, π-π interactions, and pore-filling via film, intraparticle, and pore diffusion steps. Adsorption reaction generally approached an equilibrium after 10 h, with the adsorption capacity being ca. 226 mg g-1 for 0.2 g L-1 adsorbent at 25 °C. Adsorbate (acetochlor) degradation and adsorbent regeneration were simultaneously achieved through heat-activated peroxymonosulfate (PMS) oxidation catalyzed by MnFe2O4 on the AC surface with >90% degradation efficiency at ≥9.6 mM PMS concentration at 70 °C within 12 h. However, the adsorption capacity of the regenerated adsorbent decreased by 50% of its original capacity. This needs to be addressed in future studies. MnFe2O4@AC adsorbent has the advantages of high adsorption capacity, good magnetism, and catalyzation, which are promising for adsorption, separation, and degradation for the effective removal and treatment of acetochlor as well as other organic contaminants in different types of waters.
Collapse
Affiliation(s)
- Yiqing Wang
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Chunye Lin
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
| | - Xitao Liu
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
| | - Wenbo Ren
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Xiaokai Huang
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Mengchang He
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Wei Ouyang
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
| |
Collapse
|
12
|
Liu X, Graham N, Liu T, Cheng S, Yu W. A comparison of the coagulation performance of PAFC and FeSO4 for the treatment of leach liquor from Stevia processing. Sep Purif Technol 2021. [DOI: 10.1016/j.seppur.2020.117680] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
13
|
Deng Y, Zhu X, Chen N, Feng C, Wang H, Kuang P, Hu W. Review on electrochemical system for landfill leachate treatment: Performance, mechanism, application, shortcoming, and improvement scheme. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 745:140768. [PMID: 32726696 DOI: 10.1016/j.scitotenv.2020.140768] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Revised: 05/26/2020] [Accepted: 07/03/2020] [Indexed: 05/21/2023]
Abstract
Landfill leachate is a type of complex organic wastewater, which can easily cause serious negative impacts on the human health and ecological environment if disposed improperly. Electrochemical technology provides an efficient approach to effectively reduce the pollutants in landfill leachate. In this review, the electrochemical standalone processes (electrochemical oxidation, electrochemical reduction, electro-coagulation, electro-Fenton process, three-dimensional electrode process, and ion exchange membrane electrochemical process) and the electrochemical integrated processes (electrochemical-advanced oxidation process (AOP) and biological electrochemical process) for landfill leachate treatment are summarized, which include the performance, mechanism, application, existing problems, and improvement schemes such as cost-effectiveness. The main objective of this review is to help researchers understand the characteristics of electrochemical treatment of landfill leachate and to provide a useful reference for the design of the process and reactor for the harmless treatment of landfill leachate.
Collapse
Affiliation(s)
- Yang Deng
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, China
| | - Xu Zhu
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, China
| | - Nan Chen
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, China.
| | - Chuanping Feng
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, China.
| | - Haishuang Wang
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, China
| | - Peijing Kuang
- College of Environment and Resources, Dalian Minzu University, Dalian 116600, China
| | - Weiwu Hu
- China University of Geosciences (Beijing), Journal Center, Beijing 100083, China
| |
Collapse
|
14
|
Zhao C, Zhang T, Hu G, Ma J, Song R, Li J. Efficient removal of perfluorooctane sulphonate by nanofiltration: Insights into the effect and mechanism of coexisting inorganic ions and humic acid. J Memb Sci 2020. [DOI: 10.1016/j.memsci.2020.118176] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
15
|
Zhang W, Wei Q, Xiao J, Liu Y, Yan C, Liu J, Sand W, Chow CWK. The key factors and removal mechanisms of sulfadimethoxazole and oxytetracycline by coagulation. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:16167-16176. [PMID: 32112357 DOI: 10.1007/s11356-019-06884-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 10/25/2019] [Indexed: 06/10/2023]
Abstract
The effects of coagulant dosage, alkalinity, turbidity, ionic strength, and dissolved organic matter (DOM) on the removal of sulfadimethoxazole (SMZ) and oxytetracycline (OTC) by coagulation were studied and the reaction mechanisms of the coagulation process were revealed in this research. From our results, alkalinity, turbidity, ionic strength, and DOM had different effects on the removal of antibiotics. The SMZ and OTC removals were improved with increase in poly-aluminum chloride (PACl) dosage, whereas the turbidity had less influence on the removal of SMZ and OTC because the adsorption of SMZ and OTC to kaolin was low, confirmed by a control when no PACl added. The hydrolysate of PACl played a more important role than turbidity in SMZ and OTC removals. The SMZ and OTC removals were significantly increased with the increase in alkalinity, which provided a suitable condition in situ for coagulant to form more optimal species of hydrolysate. The ionic strength, which was adjusted by NaNO3, also had a positive effect on the removal of SMZ but no obvious effect on the OTC removal. Furthermore, DOM had a higher effect on the removal of SMZ than that of OTC. In another word, if a water plant wants to improve the removal of SMZ and OTC by coagulation unit, PACl hydrolysate, alkalinity, and DOM are the three key factors to be considered primarily. Moreover, an experiment for the recovery of antibiotics from the flocs was done and the results showed that OTC and SMZ were removed by different mechanisms. The OTC was removed via complexation formed through the reaction between OTC and coagulant while the SMZ was removed through the pathway of adsorption and inter-particle bridging to the surface of coagulant hydrolysate.
Collapse
Affiliation(s)
- Weichao Zhang
- School of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China
- Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China
- Northwest Institute of Nuclear Technology, Xi'an, 710024, China
- Textile Pollution Controlling Engineering Centre of Ministry of Environmental Protection, Shanghai, 201620, China
| | - Qunshan Wei
- School of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China.
- Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China.
- Textile Pollution Controlling Engineering Centre of Ministry of Environmental Protection, Shanghai, 201620, China.
| | - Jiuhua Xiao
- School of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China
- Textile Pollution Controlling Engineering Centre of Ministry of Environmental Protection, Shanghai, 201620, China
| | - Yanbiao Liu
- School of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China.
- Textile Pollution Controlling Engineering Centre of Ministry of Environmental Protection, Shanghai, 201620, China.
| | - Changzhou Yan
- Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China
| | - Jianshe Liu
- School of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China
- Textile Pollution Controlling Engineering Centre of Ministry of Environmental Protection, Shanghai, 201620, China
| | - Wolfgang Sand
- School of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China
- Textile Pollution Controlling Engineering Centre of Ministry of Environmental Protection, Shanghai, 201620, China
| | - Christopher W K Chow
- Natural and Built Environments Research Centre, School of Natural and Built Environments, University of South Australia, Adelaide, SA, 5095, Australia
| |
Collapse
|
16
|
Yang Y, Yang M, Zheng Z, Zhang X. Highly effective adsorption removal of perfluorooctanoic acid (PFOA) from aqueous solution using calcined layer-like Mg-Al hydrotalcites nanosheets. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:13396-13408. [PMID: 32026363 DOI: 10.1007/s11356-020-07892-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 01/27/2020] [Indexed: 06/10/2023]
Abstract
To study the influence factors of calcined layer-like Mg-Al hydrotalcites nanosheets adsorbing perfluorooctanoic acid (PFOA) in aqueous solution, Mg-Al hydrotalcite (HMA) nanosheets were prepared by one-step hydrothermal synthesis. The effect of calcination temperature on adsorption properties and structure of HMA (CHMA-x, x means different calcination temperature) was investigated. The prepared samples were systematically characterized by the Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG), X-ray diffraction (XRD), scanning electronic microscopy (SEM), and nitrogen adsorption-desorption isotherms. The adsorption isotherms and kinetics showed the adsorption equilibrium reached within 2 h, and the factors, such as adsorption dosage, pH, and cycles were investigated. It was found that CHMA with 600 °C displayed a uniformly morphology, higher surface area about 106.3 m2/g, and excellent adsorption properties (1969 mg/g). The equilibrium adsorption data perfectly fitted to the pseudo-second-order kinetic model (R2 = 0.999) and the Freundlich model (R2 = 0.994). The main mechanism of CHMA adsorbing PFOA might be the "memory effect." This study provided a new insight to prepare highly effective adsorbents in water treatment.
Collapse
Affiliation(s)
- Yiqiong Yang
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, China
| | - Minhui Yang
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, China
| | - Zenghui Zheng
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, China
| | - Xiaodong Zhang
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, China.
| |
Collapse
|
17
|
Deng Y, Chen N, Feng C, Wang H, Zheng Y, Chen F, Lu W, Kuang P, Feng H, Gao Y, Hu W. Degradation of nitrogen-containing refractory organic wastewater using a novel alternating-anode electrochemical system. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 697:134161. [PMID: 32380621 DOI: 10.1016/j.scitotenv.2019.134161] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Revised: 08/11/2019] [Accepted: 08/27/2019] [Indexed: 06/11/2023]
Abstract
This study presented a novel alternating-anode electrochemical system (AAES) based on single electrolytic cell for the treatment of nitrogen-containing refractory organic wastewater (NOW). The core of AAES lies in the alternating working of iron anode and DSA anode to integrate different electrochemical processes. The biologically treated landfill leachate (BTLL) was selected as a practical NOW for assessing the performance of AAES. The results indicated that after 140 min of electrolytic reaction, the removal efficiency of chemical oxygen demand and total nitrogen (TN) using AAES was found to be 76.9 and 98.9%, respectively. The main component of dissolved organic matter (DOM) in BTLL included humic-like substances, which could be degraded into small-molecule DOM, such as fulvic-like substances and protein-like substances, by available chlorine and hydroxyl radicals present in AAES. Cathode reduction (NOx--N → NH4+-N and N2) under iron anode and indirect oxidation (NH4+-N → N2) under DSA anode were the main pathways to remove TN from NOW. Owing to the redox conditions created by the alternating anodes, the main stable crystalline forms of precipitates obtained from AAES were Fe3O4 and γ-Fe2O3, which could be separated by using the external magnetic field. The findings of this study may provide a feasible solution for the advanced electrochemical treatment of NOW in a single electrolytic cell as well as rapid separation of precipitates.
Collapse
Affiliation(s)
- Yang Deng
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, PR China
| | - Nan Chen
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, PR China.
| | - Chuanping Feng
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, PR China.
| | - Haishuang Wang
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, PR China
| | - Yuhan Zheng
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, PR China
| | - Fangxin Chen
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, PR China
| | - Wang Lu
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, PR China
| | - Peijing Kuang
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, PR China
| | - Hanguang Feng
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, PR China
| | - Yu Gao
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao 266590, PR China
| | - Weiwu Hu
- China University of Geosciences (Beijing), Journal Center, Beijing 100083, China
| |
Collapse
|
18
|
Regulation of Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonic Acid (PFOS) in Drinking Water: A Comprehensive Review. WATER 2019. [DOI: 10.3390/w11102003] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are receiving global attention due to their persistence in the environment through wastewater effluent discharges and past improper industrial waste disposal. They are resistant to biological degradation and if present in wastewater are discharged into the environment. The US Environmental Protection Agency (USEPA) issued drinking water Health Advisories for PFOA and PFOS at 70 ng/L each and for the sum of the two. The need for an enforceable primary drinking water regulation under the Safe Drinking Water Act (SDWA) is currently being assessed. The USEPA faces stringent legal constraints and technical barriers to develop a primary drinking water regulation for PFOA and PFOS. This review synthesizes current knowledge providing a publicly available, comprehensive point of reference for researchers, water utilities, industry, and regulatory agencies to better understand and address cross-cutting issues associated with regulation of PFOA and PFOS contamination of drinking water.
Collapse
|
19
|
Meng P, Fang X, Maimaiti A, Yu G, Deng S. Efficient removal of perfluorinated compounds from water using a regenerable magnetic activated carbon. CHEMOSPHERE 2019; 224:187-194. [PMID: 30825849 DOI: 10.1016/j.chemosphere.2019.02.132] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 02/19/2019] [Accepted: 02/21/2019] [Indexed: 05/08/2023]
Abstract
Adsorption by powder activated carbon (PAC) is recognized as an efficient method for the removal of perfluorinated compounds (PFCs) in water, while the poor separation of spent PAC makes it difficult for further regeneration, increasing the treatment cost significantly. In this study, an ultrafine magnetic activated carbon (MAC) consisting of Fe3O4 and PAC was prepared by ball milling to remove PFCs from water efficiently. Increasing the percentage of Fe3O4 and balling milling time decreased its adsorption capacity for perfluoroctane sulfonate (PFOS), whereas increased the magnetic separation property to some degree. The optimized MAC was prepared with a Fe3O4 to PAC mass ratio of 1:3 after ball milling for 2 h, and the adsorption equilibriums of all the four PFCs on the optimal MAC were reached within less than 2 h, with the adsorption capacities of 1.63, 0.90, 0.33 and 0.21 mmol/g for PFOS, perfluorooctanoic acid (PFOA), perfluorohexane sulfonate (PFHxS) and perfluorobutane sulfonate (PFBS), respectively. Increasing the solution pH hindered the adsorption of PFOS significantly when the pH was less than the zero potential point (around 6) of the MAC, due to the decreased electrostatic attraction. The spent MAC could be easily separated with a magnet and regenerated by a small volume of methanol, and the regenerated MAC could be reused for more than 5 time and remain stable adsorption capacity for PFOS after 3 cycles. This study provides useful insights into the removal of PFCs by separable magnetic PAC in wastewater.
Collapse
Affiliation(s)
- Pingping Meng
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Xiaolu Fang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Ayiguli Maimaiti
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Gang Yu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Shubo Deng
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing, 100084, China.
| |
Collapse
|
20
|
Midya L, Patra AS, Banerjee C, Panda AB, Pal S. Novel nanocomposite derived from ZnO/CdS QDs embedded crosslinked chitosan: An efficient photocatalyst and effective antibacterial agent. JOURNAL OF HAZARDOUS MATERIALS 2019; 369:398-407. [PMID: 30784969 DOI: 10.1016/j.jhazmat.2019.02.022] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 01/09/2019] [Accepted: 02/08/2019] [Indexed: 06/09/2023]
Abstract
A novel nanocomposite (cl-Ch-pMAc@ZnO/CdSQDs) has been developed under microwave irradiation via fabrication of ZnO/CdS quantum dots on anionically functionalized chitosan [i.e. poly (methacrylic acid) crosslinked chitosan (cl-Ch-pMAc) in the presence of diethylene glycol dimethacrylate (DEGDMA) crosslinker]. The structural, morphological and chemical/physical properties of crosslinked chitosan and the nanocomposites have been investigated using 13C nuclear magnetic resonance spectroscopy (13C NMR spectroscopy), high resolution-transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) analyses. The nanocomposite demonstrates outstanding efficacy towards the photocatalytic degradation of cationic dyes [malachite green (MG), and safranin (SF)] and toxic organic molecule 2,4-dichloro phenol (2,4-DCP) under the exposure of sunlight. Liquid chromatography mass spectroscopy (LC-MS) studies predict that small molecules are produced by degradation. Moreover, the composite exhibits excellent antibacterial activity towards E-coli and B. subtilis. Finally, the nanocomposite can be regenerated effectively with changing the solution pH and also shows 5 times reusability without significant reduction on its efficiency.
Collapse
Affiliation(s)
- Lipi Midya
- Department of Applied Chemistry, Indian Institute of Technology (ISM), Dhanbad, 826004, India
| | | | - Chranjib Banerjee
- Department of Environmental Science & Engineering, Indian Institute of Technology (ISM), Dhanbad, 826004, India
| | - Asit Baran Panda
- Discipline of Inorganic Materials and Catalysis, Central Salt and Marine Chemicals Research Institute (CSIR), Bhavnagar, 364002, Gujarat, India.
| | - Sagar Pal
- Department of Applied Chemistry, Indian Institute of Technology (ISM), Dhanbad, 826004, India.
| |
Collapse
|
21
|
Chang PH, Jiang WT, Li Z. Removal of perfluorooctanoic acid from water using calcined hydrotalcite - A mechanistic study. JOURNAL OF HAZARDOUS MATERIALS 2019; 368:487-495. [PMID: 30710777 DOI: 10.1016/j.jhazmat.2019.01.084] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 12/26/2018] [Accepted: 01/23/2019] [Indexed: 06/09/2023]
Abstract
Calcined hydrotalcite (CHT) was evaluated for its potential removal of perfluorooctanoic acid (PFOA) from water in this study. The uptake of PFOA by CHT could be as high as 1587 mg/g (ca. 3.8 mmol/g), slightly larger than the anion exchange capacity (AEC) of the hydrotalcite (HT). Such a high removal was fast and pH independent, suggesting the versatile use of CHT. Due to the structural memory effect of HT, the removal involved adsorption of PFOA during HT recovery and intercalation of PFOA into the interlayer of restructured HT at low and high initial concentrations, respectively. Limited by the specific surface area and AEC, the intercalated PFOA would form a vertical bilayer or admicelle conformation. As such, the HT intercalated with PFOA became one-layer stacking with a basal spacing of 2.04 nm in contrast to the 3R polytype of recovered HT having a layer thickness of 0.78 nm, as confirmed by X-ray diffraction, thermogravimetric, and infra-red analyses. Due to its high PFOA removal capacity and large partitioning coefficient, the amount of CHT used, thus, the disposal of PFOA-laden solid could be minimized.
Collapse
Affiliation(s)
- Po-Hsiang Chang
- Department of Earth Sciences, National Cheng Kung University, 1 University Road, Tainan, 70101, Taiwan
| | - Wei-Teh Jiang
- Department of Earth Sciences, National Cheng Kung University, 1 University Road, Tainan, 70101, Taiwan.
| | - Zhaohui Li
- Department of Earth Sciences, National Cheng Kung University, 1 University Road, Tainan, 70101, Taiwan; Department of Geosciences, University of Wisconsin - Parkside, 900 Wood Road, Kenosha, WI 53144, USA.
| |
Collapse
|
22
|
Shang E, Li Y, Niu J, Li S, Zhang G, Wang X. Photocatalytic degradation of perfluorooctanoic acid over Pb-BiFeO 3/rGO catalyst: Kinetics and mechanism. CHEMOSPHERE 2018; 211:34-43. [PMID: 30071434 DOI: 10.1016/j.chemosphere.2018.07.130] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 06/08/2018] [Accepted: 07/22/2018] [Indexed: 06/08/2023]
Abstract
Degradation of perfluorooctanoic acid (PFOA) is important because of its global distribution, persistence and toxicity to organisms. In this work, the PbBiFeO3 photocatalyst was prepared by the hydrothermal method. The effect of doping amount of reduced graphene oxide (rGO) on the decomposition of PFOA was investigated under 254 nm UV light. The results indicated that 100 mg L-1 PbBiFeO3 with 0.5 wt% rGO exhibited the highest degradation efficiency for 50 mg L-1 PFOA at pH = 2.0 from aqueous solution. The removal rate of PFOA reached 69.6% after 8 h UV irradiation under the optimal conditions (PFOA concentration of 50 mg L-1, Pb BiFeO3/0.5% rGO concentration of 100 mg L-1, and pH of 2.0). The total organic carbon removal rate and defluorination rate were 28.0% and 37.6%, respectively. During the degradation process, four major intermediates with shorter chain length than PFOA (∼C4C7) were identified. The mechanism responsible for PFOA decomposition was supposed that OH attacked PFOA to form perfluoroalkyl alcohol and then was transferred to perfluoroalkyl fluoride which can easily undergo hydrolysis to form shorter-chain perfluorocarboxylic acids than PFOA. This indicated that the photocatalytic degradation of PFOA was an oxidation process through stepwise losing of CF2 group.
Collapse
Affiliation(s)
- Enxiang Shang
- Research Center for Eco-Environmental Engineering, Dongguan University of Technology, Dongguan, 523808, PR China; State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, PR China
| | - Yang Li
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, PR China
| | - Junfeng Niu
- Research Center for Eco-Environmental Engineering, Dongguan University of Technology, Dongguan, 523808, PR China.
| | - Shuo Li
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, PR China
| | - Guangshan Zhang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, PR China.
| | - Xinjie Wang
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, PR China
| |
Collapse
|
23
|
Sun M, Zhou H, Xu B, Bao J. Distribution of perfluorinated compounds in drinking water treatment plant and reductive degradation by UV/SO 32- process. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:7443-7453. [PMID: 29280103 DOI: 10.1007/s11356-017-1024-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 12/11/2017] [Indexed: 06/07/2023]
Abstract
Perfluorinated compounds (PFCs), which are widely used in industrial and residential areas, have a large negative impact on the environment. This study investigated the removal efficiency of five PFCs in a drinking water treatment plant. The results indicate that the total PFC concentration in raw water is 261.51 ng L-1 and that perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are the predominant pollutants. Among all of the treatment processes, coagulation sedimentation process had the highest removal ratio of PFCs (36.12%), and removal ratio was the least in the sand filtration process. The ozonation/activated carbon and disinfection processes increased the concentration of PFCs. Therefore, developing an effective treatment to degrade PFCs is feasible. In this study, we proposed a method using UV irradiation of SO32- at 365 nm to degrade PFCs. The SO32- concentration, pH, and initial concentration had profound impacts on the degradation of PFCs. When the PFC initial concentration was 20 mg L-1, the SO32- concentration was 2.4 g L-1, and in the presence of buffer, the degradation of PFCs was the most efficient, with the degradation ratio close to 100% after 60 min of reaction. During the degradation of PFCs, short-chain PFCs and hydrofluorinated carboxylic acid were generated. From the above, we proposed a detailed mechanism of degradation and its possible pathways.
Collapse
Affiliation(s)
- Min Sun
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing, 210098, People's Republic of China.
- College of Environment, Hohai University, Nanjing, 210098, People's Republic of China.
| | - Hao Zhou
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing, 210098, People's Republic of China
- College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Bei Xu
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing, 210098, People's Republic of China
- College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Junxin Bao
- College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| |
Collapse
|
24
|
Omorodion H, Palenzuela M, Ruether M, Twamley B, Platts JA, Baker RJ. A rationally designed perfluorinated host for the extraction of PFOA from water utilising non-covalent interactions. NEW J CHEM 2018. [DOI: 10.1039/c7nj03026f] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Three hosts for the encapsulation of perfluorooctanoic acid have been synthesized. The host:guest complexes have been characterized by multinuclear NMR spectroscopy in solution and the solid state.
Collapse
Affiliation(s)
| | - Miguel Palenzuela
- School of Chemistry
- University of Dublin
- Trinity College
- Dublin 2
- Ireland
| | - Manuel Ruether
- School of Chemistry
- University of Dublin
- Trinity College
- Dublin 2
- Ireland
| | - Brendan Twamley
- School of Chemistry
- University of Dublin
- Trinity College
- Dublin 2
- Ireland
| | | | - Robert J. Baker
- School of Chemistry
- University of Dublin
- Trinity College
- Dublin 2
- Ireland
| |
Collapse
|
25
|
Mudumbi JBN, Ntwampe SKO, Matsha T, Mekuto L, Itoba-Tombo EF. Recent developments in polyfluoroalkyl compounds research: a focus on human/environmental health impact, suggested substitutes and removal strategies. ENVIRONMENTAL MONITORING AND ASSESSMENT 2017; 189:402. [PMID: 28721589 DOI: 10.1007/s10661-017-6084-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 06/20/2017] [Indexed: 06/07/2023]
Abstract
Between the late 1940s and early 1950s, humans manufactured polyfluoroalkyl compounds (PFCs) using electrochemical fluorination and telomerisation technologies, whereby hydrogen atoms are substituted by fluorine atoms, thus conferring unnatural and unique physicochemical properties to these compounds. Presently, there are wide ranges of PFCs, and owing to their bioaccumulative properties, they have been detected in various environmental matrices and in human sera. It has thus been suggested that they are hazardous. Hence, this review aims at highlighting the recent development in PFC research, with a particular focus on perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS), the most studied and predominantly found PFCs in various environmental matrices, although recent reports have included perfluorobutane sulfonate (PFBS), which was previously regarded as innocuously harmless, when compared to its counterparts, PFOA and PFOS. As such, proper investigations are thus required for a better understanding of short-chain PFC substitutes, which have been suggested as suitable replacements to long-chained PFCs, although these substitutes have also been suggested to pose various health risks comparable to those associated with long-chain PFCs. Similarly, several novel technologies, such as PFC reduction using zero-valent iron, including removal at point of use, adsorption and coagulation, have been proposed. However, regardless of how efficient removers some of these techniques have proven to be, short-chain PFCs remain a challenge to overcome for scientists, in this regard.
Collapse
Affiliation(s)
- John Baptist Nzukizi Mudumbi
- Bioresource Engineering Research Group (BioERG), Department of Biotechnology, Cape Peninsula University of Technology, PO Box 652, Cape Town, 8000, South Africa.
| | - Seteno Karabo Obed Ntwampe
- Bioresource Engineering Research Group (BioERG), Department of Biotechnology, Cape Peninsula University of Technology, PO Box 652, Cape Town, 8000, South Africa
| | - Tandi Matsha
- Department of Bio-Medical Sciences, Faculty of Health and Wellness Science, Cape Peninsula University of Technology, PO Box 1906, Bellville, 7535, South Africa
| | - Lukhanyo Mekuto
- Bioresource Engineering Research Group (BioERG), Department of Biotechnology, Cape Peninsula University of Technology, PO Box 652, Cape Town, 8000, South Africa
| | - Elie Fereche Itoba-Tombo
- Bioresource Engineering Research Group (BioERG), Department of Biotechnology, Cape Peninsula University of Technology, PO Box 652, Cape Town, 8000, South Africa
| |
Collapse
|
26
|
Liu R, Pu WF, Du DJ. Synthesis and characterization of core–shell associative polymer that prepared by oilfield formation water for chemical flooding. J IND ENG CHEM 2017. [DOI: 10.1016/j.jiec.2016.10.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
27
|
Santos A, Rodríguez S, Pardo F, Romero A. Use of Fenton reagent combined with humic acids for the removal of PFOA from contaminated water. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 563-564:657-663. [PMID: 26412418 DOI: 10.1016/j.scitotenv.2015.09.044] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 09/09/2015] [Accepted: 09/09/2015] [Indexed: 06/05/2023]
Abstract
Perfluorinated compounds (PFCs) are receiving significant attention due to its global distribution, high persistence, and bioaccumulation properties. Among them, perfluorooctanoic acid (PFOA) is one of the most commonly found in the environment. The strong bond C-F in PFOA is extremely difficult to degrade, therefore advanced oxidation processes (AOPs) at room temperature and pressure are not able to oxidize them, as was noticed here using Fenton like reagent (FR) or persulfate (PS) at 25°C. On the contrary, by using persulfate activated by heat (100mM and T=70°C) a complete defluorination of PFOA 0.1mM was noticed after 18h, with a sequential degradation mechanism of losing one CF2 unit from PFOA and its intermediates (perfluoroheptanoic acid (PFHpA), perfluorohexanoic acid (PFHxA), perfluoropentanoic acid (PFPA) and perfluorobutanoic acid (PFBA)). Since this thermal treatment is not usually desirable from an economical point of view, alternative process has been tested. For this scope, a hybrid process is proposed in this work, by adding humic acid, HA, (600mgL(-1)) and FR, (165mM in H2O2 and 3mM in Fe(3+)) to the 0.1mM PFOA solution. It was found that the HA was oxidized by FR. PFOA was entrapped quantitatively and irreversibly during HA oxidation, resulting PFOA non-available to the aqueous phase. Oxidized HA with PFOA entrapped precipitates. Both, the leftover Fe(III) acting as a coagulant and neutral pH enhance the separation of this solid phase. The precipitation noticed by adding HA to the PFOA solution in absence of FR was negligible.
Collapse
Affiliation(s)
- Aurora Santos
- Av. Complutense s/N, Facultad de Ciencias Químicas, Departamento de Ingeniería Química, UCM, Spain.
| | - Sergio Rodríguez
- Av. Complutense s/N, Facultad de Ciencias Químicas, Departamento de Ingeniería Química, UCM, Spain
| | - Fernando Pardo
- Av. Complutense s/N, Facultad de Ciencias Químicas, Departamento de Ingeniería Química, UCM, Spain
| | - Arturo Romero
- Av. Complutense s/N, Facultad de Ciencias Químicas, Departamento de Ingeniería Química, UCM, Spain
| |
Collapse
|
28
|
Perfluorooctane sulfonate removal by nanofiltration membrane—the effect and interaction of magnesium ion / humic acid. J Memb Sci 2016. [DOI: 10.1016/j.memsci.2015.12.049] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
29
|
Zhao HZ, Wang L, Chang YY, Xu Y. High-efficiency removal of perfluorooctanoic acid from water by covalently bound hybrid coagulants (CBHyC) bearing a hydrophobic quaternary ammonium group. Sep Purif Technol 2016. [DOI: 10.1016/j.seppur.2015.11.044] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
30
|
Lin H, Wang Y, Niu J, Yue Z, Huang Q. Efficient Sorption and Removal of Perfluoroalkyl Acids (PFAAs) from Aqueous Solution by Metal Hydroxides Generated in Situ by Electrocoagulation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:10562-10569. [PMID: 26244813 DOI: 10.1021/acs.est.5b02092] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Removal of environmentally persistent perfluoroalkyl acids (PFAAs), that is, perfluorooctanesulfonate (PFOS) and perfluorocarboxylic acids (PFCAs, C4 ∼ C10) were investigated through sorption on four metal hydroxide flocs generated in situ by electrocoagulation in deionized water with 10 mM NaCl as supporting electrolyte. The results indicated that the zinc hydroxide flocs yielded the highest removal efficiency with a wide range concentration of PFOA/PFOS (1.5 μM ∼ 0.5 mM) at the zinc dosage <150 mg L(-1) with the energy consumption <0.18 Wh L(-1). The sorption kinetics indicated that the zinc hydroxide flocs had an equilibrium adsorbed amount (qe) up to 5.74/7.69 mmol g(-1) (Zn) for PFOA/PFOS at the initial concentration of 0.5 mM with an initial sorption rate (v0) of 1.01 × 10(3)/1.81 × 10(3) mmol g(-1) h(-1). The sorption of PFOA/PFOS reached equilibrium within <10 min. The sorption mechanisms of PFAAs on the zinc hydroxide flocs were proposed based on the investigation of various driving forces. The results indicated that the hydrophobic interaction was primarily responsible for the PFAAs sorption. The electrocoagulation process with zinc anode may have a great potential for removing PFAAs from industrial wastewater as well as contaminated environmental waterbody.
Collapse
Affiliation(s)
- Hui Lin
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University , Beijing 100875, P.R. China
- College of Agricultural and Environmental Sciences, Department of Crop and Soil Sciences, University of Georgia , Griffin, Georgia 30223, United States
| | - Yujuan Wang
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University , Beijing 100875, P.R. China
| | - Junfeng Niu
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University , Beijing 100875, P.R. China
| | - Zhihan Yue
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University , Beijing 100875, P.R. China
| | - Qingguo Huang
- College of Agricultural and Environmental Sciences, Department of Crop and Soil Sciences, University of Georgia , Griffin, Georgia 30223, United States
| |
Collapse
|
31
|
Pramanik BK, Pramanik SK, Suja F. A comparative study of coagulation, granular- and powdered-activated carbon for the removal of perfluorooctane sulfonate and perfluorooctanoate in drinking water treatment. ENVIRONMENTAL TECHNOLOGY 2015; 36:2610-2617. [PMID: 25860623 DOI: 10.1080/09593330.2015.1040079] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) are persistent organic pollutants in the environment and their occurrence causes toxicological effects on humans. We examined different conventional coagulant treatments such as alum, ferric chloride and polyaluminium chloride in removing these compounds. These were then compared with a natural coagulant (Moringa oleifera). We also investigated the powdered-activated carbon (PAC) and granular-activated carbon (GAC) for removing these compounds. At an initial dose of 5 mg/L, polyaluminium chloride led to a higher reduction of PFOS/PFOA compared with alum which in turn was higher than ferric. The removal efficiency increased with the increase in coagulant dose and decrease in pH. M. oleifera was very effective in reducing PFOS and PFOA than conventional coagulants, with a reduction efficiencies of 65% and 72%, respectively, at a dose of 30 mg/L. Both PAC and GAC were very effective in reducing these compounds than coagulations. PAC led to a higher reduction in PFOS and PFOA than GAC due to its greater surface area and shorter internal diffusion distances. The addition of PAC (10 min contact time) with coagulation (at 5 mg/L dosage) significantly increased the removal efficiency, and the maximum removal efficiency was for M. oleifera with 98% and 94% for PFOS and PFOA, respectively. The reduction efficiency of PFOS/PFOA was reduced with the increase in dissolved organic concentration due to the adsorption competition between organic molecules and PFOS/PFOA.
Collapse
Affiliation(s)
- Biplob Kumar Pramanik
- a School of Civil, Environmental and Chemical Engineering , RMIT University , GPO Box 2476, Melbourne , 3001 , Australia
| | | | | |
Collapse
|
32
|
|
33
|
Fabrication of novel poly(m-phenylene isophthalamide) hollow fiber nanofiltration membrane for effective removal of trace amount perfluorooctane sulfonate from water. J Memb Sci 2015. [DOI: 10.1016/j.memsci.2014.12.038] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
34
|
Removal of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) from water by coagulation: Mechanisms and influencing factors. J Colloid Interface Sci 2014; 434:59-64. [DOI: 10.1016/j.jcis.2014.07.041] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Revised: 07/23/2014] [Accepted: 07/25/2014] [Indexed: 01/09/2023]
|
35
|
Pan G, Zhou Q, Luan X, Fu QS. Distribution of perfluorinated compounds in Lake Taihu (China): impact to human health and water standards. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 487:778-784. [PMID: 24325846 DOI: 10.1016/j.scitotenv.2013.11.100] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 10/31/2013] [Accepted: 11/19/2013] [Indexed: 06/03/2023]
Abstract
The distribution in water and sediment, the sources/sinks and the risk of perfluorinated compounds (PFCs) in Lake Taihu, China were investigated. The total PFCs concentration was 164 to 299 ng L(-1) in water and 5.8 to 35 ng g(-1) (dw) in sediment. The highest concentrations of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in water were 29.2 ng L(-1) and 136ngL(-1). PFOS was largely associated with sediment, whereas short chain PFCs predominated in water. The partition coefficient (Kd) was positively correlated with the organic carbon fraction (ƒoc) for PFOS but not for the other PFCs. The organic carbon normalized partition coefficient (Koc) increased by 0.51 log units for each additional CF2 moiety from perfluoro-butanesulfonate (PFBS) to PFOS. For the same chain length but different functional groups, the log Koc of PFOS was 1.35 units higher than PFOA. PFOS exhibited the highest affinity for sediment through the partition mechanism, and ƒoc affected the sediment as a sink of PFOS. Although there was no immediate health impact by the intake of the water alone, the consumption of aquatic products may cause potential health risks for animals/humans on the time scale of months to years. The relationship between the concentration, water-sediment distribution, bioaccumulation and toxicity should be considered in determining the water standards of PFCs.
Collapse
Affiliation(s)
- Gang Pan
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Qin Zhou
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Xuan Luan
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Q Shiang Fu
- School of Environmental Science and Technology, Dalian University of Technology, Dalian, China
| |
Collapse
|
36
|
Zhou Q, Pan G, Zhang J. Effective sorption of perfluorooctane sulfonate (PFOS) on hexadecyltrimethylammonium bromide immobilized mesoporous SiO2 hollow sphere. CHEMOSPHERE 2013; 90:2461-6. [PMID: 23219049 DOI: 10.1016/j.chemosphere.2012.11.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 10/27/2012] [Accepted: 11/04/2012] [Indexed: 05/12/2023]
Abstract
The hexadecyltrimethylammonium bromide (HDTMAB) immobilized hollow mesoporous silica spheres were prepared for the efficient removal of perfluorooctane sulfonate (PFOS) from aqueous solution. Besides the traditional sorption behavior including sorption kinetics as well as effect of solution pH and temperature, the effect of increasing volume which simulated the natural river where the rate of solute and solvent was relatively constant and solution volume was always changing was investigated. The result indicated that the residual PFOS concentrations in aqueous phase decreased with increasing solution pH and ionic strength, whereas they increased with increasing temperature. The HDTMAB immobilized material still maintained high efficiency after increasing volume, that is, the removal kept more than 99% after the treatment when the initial PFOS concentration was 1 mg L(-1). The uptake behavior and morphology of spheres which was characterized by transmission electron microscopy (TEM) revealed that the additional HDTMAB and mesoporous shell were responsible for the enhanced sorption of PFOS. It was concluded that electrostatic interaction and Ca-bridge role played an important role in the sorption of PFOS on the mesoporous SiO(2) hollow spheres, whereas, hydrophobic interaction contributed to the nice sorption performance of PFOS on the HDTMAB immobilized sorbent.
Collapse
Affiliation(s)
- Qin Zhou
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | | | | |
Collapse
|
37
|
Xiao F, Simcik MF, Gulliver JS. Mechanisms for removal of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) from drinking water by conventional and enhanced coagulation. WATER RESEARCH 2013; 47:49-56. [PMID: 23123052 DOI: 10.1016/j.watres.2012.09.024] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Revised: 09/02/2012] [Accepted: 09/09/2012] [Indexed: 05/12/2023]
Abstract
Perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) are persistent organic pollutants that have been found to be ubiquitous in the environment. This article, for the first time, delineates removal areas of these polar compounds on a coagulation diagram that associates chemical conditions with different coagulation mechanisms. Variables considered were solution pH, coagulant dosage, coagulants (alum and ferric chloride), natural organic matter (NOM), initial turbidity, and flocculation time. The jar-test results show that conventional coagulation (alum dosage of 10-60 mg/L and final pH of 6.5-8.0) removed ≤20% of PFOS and PFOA. These chemicals tended to be removed better by enhanced coagulation at higher coagulant dosages (>60 mg/L) and (thus) lower final pH (4.5-6.5). A coagulation diagram was developed to define the coagulant dosage and solution pH for PFOS/PFOA removal. The results suggest that the primary PFOS/PFOA removal mechanism is adsorption to fine Al hydroxide flocs freshly formed during the initial stage of coagulation; increasing flocculation time from 2 to 90 min could not further improve PFOS and PFOA removals. Furthermore, the effect of NOM on PFOS/PFOA removal by coagulation was examined, and possible removal mechanisms were discussed.
Collapse
Affiliation(s)
- Feng Xiao
- Department of Civil Engineering, University of Minnesota, Minneapolis, MN 55414, USA.
| | | | | |
Collapse
|
38
|
Gao P, Xue G, Song XS, Liu ZH. Depth filtration using novel fiber-ball filter media for the treatment of high-turbidity surface water. Sep Purif Technol 2012. [DOI: 10.1016/j.seppur.2012.04.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
39
|
Lin H, Niu J, Ding S, Zhang L. Electrochemical degradation of perfluorooctanoic acid (PFOA) by Ti/SnO2-Sb, Ti/SnO2-Sb/PbO2 and Ti/SnO2-Sb/MnO2 anodes. WATER RESEARCH 2012; 46:2281-2289. [PMID: 22381981 DOI: 10.1016/j.watres.2012.01.053] [Citation(s) in RCA: 212] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Revised: 01/12/2012] [Accepted: 01/29/2012] [Indexed: 05/31/2023]
Abstract
Electrochemical decomposition of environmentally persistent perfluorooctanoic acid (PFOA) in aqueous solution was investigated over Ti/SnO(2)-Sb, Ti/SnO(2)-Sb/PbO(2), and Ti/SnO(2)-Sb/MnO(2) anodes. The degradation of PFOA followed pseudo-first-order kinetics. The degradation ratios on Ti/SnO(2)-Sb, Ti/SnO(2)-Sb/PbO(2), and Ti/SnO(2)-Sb/MnO(2) anodes achieved 90.3%, 91.1%, and 31.7%, respectively, after 90 min electrolysis at an initial 100 mg/L PFOA concentration at a constant current density of 10 mA/cm(2) with a 10 mmol/L NaClO(4) supporting electrolyte solution. The defluorination rates of PFOA on these three anodes were 72.9%, 77.4%, 45.6%, respectively. The main influencing factors on electrochemical decomposition of PFOA over Ti/SnO(2)-Sb anode were evaluated, including current density (5-40 mA/cm(2)), initial pH value (3-11), plate distance (0.5-2.0 cm), and initial concentration (5-500 mg/L). The results indicated that PFOA (100 mL of 100 mg/L) degradation ratio and defluorination ratio achieved 98.8% and 73.9%, respectively, at the optimal conditions after 90 min electrolysis. Under this optimal condition, the degradation rate constant and the degradation half-life were 0.064 min(-1) and 10.8 min, respectively. The intermediate products including short-chain perfluorinated carboxylic acids (PFCAs, C(2) ≈ C(6)) and perfluorocarbons (C(2) ≈ C(7)) were detected by electrospray ionization (ESI) mass spectrum. A possible electrochemical degradation mechanism of PFOA including electron transfer, Kolbe decarboxylation, radical reaction, decomposition, and hydrolysis was proposed. The electrochemical technique could be employed to degrade PFOA from contaminated wastewater as well as to reduce the toxicity of PFOA.
Collapse
Affiliation(s)
- Hui Lin
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China
| | | | | | | |
Collapse
|
40
|
Xiao F, Davidsavor KJ, Park S, Nakayama M, Phillips BR. Batch and column study: Sorption of perfluorinated surfactants from water and cosolvent systems by Amberlite XAD resins. J Colloid Interface Sci 2012; 368:505-11. [DOI: 10.1016/j.jcis.2011.11.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2011] [Revised: 10/25/2011] [Accepted: 11/03/2011] [Indexed: 10/15/2022]
|
41
|
Xiao F, Zhang X, Penn L, Gulliver JS, Simcik MF. Effects of monovalent cations on the competitive adsorption of perfluoroalkyl acids by kaolinite: experimental studies and modeling. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2011; 45:10028-35. [PMID: 21985009 DOI: 10.1021/es202524y] [Citation(s) in RCA: 125] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Our hypothesis that longer-chained perfluoroalkyl acids (PFAAs) outcompete shorter-chained PFAAs during adsorption was tested in this study, wherein the adsorption interactions of six frequently detected PFAAs with kaolinite clay were modeled and examined experimentally using various suspension compositions. Competitive adsorption of PFAAs on the kaolinite surface was observed for the first time, and longer-chained PFAAs outcompeted those with a shorter chain. The electrostatic repulsion between adsorbed PFAA molecules is a primary inhibitory factor in PFAA adsorption. An increase in aqueous sodium or hydrogen ion concentration weakened electrostatic repulsions and changed the adsorption free energy. Therefore, the adsorption of a shorter-chained PFAA with weaker hydrophobicity could occur at high sodium or hydrogen ion concentrations. The experimental and modeling data suggest that the adsorption of shorter-chained PFAAs (≤4 perfluorinated carbons) in freshwater with a typical ionic strength of 10(-2.5) is not thermodynamically favorable. Furthermore, by measuring the electrokinetic potential of kaolinite suspension in the presence of PFAAs, we found that the kaolinite surface became more negatively charged because of the adsorption of PFAAs. This observation indicates that the adsorbed PFAA molecules were within the electrical double layer of the kaolinite surface and that they contributed to the potential at the slipping plane. The possible alignments of adsorbed PFAA molecules on the kaolinite surface were then proposed.
Collapse
Affiliation(s)
- Feng Xiao
- Department of Civil Engineering, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | | | | | | | | |
Collapse
|