1
|
Chen L, Shao H, Ren Y, Mao C, Chen K, Wang H, Jing S, Xu C, Xu G. Investigation of the adsorption behavior and adsorption mechanism of pollutants onto electron beam-aged microplastics. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 917:170298. [PMID: 38272098 DOI: 10.1016/j.scitotenv.2024.170298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 01/15/2024] [Accepted: 01/18/2024] [Indexed: 01/27/2024]
Abstract
Microplastics, as an emerging pollutant, are widely distributed worldwide. Extensive research has been conducted to address the issue of microplastic pollution; however, effective methods for microplastic treatment are still lacking. This study innovatively utilizes electron beam technology to age and degrade microplastics. Compared to other treatment methods, electron beam technology can effectively promote the aging and degradation of microplastics. The Oxygen - carbon ratio of aged microplastics reached 0.071, with a mass loss of 48 % and a carbonyl index value of 0.69, making it the most effective method for short-term aging treatment in current research efforts. Theoretical calculations and experimental results demonstrate that a large number of oxygen-containing functional groups are generated on the surface of microplastics after electron beam irradiation, changing their adsorption performance for pollutants. Theoretical calculations show that an increase in oxygen-containing functional groups on the surface leads to a gradual decrease in hydrophobic pollutant adsorption capacity while increasing hydrophilic pollutant adsorption capacity for aged microplastics. Experimental studies were conducted to investigate the adsorption behavior and process of typical pollutants by aged microplastics which conform to pseudo-second-order kinetics and Henry model during the adsorption process, and the adsorption results are consistent with theoretical calculations. The results show that the degradation of microplastics is mainly due to hydroxyl radicals generated by electron beam irradiation, which can break the carbon chain of microplastics and gradually degrade them into small molecular esters and alcohols. Furthermore, studies have shown that microplastics can desorb pollutants in pure water and simulated gastric fluid. Overall, electron beam irradiation is currently the most effective method for degrading microplastics. These results also clearly elucidate the characteristics and mechanisms of the interaction between aged microplastics and organic pollutants, providing further insights for assessing microplastic pollution in real-world environments.
Collapse
Affiliation(s)
- Lei Chen
- School of Environmental and Chemical Engineering, Shanghai University, 99 Shangda Road, Shanghai 200444, PR China
| | - Haiyang Shao
- School of Environmental and Chemical Engineering, Shanghai University, 99 Shangda Road, Shanghai 200444, PR China
| | - Yingfei Ren
- School of Environmental and Chemical Engineering, Shanghai University, 99 Shangda Road, Shanghai 200444, PR China
| | - Chengkai Mao
- School of Environmental and Chemical Engineering, Shanghai University, 99 Shangda Road, Shanghai 200444, PR China
| | - Kang Chen
- School of Environmental and Chemical Engineering, Shanghai University, 99 Shangda Road, Shanghai 200444, PR China
| | - Hongyong Wang
- Key Laboratory of Organic Compound Pollution Control Engineering, Ministry of Education, Shanghai 200444, PR China.
| | - Shuting Jing
- School of Environmental and Chemical Engineering, Shanghai University, 99 Shangda Road, Shanghai 200444, PR China
| | - Chengwei Xu
- School of Environmental and Chemical Engineering, Shanghai University, 99 Shangda Road, Shanghai 200444, PR China
| | - Gang Xu
- School of Environmental and Chemical Engineering, Shanghai University, 99 Shangda Road, Shanghai 200444, PR China; Key Laboratory of Organic Compound Pollution Control Engineering, Ministry of Education, Shanghai 200444, PR China.
| |
Collapse
|
2
|
Wang X, Dai Y, Li Y, Yin L. Application of advanced oxidation processes for the removal of micro/nanoplastics from water: A review. CHEMOSPHERE 2024; 346:140636. [PMID: 37949189 DOI: 10.1016/j.chemosphere.2023.140636] [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: 11/03/2023] [Accepted: 11/05/2023] [Indexed: 11/12/2023]
Abstract
Micro/nanoplastics (MNPs) have been increasingly found in environments, food, and organisms, arousing wide public concerns. MNPs may enter food chains through water, posing a threat to human health. Therefore, efficient and environmentally friendly technologies are needed to remove MNPs from contaminated aqueous environments. Advanced oxidation processes (AOPs) produce a vast amount of active species, such as hydroxyl radicals (·OH), known for their strong oxidation capacity. As a result, an increasing number of researchers have focused on using AOPs to decompose and remove MNPs from water. This review summarizes the progress in researches on the removal of MNPs from water by AOPs, including ultraviolet photolysis, ozone oxidation, photocatalysis, Fenton oxidation, electrocatalysis, persulfate oxidation, and plasma oxidation, etc. The removal efficiencies of these AOPs for MNPs in water and the influencing factors are comprehensively analyzed, meanwhile, the oxidation mechanisms and reaction pathways are also discussed in detail. Most AOPs can achieve the degradation of MNPs, mainly manifest as the decrease of particle size and the increase of mass loss, but the mineralization rate is low, thus requiring further optimization for improved performance. Investigating various AOPs is crucial for achieving the complete decomposition of MNPs in water. AOPs will undoubtedly play a vital role in the future for the removal of MNPs from water.
Collapse
Affiliation(s)
- Xiaojie Wang
- School of Water Resources and Environment, Beijing Key Laboratory of Water Resources & Environmental Engineering, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing, 100083, China.
| | - Yunrong Dai
- School of Water Resources and Environment, Beijing Key Laboratory of Water Resources & Environmental Engineering, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing, 100083, China.
| | - Yang Li
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, China.
| | - Lifeng Yin
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, China.
| |
Collapse
|
3
|
Su X, Liu M, Dai H, Dou J, Lu Z, Xu J, He Y. Novel insight into the aging process of microplastics: An in-situ study in coastal wetlands. WATER RESEARCH 2024; 248:120871. [PMID: 37979566 DOI: 10.1016/j.watres.2023.120871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 11/08/2023] [Accepted: 11/12/2023] [Indexed: 11/20/2023]
Abstract
Coastal wetlands, the critical interface between the terrestrial and marine environments, provide a dynamic and unique environment for the aging of microplastics (MPs). Nevertheless, both abiotic and biotic processes that contribute to the aging of MPs in coastal wetlands have been largely neglected. In this study, the aging of MPs was continuously characterized in Hangzhou Bay, a representative coastal wetland in Zhejiang, China. Three-month exposure of polymers in sediment-water interface induced the aging phenomenon with embrittlement and exfoliation, as evidenced by simultaneous observed alternations in crystallinity and functional groups. A first-order kinetic model was fitted to describe the rate and degree of aging quantitatively. As evidenced by the carbonyl index, the residence time of all the examined MPs exhibited significant variance, ranging from 335 to 661 days. These variations might be caused by the selective attachment of plastic-degrading microorganisms (such as Moraxella sp. and Rhodococcus sp.). A positive correlation between the carbonyl index, the number of OTUs in the MP-associated biofilm, and irradiation was observed (p < 0.001), suggesting that the aging process may be co-regulated by natural sunlight and wetland microbial colonization. This study sheds new light on the long-term environmental fate of MPs and their associated ecological risks.
Collapse
Affiliation(s)
- Xin Su
- Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Meng Liu
- Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Hengyi Dai
- Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Jibo Dou
- Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Zhijiang Lu
- Department of Environmental Science and Geology, Wayne State University, Detroit, MI 48201, United States
| | - Jianming Xu
- Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yan He
- Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, Hangzhou 310058, China.
| |
Collapse
|
4
|
Potential of Advanced Oxidation as Pretreatment for Microplastics Biodegradation. SEPARATIONS 2023. [DOI: 10.3390/separations10020132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
In the last two decades, microplastics (MP) have been identified as an emerging environmental pollutant. Due to their small size, MP particles may easily enter the food chain, where they can have adverse effects on organisms and the environment in general. The common methods for the removal of pollutants from the environment are not fully effective in the elimination of MP; thus, it is necessary to find a more suitable treatment method(s). Among the various approaches tested, biodegradation is by far the most environmentally friendly and economically acceptable remediation approach. However, it has serious drawbacks, generally related to the rather low removal rate and often insufficient efficiency. Therefore, it would be beneficial to use some of the less economical but more efficient methods as pretreatment prior to biodegradation. Such pretreatment would primarily serve to increase the roughness and hydrophilicity of the surface of MP, making it more susceptible to bioassimilation. This review focuses on advanced oxidation processes (AOPs) as treatment methods that can enhance the biodegradation of MP particles. It considers MP particles of the six most commonly used plastic polymers, namely: polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyethylene terephthalate and polyurethane. The review highlights organisms with a high potential for biodegradation of selected MP particles and presents the potential benefits that AOP pretreatment can provide for MP biodegradation.
Collapse
|
5
|
Jeong Y, Gong G, Lee HJ, Seong J, Hong SW, Lee C. Transformation of microplastics by oxidative water and wastewater treatment processes: A critical review. JOURNAL OF HAZARDOUS MATERIALS 2023; 443:130313. [PMID: 36372022 DOI: 10.1016/j.jhazmat.2022.130313] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 10/29/2022] [Accepted: 11/01/2022] [Indexed: 06/16/2023]
Abstract
Microplastics (MPs) are contaminants of emerging concern that accumulate in various environments, where they pose threats to both the ecosystem and public health. Since MPs have been detected in drinking water resources and wastewater effluents, more efficient treatment is needed at wastewater treatment plants (WWTPs) and drinking water treatment plants (DWTPs). This review discusses the potential of biological, photochemical, Fenton (-like) systems, ozonation, and other oxidation processes in the treatment of MPs in terms of their indicators of oxidation such as mass loss and surface oxidation. The oxidation processes were further analyzed in terms of limitations and environmental implications. Most previous studies examining MPs degradation using conventional treatments-such as UV disinfection, ozonation, and chlorination-employed significantly higher doses than the common doses applied in DWTPs and WWTPs. Owing to such dose gaps, the oxidative transformation of MPs observed in many previous studies are not likely to occur under practical conditions. Some novel oxidation processes showed promising MPs treatment efficiencies, while many of them have not yet been applied on a larger scale due to high costs and the lack of extensive basic research. Health and environmental impacts related to the discharge of oxidized MPs in effluents should be considered carefully in different aspects: the role as vectors of external pollutants, release of organic compounds (including organic byproducts from oxidation) and fragmentation into smaller particles as MPs circulate in the ecosystem as well as the possibility of bioaccumulation. Future research should also focus on ways to incorporate developed oxidation processes in DWTPs and WWTPs to mitigate MPs contamination.
Collapse
Affiliation(s)
- Yeonseo Jeong
- Department of Chemical Engineering and Materials Science, University of Minnesota, 21 Washington Ave. SE, Minneapolis, MN 55455-0132, United States
| | - Gyeongtaek Gong
- Clean Energy Research Center, Division of Energy and Environment Technology, KIST-School, University of Science and Technology, Korea Institute of Science and Technology, 5, Hwarang-ro, Seongbuk-gu, Seoul 02792, Republic of Korea
| | - Hye-Jin Lee
- School of Chemical and Biological Engineering, Institute of Chemical Process (ICP), and Institute of Engineering Research, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Jihye Seong
- School of Chemical and Biological Engineering, Institute of Chemical Process (ICP), and Institute of Engineering Research, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Seok Won Hong
- Center for Water Cycle Research, Division of Energy and Environment Technology, KIST-School, University of Science and Technology, Korea Institute of Science and Technology, 5, Hwarang-ro, Seongbuk-gu, Seoul 02792, Republic of Korea.
| | - Changha Lee
- School of Chemical and Biological Engineering, Institute of Chemical Process (ICP), and Institute of Engineering Research, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
| |
Collapse
|
6
|
Separation of plastic wastes using froth flotation - An overview. Adv Colloid Interface Sci 2022; 308:102769. [PMID: 36116142 DOI: 10.1016/j.cis.2022.102769] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 08/29/2022] [Accepted: 08/30/2022] [Indexed: 11/22/2022]
Abstract
Despite various initiatives and efforts, plastic solid waste (PSW) has become a major global problem due to decades of relentless use of plastics. Since non-biodegradable plastics can persist in the environment for hundreds of years, threatening animal and human life, discarding them into the environment is not a viable option. Plastic recycling is a critical research area that requires urgent attention since less than 10% of the seven billion tons of globally generated plastic waste has been recycled so far. With recent technological developments, it is now possible to recycle many types of PSW using a variety of methods. This review provides an overview of the froth flotation technology that is currently being researched for PSW recycling. Fundamental working principles, the current state of the development, and limitations of this technique are reviewed. It is suggested that froth flotation with continuous development has tremendous potential to result in a more efficient and environmentally friendly approach to PSW recycling.
Collapse
|
7
|
Lv M, Jiang B, Xing Y, Ya H, Zhang T, Wang X. Recent advances in the breakdown of microplastics: strategies and future prospectives. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:65887-65903. [PMID: 35876989 DOI: 10.1007/s11356-022-22004-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Accepted: 07/10/2022] [Indexed: 05/26/2023]
Abstract
Microplastics pollution is becoming a major environmental issue, and exposure to microplastics has been associated with numerous adverse results to both the ecological system and humans. This work summarized the state-of-the-art developments in the breakdown of microplastics, including natural weathering, catalysts-assisted breakdown and biodegradation. Characterization techniques for microplastic breakdown involve scanning electron microscopy, Fourier infrared spectroscopy, X-ray photoelectron spectroscopy, etc. Bioavailability and adsorption capacity of microplastics may change after they are broken down, therefore leading to variety in microplastics toxicity. Further prospectives for should be focused on the determination and toxicity evaluation of microplastics breakdown products, as well as unraveling uncultivable microplastics degraders via cultivation-independent approaches. This work benefits researchers interested in environmental studies, particularly the removal of microplastics from environmental matrix.
Collapse
Affiliation(s)
- Mingjie Lv
- School of Energy and Environmental Engineering, University of Science & Technology Beijing, Beijing, 100083, People's Republic of China
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science & Technology Beijing, Beijing, 100083, People's Republic of China
| | - Bo Jiang
- School of Energy and Environmental Engineering, University of Science & Technology Beijing, Beijing, 100083, People's Republic of China.
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science & Technology Beijing, Beijing, 100083, People's Republic of China.
- National Engineering Laboratory for Site Remediation Technologies, Beijing, 100015, People's Republic of China.
| | - Yi Xing
- School of Energy and Environmental Engineering, University of Science & Technology Beijing, Beijing, 100083, People's Republic of China
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science & Technology Beijing, Beijing, 100083, People's Republic of China
| | - Haobo Ya
- School of Energy and Environmental Engineering, University of Science & Technology Beijing, Beijing, 100083, People's Republic of China
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science & Technology Beijing, Beijing, 100083, People's Republic of China
- Zhejiang Development & Planning Institute, Hangzhou, 310030, China
| | - Tian Zhang
- School of Energy and Environmental Engineering, University of Science & Technology Beijing, Beijing, 100083, People's Republic of China
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science & Technology Beijing, Beijing, 100083, People's Republic of China
| | - Xin Wang
- School of Energy and Environmental Engineering, University of Science & Technology Beijing, Beijing, 100083, People's Republic of China
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science & Technology Beijing, Beijing, 100083, People's Republic of China
| |
Collapse
|
8
|
Is the presence of Cu(II) and p-benzoquinone a challenge for the removal of microplastics from landfill leachate? THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 851:158395. [PMID: 36049677 DOI: 10.1016/j.scitotenv.2022.158395] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 08/25/2022] [Accepted: 08/25/2022] [Indexed: 10/18/2022]
Abstract
A large number of plastic wastes generated eventually end up in landfills. The leachate from landfills has become a potential destination for microplastics (MPs). Many researchers have turned their attention to the distribution of MPs in landfill leachate. However, rare researchers mentioned that the efficient removal of MPs in landfill leachate was hard to realized. In this work, we analyzed MPs distribution and composition in leachate from a municipal landfill. Subsequently, to understand the causes of hydrophilization of MPs in leachate, we investigated the flotation percentage of polyvinyl chloride (PVC), polyethylene terephthalate (PET), and polystyrene (PS) MPs when exposure to p-benzoquinone and Cu2+. We conducted experiments on factors including the concentration of pollutants, pH, and interaction time. Meanwhile, the adsorption kinetics, adsorption isotherms, and synergistic effects of p-benzoquinone and Cu2+ were further investigated. The order of the strength of the hydrophilic effect of contaminants on MPs in leachate was p-benzoquinone + Cu2+ > p-benzoquinone > Cu2+. The physisorption and chemisorption of p-benzoquinone and Cu2+ on the MPs surface, respectively, resulted in the hydrophilization of the MPs surface. The order of hydrophilization and the adsorption capacity for pollutants of the three MPs were consistent: PVC > > PET ≈ PS. We proposed a feasible scheme with the oleic acid to restore the hydrophobicity of MPs, which could increase the removal rate of MPs by 87.37 %. This work revealed the hydrophilization effects of pollutants on MPs and proposed a novel insight into the MPs removal from landfill leachate.
Collapse
|
9
|
Lievens S, Slegers T, Mees MA, Thielemans W, Poma G, Covaci A, Van Der Borght M. A simple, rapid and accurate method for the sample preparation and quantification of meso- and microplastics in food and food waste streams. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 307:119511. [PMID: 35613682 DOI: 10.1016/j.envpol.2022.119511] [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: 02/22/2022] [Revised: 05/04/2022] [Accepted: 05/17/2022] [Indexed: 06/15/2023]
Abstract
Plastics are produced and used in large quantities worldwide (e.g. as food packaging). In line with this, plastic particles are found throughout the ecosphere and in various foods. As a result, plastics are also present in energy-rich waste biomass derived from the food industry, supermarkets, restaurants, etc. These waste streams are a valuable source for biogas production but can also be used to feed insects that in turn upcycle it into new high-value biomass. In both applications, the remaining residue can be used as fertilizer. Due to the present plastic particles, these applications could pose a continued threat to the environment, and both human and animal health. Therefore, the need of determining the (micro)plastic content to assess the potential danger is rising. In this research, a closed-vessel microwave-assisted acid digestion method was developed to accurately determine meso- and microplastic contents in food (waste) matrices by solubilising this food matrix. Polyvinyl chloride (PVC) food packaging foil was used to develop the method, using a full factorial design with three parameters (nitric acid concentration (c(HNO3)), temperature (T), and time (t)). According to this model, the best practical conditions were c(HNO3) = 0.50 mol/L, T = 170 °C, and t = 5.00 min. Subsequently, the method was tested on five other plastics, namely high- and low-density polyethylene (HDPE and LDPE), polypropylene (PP), polystyrene (PS), and polyethylene terephthalate (PET), mixed with a food matrix, resulting in a mean plastic recovery of 102.2 ± 4.1%. Additionally, the polymers were not oxidised during the microwave digestion. For PVC and PS hardly any degradation was found, while HDPE, LDPE, and PP showed slight chain degradation, although without recovery loss. In conclusion, the method is an accurate approach to quantify the total meso- and microplastic content in food (waste) matrices with minimal change in their intrinsic characteristics.
Collapse
Affiliation(s)
- Siebe Lievens
- KU Leuven - Campus Geel, Department of Microbial and Molecular Systems, Faculty of Engineering Technology, Research Group for Insect Production and Processing, Kleinhoefstraaat 4, 2440, Geel, Belgium; University of Antwerp - Campus Drie Eiken, Department of Pharmaceutical Sciences, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, Toxicological Centre, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - Thomas Slegers
- KU Leuven - Campus Geel, Department of Microbial and Molecular Systems, Faculty of Engineering Technology, Research Group for Insect Production and Processing, Kleinhoefstraaat 4, 2440, Geel, Belgium
| | - Maarten A Mees
- KU Leuven - Campus Kulak Kortrijk, Department of Chemical Engineering, Faculty of Engineering Science, Sustainable Materials Lab, Etienne Sabbelaan 53, 8500, Kortrijk, Belgium
| | - Wim Thielemans
- KU Leuven - Campus Kulak Kortrijk, Department of Chemical Engineering, Faculty of Engineering Science, Sustainable Materials Lab, Etienne Sabbelaan 53, 8500, Kortrijk, Belgium
| | - Giulia Poma
- University of Antwerp - Campus Drie Eiken, Department of Pharmaceutical Sciences, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, Toxicological Centre, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - Adrian Covaci
- University of Antwerp - Campus Drie Eiken, Department of Pharmaceutical Sciences, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, Toxicological Centre, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - Mik Van Der Borght
- KU Leuven - Campus Geel, Department of Microbial and Molecular Systems, Faculty of Engineering Technology, Research Group for Insect Production and Processing, Kleinhoefstraaat 4, 2440, Geel, Belgium.
| |
Collapse
|
10
|
Jiang H, Zhang Y, Wang C, Wang H. A clean and efficient flotation towards recovery of hazardous polyvinyl chloride and polycarbonate microplastics through selective aluminum coating: Process, mechanism, and optimization. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 299:113626. [PMID: 34488105 DOI: 10.1016/j.jenvman.2021.113626] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 08/21/2021] [Accepted: 08/24/2021] [Indexed: 06/13/2023]
Abstract
Polyvinyl chloride (PVC) and polycarbonate (PC) microplastics are major sources of hazardous chlorine and bisphenol A, threatening the ecosystem and environment. Plastic recycling can control the source of microplastics pollution, but the recycling of PVC and PC will be prevented by invalid separation. We established a novel and clean flotation method to separate PVC and PC microplastics by using aluminum coating. Trace amounts of Al(OH)3 can selectively coat the PVC microplastics surface due to its strong affinity for PVC. The contact angle of PVC decreases by 24° due to abundant hydroxyl groups of Al(OH)3 coating, whereas PC remained hydrophobic. Response surface methodology (RSM) combining Box-Behnken design (BBD) is used to optimize modification. A quadratic model is established to predict PC purity, explore the interaction between pH, aluminum chloride concentration, and ultrasonic duration. The recovery and purity of microplastics can exceed 99.65% with parameter optimization. The effects of multi-component, brand, shape, size, and mass ratio of plastics are utilized to evaluate the application potential. The suitable situations and limits of this method are disclosed. The aluminum coating offers significant benefits over other modifications in terms of reaction temperature, treatment time, and pollution prevention. Flotation based on aluminum coating provides a new insight for separating and recycling microplastics.
Collapse
Affiliation(s)
- Hongru Jiang
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, Hunan, PR China
| | - Yingshuang Zhang
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, Hunan, PR China
| | - Chongqing Wang
- School of Chemical Engineering, Zhengzhou University, Zhengzhou, 450001, PR China
| | - Hui Wang
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, Hunan, PR China.
| |
Collapse
|
11
|
Miao Y, Wen S, Feng Q, Liao R. Enhanced adsorption of salicylhydroxamic acid on ilmenite surfaces modified by Fenton and its effect on floatability. Colloids Surf A Physicochem Eng Asp 2021. [DOI: 10.1016/j.colsurfa.2021.127057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
12
|
Du H, Xie Y, Wang J. Microplastic degradation methods and corresponding degradation mechanism: Research status and future perspectives. JOURNAL OF HAZARDOUS MATERIALS 2021; 418:126377. [PMID: 34130168 DOI: 10.1016/j.jhazmat.2021.126377] [Citation(s) in RCA: 78] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 04/22/2021] [Accepted: 04/23/2021] [Indexed: 06/12/2023]
Abstract
Microplastics (MPs) pollution has become a global environmental concern because of their severe threat to biota. However, limited studies on the elimination of MPs pollution were reported. The conventional treatment methods were not suitable for MPs owing to their smaller size than plastic items. Hence many methods for MPs treatment have been examined. This review summarized the recently reported MPs degradation methods including AOPs (direct photodegradation, photocatalytic oxidation, and electrochemical oxidation) and biodegradation, corresponding degradation mechanism as well as current development state. The characteristics and limitations of each technique were discussed in detail. We found that all of them achieved almost satisfying degradation performance of MPs, but most of them exhibited that MPs can only be degraded partially into useful products or even CO2 and H2O under lab conditions. Given these, some recommendations for future research directions were proposed based on the knowledge gaps in these reported literatures. The aim of this review is to give a comprehensive introduction of several MPs degradation methods and acquaint the readers with the current research status of MPs degradation.
Collapse
Affiliation(s)
- Hao Du
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou 510642, China
| | - Yuqun Xie
- School of Bioengineering and Food Science, Hubei University of Technology, Wuhan 430068, Hubei, China
| | - Jun Wang
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou 510642, China; Institute of Eco-Environmental Research, Guangxi Academy of Sciences, Nanning 530007, China.
| |
Collapse
|
13
|
Hu K, Tian W, Yang Y, Nie G, Zhou P, Wang Y, Duan X, Wang S. Microplastics remediation in aqueous systems: Strategies and technologies. WATER RESEARCH 2021; 198:117144. [PMID: 33933920 DOI: 10.1016/j.watres.2021.117144] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 04/05/2021] [Accepted: 04/11/2021] [Indexed: 06/12/2023]
Abstract
In recent years, the ubiquitous detection and accumulation of microplastics (MPs) in the aquatic environment have raised significant concerns on water security and long-term ecological impacts all around the world. Nevertheless, critical reviews on strategic control and effective remediation of MPs in the aqueous phase are still lacking. In this work, we summarise the origins and types of MPs, and then introduce the methodologies for extraction, identification and quantification. More importantly, we for the first time provide a comprehensive overview of the recent advances in the emerging MPs removal and transformation technologies. Except for biodegradation, this review presents new applications of advanced oxidation processes (AOPs) for MPs degradation and utilisation, including photocatalysis, photoreforming and Fenton-like reactions. Physical or catalytic thermal treatment can transform plastics into value-added nanocarbons or hydrocarbons. These transformation technologies demonstrate great potentials in dealing with MPs. The review will guide researchers to further explore the feasible approaches and develop new strategies for advanced control and remediation of MPs in the future.
Collapse
Affiliation(s)
- Kunsheng Hu
- School of Chemical Engineering and Advanced Materials, The University of Adelaide, Adelaide SA 5005, Australia
| | - Wenjie Tian
- School of Chemical Engineering and Advanced Materials, The University of Adelaide, Adelaide SA 5005, Australia
| | - Yangyang Yang
- School of Chemical Engineering and Advanced Materials, The University of Adelaide, Adelaide SA 5005, Australia
| | - Gang Nie
- Department of Environmental Science and Engineering, Wuhan University, Wuhan 430079, China
| | - Peng Zhou
- College of Architecture & Environment, Sichuan University, Chengdu 610065, China
| | - Yuxian Wang
- State Key Laboratory of Heavy Oil Processing, State Key Laboratory of Petroleum Pollution Control, China University of Petroleum-Beijing, Beijing 102249, China
| | - Xiaoguang Duan
- School of Chemical Engineering and Advanced Materials, The University of Adelaide, Adelaide SA 5005, Australia.
| | - Shaobin Wang
- School of Chemical Engineering and Advanced Materials, The University of Adelaide, Adelaide SA 5005, Australia.
| |
Collapse
|
14
|
Liu P, Shi Y, Wu X, Wang H, Huang H, Guo X, Gao S. Review of the artificially-accelerated aging technology and ecological risk of microplastics. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 768:144969. [PMID: 33736298 DOI: 10.1016/j.scitotenv.2021.144969] [Citation(s) in RCA: 91] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 01/01/2021] [Accepted: 01/02/2021] [Indexed: 05/21/2023]
Abstract
After being discarded into the environment, the microplastics (MPs) will undergo weathering effects. However, the low degradation rate of MPs in natural processes greatly limits the understanding of long-term aging behavior. By critically reviewing 82 articles in Web of Science from 2015 to 2020, the paper summarized different laboratory technologies including light irradiation, chemical oxidation, heat treatment and γ-ray irradiation to simulate and accelerate the aging of MPs, and evaluated the feasibility by comparison with natural processes. The advantages of laboratory technologies are that aging conditions can be artificially controlled and that the labor and time costs can be saved, whereas the laboratory system is too simple to simulate complex aging processes in the environment. We further reviewed the potential impacts of aging process on the risks of MPs (i.e. physical injury, combined toxicity with external pollutants and chemical risk of additives and low-molecular products). The overall risks are seemingly enhanced by aging process due to the high ingestion by organisms, the strong interaction with pollutants and the release of MP-derived organic compounds. Further studies on the aging behavior of MPs should be focused on the laboratory techniques that can simulate multiple processes of natural aging, the long-term fragmentation behavior of MPs, the effect of aging on growth rate of biofilm in MPs and ingestion property by organisms, and the relationship between aging property of MPs and release rate of chemicals in leachates.
Collapse
Affiliation(s)
- Peng Liu
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China; Key Laboratory of Plant Nutrition and the Agri-Environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi 712100, China; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, China
| | - Yanqi Shi
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, China
| | - Xiaowei Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, China
| | - Hanyu Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, China
| | - Hexinyue Huang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, China
| | - Xuetao Guo
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China; Key Laboratory of Plant Nutrition and the Agri-Environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi 712100, China
| | - Shixiang Gao
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, China.
| |
Collapse
|
15
|
Thanh Truc NT, Le HA, Lee BK. Sono-oxidation treatment of hazardous ABS/PC surface for its selective separation from ESR styrene plastics. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:24771-24784. [PMID: 33244696 DOI: 10.1007/s11356-020-11796-8] [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: 04/16/2020] [Accepted: 11/23/2020] [Indexed: 06/11/2023]
Abstract
This study reports the selective hydrophilization of the ABS/PC blend surface using the peroxide-sonochemical system and then its selective separation by froth flotation technique from other ABS-based plastics (ABS, ABS/PMMA) and PS/HIPS in electronic shredder residue (ESR). FT-IR and XPS measurements confirm that the hydrophilic moiety development on the ABS/PC surface led to increasing the wettability of ABS/PC and then decreased its floatability. The confocal scanning results also support the enhancement of microscale roughness of the treated ABS/PC surface. The enhanced surface roughness is attributed to the oxidative process which degrades hydrophobic moieties and promotes hydrophilic functional groups on the ABS/PC surface using commercial oxidant peroxide and ultrasound. This study also investigated removal of Br-containing compounds on the ABS/PC surface. The optimum conditions for selectively ABS/PC separation are peroxide concentration 2%, power cycle 70%, treatment time 5 min, temperature 50 °C, floating agent concentration 0.4 mg/L, flotation time 2 min, and airflow rate 0.5 L/min. ABS/PC was selectively separated from ESR styrene plastics with high recovery and purity of 98.9% and 99.8%, respectively. Hence, the developed novel surface treatments having removal of hazardous Br chemicals and none-formation of secondary pollutants should be applied for upgrading plastic recycling quality.
Collapse
Affiliation(s)
- Nguyen Thi Thanh Truc
- Institute for the Environmental Science, Engineering and Management, Industrial University of Ho Chi Minh City, No.12, Nguyen Van Bao Street, Ward 4, Go Vap District, Ho Chi Minh City, 70000, Vietnam
| | - Hung Anh Le
- Institute for the Environmental Science, Engineering and Management, Industrial University of Ho Chi Minh City, No.12, Nguyen Van Bao Street, Ward 4, Go Vap District, Ho Chi Minh City, 70000, Vietnam
| | - Byeong-Kyu Lee
- Department of Civil and Environmental Engineering, University of Ulsan, Daehakro 93, Namgu, Ulsan, 44610, Republic of Korea.
| |
Collapse
|
16
|
Nchoe OB, Ntuli TD, Klink MJ, Mtunzi FM, Pakade VE. A comparative study of acid-treated, base-treated, and Fenton-like reagent-treated biomass for Cr(VI) sequestration from aqueous solutions. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2021; 93:370-383. [PMID: 32735759 DOI: 10.1002/wer.1421] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 07/14/2020] [Accepted: 07/18/2020] [Indexed: 06/11/2023]
Abstract
A wide variety of biomass materials have been used for the removal of toxic chromium(VI) by biosorption. The current study investigated the efficacy of Macadamia nutshells treated with sodium hydroxide, nitric acid, and the Fenton-like reagent in the removal of Cr(VI). The adsorbents were characterized by FTIR, SEM, TGA, and elemental analysis. Effects of functional parameters influencing the adsorption of Cr(VI), solution pH (pH 1-11), contact time (5-250 min), concentration of adsorbent (1-10 g/L), and adsorbate concentration (10-200 mg/L) were investigated. The optimum conditions for biosorption were pH 1.4, adsorbent dose of 5 g/L, and 160 min of contact time. In all cases, the base-treated adsorbent displayed superior performance compared to others, with highest percent removal of 98%. The adsorbate-adsorbent interactions were better explained by the Freundlich isotherm and the pseudo-first-order rate model. The Macadamia-based adsorbents are potentially useful for Cr(VI) removal from aqueous solutions. PRACTITIONER POINTS: Three different chemical activators were investigated for the modification of Macadamia surface. The base-treated material exhibited the highest specific surface area of 12.1 m2 /g. The Cr(VI) adsorption performance for the base-treated material dwarfed the other materials. Excellent Cr(VI) removal efficiency in the presence of competitors was achieved.
Collapse
Affiliation(s)
- Obakeng B Nchoe
- Department of Chemistry, Vaal University of Technology, Vanderbijlpark, South Africa
| | - Themba D Ntuli
- Department of Chemistry, Vaal University of Technology, Vanderbijlpark, South Africa
| | - Michael J Klink
- Department of Chemistry, Vaal University of Technology, Vanderbijlpark, South Africa
| | - Fanyana M Mtunzi
- Department of Chemistry, Vaal University of Technology, Vanderbijlpark, South Africa
| | - Vusumzi E Pakade
- Department of Chemistry, Vaal University of Technology, Vanderbijlpark, South Africa
| |
Collapse
|
17
|
Jing Y, Wang Y, Furukawa S, Xia J, Sun C, Hülsey MJ, Wang H, Guo Y, Liu X, Yan N. Towards the Circular Economy: Converting Aromatic Plastic Waste Back to Arenes over a Ru/Nb
2
O
5
Catalyst. Angew Chem Int Ed Engl 2021; 60:5527-5535. [DOI: 10.1002/anie.202011063] [Citation(s) in RCA: 69] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 11/23/2020] [Indexed: 12/12/2022]
Affiliation(s)
- Yaxuan Jing
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Feringa Nobel Prize Scientist Joint Research Center Research Institute of Industrial Catalysis School of Chemistry and Molecular Engineering East China University of Science and Technology Shanghai 200237 China
- Department of Chemical & Biomolecular Engineering National University of Singapore 4 Engineering Drive 4 Singapore 117585 Singapore
| | - Yanqin Wang
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Feringa Nobel Prize Scientist Joint Research Center Research Institute of Industrial Catalysis School of Chemistry and Molecular Engineering East China University of Science and Technology Shanghai 200237 China
| | - Shinya Furukawa
- Institute for Catalysis Hokkaido University N-21, W-10 Sapporo 001-0021 Japan
- Elements Strategy Initiative for Catalysis and Battery Kyoto University, Kyoto Daigaku Katsura, Nishikyo-ku Kyoto 615-8510 Japan
| | - Jie Xia
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Feringa Nobel Prize Scientist Joint Research Center Research Institute of Industrial Catalysis School of Chemistry and Molecular Engineering East China University of Science and Technology Shanghai 200237 China
| | - Chengyang Sun
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Feringa Nobel Prize Scientist Joint Research Center Research Institute of Industrial Catalysis School of Chemistry and Molecular Engineering East China University of Science and Technology Shanghai 200237 China
| | - Max J. Hülsey
- Department of Chemical & Biomolecular Engineering National University of Singapore 4 Engineering Drive 4 Singapore 117585 Singapore
| | - Haifeng Wang
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Feringa Nobel Prize Scientist Joint Research Center Research Institute of Industrial Catalysis School of Chemistry and Molecular Engineering East China University of Science and Technology Shanghai 200237 China
| | - Yong Guo
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Feringa Nobel Prize Scientist Joint Research Center Research Institute of Industrial Catalysis School of Chemistry and Molecular Engineering East China University of Science and Technology Shanghai 200237 China
| | - Xiaohui Liu
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Feringa Nobel Prize Scientist Joint Research Center Research Institute of Industrial Catalysis School of Chemistry and Molecular Engineering East China University of Science and Technology Shanghai 200237 China
| | - Ning Yan
- Department of Chemical & Biomolecular Engineering National University of Singapore 4 Engineering Drive 4 Singapore 117585 Singapore
| |
Collapse
|
18
|
Jing Y, Wang Y, Furukawa S, Xia J, Sun C, Hülsey MJ, Wang H, Guo Y, Liu X, Yan N. Towards the Circular Economy: Converting Aromatic Plastic Waste Back to Arenes over a Ru/Nb
2
O
5
Catalyst. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202011063] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Yaxuan Jing
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Feringa Nobel Prize Scientist Joint Research Center Research Institute of Industrial Catalysis School of Chemistry and Molecular Engineering East China University of Science and Technology Shanghai 200237 China
- Department of Chemical & Biomolecular Engineering National University of Singapore 4 Engineering Drive 4 Singapore 117585 Singapore
| | - Yanqin Wang
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Feringa Nobel Prize Scientist Joint Research Center Research Institute of Industrial Catalysis School of Chemistry and Molecular Engineering East China University of Science and Technology Shanghai 200237 China
| | - Shinya Furukawa
- Institute for Catalysis Hokkaido University N-21, W-10 Sapporo 001-0021 Japan
- Elements Strategy Initiative for Catalysis and Battery Kyoto University, Kyoto Daigaku Katsura, Nishikyo-ku Kyoto 615-8510 Japan
| | - Jie Xia
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Feringa Nobel Prize Scientist Joint Research Center Research Institute of Industrial Catalysis School of Chemistry and Molecular Engineering East China University of Science and Technology Shanghai 200237 China
| | - Chengyang Sun
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Feringa Nobel Prize Scientist Joint Research Center Research Institute of Industrial Catalysis School of Chemistry and Molecular Engineering East China University of Science and Technology Shanghai 200237 China
| | - Max J. Hülsey
- Department of Chemical & Biomolecular Engineering National University of Singapore 4 Engineering Drive 4 Singapore 117585 Singapore
| | - Haifeng Wang
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Feringa Nobel Prize Scientist Joint Research Center Research Institute of Industrial Catalysis School of Chemistry and Molecular Engineering East China University of Science and Technology Shanghai 200237 China
| | - Yong Guo
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Feringa Nobel Prize Scientist Joint Research Center Research Institute of Industrial Catalysis School of Chemistry and Molecular Engineering East China University of Science and Technology Shanghai 200237 China
| | - Xiaohui Liu
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Feringa Nobel Prize Scientist Joint Research Center Research Institute of Industrial Catalysis School of Chemistry and Molecular Engineering East China University of Science and Technology Shanghai 200237 China
| | - Ning Yan
- Department of Chemical & Biomolecular Engineering National University of Singapore 4 Engineering Drive 4 Singapore 117585 Singapore
| |
Collapse
|
19
|
Du Y, Zhang Y, Jiang H, Li T, Luo M, Wang L, Wang C, Wang H. Hydrophilic modification of polycarbonate surface with surface alkoxylation pretreatment for efficient separation of polycarbonate and polystyrene by froth flotation. WASTE MANAGEMENT (NEW YORK, N.Y.) 2020; 118:471-480. [PMID: 32979778 DOI: 10.1016/j.wasman.2020.09.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 09/02/2020] [Accepted: 09/06/2020] [Indexed: 06/11/2023]
Abstract
Waste polystyrene (PS) and polycarbonate (PC) are crucial components arising from mixtures of plastic products, whose recycling is significantly limited by separation efficiency. In this work, to assist the flotation separation of PC and PS, we proposed a novel modification technology of surface alkoxylation pretreatment (SAP) where PC surface reacted with glycerol and urea. The SAP could selectively transform the hydrophobic PC into hydrophilic plastic, while the PS remained its hydrophobic surface owing to the exclusion from SAP process. Benefiting from the hydrophilic PC, the separation efficiency of PS and PC could reach the maximum of 99.34% under optimum conditions (urea dosage of 5 g, pretreatment temperature of 130 °C, pretreatment time of 10 min, flotation time of 2.5 min, frother concentration of 16.5 mg/L, and airflow rate of 7.2 mL/min). The mechanism of SAP was systematically analyzed by wettability, surface morphology, molecular weight, and chemical reactions. Compared with PS plastic, the pretreated PC presented better wettability, rougher surface, and significantly reducing molecular weight. The improvement of PC hydrophilicity can be attributed to the cleavage of ester bonds on backbone chains and the introduction of hydrophilic hydroxyl groups. The effective SAP process proves that chemical recycling of waste plastic can provide a novel strategy for surface modification and flotation separation of PS and PC.
Collapse
Affiliation(s)
- Yichen Du
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China
| | - Yingshuang Zhang
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China
| | - Hongru Jiang
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China
| | - Tianshu Li
- Ansteel Mining Co. Ltd., Anshan 114001, China
| | - Maozhi Luo
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China
| | - Ling Wang
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China
| | - Chongqing Wang
- School of Chemical Engineering and Energy, Zhengzhou University, Zhengzhou 450001, China
| | - Hui Wang
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China.
| |
Collapse
|
20
|
Lee H, Lee H. Separation of auto shredder residue materials using an air table to achieve highly efficient recycling rate. SEP SCI TECHNOL 2020. [DOI: 10.1080/01496395.2020.1824239] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Hansol Lee
- Resources Recycling, University of Science and Technology, Daejeon, Republic of Korea
| | - Hoon Lee
- Mineral Resources Research Division, Korea Institute of Geoscience and Mineral Resources, Daejeon, Republic of Korea
| |
Collapse
|
21
|
Jiang H, Zhang Y, Wang H. Surface Reactions in Selective Modification: The Prerequisite for Plastic Flotation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:9742-9756. [PMID: 32659077 DOI: 10.1021/acs.est.9b07861] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Improper disposal of waste plastic has caused much environmental pollution, but plastic recycling can reduce the amount of new and residual waste plastic in the environment through source control. Plastic flotation can separate waste plastics with similar physical and chemical properties, which suggests its promising application in plastic recycling. With the help of the different hydrophilicities waste plastic can be separated by flotation, and hydrophilization can be accomplished by surface modifications. However, no systematic studies addressing these surface reactions have been published yet, and such modifications are a prerequisite for plastic flotation. In this critical review, we not only summarize the various modification mechanisms, including physical regulation, surface oxidation, surface degradation, dechlorination, and coating, but also have reasonably added additional information for some reactions covering surface reconstruction, plastic degradation, polymer stability, wastewater treatment, soil remediation, and chemical recycling of plastic. An entirely novel concept, the "plastic gene", is also proposed to elaborate on some contradictory results. Plastic flotation with clear surface reactions may promote plastic recycling and thereby control waste plastic at the source, save energy, and reduce microplastics. We also predict challenges for clean, efficient, and practical surface modifications and plastic flotation.
Collapse
Affiliation(s)
- Hongru Jiang
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan P.R. China
| | - Yingshuang Zhang
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan P.R. China
| | - Hui Wang
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan P.R. China
| |
Collapse
|
22
|
Wang J, Wang H, Yue D. Optimizing green ferrate (VI) modification towards flotation separation of waste polyvinylchloride and acrylonitrile-butadiene-styrene mixtures. WASTE MANAGEMENT (NEW YORK, N.Y.) 2020; 101:83-93. [PMID: 31604161 DOI: 10.1016/j.wasman.2019.09.039] [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: 07/14/2019] [Revised: 09/06/2019] [Accepted: 09/28/2019] [Indexed: 06/10/2023]
Abstract
The recycling of waste plastics is of considerable significance with environmental and economic benefits, while available separation approaches have been considered as a major bottleneck for its widespread application. Thus, we proposed a simple method, flotation along with surface modification, to separate waste acrylonitrile-butadienestyrene and polyvinylchloride mixtures. Single-factor experiment was conducted to determine the critical parameters in surface modification. Surface response methodology using Box-Behnken Design was performed to optimize separation performance. The quadratic models were generated to predict the floatability of acrylonitrile-butadienestyrene and the difference between the floatability of polyvinylchloride and acrylonitrile-butadienestyrene. The model was also utilized to determine optimized conditions by desirability approaches. The optimized conditions were: concentration = 0.18 M, temperature = 75.00 °C, treatment time = 11.50 min along with stirring rate = 200 rpm. The efficient separation of acrylonitrile-butadienestyrene and polyvinylchloride was achieved, yielding recovery of 98.40% and purity of 98.43%. The experimental responses well agreed with predicted values, demonstrating the accuracy of the prediction model. The formed hydrophilic groups, coated iron oxide, and signs of corrosion were confirmed as the major mechanism for the selective surface hydrophilization of acrylonitrile-butadienestyrene. Consequently, this method is feasible for separation of waste acrylonitrile-butadienestyrene and polyvinylchloride mixtures, and can be expected to promote the sustainable recycling of waste plastics.
Collapse
Affiliation(s)
- Jianchao Wang
- School of Environment, Tsinghua University, Beijing 100084 China
| | - Hui Wang
- School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, China.
| | - Dongbei Yue
- School of Environment, Tsinghua University, Beijing 100084 China.
| |
Collapse
|
23
|
Zhong Y, Wang H, Wang J, Zhang Y, Wang K, Guo C, Chen S, Luo M, Du Y, Wang L. Combination of sodium hypochlorite pretreatment and flotation towards separation of polycarbonate from waste plastic mixtures. WASTE MANAGEMENT (NEW YORK, N.Y.) 2019; 99:112-121. [PMID: 31476636 DOI: 10.1016/j.wasman.2019.08.040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 07/15/2019] [Accepted: 08/25/2019] [Indexed: 06/10/2023]
Abstract
This study developed a novel method, surface pretreatment using sodium hypochlorite along with flotation, to facilitate separation of waste polycarbonate from plastic mixtures for recycling. Surface pretreatment was observed that has an obviously negative effect on the floating ratio of polycarbonate and the floating ratio of poly-methyl-methacrylate, polystyrene, and polyvinylchloride was not affected in flotation, and this difference in floating ratio can be expected to separate polycarbonate from plastic mixtures. The optimum conditions obtained included sodium hypochlorite concentration of 0.05 M, pretreatment temperature of 70.0 °C, pretreatment time of 60.0 min, frother dosage of 10.8 mg/L, and flotation time of 4.0 min. Under optimum conditions, polycarbonate was separated effectively from multiple plastic mixtures, and the purity and recovery were 99.8% and 100.0%, respectively. The major mechanism of surface pretreatment was ascertained by the aid of Fourier transform infrared, scanning electron microscope, energy dispersive spectrometer, and X-ray photoelectron spectroscopy, and the hydrophilic groups, pitting, and protuberances introduced on polycarbonate surface caused the reduced floating ratio of polycarbonate. Accordingly, this method can be expected to improve the recycling quality of waste plastics, and provides technological insights in the environmentally friendly disposal of waste plastics.
Collapse
Affiliation(s)
- Yiwei Zhong
- School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, PR China
| | - Hui Wang
- School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, PR China.
| | - Jianchao Wang
- School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, PR China; School of Environment, Tsinghua University, Beijing 100084, PR China.
| | - Yingshuang Zhang
- School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, PR China
| | - Kangyu Wang
- School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, PR China
| | - Chenchao Guo
- School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, PR China
| | - Shuaijun Chen
- School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, PR China
| | - Maozhi Luo
- School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, PR China
| | - Yichen Du
- School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, PR China
| | - Ling Wang
- School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, PR China
| |
Collapse
|
24
|
Wang H, Zhang Y, Wang C. Surface modification and selective flotation of waste plastics for effective recycling——a review. Sep Purif Technol 2019. [DOI: 10.1016/j.seppur.2019.05.052] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
|
25
|
Luo M, Wang H, Zhang Y, Zhong Y, Wang K. Surface treatment by the Fe(III)/sulfite system for flotation separation of hazardous chlorinated plastics from the mixed waste plastics. JOURNAL OF HAZARDOUS MATERIALS 2019; 377:34-41. [PMID: 31132679 DOI: 10.1016/j.jhazmat.2019.05.049] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2018] [Revised: 05/18/2019] [Accepted: 05/20/2019] [Indexed: 06/09/2023]
Abstract
A novel advanced oxidation process by a combination of Fe(III) and sulfite for surface treatment of waste plastic mixtures is proposed. The Fe(III)/sulfite system has been found to enhance hydrophilicity of the mixed waste plastics, including acrylonitrile butadiene styrene (ABS), polystyrene (PS) and polycarbonate (PC), while it has little effect on hazardous polyvinyl chloride (PVC), thus promoting separation of PVC from the mixed waste plastics by flotation. Radical scavenging experiments indicate that sulfate radicals are the main reactive species. Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS) results imply the formation of CO or CO groups on the treated plastics surface except for PVC and a plausible mechanism for oxidizing plastics with sulfate radicals is proposed. PVC with 100.00% recovery and 99.84% purity is achieved under optimum surface treatment conditions of sodium sulfite concentration 10 mM, ferric sulfate concentration 0.4 mM, pH 6.0, temperature 25 °C and treatment time 15 min. Consequently, surface treatment by the Fe(III)/sulfite system is an effective technology for separating hazardous PVC from the mixed waste plastics by flotation.
Collapse
Affiliation(s)
- Maozhi Luo
- School of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, Hunan, China
| | - Hui Wang
- School of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, Hunan, China.
| | - Yingshuang Zhang
- School of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, Hunan, China
| | - Yiwei Zhong
- School of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, Hunan, China
| | - Kangyu Wang
- School of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, Hunan, China
| |
Collapse
|
26
|
Zhang Y, Chen S, Wang H, Luo M. Separation of polyvinylchloride and acrylonitrile-butadiene-styrene combining advanced oxidation by S 2O 82-/Fe 2+ system and flotation. WASTE MANAGEMENT (NEW YORK, N.Y.) 2019; 91:80-88. [PMID: 31203945 DOI: 10.1016/j.wasman.2019.04.048] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 04/21/2019] [Accepted: 04/22/2019] [Indexed: 06/09/2023]
Abstract
A combining technology of advanced oxidation by S2O82-/Fe2+ system and flotation was proposed for separating polyvinyl chloride (PVC) and acrylonitrile butadiene styrene (ABS). In this research, sodium persulfate was activated by heating and ferrous ions. The separation efficiency of PVC/ABS oxidized by S2O82-/Fe2+ was higher than that by sodium persulfate. The mechanism of this process was investigated through contact angle, Fourier transform infrared spectroscopy (FT-IR) inductively coupled plasma (ICP), nuclear magnetic resonance (NMR) and X-ray photoelectron spectroscopy (XPS). The floatability of ABS reduced owing to the introduction of oxygen-containing functional groups such as carbonyl (OCO) and hydroxyl (OH), which was a result of oxidation by sulfate radicals (SO4·-). The optimal conditions for separating PVC and ABS were: Na2S2O8 concentration 0.1 M, molar ratio (S2O82-/Fe2+) 200, treatment time 10 min, flotation time 4 min, frother concentration 14.7 mg L-1 and airflow rate 6.8 mL min-1. Novel kinetics of pretreatment time and flotation were proposed and researched in this work. The max rate constant of PVC/ABS flotation was 0.64 min-1. In addition, the pretreatment solution can be reused for three times with superior performance. The recovery and purity of PVC reached 100% and 99.7%, respectively. According to reasonable evaluation, the combination of S2O82-/Fe2+ advanced oxidation and flotation is a practical and efficient technology for separating PVC and ABS.
Collapse
Affiliation(s)
- Yingshuang Zhang
- School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China
| | - Shuaijun Chen
- School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China
| | - Hui Wang
- School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China.
| | - Maozhi Luo
- School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China
| |
Collapse
|
27
|
Liu P, Qian L, Wang H, Zhan X, Lu K, Gu C, Gao S. New Insights into the Aging Behavior of Microplastics Accelerated by Advanced Oxidation Processes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:3579-3588. [PMID: 30829479 DOI: 10.1021/acs.est.9b00493] [Citation(s) in RCA: 388] [Impact Index Per Article: 77.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
In the environment, microplastics are subjected to multiple aging processes; however, information regarding the impact of aging on the environmental behavior of microplastics is still lacking. This study investigated the alteration properties of polystyrene and high-density polyethylene microplastics by heat-activated K2S2O8 and Fenton treatments to improve the understanding of their long-term natural aging in aquatic environments. Our results indicated that the O/C ratio was an alternative parameter to the carbonyl index (CI) to quantitatively describe the surface alteration properties of microplastics. The correlation model of the O/C ratio or CI versus alteration time was developed and compared by natural alteration of microplastics in freshwater samples. Moreover, the regression equation of the equilibrium adsorption capacity of altered microplastics versus the O/C ratio and average size was proposed. This study is the first effort in differentiating the relationships between the alteration properties and alteration time/adsorption capacity of microplastics, which would be helpful for predicting the weathering degree and accumulation of hydrophilic antibiotics onto aged microplastics in aquatic environments. This research develops promising strategies to accelerate the aging reactions using advanced oxidation processes, which would provide further information to assess the microplastic pollution in actual environments.
Collapse
Affiliation(s)
- Peng Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Nanjing , Jiangsu 210093 , People's Republic of China
| | - Li Qian
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Nanjing , Jiangsu 210093 , People's Republic of China
| | - Hanyu Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Nanjing , Jiangsu 210093 , People's Republic of China
| | - Xin Zhan
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Nanjing , Jiangsu 210093 , People's Republic of China
| | - Kun Lu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Nanjing , Jiangsu 210093 , People's Republic of China
| | - Cheng Gu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Nanjing , Jiangsu 210093 , People's Republic of China
| | - Shixiang Gao
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Nanjing , Jiangsu 210093 , People's Republic of China
| |
Collapse
|
28
|
Zhao Y, Yang S, Wen H, Shen Z, Han F. Adsorption behavior and selectivity mechanism of flotation reagents applied in ternary plastic mixtures. WASTE MANAGEMENT (NEW YORK, N.Y.) 2019; 87:565-576. [PMID: 31109557 DOI: 10.1016/j.wasman.2019.02.044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 02/21/2019] [Accepted: 02/23/2019] [Indexed: 06/09/2023]
Abstract
Plastic flotation attracts increasing attention in the process of recycling and will bring potential application in industry after theoretical perfection. For a separated ternary system of polyethylene terephthalate (PET), polyvinyl chloride (PVC) and polyethylene (PE), adsorption behavior and selectivity mechanism of flotation reagents were investigated by multi-characterization tests and batch equilibrium adsorption method. Quantitative adsorption results indicate that frother polyethylene glycol (PEG) only acts on gas and liquid phases in the flotation system with negligible adsorption capacity onto solid phase. For depressant sodium lignosulphonate (SL), the pseudo-first-order and Langmuir isotherm models are suitable for corresponding kinetic and equilibrium data of PET or PVC. Thermodynamic parameters further indicate that the adsorption of SL is a spontaneous and endothermic process, which neither belongs to the pure physisorption nor to the pure chemisorption. Adsorption models of SL were established based on hydrogen bond, with three clear bonding types (OH…π*, OH…O, and OH…Cl). Selectivity mechanism can be attributed to the selective hydrogen bond acceptors and donors, which are provided by specific plastic and depressant, respectively. In the light of these theoretical fundings, new targeted reagents or pre-treatments are expected to be developed towards more complex flotation system.
Collapse
Affiliation(s)
- Yue Zhao
- Shaanxi Key Laboratory of Disaster Monitoring & Mechanism Simulating, College of Geography and Environment, Baoji University of Arts and Sciences, Baoji 721013, China.
| | - Shengke Yang
- Key Laboratory of Subsurface Hydrology and Ecology in Arid Areas, Ministry of Education, School of Environmental Science and Engineering, Chang'an University, Xi'an 710054, China
| | - Hao Wen
- Key Laboratory of Subsurface Hydrology and Ecology in Arid Areas, Ministry of Education, School of Environmental Science and Engineering, Chang'an University, Xi'an 710054, China
| | - Zhou Shen
- Université de Toulouse, INSA, UPS, INP, LISBP, 135 Avenue de Rangueil, F-31077 Toulouse, France
| | - Fengrong Han
- Laboratory of Intelligent Information Processing, School of Computer, Baoji University of Arts and Sciences, Baoji 721016, China
| |
Collapse
|
29
|
Wang J, Wang H, Yue D. Optimization of Surface Treatment Using Sodium Hypochlorite Facilitates Coseparation of ABS and PC from WEEE Plastics by Flotation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:2086-2094. [PMID: 30642166 DOI: 10.1021/acs.est.8b06432] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Waste acrylonitrile butadiene styrene (ABS) and polycarbonate (PC) as dominant components in waste electrical and electronic equipment (WEEE) plastics show significant potential for recycling, which is severely restricted by efficient separation method. We proposed a novel surface treatment method using sodium hypochlorite for facilitating coseparation of ABS and PC from WEEE plastics by flotation for recycling. Optimization of surface treatment process was performed with response surface methodology using Box-Behnken design. A quadratic model was generated for predicting the floating rate of ABS and PC, and it was also used to optimize the coseparation performance. The optimum conditions were determined and included concentration of 0.05 M, temperature of 69.5 °C, contact time of 56.5 min, and stirring rate of 200 rpm. Under optimum conditions, the coseparation of ABS and PC was effectively achieved; the recovery and the purity of ABS and PC reached 97.4% and 100.0%, respectively. The formation of oxygen-bearing groups and morphological changes were confirmed as major mechanism to induce the surface hydrophilization of ABS and PC. Consequently, this method is feasible for selective coseparation of ABS and PC from WEEE plastics, and it provides technological insights in the sustainable deposal of WEEE plastics.
Collapse
Affiliation(s)
- Jianchao Wang
- School of Environment , Tsinghua University , Beijing 100084 , PR China
- Key Laboratory of Solid Waste Management and Environment Safety (Tsinghua University), Ministry of Education , Tsinghua University , Beijing 100084 , PR China
- School of Chemistry and Chemical Engineering , Central South University , Changsha 410083 , Hunan China
| | - Hui Wang
- School of Chemistry and Chemical Engineering , Central South University , Changsha 410083 , Hunan China
| | - Dongbei Yue
- School of Environment , Tsinghua University , Beijing 100084 , PR China
- Key Laboratory of Solid Waste Management and Environment Safety (Tsinghua University), Ministry of Education , Tsinghua University , Beijing 100084 , PR China
| |
Collapse
|
30
|
Guo C, Zou Q, Wang J, Wang H, Chen S, Zhong Y. Application of surface modification using sodium hypochlorite for helping flotation separation of acrylonitrile-butadiene-styrene and polystyrene plastics of WEEE. WASTE MANAGEMENT (NEW YORK, N.Y.) 2018; 82:167-176. [PMID: 30509579 DOI: 10.1016/j.wasman.2018.10.031] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 09/16/2018] [Accepted: 10/20/2018] [Indexed: 06/09/2023]
Abstract
Acrylonitrile-butadiene-styrene (ABS) and polystyrene (PS), as important fractions of Waste from Electric and Electronic Equipment (WEEE) plastics, show great significances to the recycling of WEEE. The objective of this study is to develop a simple, practical and efficient surface modification method using sodium hypochlorite (NaClO) for separation of waste ABS and PS plastics by the aid of froth flotation. After surface modification, more hydrophilic groups are introduced on ABS surface than that of PS, enhancing its surface hydrophilicity clearly and reducing its recovery in floated products. Single parameter experiments demonstrate NaClO concentration, treatment temperature, treatment time are key parameters in surface modification. Optimization of conditions for surface modification of ABS was conducted by Response Surface Methodology with a Box-Behnken design, and a predicting model was obtained also. The optimum conditions are NaClO concentration of 0.05 M/L, temperature of 67.50 °C, treatment time 59.50 min and stirring rate of 200 rpm. Under optimum conditions, ABS and PS with different particle sizes can be separated efficiently with recovery of 99.18% and 99.47%, and purity of 99.45% and 99.18% respectively. The application of surface modification using sodium hypochlorite can facilitate efficient flotation separation of waste ABS and PS plastics for the recycling of WEEE.
Collapse
Affiliation(s)
- Chenchao Guo
- School of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan, China
| | - Qiangpin Zou
- Zhejiang University, Yuquan Campus, Hangzhou, 310007 Zhejiang, China
| | - Jianchao Wang
- School of Environment, Tsinghua University, Beijing 100084, PR China; Key Laboratory of Solid Waste Management and Environment Safety (Tsinghua University), Ministry of Education, Tsinghua University, Beijing 100084, PR China.
| | - Hui Wang
- School of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan, China.
| | - Shuaijun Chen
- School of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan, China
| | - Yiwei Zhong
- School of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan, China
| |
Collapse
|
31
|
Suyantara GPW, Hirajima T, Miki H, Sasaki K, Yamane M, Takida E, Kuroiwa S, Imaizumi Y. Effect of Fenton-like oxidation reagent on hydrophobicity and floatability of chalcopyrite and molybdenite. Colloids Surf A Physicochem Eng Asp 2018. [DOI: 10.1016/j.colsurfa.2018.06.029] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
32
|
Treatment of Cutting Fluid Waste using Activated Carbon Fiber Supported Nanometer Iron as a Heterogeneous Fenton Catalyst. Sci Rep 2018; 8:10650. [PMID: 30006546 PMCID: PMC6045638 DOI: 10.1038/s41598-018-29014-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 07/04/2018] [Indexed: 01/12/2023] Open
Abstract
Addressing the problem of high chemical oxygen demands (COD) of cutting fluid waste generated in the machining process, its complex composition, and the specific conditions required for the treatment process, a heterogeneous Fenton fibre catalyst (NZVI@ACF) made of nanometer-iron supported on activated carbon fiber using dip-molding was developed. NZVI was homogeneously loaded onto ACF surfaces to form NZVI@ACF, with a specific surface area (SBET) of 726.3642 m2/g. Using a multistage chemical pretreatment, the NZVI@ACF/H2O2 system was used to effectively treat cutting fluid waste. The results indicated that the rate of COD removal in the cutting fluid waste liquid pretreated with NZVI@ACF/H2O2 system was 99.8% when the reactions conditions were optimized to 20 nmol/L H2O2, 6 g/L NZVI@ACF, total reaction time of 120 min and pH 5. The treated waste solution passed China’s tertiary wastewater discharge standards. NZVI@ACF/H2O2 demonstrated an excellent catalytic performance compared to the traditional Fenton catalyst, increased the effective pH reaction range and had an adsorption effect on the waste liquid after the reaction.
Collapse
|
33
|
Zhao P, Xie J, Gu F, Sharmin N, Hall P, Fu J. Separation of mixed waste plastics via magnetic levitation. WASTE MANAGEMENT (NEW YORK, N.Y.) 2018; 76:46-54. [PMID: 29506775 DOI: 10.1016/j.wasman.2018.02.051] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 02/11/2018] [Accepted: 02/24/2018] [Indexed: 05/15/2023]
Abstract
Separation becomes a bottleneck of dealing with the enormous stream of waste plastics, as most of the extant methods can only handle binary mixtures. In this paper, a novel method that based on magnetic levitation was proposed for separating multiple mixed plastics. Six types of plastics, i.e., polypropylene (PP), acrylonitrile butadiene styrene (ABS), polyamide 6 (PA6), polycarbonate (PC), polyethylene terephthalate (PET), and polytetrafluoroethylene (PTFE), were used to simulate the mixed waste plastics. The samples were mixed and immersed into paramagnetic medium that placed into a magnetic levitation configuration with two identical NdFeB magnets with like-poles facing each other, and Fourier transform infrared (FTIR) spectroscopy was employed to verify the separation outputs. Unlike any conventional separation methods such as froth flotation and hydrocyclone, this method is not limited by particle sizes, as mixtures of different size fractions reached their respective equilibrium positions in the initial tests. The two-stage separation tests demonstrated that the plastics can be completely separated with purities reached 100%. The method has the potential to be industrialised into an economically-viable and environmentally-friendly mass production procedure, since quantitative correlations are determined, and the paramagnetic medium can be reused indefinitely.
Collapse
Affiliation(s)
- Peng Zhao
- State Key Lab of Fluid Power Transmission and Control, School of Mechanical Engineering, Zhejiang University, Hangzhou, China; Key Laboratory of 3D Printing Process and Equipment of Zhejiang Province, School of Mechanical Engineering, Zhejiang University, Hangzhou, China
| | - Jun Xie
- State Key Lab of Fluid Power Transmission and Control, School of Mechanical Engineering, Zhejiang University, Hangzhou, China; Key Laboratory of 3D Printing Process and Equipment of Zhejiang Province, School of Mechanical Engineering, Zhejiang University, Hangzhou, China
| | - Fu Gu
- State Key Lab of Fluid Power Transmission and Control, School of Mechanical Engineering, Zhejiang University, Hangzhou, China; Department of Industrial Engineering, Zhejiang University, Hangzhou, China.
| | - Nusrat Sharmin
- Department of Chemical and Environmental Engineering, University of Nottingham, Ningbo, China
| | - Philip Hall
- Department of Chemical and Environmental Engineering, University of Nottingham, Ningbo, China
| | - Jianzhong Fu
- State Key Lab of Fluid Power Transmission and Control, School of Mechanical Engineering, Zhejiang University, Hangzhou, China; Key Laboratory of 3D Printing Process and Equipment of Zhejiang Province, School of Mechanical Engineering, Zhejiang University, Hangzhou, China
| |
Collapse
|