1
|
Zhong Y, Zhuo L, Lu W. Analysis of photocatalytic degradation of polyamide microplastics in metal salt solution by high resolution mass spectrometry. J Environ Sci (China) 2024; 139:473-482. [PMID: 38105070 DOI: 10.1016/j.jes.2023.06.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 06/12/2023] [Accepted: 06/12/2023] [Indexed: 12/19/2023]
Abstract
Microplastic pollution has become one of the most concerned focuses in the world. Among many treatment methods, photocatalysis is considered to be one of the most environmentally friendly methods. In this work, the photodegradation behavior of polyamide microplastics is studied by using polyamide 6 PA6) as model microplastics and FeCl3 as catalyst. It is hoped that the PA6 fiber can be effectively degraded by utilizing the strong oxidizing active species that can be produced after FeCl3 is irradiated in water. The results shows that PA6 fiber can be almost completely degraded after 10 days of irradiation in FeCl3 aqueous solution, indicating that it is promising to use this new method to solve the problem of PA6 type microplastics. In addition, the chain scission mechanism and degradation process of PA6 are analyzed in detail by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS), which provides a new insight for the study of polymer degradation mechanism.
Collapse
Affiliation(s)
- Yunjin Zhong
- National Engineering Lab for Textile Fiber Materials & Processing Technology (Zhejiang), School of Materials Science & Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Lebing Zhuo
- National Engineering Lab for Textile Fiber Materials & Processing Technology (Zhejiang), School of Materials Science & Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Wangyang Lu
- National Engineering Lab for Textile Fiber Materials & Processing Technology (Zhejiang), School of Materials Science & Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, China.
| |
Collapse
|
2
|
Tang Y, Fan K, Herath I, Gustave W, Lin C, Qin J, Qiu R. Contribution of free hydroxyl radical to the formation of micro(nano)plastics and release of additives during polyethylene degradation in water. Environ Pollut 2023; 337:122590. [PMID: 37734629 DOI: 10.1016/j.envpol.2023.122590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 08/24/2023] [Accepted: 09/19/2023] [Indexed: 09/23/2023]
Abstract
The omnipresence of secondary microplastics (MPs) in aquatic ecosystems has become an increasingly alarming public health concern. Hydrogen peroxide (H2O2) is an important oxidant in nature and the most stable reactive oxygen species occurred in natural water. In order to explore the contribution of free ˙OH generated from H2O2-driven Fenton-like reactions on the degradation of polyethylene (PE) and generation of micro- and nano-scale plastics in water, a batch experiment was conducted over a period of 620 days in water treated with micromolar H2O2. The incorporation of H2O2 in water induced the formation of flake-like micro(nano)-sized particles due to intensified oxidative degradation of PE films. The presence of ˙OH significantly enhanced the generation of both micro- and nano-scale plastics exhibiting a higher proportion of particles in the range of 200-500 nm compared to the Control. Total organic carbon in the H2O2 treated solution was nearly 174-fold higher than that of the Control indicating a substantial liberation of organic compounds due to the oxidative degradation of native carbon chain of PE and subsequent decomposition of its additives. The highly toxic butylated hydroxytoluene detected from the gas chromatography-mass spectrometry (GC-MS) analysis implied the toxicological behavior of secondary micro(nano)plastics influenced by the oxidation and decomposition processes The findings from this study further expand our understanding of the role of ˙OH in degrading PE micro-scale plastics into nanoparticles as an implication of naturally occurring H2O2 in aquatic environments. In the future, further attention should be drawn to the underlying mechanisms of H2O2-driven in-situ Fenton reaction mediated by natural environmental conditions targeting the alternation of light and darkness on the oxidative degradation of plastics.
Collapse
Affiliation(s)
- Yu Tang
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, China
| | - Kaiqing Fan
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, China
| | - Indika Herath
- Centre for Regional and Rural Futures, Faculty of Science, Engineering and Built Environment, Deakin University, Waurn Ponds, VIC, 3216, Australia
| | - Williamson Gustave
- The School of Chemistry, Environmental & Life Sciences, University of The Bahamas, Nassau, Bahamas
| | - Chuxia Lin
- Centre for Regional and Rural Futures, Faculty of Science, Engineering and Built Environment, Deakin University, Burwood, VIC, 3125, Australia
| | - Junhao Qin
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, China.
| | - Rongliang Qiu
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, China
| |
Collapse
|
3
|
Shi Y, Liu P, Wu X, Shi H, Huang H, Wang H, Gao S. Insight into chain scission and release profiles from photodegradation of polycarbonate microplastics. Water Res 2021; 195:116980. [PMID: 33684678 DOI: 10.1016/j.watres.2021.116980] [Citation(s) in RCA: 78] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 02/23/2021] [Accepted: 02/24/2021] [Indexed: 05/27/2023]
Abstract
Bisphenol A polycarbonate (BPA-PC) is a kind of widely used engineering plastics. However, excessive usage causes the production of plastic wastes, following property changes of polymers and high risks of released chemicals during outdoor weathering. In this study, we systematically investigated the photoaging behavior of PC microplastics (MPs) in aquatic environment and evaluated the potential risk of released intermediates. Light irradiation along with mechanical abrasion facilitated the fragmentation of PC MPs and stimulated photooxidative modification during 640 h of ultraviolet (UV) exposure. Continuous degradation of the polymer was accompanied with dramatic decline of molecular weight. Also, BPA was released from irradiated PC MPs with a trend of an initial rapid increase followed by a decrease versus the irradiation time, and the maximum concentration of dropped BPA was detected up to 652.80 ± 72.89 μg/g (43.39% and 56.61% respectively in particles and leachates). However, the releasing amount of BPA in the leachate merely occupied 2.7% of the total organic carbon (TOC) leached out, suggesting that a great number of unknown organic products were produced other than BPA. Liquid chromatography-time-of-flight-mass spectrometry (LC-TOF-MS) analysis showed that these organic compounds forming MPs-derived dissolved organic matter (MPs DOM) were partly composed of 4,4'-dihydroxybenzophenone (DHB), p-hydroxybenzoic acid (p-HBA) and methyparaben (MeP), which would also contribute to the estrogenic activity. The degradation pathway of PC MPs was elaborated with the photolysis process of PC dimer and BPA, and the remarkable photoaging of PC MPs was mainly dominated by the generated reactive oxygen species (ROS). The findings of this study indicated that understanding the photoaging process of PC MPs was vital to evaluate their integral cumulative estrogenic activity in aquatic environment, and further highlighted the notable possible risks of plastic leachates to exposed biota.
Collapse
Affiliation(s)
- Yanqi Shi
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210093, People's Republic of China
| | - 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; College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi, 712100, People's Republic of China
| | - Xiaowei Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210093, People's Republic of China
| | - Huanhuan Shi
- School of Ecology and Environment, Zhengzhou University, Zhengzhou, Henan, 450001, People's Republic of China
| | - Hexinyue Huang
- 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
| | - 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
|
4
|
Saleh HM, Annuar MSM, Simarani K. Ultrasound degradation of xanthan polymer in aqueous solution: Its scission mechanism and the effect of NaCl incorporation. Ultrason Sonochem 2017; 39:250-261. [PMID: 28732944 DOI: 10.1016/j.ultsonch.2017.04.038] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 04/23/2017] [Accepted: 04/24/2017] [Indexed: 06/07/2023]
Abstract
Degradation of xanthan polymer in aqueous solution by ultrasonic irradiation was investigated. The effects of selected variables i.e. sonication intensity, irradiation time, concentration of xanthan gum and molar concentration of NaCl in solution were studied. Combined approach of full factorial design and conventional one-factor-at-a-time was applied to obtain optimum degradation at sonication power intensity of 11.5Wcm-2, irradiation time 120min and 0.1gL-1 xanthan in a salt-free solution. Molecular weight reduction of xanthan gum under sonication was described by an exponential decay function with higher rate constant for polymer degradation in the salt free solution. The limiting molecular weight where fragments no longer undergo scission was determined from the function. The incorporation of NaCl in xanthan solution resulted in a lower limiting molecular weight. The ultrasound-mediated degradation of aqueous xanthan polymer chain agreed with a random scission model. Side chain of xanthan polymer is proposed to be the primary site of scission action.
Collapse
Affiliation(s)
- H M Saleh
- Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - M S M Annuar
- Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia; Centre for Research in Biotechnology for Agriculture (CEBAR), University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - K Simarani
- Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| |
Collapse
|