Identification and quantification of microplastics in wastewater treatment plants by spectroscopic and microscopic techniques in Johannesburg East, South Africa
The occurrence of microplastics in water, their chemistry, physical characteristics, and the efficiency of public wastewater treatment work (WWTW) processes in the removal of microplastics are investigated. Samples were collected from the period 2021 December to 2022 September from two WWTWs in Joha...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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IWA Publishing
2023-12-01
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| Series: | Water Practice and Technology |
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| Online Access: | http://wpt.iwaponline.com/content/18/12/3124 |
| _version_ | 1827392613975588864 |
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| author | Tendani Mphaga T. N. Mhlongo Sithembele Zikalala James Topkin |
| author_facet | Tendani Mphaga T. N. Mhlongo Sithembele Zikalala James Topkin |
| author_sort | Tendani Mphaga |
| collection | DOAJ |
| description | The occurrence of microplastics in water, their chemistry, physical characteristics, and the efficiency of public wastewater treatment work (WWTW) processes in the removal of microplastics are investigated. Samples were collected from the period 2021 December to 2022 September from two WWTWs in Johannesburg East using 24-h autosamplers. The microplastics were imaged using polarised optical microscopy (POM) and the images were processed using image J 1.53 K to determine the particle counts. The total concentration of microplastics at WWTW A was 3,098 MP/L while WWTW B had 3,561 MP/L. The microplastics identified across the seasons were dominated by angular, fibres, fragments, and films. Fourier transforms infrared (FTIR) spectroscopy identified the polymers such as polyethylene, acrylic, polyethylene terephthalate, and polystyrene in WWTW A and B influent while identifying the polymers such as polystyrene, polyacrylamide, polypropylene, polycarbonate, acrylonitrile butadiene styrene, poly(ethyl cyanoacrylate), carboxyl, poly(ethylene terephthalate), polyethylene, poly(methyl methacrylate), and cellulose in the final effluent. Scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX) identified Cr, Ca, Fe, Al, Na, Mg, Zn, Cl, P, S, and silicon as additives to microplastics with high-intensity peaks of oxygen and carbon. It is recommended to monitor and regulate microplastics in discharged effluents from WWTWs to minimise environmental pollution.
HIGHLIGHTS
Quantity, polymer functionality, and physical morphology of microplastics are studied.;
Variations of microplastic concentration across seasons are studied.;
Different polymers are composed of a variety of functional groups.;
Microplastics are carriers of metals.; |
| first_indexed | 2024-03-08T17:34:35Z |
| format | Article |
| id | doaj.art-3caed26c26294d25a402b069bf7beaf5 |
| institution | Directory Open Access Journal |
| issn | 1751-231X |
| language | English |
| last_indexed | 2024-03-08T17:34:35Z |
| publishDate | 2023-12-01 |
| publisher | IWA Publishing |
| record_format | Article |
| series | Water Practice and Technology |
| spelling | doaj.art-3caed26c26294d25a402b069bf7beaf52024-01-02T12:58:07ZengIWA PublishingWater Practice and Technology1751-231X2023-12-0118123124314010.2166/wpt.2023.215215Identification and quantification of microplastics in wastewater treatment plants by spectroscopic and microscopic techniques in Johannesburg East, South AfricaTendani Mphaga0T. N. Mhlongo1Sithembele Zikalala2James Topkin3 Department of Environmental Sciences, Faculty of Agriculture and Environmental Sciences, University of South Africa, UNISA Science Campus, P.O. Box 392 UNISA 003, Florida 1709, Johannesburg, South Africa Centre for Postgraduate Studies, Cape Peninsula University of Technology, Bellville South Industrial, Cape Town 7530, South Africa Department of Sciences Engineering and Technology, Institute for Nanotechnology and Water Sustainability Research Department, Scientific Services, Ekurhuleni Water Care, P.O. Box 13108 Norkem Park, 1631, Kempton Park, South Africa The occurrence of microplastics in water, their chemistry, physical characteristics, and the efficiency of public wastewater treatment work (WWTW) processes in the removal of microplastics are investigated. Samples were collected from the period 2021 December to 2022 September from two WWTWs in Johannesburg East using 24-h autosamplers. The microplastics were imaged using polarised optical microscopy (POM) and the images were processed using image J 1.53 K to determine the particle counts. The total concentration of microplastics at WWTW A was 3,098 MP/L while WWTW B had 3,561 MP/L. The microplastics identified across the seasons were dominated by angular, fibres, fragments, and films. Fourier transforms infrared (FTIR) spectroscopy identified the polymers such as polyethylene, acrylic, polyethylene terephthalate, and polystyrene in WWTW A and B influent while identifying the polymers such as polystyrene, polyacrylamide, polypropylene, polycarbonate, acrylonitrile butadiene styrene, poly(ethyl cyanoacrylate), carboxyl, poly(ethylene terephthalate), polyethylene, poly(methyl methacrylate), and cellulose in the final effluent. Scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX) identified Cr, Ca, Fe, Al, Na, Mg, Zn, Cl, P, S, and silicon as additives to microplastics with high-intensity peaks of oxygen and carbon. It is recommended to monitor and regulate microplastics in discharged effluents from WWTWs to minimise environmental pollution. HIGHLIGHTS Quantity, polymer functionality, and physical morphology of microplastics are studied.; Variations of microplastic concentration across seasons are studied.; Different polymers are composed of a variety of functional groups.; Microplastics are carriers of metals.;http://wpt.iwaponline.com/content/18/12/3124chemical compositionmicroplasticsmicroscopypolymersspectroscopy |
| spellingShingle | Tendani Mphaga T. N. Mhlongo Sithembele Zikalala James Topkin Identification and quantification of microplastics in wastewater treatment plants by spectroscopic and microscopic techniques in Johannesburg East, South Africa Water Practice and Technology chemical composition microplastics microscopy polymers spectroscopy |
| title | Identification and quantification of microplastics in wastewater treatment plants by spectroscopic and microscopic techniques in Johannesburg East, South Africa |
| title_full | Identification and quantification of microplastics in wastewater treatment plants by spectroscopic and microscopic techniques in Johannesburg East, South Africa |
| title_fullStr | Identification and quantification of microplastics in wastewater treatment plants by spectroscopic and microscopic techniques in Johannesburg East, South Africa |
| title_full_unstemmed | Identification and quantification of microplastics in wastewater treatment plants by spectroscopic and microscopic techniques in Johannesburg East, South Africa |
| title_short | Identification and quantification of microplastics in wastewater treatment plants by spectroscopic and microscopic techniques in Johannesburg East, South Africa |
| title_sort | identification and quantification of microplastics in wastewater treatment plants by spectroscopic and microscopic techniques in johannesburg east south africa |
| topic | chemical composition microplastics microscopy polymers spectroscopy |
| url | http://wpt.iwaponline.com/content/18/12/3124 |
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