Microplastics in freshwater sediments: Analytical methods, temporal trends, and risk of associated organophosphate esters as exemplar plastics additives

Onoja, Simeon; Nel, Holly; Abdallah, Mohamed Abou-Elwafa; Harrad, Stuart

doi:10.1016/j.envres.2021.111830

Cited by 42 publications

(16 citation statements)

References 170 publications

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“…Polymers produced for commercial use contain additives such as fillers/reinforcements, flame retardants, plasticizers, and colorants that are added during manufacturing to enhance physical and mechanical properties (Lithner et al, 2011 ; Omowunmi et al, 2020 ; Onoja et al, 2022 ). Additives are often of low molecular weight and not chemically bound to the matrix of the polymer (with the exception of a few that are copolymerized); therefore, they can easily leach from microplastics in a manner that enables them to reach thermodynamic equilibrium with their surroundings (Koelmans et al, 2014 ; World Health Organization, 2019 ).…”

Section: Discussionmentioning

confidence: 99%

Comparative Assessment of Microplastics in Surface Waters and Sediments of the Vaal River, South Africa: Abundance, Composition, and Sources

Ramaremisa

Ndlovu

Saad

2022

Enviro Toxic and Chemistry

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We extracted microplastics from surface water and sediment samples from the Vaal River in Johannesburg, South Africa. Average abundances of 0.61 ± 0.57 particles/m 3 and 4.6 × 10 2 ± 2.8 × 10 2 particles/kg dry weight were recorded for water and sediment samples, respectively. In both sediment and water samples, more than 80% of microplastics were fragments and fibers of smaller than 2 mm. High-density polyethylene, low-density polyethylene, and polypropylene were the dominant polymers identified in both sample types. In addition, polyethylene co-vinyl acetate, polyester, polyurethane, and polyethylene/ hexene-1-copolymer were also detected in sediment samples. Colored microplastics were the most commonly observed in both sample types; pigment yellow 83 was detected in surface water, and carbon black was detected in both sediment and water samples during Raman analysis. Taking into consideration the physical and chemical characteristics of the detected microplastics, their potential sources include inflow from tributaries, surface run-off from urban city centers, recreational activities, and wastewater effluent from industries and households.

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Section: Discussionmentioning

confidence: 99%

Comparative Assessment of Microplastics in Surface Waters and Sediments of the Vaal River, South Africa: Abundance, Composition, and Sources

Ramaremisa

Ndlovu

Saad

2022

Enviro Toxic and Chemistry

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“…There is a lack of standardized procedures in plastic sampling, leading to the reporting of data in a variety of units. The best unit is plastic pieces per m 2 (Wessel et al, 2016 cited in Onoja et al, 2022 ).…”

Section: Methodsmentioning

confidence: 99%

“…Once marine plastics are collected, the next objective is to separate the different items of plastics from non-plastic particles based on physical properties that are unique to plastics. A standard method for doing this is yet to be established ( Onoja et al, 2022 ).…”

Section: Methodsmentioning

confidence: 99%

“…Microplastics (having size <5 ml) have an enormous impact on the marine ecosystem and they are considered a potential threat ( Gewert et al, 2015 ; James et al, 2021 ; Patrício et al, 2021 ). These plastics can travel thousands of miles, carried by water currents and wind action ( Barnes et al, 2009 ; Al-Salem et al, 2021 ; Onoja et al, 2022 ).…”

Section: Introductionmentioning

confidence: 99%

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Contamination of the marine environment in Egypt and Saudi Arabia with personal protective equipment during COVID-19 pandemic: A short focus

Hassan

Younis

Ghamdi

et al. 2022

Science of The Total Environment

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“…However, some of these additives are not absorbed during the process: they are removed during the polypropylene washing and cleaning stages and are later discarded in wastewater and eventually in bodies of water [ 38 ]. Irgafos 168, which may be present in this discharge, is a compound with a chemical structure comprising an organophosphate (see Figure 1 ) attached to three rings of phenols that can be toxic to aquatic organisms and can affect water quality [ 39 , 40 , 41 , 42 ]. Irgafos P-168 can break down into potentially harmful secondary compounds [ 26 , 43 , 44 , 45 ].…”

Section: Introductionmentioning

confidence: 99%

Valoration of the Synthetic Antioxidant Tris-(Diterbutyl-Phenol)-Phosphite (Irgafos P-168) from Industrial Wastewater and Application in Polypropylene Matrices to Minimize Its Thermal Degradation

2023

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Industrial wastewater from petrochemical processes is an essential source of the synthetic phenolic phosphite antioxidant (Irgafos P-168), which negatively affects the environment. For the determination and analysis of Irgafos P-168, DSC, HPLC-MS, and FTIR methodologies were used. Solid phase extraction (SPE) proved to be the best technique for extracting Irgafos from wastewater. HPLC-MS and SPE determined the repeatability, reproducibility, and linearity of the method and the SPE of the standards and samples. The relative standard deviations, errors, and correlation coefficients for the repeatability and reproducibility of the calibration curves were less than 4.4% and 4.2% and greater than 0.99955, respectively. The analysis of variance (ANOVA), using the Fisher method with confidence in 95% of the data, did not reveal significant differences between the mentioned parameters. The removal of the antioxidant from the wastewater by SPE showed recovery percentages higher than 91.03%, and the chemical characterization of this antioxidant by FTIR spectroscopy, DSC, TGA, and MS showed it to be structurally the same as the Irgafos P-168 molecule. The recovered Irgafos was added to the polypropylene matrix, significantly improving its oxidation times. An OIT analysis, performed using DSC, showed that the recovered Irgafos-blended polypropylene (PP) demonstrated oxidative degradation at 8 min. With the addition of the Irgafos, the oxidation time was 13 min. This increases the polypropylene’s useful life and minimizes the environmental impact of the wastewater.

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Microplastics in freshwater sediments: Analytical methods, temporal trends, and risk of associated organophosphate esters as exemplar plastics additives

Cited by 42 publications

References 170 publications

Comparative Assessment of Microplastics in Surface Waters and Sediments of the Vaal River, South Africa: Abundance, Composition, and Sources

Comparative Assessment of Microplastics in Surface Waters and Sediments of the Vaal River, South Africa: Abundance, Composition, and Sources

Contamination of the marine environment in Egypt and Saudi Arabia with personal protective equipment during COVID-19 pandemic: A short focus

Valoration of the Synthetic Antioxidant Tris-(Diterbutyl-Phenol)-Phosphite (Irgafos P-168) from Industrial Wastewater and Application in Polypropylene Matrices to Minimize Its Thermal Degradation

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