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Municipal wastewater treatment plants (WWTPs) play a crucial role in the collection and redistribution of plastic particles from both households and industries, contributing to their presence in the environment. Previous studies investigating the levels of plastics in WWTPs, and their removal rates have primarily focused on polymer type, size, shape, colour, and particle count, while comprehensive understanding of the mass concentration of plastic particles, particularly those <1 µm (nanoplastics), remains unclear and lacking. In this study, pyrolysis gas chromatography-mass spectrometry was used to simultaneously determine the mass concentration of nine selected polymers (i.e., polyethylene (PE), polypropylene (PP), polystyrene (PS), poly(ethylene terephthalate) (PET), nylon 6, nylon 66, polyvinylchloride (PVC), poly(methyl methacrylate) (PMMA) and polycarbonate (PC)) below 1 µm in size across the treatment processes or stages of three WWTPs in Australia. All the targeted nanoplastics were detected at concentrations between 0.04 and 7.3 µg/L. Nylon 66 (0.2-7.3 µg/L), PE (0.1-6.6 µg/L), PP (0.1-4.5 µg/L), Nylon 6 (0.1-3.6 µg/L) and PET (0.1-2.2 µg/L), were the predominant polymers in the samples. The mass concentration of the total nanoplastics decreased from 27.7, 18 and 9.1 µg/L in the influent to 1, 1.4 and 0.8 µg/L in the effluent, with approximate removal rates of 96 %, 92 % and 91 % in plants A, B and C, respectively. Based on annual wastewater effluent discharge, it is estimated that approximately 24, 2 and 0.7 kg of nanoplastics are released into the environment per year for WWTPs A, B and C, respectively. This study investigated the mass concentrations and removal rates of nanoplastics with a size range of 0.01-1 µm in wastewater, providing important insight into the pollution levels and distribution patterns of nanoplastics in Australian WWTPs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Municipal wastewater treatment plants (WWTPs) are a central point of collection of plastic particles from households and industry and for their re-distribution into the environment. Existing studies evaluating levels of plastics in WWTPs, and their removal rates have reported and used data on polymer type, size, shape, colour, and number of plastic particles, while the total mass concentration of plastic particles (especially >1 μm) remains unclear and unknown. To address this knowledge gap, raw influent, effluent, and reference water samples from three WWTPs in Australia were collected to analyse the mass concentrations and removal rates of seven common plastics (>1 μm in size) across the treatment schemes. Quantitative analysis was performed by pressurized liquid extraction followed by pyrolysis coupled to gas chromatography mass spectrometry. Results showed that the total plastic content in the WWTPs raw influent samples was between 840 and 3116 μg/L, resulting in an inflow of between about 2.1 and 196.4 kg/day of the total measured plastics. Overall, >99 % by mass of the plastics entering the three WWTPs from the raw influent was removed during the pre-treatment stages, presumably ending up in the sewage sludge, which means emissions (via treated effluent) from the treatment plants are low. Compared with the raw influent, the plastic mass concentrations in the treated effluents (i.e., Class C, A, and final effluent) from the three WWTPs, as well as the reference water samples within their catchments were below the limits of reporting. Of the five quantified plastic types, polyethylene (PE, 76.4 %), and polyvinylchloride (PVC, 21 %) dominated by mass, while polyethylene terephthalate (PET, 1.9 %), polypropylene (PP, 0.4 %) and polymethyl methacrylate (PMMA, 0.3 %) accounted for a small proportion of the total. Overall, this study investigated the mass concentrations of plastic particles above 1 μm in wastewater and their removal, which provided valuable information regarding the pollution level and distribution characteristics of plastic polymers in Australian WWTPs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

This study investigated the occurrence and contribution of plastic particles associated with size fractionated biosolids to the total concentration in biosolids (treated sewage sludge) samples collected from 20 wastewater treatment plants (WWTP) across Australia. This was achieved through sequential size fractionation of biosolids samples to quantify the mass concentration of 7 common plastics across a range of biosolids size fractions, including below 25 μm which has not been assessed in many previous studies. Quantitative analysis was performed by pressurized liquid extraction followed by pyrolysis coupled to gas chromatography - mass spectrometry. Of the total quantified plastics (Σ 7 plastics), the greatest proportion (27%) of the total mass were identified in the nominal <25 μm sized biosolids fraction. Polyethylene dominated the polymer mass in every size fraction, even though profiles varied between WWTPs. When comparing the sum of all sites for each sized biosolids fraction, the plurality of the polyethylene, polyvinyl-chloride, polystyrene, polypropylene, polycarbonate, and polyethylene-terephthalate concentrations were associated with the smallest size fraction (<25 μm). We confirm for the first time the presence of plastic particles in biosolids below a size fraction that is not captured by many methods. This is important, because of the potential greater significance of plastics in the low sizes to environmental and human health., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Sampling, separation, detection, and characterization of microplastics (MPs) dispersed in natural water bodies and ecosystems is a challenging and critical issue for a better understanding of the hazards for the environment posed by such nearly ubiquitous and still largely unknown form of pollution. There is still the need for exhaustive, reliable, accurate, reasonably fast, and cost-efficient analytical protocols allowing the quantification not only of MPs but also of nanoplastics (NPs) and of the harmful molecular pollutants that may result from degrading plastics. Here a set of newly developed analytical protocols, integrated with specialized techniques such as pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS), for the accurate and selective determination of the polymers most commonly found as MPs polluting marine and freshwater sediments are presented. In addition, the results of an investigation on the low molecular weight volatile organic compounds (VOCs) released upon photo-oxidative degradation of microplastics highlight the important role of photoinduced fragmentation at a molecular level both as a potential source of hazardous chemicals and as accelerators of the overall degradation of floating or stranded plastic debris., (© 2021. The Author(s).)

Fish ingestion of microplastic has been widely documented throughout freshwater, marine, and estuarine species. While numerous studies have quantified and characterized microplastic particles, analytical methods for polymer identification are limited. This study investigated the applicability of pyr-GC/MS for polymer identification of microplastics extracted from the stomach content of marine fish from the Texas Gulf Coast. A total of 43 microplastic particles were analyzed, inclusive of 30 fibers, 3 fragments, and 10 spheres. Polyvinyl chloride (PVC) and polyethylene terephthalate (PET) were the most commonly identified polymers (44.1%), followed by nylon (9.3%), silicone (2.3%), and epoxy resin (2.3%). Approximately 42% of samples could not be classified into a specific polymer class, due to a limited formation of pyrolytic products, low product abundance, or a lack of comparative standards. Diethyl phthalate, a known plasticizer, was found in 16.3% of the total sample, including PVC (14.3%), silicone (14.3%), nylon (14.3%), and sample unknowns (57.2%)., (Copyright © 2018 Elsevier Ltd. All rights reserved.)