An innovative evaluation method based on polymer mass detection to evaluate the contribution of microfibers from laundry process to municipal wastewater

Proposed validation stages for MPs extraction from edible mussels (Mytilus galloprovincialis)

The potential presence of microplastics (MPs) in seafood products presents significant health concerns, demanding the adoption of standardized and validated methodologies. In this study, we introduce a validated method and an innovative technique for extracting MPs from mussels using an oxidizing agent, Corolase enzyme, and a surfactant, thus eliminating the need for mechanical agitation. Evaluation of the extraction process focused on three critical parameters: recovery percentage, repeatability, and chemical integrity, along with color stability. To ensure precision and reliability, low-density infrared spectroscopy (LDIR) was employed to analyze the effect of spectrum quality (Q). Ultimately, this methodology was applied to identify MPs in commercial mussels, with results showcasing the viability of the proposed validation stages for MPs extraction, maintaining MPs integrity with high recovery percentages.

Understanding microplastic presence in different wastewater treatment processes: Removal efficiency and source identification

Municipal effluents discharged from wastewater treatment plants (WWTPs) are a considerable source of microplastics in the environment. The dynamic profiles of microplastics in treatment units in WWTPs with different treatment processes remain unclear. This study quantitatively analyzed microplastics in wastewater samples collected from different treatment units in two tertiary treatment plants with distinct processes. The influents contained an average of 15.5 ± 3.5 particles/L and 38.5 ± 2.5 particles/L in the two WWTPs with in the oxidation ditch process and the integrated fixed-film activated sludge process, respectively. Interestingly, microplastic concentrations in the influent were more influenced by the population density in the served area than sewage volume or served population equivalent. Throughout the treatment process, concentrations were reduced to 1.5 ± 0.5 particles/L and 1.0 ± 1.0 particles/L in the final effluents, representing an overall decrease of 90% and 97%, in WWTPs with the oxidation ditch process and integrated fixed-film activated sludge process, respectively. A significant proportion of the microplastics were removed during the primary treatment stage in both WWTPs, with better performance for foam, film, line-shaped and large-sized microplastics. Most microplastics were accumulated in activated sludge, indicating its key role as the primary sink in WWTPs. The multiple correspondence analysis identified laundry washing and daily necessities such as packaging and containers as the major contributors to microplastics in WWTPs. The study proposed recommendations for upgrading WWTPs, modifying designs, and implementing strategies to reduce microplastic sources, aiming to minimize the release of microplastics into the environment. These findings can shed lights on the sources of microplastics in WWTPs, and advance our understanding of the mechanisms for more effective microplastic removals in wastewater treatment technologies in future applications.

Analysing micro- and nanoplastics with cutting-edge infrared spectroscopy techniques: a critical review

The escalating prominence of micro- and nanoplastics (MNPs) as emerging anthropogenic pollutants has sparked widespread scientific and public interest. These minuscule particles pervade the global environment, permeating drinking water and food sources, prompting concerns regarding their environmental impacts and potential risks to human health. In recent years, the field of MNP research has witnessed the development and application of cutting-edge infrared (IR) spectroscopic instruments. This review focuses on the recent application of advanced IR spectroscopic techniques and relevant instrumentation to analyse MNPs. A comprehensive literature search was conducted, encompassing articles published within the past three years. The findings revealed that Fourier transform infrared (FTIR) spectroscopy stands as the most used technique, with focal plane array FTIR (FPA-FTIR) representing the cutting edge in FTIR spectroscopy. The second most popular technique is quantum cascade laser infrared (QCL-IR) spectroscopy, which has facilitated rapid analysis of plastic particles. Following closely is optical photothermal infrared (O-PTIR) spectroscopy, which can furnish submicron spatial resolution. Subsequently, there is atomic force microscopy-based infrared (AFM-IR) spectroscopy, which has made it feasible to analyse MNPs at the nanoscale level. The most advanced IR instruments identified in articles covered in this review were compared. Comparison metrics encompass substrates/filters, data quality, spatial resolution, data acquisition speed, data processing and cost. The limitations of these IR instruments were identified, and recommendations to address these limitations were proposed. The findings of this review offer valuable guidance to MNP researchers in selecting suitable instrumentation for their research experiments, thereby facilitating advancements in research aimed at enhancing our understanding of the environmental and human health risks associated with MNPs.

Response mechanism of non-biodegradable polyethylene terephthalate microplastics and biodegradable polylactic acid microplastics to nitrogen removal in activated sludge system

The issue of microplastics (MPs) has gained more attention among researchers and the public; however, there is still a lot to be studied about its impact on biological wastewater treatment. In this study, the effects of non-biodegradable polyethylene terephthalate (PET) and biodegradable polylactic acid (PLA) on wastewater treatment by sequencing batch reactor (SBR) were compared. The results showed that PET and PLA reduced the removal efficiency of NH4+-N by 1.7 % and 21.2 %, respectively. Structural equation functional model (SEM) analysis was used to infer the potential mechanism of PLA affecting ammonia oxidation. PLA primarily inhibits the activity of ammonia monooxygenase (AMO), while promoting an increase in reactive oxygen species (ROS) and antioxidant enzyme activity. Accordingly, the toxic effect of PLA further reduced the abundance of ammonia-oxidizing bacteria. This study showed that biodegradable MPs have a greater potential impact on wastewater treatment than non-biodegradable MPs, which warrants further investigation.

A reliable method to determine airborne microplastics using quantum cascade laser infrared spectrometry

The number of studies dealing with airborne microplastics (MPs) is increasing but sampling and sample treatment are not standardized, yet. Here, a fast and reliable method to characterize MPs is presented. It involves the study of two passive sampling devices to collect atmospheric bulk deposition (wet and dry deposition) and three digestion methods (two alkaline-oxidative and an oxidative) to treat the samples. The alkaline-oxidative method based on KOH and NaClO was selected for a mild organic matrix digestion. In addition, some operational parameters of a high-throughput quantum cascade laser-based infrared device (LDIR) were optimized: an effective automatic tiered approach to differentiate fibres from particles (>90 % success in validation) and a criterion to establish positive matches when comparing an unknown spectrum against the spectral database (proposed match index > 0.85). The procedural analytical recoveries were very good for particles (82-90 %) and slightly lower for fibres (62-73 %). Finally, the amount and type of MPs deposited at a sub-urban area NW Spain were evaluated. Most common polymers were Polyethylene (PE), Polypropylene (PP) and Polyethylene terephthalate (PET). The deposition rates ranged 98-1220 MP/m2/day, ca. 1.7 % of the total collected particles. More than 50 % of the total MPs deposited were in the 20-50 μm size range, whereas fibres were mostly in the 50-500 μm size range.

Occurrence Characteristics and Ecotoxic Effects of Microplastics in Environmental Media: a Mini Review

The issue of environmental pollution caused by the widespread presence of microplastics (MPs) in environmental media has garnered significant attention. However, research on MPs pollution has mainly focused on aquatic ecosystems in recent years. The sources and pollution characteristics of MPs in the environment, especially in solid waste, have not been well-described. Additionally, there are few reports on the ecotoxicity of MPs, which highlights the need to fill this gap. This review first summarizes the occurrence characteristics of MPs in water, soil, and marine environments, and then provides an overview of their toxic effects on organisms and the relevant mechanisms. This paper also provides an outlook on the hotspots of research on pollution characterization and ecotoxicity of MPs. Finally, this review aims to provide insights for future ecotoxicity control of MPs. Overall, this paper expands our understanding of the pollution characteristics and ecological toxicity of MPs in current environmental media, providing forward-looking guidance for future research.

Removal characteristics of microplastics in sewage flowing through a long-term operation surface flow wetland

Microplastics (MPs) in sewage pose significant threats to aquatic system. Surface flow wetland (SFW) is a common natural wetland type, and is also used as a cheap and easy-to-build sewage treatment system for small and scattered settlements. However, seasonal variation patterns of MPs in sewage removed by SFW are still limited. Therefore, a field investigation was conducted in an SFW that has been operated for 17 years. The concentration of microplastics in the influent of the SFW (CMPs, in) ranged from 56 ± 6 to 250 ± 14 items L-1. The dominant plastic types were fibers and polyethylene terephthalate (PET). CMPs, in were high in summer and winter, significantly related to the seasonal dressing habits. The removal efficiencies of MPs in SFW were 48.03-92.32 % in different seasons, and the mechanisms of MP removal were different with traditional pollutants. Before flowing out occasionally or by heavy precipitation, MPs were primarily trapped in the SFW and underwent certain oxidation. Simulation experiments demonstrated that 47.5-92.9 % of MPs would be trapped in the SFW, and plants would significantly enhance the trapping capacities. This study sheds light on the seasonal variation characteristics and patterns of MPs in actual sewage, and clarifies the fate of MPs in a long-term operation SFW.

Nanoplastics removal from spiked laundry wastewater using electro-peroxidation process

Microplastics and nanoplastics (NPs) in laundry wastewater (LWW) are major sources of plastic particles in wastewater treatment plants. Unlike microplastics, almost no information exists in the literature on the degradation of NPs in LWW. In this work, the degradation of NPs in commercial LWW by the electro-peroxidation process is investigated. The obtained results demonstrated that already existing ions in LWW such as Cl- contribute to faster degradation of NPs and a complete removal could be obtained as fast as 40 min. In addition, three-dimensional excitation and emission matrix fluorescence analysis was performed, which revealed humic acid-like, aromatic proteins-like, and fulvic acid-like compounds could be oxidized after 20, 40, and 60 min of treatment respectively. The effects of operating parameters on the process performance were then examined by response surface methodology (RSM) models. The results showed that initial TOC concentration was the most important parameter influencing negatively the percentage of NP degradation. Afterward, optimization of the process revealed that the energy consumption could be minimized at 31.2 mA/cm2, 0.025 mol/L [Na2SO4], and 52 min treatment time for 52.2 mg/L initial TOC. Finally, analysis of treated LWW showed no toxicity on Daphnia magna. This study showed that the electro-peroxidation process can completely degrade NPs in LWW without any remaining toxic compounds.

Modified polyamide fibers with low surface friction coefficient to reduce microplastics emission during domestic laundry

The widespread presence of microplastics has become a serious threat to humans and ecological environments because they carry many pollutants and can be easily ingested by aquatic organisms. Fibrous microplastics (FMPs) released from synthetic fiber garments during domestic laundry are a major source of contamination. Herein, we report a facile FMPs mitigation strategy for polyamide 6 (PA6) fibers by incorporating environmentally friendly polydimethylsiloxane (PDMS) during melt spinning. The obtained PA6/PDMS fibers showed a lower friction coefficient than the pure PA6 fibers. Surface morphology, tribology, and washing characterizations verified that a 60% reduction in FMPs shedding was achieved by reducing the friction. In addition, the low-surface-friction PA6/PDMS fabrics with high hydrophobicity exhibited improved waterproof and anti-stain behaviors. It is important to note that none of the essential properties, such as surface structure, dyeing and printing of the fabrics were compromised after PDMS blending. This study provides a green and scalable route for mitigating laundry microfibers using a fiber domain design.

Source apportionment of microplastics in indoor dust: Two strategies based on shape and composition

Microplastic (MP) pollution is widely distributed in the environment. However, methods for source apportionment of MPs are still lacking. In this study, the shape and size of 102,860 MPs in indoor dust from 39 cities of China were analyzed by laser direct infrared, and accordingly, a shape index (fshape) based on MP's aspect ratio was developed to assess the contribution of textiles release. In addition, a composition index (fcomp) based on the ratio of the mass concentration of polyethylene terephthalate (PET) to polyamide (PA), which were detected by liquid chromatography-tandem mass spectrometry, was proposed. The contribution of textile source and non-textile source to the indoor MPs were also estimated based on fcomp. It is estimated by fshape that 43% of MPs in indoor dust was released from textiles. Among the most abundant MPs in indoor dust, 98% of polyurethane, 94% of PA and 92% of PET come from the textile source, 76% of polypropylene and almost all of polyethylene come from the non-textile source. fcomp indicates that 83% of PET MPs comes from textile source, i.e., polyester. Considering the application proportion of PET in textile and non-textile industry, it is estimated that 59% of MPs in indoor dust comes from textile source, which is similar to the result obtained by fshape.

A novel simplified method for extraction of microplastic particles from face scrub and laundry wastewater

Microplastic pollution in different environmental matrices is a serious concern in the recent times. Personal care products and washing of synthetic fabrics are some of the main sources of microplastic pollution. In this work, a novel simplified, effective and sustainable method for extraction of microplastic particles from face scrub and laundry wastewater was developed. Different parameters affecting the extraction were analysed and the extraction process was optimised. The extraction efficiency of the proposed method was found to be ~ 94.1 ± 1.65%, which was slightly better than the previously available method with an advantage of ease in extraction and lesser time and resource consuming. The developed method was used to demonstrate the extraction of microplastic particles from 12 face scrub samples with different brands. It was found that the samples contained microplastic particles of varying size. The physical and chemical structure intactness of microplastic particles during the extraction was also analysed and found to be acceptable. The developed extraction method was also applied for the extraction of microfibers from the laundry wastewater. It was found that this proposed method is suitable to make the cleaner extracted samples for an easy and more effective qualitative and quantitative analysis of MPs.

Impact of plastic film mulching on microplastic in farmland soils in Guangdong province, China

Plastic mulch film is often believed to be a significant contributor to microplastic pollution in farmland soil, however, its direct impact in areas with high human activities remains unclear due to the presence of multiple pollution sources. This study aims to address this knowledge gap by investigating the impact of plastic film mulching on microplastic pollution in farmland soils in Guangdong province, China's largest economic province. The macroplastic residues in soils were investigated in 64 agricultural sites, and the microplastics were analyzed in typical plastic film mulched and nearby non-mulched farmland soils. The average concentration of macroplastic residues was 35.7 kg/ha and displayed a positive correlation with mulch film usage intensity. Contrarily, no significant correlation was found between macroplastic residues and microplastics, which exhibited an average abundance of 22,675 particles/kg soil. The pollution load index (PLI) model indicated that the microplastic pollution level was category I and comparatively higher in mulched farmland soils. Interestingly, polyethylene accounted for only 2.7% of the microplastics, while polyurethane was found to be the most abundant microplastic. According to the polymer hazard index (PHI) model, polyethylene posed a lower environmental risk than polyurethane in both mulched and non-mulched soils. These findings suggest that multiple sources other than plastic film mulching primarily contribute to microplastic pollution in farmland soils. This study enhances our understanding of microplastic sources and accumulation in farmland soils, offering crucial information on potential risks to the agroecosystem.

New insights into the adsorption behavior of thiacloprid at the microfibers/water interface: Role of humic acid

Dissolved organic matter regulates the interaction between microplastics (MPs) and organic pollutants. Here, this paper investigated the effect and mechanism of humic acid (HA) on the adsorption behavior of thiacloprid at two microfibers (MFs)/water interface, and compared the differences in the performance of MFs and pure MPs. The results showed that 10 mg L^-1 HA decreased the adsorption capacity and the partition coefficient K_D of thiacloprid on MFs and pure MPs. Spectral analysis showed that HA could form hydrogen bonds and van der Waals forces with both MPs and thiacloprid, ultimately affecting the adsorption behavior of thiacloprid at MPs/water interface via competitive adsorption and bridging effect. Furthermore, two-dimensional correlation spectroscopy demonstrated that thiacloprid was preferentially adsorbed onto MPs compared with HA. Finally, density functional theory calculation demonstrated that phenolic-OH, -COOH, and alcoholic-OH played critical roles in competing adsorption and bridging effect. This study offers a theoretical foundation for a better comprehension of the adsorption behavior of organic pollutants at the MPs/water interface.

Distribution characteristics of microplastics in typical organic solid wastes and their biologically treated products

Enormous production, use, and disposal of plastic goods present great challenges to environmental sustainability. Microplastics (MPs) are added into land which may serve as a larger MP repository than the ocean. Organic solid wastes and their biologically treated products can easily enter the soil and accumulate in soil systems. The current work deals with the extraction, identification, and distribution of MPs in typical organic solid wastes (food waste, livestock manure, and sludge) and their biologically treated products. The ecological risks of MPs were also preliminarily evaluated. The results showed that the abundance of MPs in organic solid wastes was in order of sludge > food waste > livestock manure. The main categories of MPs were fibers and films including PE, PP, and PET. The colors of MPs were mainly black, red, blue, and green. MPs generally exhibited bulges, depressions, cracks, or holes after biological treatment, and would be degraded into smaller fragments with potentially greater ecological risks. It was also found that the polymer risk index (H) of MPs in semi-dynamic composting products, compound fertilizer, and biogas residue of sedimentation tank sludge were higher than 10, reflecting their high ecological risk. Thus, it is recommended that the input of (micro)plastics to organic solid wastes streams should be minimized and related management should be established for the utilization of organic solid wastes and their biologically treated products.

Mass Spectrometry as an Analytical Tool for Detection of Microplastics in the Environment

Plastic particles smaller than 5 mm accumulate in aqueous, terrestrial, and atmospheric environments and their discovery has been a serious concern when it comes to eco-toxicology and human health risk assessment. In the following review, the potential of mass spectrometry (MS) for the detection of microplastic (MP) pollutants has been elaborately reviewed. The use of various mass spectrometric techniques ranging from gas chromatography–mass spectrometry (GC-MS), liquid chromatographic mass spectrometric (LC-MS) to matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), including their variants, have been reviewed. The lapses in the detection system have been addressed and future recommendations proposed. The challenges facing microplastics and their detection have been discussed and future directions, including mitigation methods, have been presented.

Microplastics in Flathead Lake, a large oligotrophic mountain lake in the USA

Microplastics are contaminants that are closely associated with human activity and are often abundant even in remote areas. As the largest natural freshwater lake in the western USA, Flathead Lake is a suitable site to study microplastics in lakes in less-populated areas of North America. Our assessment of microplastics in lake surface water samples showed that microplastic densities and concentrations in Flathead Lake were similar to those in other lakes located in less-populated areas around the world, with densities ranging from 8.00 × 10⁴ to 4.22 × 10⁵ particles/km² with a mean concentration of 1.89 × 10⁵ particles/km². Dry deposition rates for microplastics ranged from 4 to 140 particles/m²/day with an average of 69 particles/m²/day and were significantly higher in the fall. Microplastic concentrations in wet deposition ranged from 0.006 particles/mL to 0.050 particles/mL with highest concentrations in winter and lowest in summer. Fibrous microplastics were predominant in both lake water and atmospheric deposition. The high densities of microplastics in the sample sites located near the Flathead River inlet suggests that the river is an important source of microplastics to Flathead Lake. The high densities of microplastics and high proportions of non-fibrous microplastics near populated areas of the lake imply that local human activities also affect microplastics in Flathead Lake. Although the annual flux of microplastics in dry deposition was higher than that in wet deposition, the relatively modest difference suggests that precipitation might enhance the deposition of microplastics. The results of this study indicate that instituting increased control measures that target both reducing the microfibers generated by laundry and improving the overall level of plastic waste management in the watershed may help in controlling microplastic levels in Flathead Lake.

Urban natural wetland as a sink for microplastics: A case from Lalu Wetland in Tibet, China

Microplastics have been reported in a wide range of aquatic habitats. The wetlands are considered to be important roles in microplastic migration in water bodies. Nevertheless, knowledge about the occurrence and fate of microplastics in urban natural wetland is still limited for us to better understand how they become a sink of microplastics. In this study, the distribution and characteristics of microplastics in surface water, surface sediments, and sediment cores of the Lalu Wetland watershed, China's highest urban wetland, were investigated in August 2020 and January 2021. The abundances of microplastics in the surface water were 0.06-3.05 MPs/L. Microplastic abundance in the surface sediment and sediment core was 0.01-1.10 MPs/g and 0-16.23 MPs/g, respectively. The abundance of microplastics in the water was significantly lower in the wetland than that in the channel in the watershed. Comparing the wetland inlet and outlet water, the microplastic interception rates were 53% in January and 95% in August. The characteristics and seasonal variation of microplastics in the Lalu Wetland implied that urban natural wetlands were good at intercepting microplastics, and vegetation growth might play an important role on the interception of microplastics by the wetland. The increasing of microplastics from bottom to top in the sediment cores of Lalu Wetland also indicated that the ecological risks of microplastics accumulation in sediments of urban natural wetland required further attention.

A reliable method for the isolation and characterization of microplastics in fish gastrointestinal tracts using an infrared tunable quantum cascade laser system

Societal and environmental concern due to frequent reports of microplastics in fish stomachs raised as they may accumulate along the trophic chain. The request for analysing microplastics in fish stresses two major analytical issues: sample treatment and final characterization. The, so far, workhorse for chemical characterization is infrared spectroscopy which is time-consuming. Here, a quantum cascade laser-based device is used to accelerate the characterization stage. Its novelty poses new challenges for sample processing and particle handling because the unknown particles must be transferred to a reflective slide. In this study, three sample digestion protocols (alkaline-oxidative with H₂O₂, and alkaline-oxidative with NaClO and enzymatic-oxidative) and three different procedures to transfer the filter cake to reflective slides are compared. A simplified enzymatic-oxidative digestion (validated through an interlaboratory exercise) combined with a Syncore® automatic evaporation system and a Laser Direct Infrared Imaging (LDIR) device is proposed first time as a reliable and relatively fast method to treat gastrointestinal tracts of fish. Analytical recoveries were studied using samples of Scomber scombrus and they were ca. 100% for big -i.e., >500 μm- and ca. 90% for medium -i.e., 200-300 μm- particles and ca. 75% for 10 μm thick fibres.

Occurrence and distribution of microplastics in sediments of a man-made lake receiving reclaimed water

Microplastics have been widely detected in the effluent discharged from wastewater treatment plants. However, few studies have focused on the occurrence of microplastics in the sediments of waterbodies receiving reclaimed water. The present study investigated the microplastics distribution in the sediments of such a lake in Tianjin, China receiving reclaimed water and determined the factors affecting the settlement of microplastics in the sediment column. Nine sediment cores were collected and the abundance, shape, size, and color of the microplastics were determined. The polymers of microplastics were identified and the mass concentrations of polyethylene terephthalate (PET) and polycarbonate (PC) were analyzed. Large amount of microplastics were found to accumulate in the sediments of the lake receiving reclaimed water. Eighteen polymers were found in the sediments and PA, PET, PP, PSF, and PU are much more than others. In surface sediments, PET and PC ranged from 2.43 to 10.62 mg/kg and 0.03 to 0.77 mg/kg, respectively. Fragment and fiber are the most common shapes, accounting for 67.5% and 24.8% of all the microplastics. The distribution of microplastics was influenced by polymer type, size, shape, and grain size of the sediments. Microplastic morphological diversities decreased with increasing depth of the sediments. Our findings provide evidence that the sediments of receiving waterbodies are important sinks of the microplastics in reclaimed water.

Improved Settling Velocity for Microplastic Fibers: A New Shape-Dependent Drag Model

Microplastics are abundant in aquatic environments and are an emerging environmental concern. The prediction of their settling velocities is central to predictions of the residence time and concentration depth profiles of microplastics in aquatic environments. The main scientific challenge in improving the current understanding of the settling motions of microplastics is that existing drag models are deficient at reasonably predicting the settling velocities of various microplastics, especially microplastic fibers. This is because the shape factors used in the existing drag models cannot morphologically distinguish fibers from fragments and films. In this study, a new shape factor, specifically the Aschenbrenner shape factor, is proposed as a vehicle to explicitly distinguish among the morphologies of fibers, films, and fragments. With this new shape factor, a new drag model is developed and then systematically evaluated against the unique set of data provided by new experiments conducted in this study along with four other published data sets in the literature. The proposed model allows the prediction of the terminal settling velocity of microplastic fibers more accurately than existing drag models. Moreover, the new model has also shown its applicability to microplastic films and fragments. Notwithstanding, the new model appears deficient at reasonably predicting the terminal settling velocity of weathered microplastics in the field, which requires further investigations.

Comparison of Detection Methods of Microplastics in Landfill Mineralized Refuse and Selection of Degradation Degree Indexes

A landfill is an important sink of plastic waste and potential sources of microplastics (MPs) when mineralized refuse is reused. However, limitations are still present in quantifying MPs in mineralized refuse and assessing their degradation degree. In this study, laser direct infrared spectroscopy and liquid chromatography-tandem mass spectrometry (LC-MS/MS) were used to identify MPs of mineralized refuse from a landfill. Although 25-113 items/g MPs were detected in particles subjected to flotation, 37.9-674 μg/g polyethylene terephthalate (PET) and 0.0716-1.01 μg/g polycarbonate (PC) were detected in the residual solids by LC-MS/MS, indicating a great amount of plastic polymers still presented in the residue. This suggests that the commonly used flotation-counting method will lead to significant underestimation of MP pollution in mineralized refuse, which might be due to the aging and aggregation process caused by the long-term landfill process. The ratio of "bisphenol A/PC" and "plasticizer/MPs" was found to be positively correlated and negatively correlated with the landfill age, respectively. Therefore, in addition to the spectral index such as the carbonyl index, new indexes based on the concentrations of polymers, free monomers, and plasticizers were proposed to characterize the degradation degree of MPs in a landfill.

Plastic microfibre pollution: how important is clothes' laundering?

Plastic microfibre pollution produced by domestic and commercial laundering of synthetic textiles has recently been incriminated in the press and the scientific literature as the main source (up to 90%) of primary microplastics in the oceans. Polyethylene terephthalate (PET) is the most common microfibre encountered. This review aims to provide updated information on worldwide plastic microfibre pollution caused by textile laundering and some possibilities for its control. Release of microfibres during domestic washing and tumble drying, their fate in wastewater treatment plants (WWTPs) and the oceans, and their environmental effects on the aquatic biota are discussed, as well as potential control methods at the levels of textile modification and laundry procedures. Environmental effects on aquatic biota are important; as a result of their small size and length-to-diameter ratio, microfibers are more effectively incorporated by organisms than other plastic particle groups. Simulation laundering studies may be useful in the development of a Standard Test Method and modification of WWTPs may reduce microfibre release into aquatic systems. However, improvements will be necessary in textile design and appliance design, and recommendations should be made to consumers about reducing their personal impact on the environment through their laundering choices, which can include appliances, fabric care products and washing conditions. Official regulation, such as that introduced recently by the French government, may be necessary to reduce plastic microfibre release from clothes' laundering.