Pectin based finishing to mitigate the impact of microplastics released by polyamide fabrics

Emission of fibres from textiles: A critical and systematic review of mechanisms of release during machine washing

Research about health and environmental impacts of pollution caused by natural and plastic fibres is increasing, however, the role of textile characteristics in microfibre release during washing remains poorly understood. Given that machine washing is thought to be the main contributor to microfibre pollution, we systematically and critically reviewed previous publications looking at how textile features affect fibre emissions during washing. We examined the evidence related to findings from previous studies based on their research aims, ability to control variables that could confound results, use of procedural blanks and controls, and statistical methodologies. We observed that small-scale laboratory equipment frequently used to evaluate microfibre release (e.g. Gyrowash) generates significantly more fibres than domestic washing machines and should not be used to generate environmental estimations. Our findings have implications for ecotoxicology and risk assessment, particularly regarding the overlooked role of natural and cellulosic fibres. While synthetic fibres are widely recognised as the dominant form of microplastic in the environment, environmental surveys often report larger numbers of natural and cellulosic fibres. These fibres, however, account for only 18 % of those tested in the experiments analysed, indicating the need for further research to understand the underlying causes of their release. We concluded that although many textile characteristics are perceived as having an impact on fibre release, 81 % of studies failed to demonstrate clear evidence of the findings associated with such impacts. This work highlights the need for robust experiments to clarify these gaps, which could then allow the development of textiles with minimised shedding potential. We propose a stepwise approach to first build a foundational understanding of how individual washing parameters and textile features influence fibre release, followed by exploring the complexity of how the interaction between these variables impacts emissions.

Release of microplastic fibers from synthetic textiles during household washing

Textile materials are one of the primary sources of microplastic pollution. The washing procedure is by far the most significant way that textile products release microplastic fibers (MPFs). Therefore, in this study, the effects of various textile raw materials (A acrylic, PA polyamide, PET polyester, RPET recycled polyester and PP polypropylene), fabric construction properties (woven, knitted), thickness and basis weight values on MPFs release at different washing stages (pre-washing, soaping/rinsing) were examined separately. To mimic the most popular home washing procedures, a 10-min pre-wash and a 35-min soaping/rinsing phase at 40 °C were selected for the washing procedure. Utilizing the Image J program on macroscopic images captured by a high-resolution SL. R camera, the microfibers collected by filtering the water have been visually counted. According to the results, knitted fabrics released fewer MPFs than woven fabrics, with the woven acrylic sample (A3-w) exhibiting the highest release (2405 MPFs). The number of MPFs increased along with the thickness and weight of the fabric. Recycled polyester was found to release more MPFs than virgin polyester under the same conditions (1193 MPFs vs. 908 MPFs). This study demonstrates how recycled polyester, although initially an environmentally beneficial solution, can eventually become detrimental to the environment. Furthermore, it is known that the pre-washing procedure-which is optional-releases a lot more MPFs than the soaping and rinsing procedures, and that stopping this procedure will drastically lower the amount of MPFs incorporated into the water.

Micro- and Nanoplastics Produced from Textile Finishes: A Review

The problem of increasing plastic pollution has emerged as a significant societal issue. Plastics can originate from various sources, and there is growing concern among researchers to study and investigate this new category of pollution. The plastic waste is found at the macro, micro, and nanoscale, and its study has had great significance according to the perspective of posing hazardous impacts on living organisms. Given the high demand for functional textiles, the textile industries are supporting the coating of different polymeric based finishes on the surface of textile products. The plastic debris emitted from these coated finishes are in the ranges of nanometric scale, so-called polymeric nanoplastics (PNPs). With the new terminology, polymeric nanoplastics (PNPs) released from textile finishes or coatings are being increasingly mentioned, and the term fibrous microplastics (FMPs) can be seen as outdated. This study is based on an intensive review of a very novel category of debris plastics (PNPs) mostly produced from textile finishes or coatings. In fact, FMPs and PNPs released from synthetic textiles and textiles coated with plastic-based finishes during washing activities are considered to be a major cause that contributes to the current overall load of microplastics (MPs) in the environment. A link between the concentration of NPs from textile fibers and NPs from textile polymeric-based coatings in freshwater and sediments within a particular local setting and the extent of activities of the textile industry has been demonstrated. Invested efforts have been paid to consider and concentrate on plastic pollution (nanoplastics from textile polymeric coatings). We also summarize existing methodologies to elucidate the identification and proactive quantification of nanoplastics shed from the textile polymeric coatings. To this end, more than 40 studies have been done to identify the physical, chemical, and mechanical parameters and to characterize nanoplastics.

Impact of sewing on microfiber release from polyester fabric during laundry

Microfibers released from textile materials are receiving greater attention due to their severe adverse effects on the environment. Although mitigation strategies have been developed for laundering, researchers uphold that it is crucial to start mitigating at the source. In that aspect, this research aims to analyze the cutting and sewing methods of knitted fabrics and their impact on the microfiber release of garments during laundry. The results of the study have confirmed that cutting and sewing methods have a significant impact on the microfiber release of a garment. The analysis of different cutting methods showed that laser and ultrasonic cutting methods reduce the microfiber release up to 20 times compared to the conventional scissor-cut edges. While comparing the different stitch types, the overlock stitch type showed reduced shedding than the other stitch types (flatlock stitch and single needle lockstitch). Our results also showed that the use of more needles increases the microfiber emission among different stitch variations of the same stitch type. For instance, a 45.27 % increase in microfiber emission was reported with the 4-thread overlock stitch (2 needles) than with the 3-thread stitch (1 needle). Regarding seam type, the proposed edge finishing seam (EFb) was effective in reducing 93 % of microfiber release as the edges are completely covered. When the effect of stitch density is considered, in the case of single needle lockstitch and flatlock stitch, the microfiber release is reduced with increased stitch density. However, a different trend was noted in the overlock stitch, which needed detailed exploration in the future. The results confirmed that a proper selection of stitch, stitch density, and seam type would reduce the microfiber release from a garment by up to 64.6 %.

Impact of quantification method on microfiber assessment - A comparative analysis between mass and count based methods

Microfiber from textiles is one of the new anthropogenic pollutants which attracted a wide range of researchers. Domestic laundry, being the most common cause of microfiber release from textiles, is widely studied. Studies exhibit a broad range of quantities of microfibers owing to the distinct quantification methodologies employed due to their convenience and resource availability. Out of several such estimation processes, reporting microfiber quantity in numbers or mass (mg or g) is quite common with respect to the unit area or weight of the textile used. However, results reported by different literature vary significantly. Hence, this study aims to analyze the microfiber release from knitted polyester fabric using count- and mass-based methods. Four different fabrics were used for this study with three different counting processes from literature along with direct weight difference estimation. The results of the direct counting method showed that the average microfiber release of selected fabrics is 13.28-33.16 microfibers per sq.cm, whereas, the direct weight estimation showed an average weight of 0.0664 ± 0.0289 mg/sq.cm. The subsequent conversion showed a release of 887.89 ± 633.49 microfibers/sq.cm of the fabric. Further, the microfiber mass was also estimated using the number of microfiber count and found that a sq.cm of fabric releases up to 0.0010-0.0024 mg of microfibers. While comparing the results, the weight-based estimation showed a significantly higher microfiber release (41.3-42.9 times) than the direct counting method. The deposition of surfactants in detergents, contaminants from the water, atmospheric contaminants, and finishes released from the fabric can be the sources of additional weights noted in the direct mass estimation. As the weight-based method is quite simple and the fastest way to quantify the microfibers, future studies must focus on this area to reduce the error percentage in quantification.

Investigation of ring, airjet and rotor spun yarn structures on the fragmented fibers (microplastics) released from polyester textiles during laundering

The release of fragmented fibers (FFs), including microplastics from textiles, during their service life is considered an established source of environmental pollution. The yarn structure is identified to affect the amount and length distribution profile of shed FFs from textiles. In the present work, the impact of yarn structures spun from 100% polyester staple fibers, using commercially relevant spun yarn technologies in the textile industry, on the release of FFs from textiles is studied. The bespoke woven fabric samples produced from three types of spun yarns, which include ring, airjet (air vortex) and rotor yarns, were subjected to an accelerated washing process, for up to five washes, to quantify shed FFs and their length distribution profile. The morphological shapes of FF ends associated with the nature of fiber damage were also investigated. The results demonstrated that airjet and rotor yarn structures had released 28% and 33% less mass of FFs, respectively, as compared to the ring yarn structure during the whole washing process. The length distribution profile identified that the ring yarn structure shed longer length FFs as compared to both airjet and rotor ones. The damaged ends highlight the importance of textile manufacturing processes on the generation of FFs. The results of this study give a better understanding of the yarn structural effect of commercially relevant technologies on shedding of FFs, which are released as a pollutant to the environment.

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.

Functional polymer brushes for anti-microplastic pollution

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Environmentally Friendly Approach to the Reduction of Microplastics during Domestic Washing: Prospects for Machine Vision in Microplastics Reduction

The increase in the global population is directly responsible for the acceleration in the production as well as the consumption of textile products. The use of textiles and garment materials is one of the primary reasons for the microfibers generation and it is anticipated to grow increasingly. Textile microfibers have been found in marine sediments and organisms, posing a real threat to the environment as it is invisible pollution caused by the textile industry. To protect against the damaging effects that microplastics can have, the formulation of mitigation strategies is urgently required. Therefore, the primary focus of this review manuscript is on finding an environmentally friendly long-term solution to the problem of microfiber emissions caused by the domestic washing process, as well as gaining an understanding of the various properties of textiles and how they influence this problem. In addition, it discussed the effect that mechanical and chemical finishes have on microfiber emissions and identified research gaps in order to direct future research objectives in the area of chemical finishing processes. In addition to that, it included a variety of preventative and minimizing strategies for reduction. Last but not least, an emphasis was placed on the potential and foreseeable applications of machine vision (i.e., quantification, data storage, and data sharing) to reduce the amount of microfibers emitted by residential washing machines.

Fibrous microplastics released from textiles: Occurrence, fate, and remediation strategies

Microplastics (MP), i.e., particles measuring less than 5 mm in size, are considered emerging pollutants. The ubiquity of MP is causing great concern among environmental and public health agencies. Anthropogenic activities are responsible for the extensive dispersal of MP in nature. Adverse effects on living organisms, interactions with other contaminants occurring in the environment, and the lack of effective degradation/removal techniques are significant issues related to MP. Most MP found in nature are fibrous (FMP). FMP originate from textile products, mainly synthetic fibers (e.g., polyester). Synthetic fibers are intensively used to produce countless goods due to beneficial characteristics such as high mechanical resistance and economic feasibility. FMP are ubiquitous on the planet and impart lasting adverse effects on biodiversity. Data on the consequences of long-term exposure to these pollutants are scarce in the literature. In addition, few studies address the main types of synthetic microfibers released from textiles, their occurrence, adverse effects on organisms, and remediation strategies. This review discusses the relevant topics about FMP and alerts the dangers to the planet. Furthermore, future perspectives and technological highlights for the FMP mitigation/degradation are presented.

Characterization of microfibers released from chemically modified polyester fabrics - A step towards mitigation

Synthetic textiles are one of the significant contributors to microfiber pollution, a subclass of microplastics. The impact of microfibers on the environment is irreversible. Several attempts were made to mitigate and control the microfiber release from synthetic textiles by introducing filters and laundry aids in washing machines, whereas some came up with methods to modify the textile materials to release fewer fibers. Studies have related different textile properties with their microfiber release potential. However, moisture properties, one of the essential properties that determine comfort, are not well explored. Hence, this research attempted to mitigate the microfiber release by altering the hydrophilicity of the polyester fabrics through chemical treatment (sodium hydroxide) with the hypothesis that hydrophilicity reduces the microfiber release. Both woven and knitted polyester fabrics were treated with different concentrations of the alkali solution (0.25 M, 0.50 M, 0.75 M, 1.00 M) and evaluated for their microfiber release. Treated fabrics also showed variations in their moisture and physical properties. Woven fabrics showed reduced shedding compared to knitted fabrics due to their compact structure. The results showed that the increase in alkali concentration significantly reduced the microfiber release up to 89.6 % reduction with woven fabric (from 17.37 ± 1.55 fibers/sq.cm to 2.63 ± 0.23 fibers/sq.cm) and a reduction of 68 % was noted for knitted fabric treated with 0.75 M alkali concentration (from 24.38 ± 1.30 fibers/sq.cm to 8.74 ± 1.39 fibers/sq.cm). A higher negative correlation (r = 94 % for woven and 89 % for knitted) was noted between alkali concentration and microfiber release. The alkali treatment significantly reduced the average fiber length from 450 to 230 μm, and 63-93 % of the fibers identified were in size range of 100-500 μm. When the moisture properties of the alkali-treated fabrics are concerned, an increase in moisture properties reduces the microfiber release. Water contact angle and absorbency time positively correlated with microfiber release. However, the study did not show any significant effect of moisture regain percentage and vertical wicking on microfiber shedding. Except for abrasion resistance, the physical properties of alkali-treated fabric did not show any relationship with microfiber release. The study noted the order of factors influencing the microfiber release of polyester fabric as fabric structural parameters (Woven/Knits) > fabric hydrophilicity > fabric physical property.

Microfiber mitigation from synthetic textiles - impact of combined surface modification and finishing process

The use of proper mitigation strategies to control the impact of microfiber pollution is need of the hour requirement. Though several laundry aids were developed to reduce the environmental impact caused by synthetic microfiber, due to the lack of awareness among the public, their effectiveness was limited. Hence, the mitigation measures at the production stage of textile materials can be a proactive solution with greater effectiveness in mitigating the issue at different stages rather than focussing only on domestic laundering. In this aspect, few recent attempts have been made to control the microfiber release from textiles by the surface finishing process. Thus, the current research focused on utilizing the surface modification process and surface finishing process to reduce the microfiber release behavior of knitted polyester fabrics. In this study, polyester knitted fabric (PES) was surface finished with chitosan (PES-Ch), sericin (PES-Se), and polyvinyl alcohol (PES-PVA), and their effectiveness in reducing microfiber shedding during laundry was analyzed. These finishes are applied directly on the polyester fabric and also after surface modification by alkali (Al) and enzyme (En) pre-treatments. The results reported that at the first wash, directly finished samples showed a reduction of 30-40% in microfiber shedding, and the samples finished after alkali pre-treatment showed a significant reduction of 47-84.29% (p < 0.05). Reduction in microfiber release was noted in the order of chitosan finish with alkali pre-treatment (PES-Al-Ch) > chitosan finish (PES-Ch) > sericin finish with alkali pre-treatment (PES-Al-Se) > polyvinyl alcohol finish with alkali pre-treatment (PES-Al-PVA) > polyvinyl alcohol finish (PES-PVA) for both fiber count and mass. In the case of enzyme pre-treatment, no reduction was reported, irrespective of the finishes applied. Repeated wash test results showed that the finishes could withstand and effectively control the microfiber release from the polyester fabric even after 20 washes. The performance of PES-Al-Ch fabric was superior among other modifications up to the fifth wash (with an 83.55% reduction in microfiber release). At extended washes like the 15th and 20th wash, the performance of PES-Al-PVA fabric was found to be better, with 94% and 95% microfiber reduction, respectively.

Review of research on migration, distribution, biological effects, and analytical methods of microfibers in the environment

Microplastics have been proven to be one of the critical environmental pollution issues. Moreover, microfibers, the most prominent form of microplastics in the environment, have likewise attracted the attention of various countries. With the increase in global population and industrialization, the production and use of fibers continue to increase yearly. As a result, a large number of microfibers are formed. If fiber products are not used or handled correctly, it will cause direct/indirect severe microfiber environmental pollution. Microfibers will be further broken into smaller fiber fragments when they enter the natural environment. Presently, researchers have conducted extensive research in the identification of microfibers, laying the foundation for further resourcefulness research. This work used bibliometric analysis to review the microfiber contamination researches systematically. First, the primary sources of microfibers and the influencing factors are analyzed. We aim to summarize the influence of the clothing fiber preparation and care processes on microfiber formation. Then, this work elaborated on the migration in/between water, atmosphere, and terrestrial environments. We also discussed the effects of microfiber on ecosystems. Finally, microfibers' current and foreseeable effective treatment, disposal, and resource utilization methods were explained. This paper will provide a structured reference for future microfiber research.

Development of Gelatin-Coated Hydrogel Microspheres for Novel Bioink Design: A Crosslinker Study

The development of vascularized tissue is a substantial challenge within the field of tissue engineering and regenerative medicine. Studies have shown that positively-charged microspheres exhibit dual-functions: (1) facilitation of vascularization and (2) controlled release of bioactive compounds. In this study, gelatin-coated microspheres were produced and processed with either EDC or transglutaminase, two crosslinkers. The results indicated that the processing stages did not significantly impact the size of the microspheres. EDC and transglutaminase had different effects on surface morphology and microsphere stability in a simulated colonic environment. Incorporation of EGM and TGM into bioink did not negatively impact bioprintability (as indicated by density and kinematic viscosity), and the microspheres had a uniform distribution within the scaffold. These microspheres show great potential for tissue engineering applications.

Enzyme hydrolysis of polyester knitted fabric: A method to control the microfiber shedding from synthetic textile

Synthetic textile materials are noted as one of the major contributors to microfiber release from household laundry. The higher usage of synthetic textiles was noted as one of the major reasons for the leaching of microfibers into the aquatic system. Though few laundry aids are available to control the release of microfiber from laundry, no successful methods were developed to control it in the fabric itself. Hence, this research aimed to analyze the effectiveness of surface modification of polyester fabric using lipase enzyme and its impact on microfiber shedding. Taguchi's L9 orthogonal array was adopted to optimize the enzyme treatment process parameters to reduce microfiber shedding. The results showed that enzyme concentration was the major influencing factor with a contribution of 35.56%, followed by treatment pH (35.247%), treatment time (17.46%), and treatment temperature (11.74%). The optimization with S/N ratio showed minimum microfiber shedding at an enzyme concentration of 0.5 gram per liter (gpl), treatment temperature of 55°C, 6.5 pH, and a treatment time of 45 minutes. Knitted polyester fabric treated with the optimized enzyme treatment condition showed a significant reduction (p<0.05) in microfiber shedding (count-79.11% and mass-85.68%). The surface changes and the interaction of the enzyme on the fabric were confirmed by hydrolytic activity and FTIR analysis. The optimized treatment on different knit structures and fabric with different grams per square meter (GSM) indicated the versatility of the treatment irrespective of fabric parameters. The repeated laundry process (20 washing cycles) showed that the enzyme-treated samples had a significant level (p<0.05) of reduction in shedding than the control sample. The difference in shedding after 20 washes supports the efficiency and longevity of the enzyme treatment process in reducing microfiber shedding.

Review on alternatives for the reduction of textile microfibers emission to water

The microplastics (MPs) are considered one of the most threatening pollutants. One of the main concerns is their continuous and cumulative flow to water environments, as they are very difficult to be removed. Microfibers (MFs) are a significant type of MPs, with textile articles as one of the most renowned sources. This review aims to provide the current status of these MFs as pollutants, discussing possible alternatives from the manufacturing until the final disposition of MFs. There are many alternatives to reduce these pollutants from reaching the environment but also gaps that need to be further evaluated and addressed. Besides, it should be noticed that alternatives could be complementary between them. Some viable and non-contaminating solutions to reduce this pollution are currently on the market. Also, one relevant aspect is the final disposition or usage of the retained MFs to avoid them from reaching aquatic environments.

Microplastics in Wastewater by Washing Polyester Fabrics

Microplastics have become one of the most serious environmental hazards today, raising fears that concentrations will continue to rise even further in the near future. Micro/nanoparticles are formed when plastic breaks down into tiny fragments due to mechanical or photochemical processes. Microplastics are everywhere, and they have a strong tendency to interact with the ecosystem, putting biogenic fauna and flora at risk. Polyester (PET) and polyamide (PA) are two of the most important synthetic fibres, accounting for about 60% of the total world fibre production. Synthetic fabrics are now widely used for clothing, carpets, and a variety of other products. During the manufacturing or cleaning process, synthetic textiles have the potential to release microplastics into the environment. The focus of this paper is to explore the main potential sources of microplastic pollution in the environment, providing an overview of washable polyester materials.

Is froth flotation a potential scheme for microplastics removal? Analysis on flotation kinetics and surface characteristics

Increasing microplastics (MPs) cause significant threats to the ecosystem and society. The tremendous advances concerning the sources, occurrence, chemical behavior, toxicology, and ecological effects contribute to the emerging MPs removal. Based on the intrinsic hydrophobicity of MPs, froth flotation can remove MPs from water environments via bubble attachment on hydrophobic surfaces. This study comprehensively investigated plastic, aqueous, and operating variables in the flotation removal of polyethylene terephthalate (PET) and polystyrene (PS) MPs, assisted by numerous bench-scale experiments and a first-order model with rectangular distribution of floatability. Froth flotation performed better to remove MPs with higher density, larger size, and lower concentration. K⁺ (0-50 mM), Na⁺ (0-150 mM), and Ca²⁺ (0-10 mM) did not affect the flotation recovery of MPs. MPs particles could be thoroughly removed by froth flotation when humic acid (HA) and Al³⁺ concentrations were less than 30 mg/L and 0.05 mM, respectively. 100% of MPs could be removed at a rapid flotation rate under aeration volume of 5.4 mL/min and frother dosage of 28 mg/L. Non-covalent interactions and near-surface water film might favor the adhesion of hydrophilic species and obstruct the flotation removal of MPs. The froth flotation-based MPs removal had potential application in multiple flow systems due to its simplicity and continuity.

Agricultural Use of Sewage Sludge as a Threat of Microplastic (MP) Spread in the Environment and the Role of Governance

Sewage sludge from wastewater treatment plants is commonly used as a soil amendment on agricultural land. Unfortunately, more and more research indicates that large amounts of microplastic (MP) are re-introduced to soil with sludge. This study aims to present the impact MP has on soil ecosystems, global trends in agricultural sludge management resulting from a high concentration of micropollutants in sludge, and finally propose a high-level strategy for sustainable sludge management. This strategy is mostly dedicated to the European Union and involves multiple stakeholders and the links between each of them to achieve appropriate sludge management to avoid soil pollution with MP. Governance, Technology, Consumer Acceptance, and Economy and Commercial Viability is explored in depth. To the author’s knowledge, this is the first paper to discuss these topics in the context of a changing agricultural scene and identifies ways of which sewage sludge can limit MP pollution whilst still fitting into a circular economy. As total elimination of agriculturally used sludge is not a viable option, more stringent regulation on sludge quality before its use is necessary, especially on contaminant concentrations. This includes MPs limits, to improve sludge quality, in turn improving soil health. More alternative management options for sludge that does not meet land usage requirements are necessary and will be explored in this study. Overall, the combination of factors discussed will inevitably lead to more emphasis on sewage sludge management, therefore it can be expected that the information presented in this review will be of high demand and importance for sludge producers and serves as a comprehensive foundation for researchers to build off.

Washing load influences the microplastic release from polyester fabrics by affecting wettability and mechanical stress

Microplastics released from textiles during the washing process represent the most prevalent type of microparticles found in different environmental compartments and ecosystems around the world. Release of microfibres during the washing process of synthetic textiles is due to the mechanical and chemical stresses that clothes undergo in washing machines. Several washing process parameters, conditions, formulations of laundering additives have been correlated to microfibre release and some of them have been identified to affect microfibre release during washing process, while no correlation has been evaluated between microfibre release and washing load. In the present study, microfibre release was evaluated as function of the washing load in a real washing process, indicating a progressive decrease of microfibre release with increasing washing load. The quantity of released microfibres increased by around 5 times by decreasing the washing load due to a synergistic effect between water-volume to fabric ratio and mechanical stress during washing. Moreover, the higher mechanical stress to which the fabric is subjected in the case of a low washing load, hinders the discrimination of the effect on the release of other washing parameters like the type of detergent and laundry additives used.

Impact of Chitosan Pretreatment to Reduce Microfibers Released from Synthetic Garments during Laundering

Sewage treatment can remove more than 90% of microplastics, yet large amounts of microplastics are discharged into the ocean. Because microfibers (MFs), primarily generated from the washing of synthetic clothes, are the most abundant type of microplastics among various microplastics detected in the sewage treatment, reducing the amount of MFs entering these treatment plants is necessary. This study aimed to test whether the amount of MFs released from the washing process can be reduced by applying a chitosan pretreatment to the garments before washing. Before the chitosan pretreatment, the polyester clothes released 148 MFs/L, whereas 95% of MFs were reduced after the chitosan pretreatment with 0.7% of chitosan solution. The chitosan pretreatment was applied to other types of garments, such as polyamide and acrylic garments, by treating them with 0.7% of chitosan solution; subsequently, MFs reduced by 48% and 49%, respectively. A morphology analysis conducted after washing revealed that chitosan coating on the polyamide and acrylic were more damaged than on polyester, suggesting that the binding strength of polyamide and acrylic with chitosan was weaker than that of polyester garment. Thus, the results suggested that the chitosan pretreatment might be a promising solution for reducing the amount of MFs generated in the laundering process.

Synthetic textile and microfiber pollution: a review on mitigation strategies

Microfiber pollution is one of the recent threats to sustainability. Due to the increased use of synthetic textiles, microplastic fiber release to the environment has increased exponentially. This review aims to analyze the existing literature to identify the potential preventive measures to control microfiber pollution. The review consolidates the findings under the textile properties and laundry product category. The review results show that the use of finer count yarns with filaments and compact structures reduces microfiber shedding. Similarly, mechanical finishes like shearing and raising increase the microfiber release as they damage the fabric structure. A significant increment is noted in microfiber reduction percentage after the chemical (coating) finishing process. In the case of commercial products, the available external laundry filters are reported as more efficient than the in-drum devices in the market. An analysis of the existing regulatory norms showed that very few countries had developed their laws, and no global regulation and standards were found to test microfiber pollution. In the case of laundry filters, though they filter microfiber effectively, they do not prevent it, so it can be a control measure and not a solution for the issue. Out of the review results, it is identified that controlling the textile parameter is the only effective strategy to prevent the microfiber shedding from the synthetic textile. A proper production method and parameter will yield a textile that sheds lesser or no microfiber. However, no detailed research works are found in correlating these parameters together and indicate the potential scope for future research.

Domestic laundry and microfiber pollution: Exploring fiber shedding from consumer apparel textiles

Synthetic fibers are increasingly seen to dominate microplastic pollution profiles in aquatic environments, with evidence pointing to textiles as a potentially important source. However, the loss of microfibers from textiles during laundry is poorly understood. We evaluated microfiber release from a variety of synthetic and natural consumer apparel textile samples (n = 37), with different material types, constructions, and treatments during five consecutive domestic laundry cycles. Microfiber loss ranged from 9.6 mg to 1,240 mg kg-1 of textile per wash, or an estimated 8,809 to > 6,877,000 microfibers. Mechanically-treated polyester samples, dominated by fleeces and jerseys, released six times more microfibers (161 ± 173 mg kg-1 per wash) than did nylon samples with woven construction and filamentous yarns (27 ± 14 mg kg-1 per wash). Fiber shedding was positively correlated with fabric thickness for nylon and polyester. Interestingly, cotton and wool textiles also shed large amounts of microfibers (165 ± 44 mg kg-1 per wash). The similarity between the average width of textile fibers here (12.4 ± 4.5 μm) and those found in ocean samples provides support for the notion that home laundry is an important source of microfiber pollution. Evaluation of two marketed laundry lint traps provided insight into intervention options for the home, with retention of up to 90% for polyester fibers and 46% for nylon fibers. Our observation of a > 850-fold difference in the number of microfibers lost between low and high shedding textiles illustrates the strong potential for intervention, including more sustainable clothing design.

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.

Impact of dyes and finishes on the microfibers released on the laundering of cotton knitted fabrics

The influence of common textile finishes on cotton fabrics on the generation of microfibers during laundering was assessed. Microfiber release was determined to be in the range of 9000-14,000 particles per gram of cotton fabric. Cotton knitted fabrics treated with softener and durable press generate more microfibers (1.30-1.63 mg/g fabric) during laundering by mass and number than untreated fabric (0.73 mg/g fabric). The fabrics treated with softener generated the longest average microfiber length (0.86 mm), whereas durable press and water repellent treatments produced the shortest average microfiber length (0.62 and 0.63 mm, respectively). In general, the changes in the mechanical properties of the fibers and fabrics due to the finishing treatments are the main factor affecting the microfiber release. The abrasion resistance of the fabrics decreases for durable press treatments and water repellent treatments due to the brittleness in the structure originated by the crosslinking treatment. In the case of the softener treatment, the fabric surface is soft and smooth decreasing the friction coefficient between fibers favoring the fibers loosening from the textile and resulting in a high tendency for fuzz formation and microfiber release. These findings are useful for the textile industry in the design and selection of materials and treatments for the reduction of synthetic or natural microfiber shedding from textiles.

Textile microfibers reaching aquatic environments: A new estimation approach

Textile microfibers are one of the most important sources within primary microplastics. These have raised environmental concerns since its recent identification as pollutants. However, there are still no accurate models to assess their contribution to the microplastic pollution. Hence, in this study, a method to estimate the mass flow of microfibers detached from household laundry that reaches aquatic environments has been developed. The method considers a set of parameters related to the detachment of microfibers, which are, basically: (1) the detachment rate of microfibers from different textile garments, (2) the volume of laundry effluents, (3) the percentage of municipal water that has been treated, (4) the type of used-water treatment applied, and, (5) the proportion of front- versus top-loading washing machines. In this way, 0.28 million tons of microfibers per year were estimated to reach aquatic environments, which is approximately half than the last published valuation. Finally, hypothetical situations were simulated to evaluate the reduction of microfibers by the modification of some of the parameters at different levels (consumer, government entities, and industry). Thus, depending on the implanted alternatives, microfibers that reach the aquatic environments could be reduced between 30% and 65%.

Occurrence and distribution of microplastics in domestic, industrial, agricultural and aquacultural wastewater sources: A case study in Changzhou, China

The extensive application of plastic in human life brings about microplastic (MP) pollution in the environment. Identifying the potential sources of MPs is necessary to diminish its pollution. In this study, the occurrence, composition and distribution of MPs in the influents and effluents from 9 domestic wastewater treatment plants (WWTPs), 5 industrial WWTPs, wastewater of 10 industrial plants, 4 livestock farms and 4 fish ponds in China were investigated. Water samples were enzymatically treated followed by digestion with hydrogen peroxide and density separation. MPs were characterized using micro-Raman spectroscopy and were categorized by shape, size and color. Results showed that MP abundance in the influents and effluents of domestic WWTPs was 18-890 and 6-26 n·L^-1, respectively, with the removal efficiency ranging from 35 to 98%. The effluents of industrial WWTPs contained 6-12 n·L^-1 and the levels of MPs in the wastewater of industrial plants, livestock farms and fish ponds were in the range of 8-23, 8-40 and 13-27 n·L^-1, respectively. No significant differences of MP abundance were demonstrated among effluents or wastewater of different sources, indicating they all constitute sources of MP pollution. Polyethylene (PE), polypropylene (PP) and polystyrene (PS) made up almost 83% of the total MPs. Fragment and film were the most abundant shapes and the majority of MPs were smaller than 500 μm. Polymer type and shape in different sources did not vary statistically, however, there were slight differences among different sources concerning size and color of MPs. This study could fill MP data gaps regarding different sources, guide future monitoring work and policy making.

Microfiber release from real soiled consumer laundry and the impact of fabric care products and washing conditions

Fiber release during domestic textile washing is a cause of marine microplastic pollution, but better understanding of the magnitude of the issue and role of fabric care products, appliances and washing cycles is needed. Soiled consumer wash loads from U.K. households were found to release a mean of 114 ± 66.8 ppm (mg microfiber per kg fabric) (n = 79) fibers during typical washing conditions and these were mainly composed of natural fibers. Microfiber release decreased with increasing wash load size and hence decreasing water to fabric ratio, with mean microfiber release from wash loads in the mass range 1.0–3.5 kg (n = 57) found to be 132.4 ± 68.6 ppm, significantly (p = 3.3 x 10⁻⁸) higher than the 66.3 ± 27.0 ppm of those in the 3.5–6.0 kg range (n = 22). In further tests with similar soiled consumer wash loads, moving to colder and quicker washing cycles (i.e. 15°C for 30 mins, as opposed to 40°C for 85 mins) significantly reduced microfiber generation by 30% (p = 0.036) and reduced whiteness loss by 42% (p = 0.000) through reduced dye transfer and soil re-deposition, compared to conventional 40°C cycles. In multicycle technical testing, detergent pods were selected for investigation and found to have no impact on microfiber release compared to washing in water alone. Fabric softeners were also found to have no direct impact on microfiber release in testing under both European and North American washing conditions. Extended testing of polyester fleece garments up to a 48-wash cycle history under European conditions found that microfiber release significantly reduced to a consistent low level of 28.7 ± 10.9 ppm from eight through 64 washes. Emerging North American High-Efficiency top-loading washing machines generated significantly lower microfiber release than traditional top-loading machines, likely due to their lower water fill volumes and hence lower water to fabric ratio, with a 69.7% reduction observed for polyester fleece (n = 32, p = 7.9 x 10⁻⁶) and 37.4% reduction for polyester T-shirt (n = 32, p = 0.0032). These results conclude that consumers can directly reduce the levels of microfibers generated per wash during domestic textile washing by using colder and quicker wash cycles, washing complete (but not overfilled) loads, and (in North America) converting to High-Efficiency washing machines. Moving to colder and quicker cycles will also indirectly reduce microfiber release by extending the lifetime of clothing, leading to fewer new garments being purchased and hence lower incidence of the high microfiber release occurring during the first few washes of a new item.

Microfiber Release to Water, Via Laundering, and to Air, via Everyday Use: A Comparison between Polyester Clothing with Differing Textile Parameters

Textiles are one of the major sources of microplastic pollution to aquatic environments and have also been reported in dry and wet atmospheric deposition. There is still a lack of information on the direct release of microfibers from garments to the air and on the influence of textile characteristics including structure, type of yarn, and twist. The present study examines microfiber emissions directly to the air and to water as a consequence of laundering. Polyester garments with different textile characteristics were examined including various material compositions, fabric structure, yarn twist, fiber type, and hairiness. Scaling up our data indicates release of microfibers per person per year to the air is of a similar order of magnitude to that released to wastewater by laundering. The lowest releases to both air and water were recorded for a garment with a very compact woven structure and highly twisted yarns made of continuous filaments, compared with those with a looser structure (knitted, short staple fibers, lower twist). Our results demonstrate for the first time that direct release of microfibers from garments to air as a consequence of wear is of equal importance to releases to water. Currently there is considerable interest in interventions focused on capture from wastewater. However, our results suggest more effective interventions are likely to result from changes in textile design that could reduce emissions to both air and water.

The contribution of washing processes of synthetic clothes to microplastic pollution

Microplastic pollution caused by washing processes of synthetic textiles has recently been assessed as the main source of primary microplastics in the oceans. Therefore, understanding the effective contribution of the washing process of synthetic clothes to this environmental problem, is of great importance. In this study, wash trials at real scale were performed on commercial clothes by using a household washing machine in order to gain reliable data about the release of microplastics, and to identify possible influences of textile characteristics on the release. The wastewater was collected and filtered through subsequent filters with decreasing porosity, and the amount and dimensions of microfibres were determined. Microfibre release was analysed in relation to the nature and characteristics of the washed clothes. Results showed that microfibres released during washing range from 124 to 308 mg for kg of washed fabric depending from the type of washed garment that corresponds to a number of microfibres ranging from 640,000 to 1,500,000. Some textile characteristics, such as the type of fibres constituting the yarns and their twist, influenced the release of microfibres during washing. A great amount of microfibres of cellulosic nature was also released during washing of clothes made with a blend of polyester/cellulose. Finally the most abundant fraction of microfibres shed was retained by filters with pore size of 60 µm, presenting an average length of 360–660 μm and an average diameter of 12–16 μm, indicating dimensions that could pass through wastewater treatment plants and pose a threat for marine organisms.

Design of functional textile coatings via non-conventional electrofluidodynamic processes

HYPOTHESIS

In the last years, several cost-effective technologies have been investigated to functionalize textile substrates for large scale applications and industrial production. However, several limitations of currently used technologies still restrict the capability to form functional coatings finely controlling the textile surface properties and topographic structure of the coatings at sub-micrometric scale.

EXPERIMENTS

Herein, we introduced a new non-conventional electrofluidodynamic technology - based on the use of electrostatic forces to polymer/composite solutions - for the application onto textile fabrics of functional coatings. With respect to particle/fibrous coatings usually applied through conventional electrospraying/electrospinning processes, the proposed approach is able to realize homogeneous and continuous coatings by a one-step process, imparting tailored functionalities to the textiles surfaces through the use of customized experimental setups.

FINDINGS

We proved that this process can be successfully used to realize functional coatings based on a bioderived polymer, namely polylactic acid (PLA), on commercial woven polyamide (PA) fabrics. In addition, due to the usage of graphene derivatives or photochromic dyes in combination with PLA, the applied coatings are able to confer peculiar functionalities (i.e., electrical conductivity, photochromic properties, etc.) to polyamide fabrics, as proved by SEM, conductivity and UV irradiation measurements, for innovative applications in smart textiles, e-health and wearable electronics.