Pore-size and polymer affect the ability of filters for washing-machines to reduce domestic emissions of fibres to sewage

Microfiber pollution: Assessment, emission estimation, and time-series-based forecast of microfibers from domestic washing machine laundering and mitigation measures

Microfibers are thread-like structures shorter than 5 mm and have natural, semisynthetic, or synthetic origins. These micropollutants are ubiquitous and are emerging in the environment, living organisms, and food sources. Textile laundering is a prominent source of microfibers, but limited research has been conducted on microfiber pollution from domestic washing machines in emerging economies such as India, where consumption and production rates are exorbitantly high. This study aimed to assess the abundance and size distribution of microfibers from the effluent of a semiautomatic domestic washing machine using three categories of "not-new" textiles: cotton, blended, and synthetic under "with" and "without" detergent conditions. Although most Indians still rely on hand washing, this study focused on washing machines due to their increasing use in India driven by improving socioeconomic factors. This study also developed annual emission estimation and forecasting models for India to understand pollution trends. The results revealed that microfibers were highly abundant in washing machine effluent, with a mean abundance of cotton, blended, and synthetic in "with detergent" conditions of 6476.67, 3766.67, and 8645/L, respectively, whereas in "without detergent," it was lower. All identified microfibers were divided into five size classes. The study also found that powdered detergent increased the abundance and emission of tiny fibers. The overall annual emissions estimate was 1.23 × 1011 microfibers, with cotton, synthetic, and blended categories accounting for 2.11 × 1010, 1.40 × 1010, and 6.15 × 109 microfibers, respectively. Time-series-based future estimates (autoregressive integrated moving average [ARIMA] and error-trend-seasonality [ETS]) showed an alarming increase in microfiber emissions, with forecasted annual emission reaching 1.90 × 1011 by 2030. Synthetic and cotton textiles are the most significant contributors to microfiber pollution. This study emphasized the urgent need to address the issue of microfiber pollution caused by washing machine laundering in developing countries, such as India, where sociodemographic factors intensify the problem. Integr Environ Assess Manag 2024;00:1-12. © 2024 SETAC.

Microfiber Pollution: A Systematic Literature Review to Overcome the Complexities in Knit Design to Create Solutions for Knit Fabrics

The absence of standardized procedures to assess microfiber pollution released during laundering, alongside textile complexities, has caused incomparability and inconsistency between published methodologies, data formats, and presentation of findings. Yet, this information needs to be clear and succinct to engage producers and consumers in reducing microfiber pollution through solutions, such as eco-design. This review analyses source directed interventions through design and manufacturing parameters that can prevent or reduce microfiber shedding from knit fabrics during washing. Contradicting results are critically evaluated and future research agendas, alongside potential areas for voluntary and involuntary sustainable incentives are summarized. To do this, a systematic review was carried out, using the PRISMA approach to verify which fabrics had been investigated in terms of microfiber shedding. Using selected keywords, a total number of 32 articles were included in this review after applying carefully developed inclusion and exclusion criteria. The influence of fabric parameters such as fiber polymer, length of fibers and yarn twist alongside fabric construction parameters such as gauge of knit and knit structure are critically evaluated within the systematically selected studies. This review highlights the agreed upon fabric parameters and constructions that can be implemented to reduce microfiber pollution released from knit textiles. The complexities and inconsistencies within the findings are streamlined to highlight the necessary future research agendas. This information is critical to facilitate the adoption of cross-industry collaboration to achieve pollution reduction strategies and policies. We call for more systematic studies to assess the relationship between individual textile parameters and their influence on microfiber shedding. Additionally, studies should work toward standardization to increase comparability between studies and created more comprehensive guidelines for policy development and voluntary actions for the textile and apparel industry to participate in addressing more sustainable practises through eco-design.

Microplastics in water from the confluence of tropical rivers: Overall review and a case study in Paraiba do Sul River basin

Rivers are known for carrying out a fundamental role in the transportation of human debris from continental areas to the marine environment and have been identified as hotspots for plastic pollution. We characterized microplastics (MPs) along confluence areas in the Paraíba do Sul River basin, the biggest river in southeastern Brazil. This water body crosses highly industrialized areas, with the highest population density, and the major water demand in South America. Considering the important ecological function of this extensive watershed and the implications of MP pollution, we evaluate the spatial variation of MP concentration in the confluence areas and upstream from the confluence. Samples were taken from the superficial layer of the water column in February and June 2022, using manta net with 300 μm mesh size. A total of 19 categories and 2870 plastic particles were determined. The confluences areas of rivers showed the highest concentration of MPs, highlighting the confluences of the Paraiba do Sul and Muriaé rivers (0.71 ± 0.25 MP/m3), followed by Paraíba do Sul and Dois Rios rivers (0.42 ± 0.23 MP/m3) and Paraíba do Sul and Pomba rivers (0.38 ± 0.14 MP/m3). Black fibers were the main category, followed by blue fibers and blue fragments. The MPs in the surface waters of Paraíba do Sul River is significantly influenced by the sampling points spatiality. This result corroborates other studies around the world and reinforces the argument that affluents are important sources for the introduction of MPs in larger rivers. Nevertheless, our results provide a better understanding of the different contributing factors and occurrence of MPs in river basins.

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.