Microplastics from industrial laundries - A laboratory study of laundry effluents

There is little knowledge about the release of microplastics from industrial laundries. This study was carried out to provide information about microplastics released in waste water from laundries. Six Swedish industrial laundries participated in the study. Of these two mainly washed hospital laundry, two mainly work wear, one mainly hotel laundry and one mainly mats. Small particles between 5-15 μm were dominant in this study, regardless of types of textiles washed or whether the laundry had a waste water treatment facility. From the microscopic, FTIR and SEM analyses it could be concluded that microplastics were not dominant in this size range. Most of the particles (in the 5 to 15 μm range) were of other materials (for example minerals, metal fragments, silica, aluminium silicate, yeast, starch). From the results from the measurements, calculations were made to estimate the number of released microplastic particles. The release varied significantly between the different laundries. If the calculations were based on an assumed best-case scenario, between 5 000 and 4 550 000 of microplastic particles were released per kg of washed textile. If a worst-case scenario was assumed, between 15 000 and 5 375 000 microplastic particles were released per kg of washed textile. Three laundries with either chemical or biological waste water treatment adjacent to the production facilities were involved in the study. The water treatment had a significant impact on reducing the numbers of particles. The numbers of fibre-shaped particles released were reduced by 65, 96 and 97% for the different facilities. This shows that waste water treatment at the laundry can be an efficient way of reducing the levels of particles released to the WWTP