A Janus branch filter for washing machines: Simultaneous removal of microplastics and surfactants

Emerging pollutants, such as microplastics (MPs), are becoming a significant issue worldwide. The highest percentage of MPs released into the environment occurs through daily laundry. The average weight of dreg obtained from 5 kg of laundry was 1.26 g/kg. According to energy dispersive X-ray (EDX) and thermogravimetric analysis (TGA) analyses, the dreg consisted of MPs (78.3-89 wt%, organic elements: C/O) and alien materials (11-21.7 wt%, inorganic elements: Al/Fe/Ca, etc.). Thus, to reproduce the real environment, alien materials (Fe3O4 and CaCO3) were added to various types of model MPs in the presence and absence of sodium dodecyl benzenesulfonate (SDBS) to test MP removal. Hydrophobic and hydrophilic MPs were generated upon laundering, accounting for 55-59% and 41-45% of MPs, respectively. We provide a novel approach to design a laundry filter system for the simultaneous removal of SDBS and hydrophilic/hydrophobic MPs.

Automated summary

Emerging pollutants, such as microplastics, are a global concern. Daily laundry is the main source of microplastic release into the environment. Analysis showed that the dreg from laundry consists of microplastics and other materials. To reproduce real conditions, various types of model microplastics with added alien materials were used to test microplastic removal. We propose a new approach for designing a laundry filter system to remove both sodium dodecyl benzenesulfonate and hydrophilic/hydrophobic microplastics simultaneously.