Against microplastics in wastewater: DITF develops textile cascade filter
A textile cascade filter can filter out up to 98.5 percent of microplastics in wastewater from washing processes. It could also be used additionally.
Microplastics get trapped in the textile filter layers (detail greatly enlarged).
(Image: DITF)
The German Institute for Textile and Fiber Research Denkendorf (DITF) has developed a textile-based, three-stage, three-dimensional cascade filter that is said to be able to remove up to 98.5 percent of microplastics in wastewater from washing machines. The filter could help to further minimize microplastic pollution of the environment, which occurs despite wastewater treatment plants.
During washing cycles with washing machines, certain amounts of microplastics are released from plastic-based textiles. Between 12 and 1400 mg of microplastics can enter the wastewater per wash cycle and kilogram of laundry, the DITF writes in a press release. In wastewater treatment plants, about 99 percent of microplastics can be removed. The rest enters the environment via treated wastewater discharged from the treatment plants into bodies of water, with possible effects on animals and humans.
To remove microplastics from wastewater as early as possible, the DITF has developed a microfilter. The filter essentially consists of layers of textile polypropylene fabric, interrupted by a three-dimensional spacer fabric. Filtration occurs in three stages, three-dimensionally. The textile filter layers are designed to become increasingly fine-pored, thus filtering out microplastics with increasingly finer meshes. According to the DITF scientists, microplastic particles in the order of up to 1.5 ÎĽm can be filtered out.
High Filter Performance
The scientists tested the filter in field trials in an industrial laundry and a municipal wastewater treatment plant. The microfilter cascade was able to separate between 89.7 and 98.5 percent of the microplastics. This also works at low water pressure, according to the researchers. The filter unit also includes a cleaning unit. The backwash system works with compressed air. The filter cake shifts onto the fabric of the spacer fabric so that the intervals between backwashes can be longer. The operating time of such a filter element is thus extended by about 155 percent.
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The tests have shown that the textile cascade filter has high performance and a long service life. The filter can be scaled to any size and thus adapted to different application requirements. In addition, it has a compact design and is inexpensive to produce. The DITF scientists believe that the filter can also be adapted for other filtration applications, not just for filtering microplastics.
(olb)
