Three-dimensional textile warp knitted fabrics can be adapted for filtration and separation processes in water- and air-borne material flows. This paper presents three different developments based on 3D warp knitted fabrics: a textile microfilter cascade for microplastic separation, a biologically active textile pre-filter for reducing biofouling in water treatment, and a combined exhaust air scrubber with microalgae-based nutrient recovery.

Under practical conditions, the microfilter cascade achieved separation rates of up to 99%, while the 3D structure increased the service life of the filter media by 155%. The textile-based pre-filter significantly reduced TOC (total organic carbon) and microbial load, reduced the biogenic dry mass on reverse osmosis membranes by up to 70% and extended their cleaning intervals.

The textile-based packing material in the exhaust air scrubber was able to reduce ammonia emissions from livestock farming with an average removal efficiency of 91%. The nutrients bound in the scrubbing water were subsequently fed into a microalgaebased utilisation process.

The results demonstrate the potential of 3D warp knitted fabrics as modular, scalable and application-specific functional materials for sustainable filtration and separation processes