Design and filtration mechanism of mixed-dimensional microfiltration composites

Fine particles of titanium dioxide (TiO₂) are not effectively removed during the later stages of production and use, endangering water bodies, soil ecology and human health. In the present study, mixed-dimensional composite membranes based on conventional two-dimensional woven fabrics have been rapidly produced on a large scale using hot-press composite technology for the recovery of powder particles, to mitigate ecological pollution. The filtration performance of these composites against TiO₂ was investigated by recording the effect of temperature and time on the formation of the composite filter material. It was found that the pure water flux was 4112.95 L/(m²·h), the filtrate flux was 1013.73 L/(m²·h), the turbidity value was 6.34 NTU, and the retention was 99.92 % at a temperature of 120 °C and a time of 30 s. Multi-layered composite filter media with nano- and microporous structures were produced by physical interface interaction under ambient conditions, and the mechanism of filtration of particles by the composites was revealed by the study. The composite filter media had a higher filtration efficiency for particle capture, mainly in the surface layer. With woven filter cloth for supporting layer and melt-blown nonwoven (PPMBN) for primary filtrating layer, the multilayer composite filter material was formed, providing a reference for the new generation of filters with a higher strength and filtration capability.