Due to the three-dimensional nature of the filtration, pile cloths have a higher efficiency and present advantages over conventional technologies, as they require less space than common sand filters and retain more solids than traditional (two-dimensional) microscreens. The Passavant® cloth filtration MCF downstream of classic secondary clarification enables nutrient elimination, retention of activated carbon and microplastics, fulfilling the prerequisites for downstream treatment for water reuse.
Wastewater flows inwards through the filter cloths, and the filtered solids are retained in the outer surface (precoat filter). This results in a build-up that triggers cleaning of the filter cloths above a certain level. Cleaning is carried out by external suction. The filtrate is sucked back through the cloth on the outer side, causing the fibers to straighten, allowing the adhered substances to be easily removed.