Membrane bioreactor (MBR) for wastewater treatment: Filtration performance evaluation of low cost polymeric and ceramic membranes

This work compares the filtration performance of low cost filters for wastewater treatment in a submerged MBR. Two filters viz. commercial nylon mesh of 30 μm pore size and 2–6 μm macroporous ceramic filters prepared from bagasse fly ash were investigated. Critical flux was measured by flux stepping method, and the MBR filtration performance was monitored in terms of flux, transmembrane pressure (TMP) build-up and permeate quality. It was observed that both the nylon mesh and the ash filter are good solid–liquid separators with low TMP build-up. However, the ash filter displayed higher critical flux that was comparable to commercial microporous membranes; it also does not require the formation of a secondary filtration layer to ensure consistently high suspended solids retention.