Field testing of polymeric mesh and ash-based ceramic membranes in a membrane bioreactor (MBR) for decentralised sewage treatment

This paper presents the initial findings of field testing of 2 low-cost membrane filters, viz. 30 mu m polymeric mesh and 2-6 mu m macroporous waste-ash based ceramic filter, in a submerged membrane bioreactor (MBR) employing batch anoxic and aerobic conditions. The influent was raw wastewater from a residential complex located near Delhi, India. The results indicated that the ceramic filter was able to operate for longer periods without cleaning; however, there is a limit to the transmembrane pressure it can withstand. The suspended solids retention was high with both filters (average of 96%). Moderate reduction in chemical oxygen demand (COD), total nitrogen (NH4+) and total phosphorus (PO43-) was achieved. The improvements in operation required in such systems are also underlined.