Organic matter and total nitrogen removal from wastewater using a pilot-scale membrane-aerated biofilm reactor

A pilot-scale membrane-aerated biofilm reactor (MABR) modified with Polyvinyl Alcohol (PVA) gel bio-carriers containing denitrifying bacteria was operated with the purpose of enhancing total nitrogen removal efficiency from actual domestic wastewater. MABR system was operated under 6, 9 and 12 h of hydraulic retention times (HRT) in different time periods. Addition of the bio-carriers increased nitrification and total nitrogen removal efficiencies by maximum of 11% and 18% at 12 h of HRT respectively. Maximum of 88% of nitrification and 79% of total nitrogen removal efficiencies were reported in the PVA gel modified MABR. Organic matter removal performance was mostly maintained above 90% with insignificant improvements. In addition to this, natural pH increase observed after PVA gel addition paves a new way for potential cost reduction in industrial scale MABR applications. Low sludge volume index around 80 mL/g indicated rapid settling characteristics of produced sludge. [Display omitted] •PVA gel modification in pilot scale MABR improved NH4+-N and TN removal efficiencies.•Addition of PVA gel beads containing denitrifiers increased the pH of MABR system.•Sludge produced in MABR had rapid settling characteristics.