Application of nanofiltration in membrane biological reactors

Abstract

Nitrate is practically ubiquitous in waters abstracted for municipal potable water production in many parts of the world due to improper wastewater managements and to the decades of intensive agricultural practice. Biological nitrate removal is the optimum treatment method among all treatment options due to the ability to convert the nitrate compound into nitrogen gas without influencing composition of the water matrix. Over the last two decades, implementation of membrane bioreactors (MBRs) has increased in the field of drinking water production due to their superior effluent quality and low plant footprint. However, they are still viewed as a high-cost option, both with regards to capital and operating expenditure. This thesis explores the applicability of nanofiltration (NF) in the external MBR process to extend the understanding of the influence of operating conditions on membrane performance and the influence of biological zone effluent on membrane fouling. Two research steps are considered:<br />optimizing the cross flow velocity and predicting the influence fouling potential.