An integrated rotating biological contactor and membrane separation process for domestic wastewater treatment

Abstract

Membrane fouling is a major bottleneck of almost all pressure-driven membrane filtration processes that limits their widespread applications. Improvement of hydrodynamics conditions is one of the most effective methods for membrane fouling control. This paper assesses a rotating biological contactor (RBC) integrated with membrane (RBC-MI) filtration that potentially offers inherent membrane fouling control as well as enhances biological performance, in which the membrane is placed inside the RBC bioreactor. Results show that the RBC-MI system achieves 84% of COD, 96.7% ammonium, 74% total nitrogen, 89% total phosphorus, and 96% turbidity removals. The integration of membrane placed inside the bioreactor doubles the permeability as compared to the external placement. Higher hydraulic performance is achieved at the low membrane-to-disk gap and higher disk rotational speed. The energy analysis shows that the RBC-MI consumes only 0.18 kWhm−3 signifying its viability as promission option to the energy-intensive conventional treatment systems.

Keywords

• Energy audit
• Hydrodynamics
• Membrane fouling
• Rotating biological contactor
• Shear rate
• Wastewater treatment