Performance and economic evaluation of a pilot scale embedded ends-free membrane bioreactor (EEF-MBR)

Abstract

In this work, an embedded ends-free membrane bioreactor (EEF-MBR) has been developed to overcome the fouling problem. The EEF-MBR unit has a novel configuration where a bed of granular activated carbon is placed in the bioreactor tank and fluidized by the aeration system. The performance of pilot-scale EEF-MBR was assessed based on flux and selectivity over 140h. The permeate flux fluctuated between 2 and 10 L.m-2.h-1 under operating pressure of 0.07-0.2bar when EEF-MBR was used to treat wastewater containing high organic matter. The COD removal efficiency was more than 99% after 1h of operating time. Results from the pilot-scale performance were then used to design a large-scale EEF-MBR with 1200 m3.day-1 capacity. Economic analysis showed that this new MBR configuration was cost-effective when the permeate flux was set at 10 L.m-2.h-1. The estimated additional cost for the large-scale wastewater treatment was about 0.25 US$.m-3 with a payback period of 3years. KEY POINTS: • Performance of new MBR configuration, EEF-MBR, was assessed in long term operation. • EEF-MBR shows high COD removal and relatively stable flux. • Cost estimation of large scale shows the cost effective EEF-MBR application.