Abstract
Recently, it has been shown that combining a bioelectrochemical system (BES) with an anaerobic membrane bioreactor (AnMBR) to produce electricity can reduce the overall energy consumption of wastewater treatment. In this study, we tested the recently proposed concept that integrates a microbial anode into an AnMBR, under application relevant conditions, for the treatment of synthetic brewery wastewater. We developed two system configurations: a filtering anode with stainless steel filter plate; and a hybrid anode, in which a polymeric membrane is combined with stainless steel mesh. As fouling is problematic in AnMBRs, we investigated the effect of two fouling mitigation methods, namely electrochemical cleaning and application of a turbulence promotor, on the permeate fluxes and current densities. We also investigated the effect of cathode (counter electrode) position on the permeate fluxes and current densities in filtering and hybrid anode. Our results revealed that permeate fluxes were influenced by the membrane pore size; and dropped below 5 L m-2 hr-1 on day 3 with filter grade 0.5 μm; whereas similar values of permeate flux were observed after five days of operation with the membrane with filter grade 0.1 μm. COD removal across the membrane reached up to 644 mg L-1 indicating improvement in energy efficiency and effluent quality of the AnMBR. The location of cathode did not influence permeate fluxes and current densities, but permeate pH was largely affected. Electrochemical cleaning improved permeate fluxes more than two-fold (18.9 L m-2 hr-1 after 7 days of operation) compared to the operation of the 0.1 μm membrane without a cleaning procedure. Application of a turbulence promotor increased permeate fluxes and current densities in filtering anode. The hybrid anode resulted in similar current densities, but higher permeate fluxes as compared to the filtering anode, which dropped below 20 L m-2 hr-1 only after 8 days of operation. The hybrid anode configuration is an attractive option that combines high permeate fluxes on conventional non-conductive filters with current generation on an inexpensive conductive material. In summary, our results demonstrate that combining BES with AnMBR is a promising approach towards an energy efficient wastewater treatment.
Highlights
Wastewater treatment is energy intensive, and with an increasing awareness for sustainability research toward the development of energy efficient treatment technologies has gained importance within the last decades
Effect of Pore Size in Filtering Anodes The results revealed that permeate fluxes are influenced by the membrane pore size
The differences in permeate fluxes with different pore sizes might be attributed to the infiltration of bacteria inside the pores of membrane with filter grade 0.5 μm; whereas filter grade 0.1 μm is too small for the size of bacteria to colonize
Summary
Wastewater treatment is energy intensive, and with an increasing awareness for sustainability research toward the development of energy efficient treatment technologies has gained importance within the last decades. In this context, the Anaerobic membrane bioreactor (AnMBR) is a technology that can be applied for the treatment of both low and high-strength wastewater (Skouteris et al, 2012; Shin and Bae, 2018). The Anaerobic membrane bioreactor (AnMBR) is a technology that can be applied for the treatment of both low and high-strength wastewater (Skouteris et al, 2012; Shin and Bae, 2018) Since it enables energy recovery by biogas production, it is a costeffective alternative to aerobic treatment processes. BES technologies have mainly been applied at the laboratory scale; but they have been suggested to have a potential for industrial applications (He et al, 2017)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
