Hydrodynamics of an Electrochemical Membrane Bioreactor

Abstract

An electrochemical membrane bioreactor (EMBR) has recently been developed for energy recovery and wastewater treatment. The hydrodynamics of the EMBR would significantly affect the mass transfers and reaction kinetics, exerting a pronounced effect on reactor performance. However, only scarce information is available to date. In this study, the hydrodynamic characteristics of the EMBR were investigated through various approaches. Tracer tests were adopted to generate residence time distribution curves at various hydraulic residence times, and three hydraulic models were developed to simulate the results of tracer studies. In addition, the detailed flow patterns of the EMBR were acquired from a computational fluid dynamics (CFD) simulation. Compared to the tank-in-series and axial dispersion ones, the Martin model could describe hydraulic performance of the EBMR better. CFD simulation results clearly indicated the existence of a preferential or circuitous flow in the EMBR. Moreover, the possible locations of dead zones in the EMBR were visualized through the CFD simulation. Based on these results, the relationship between the reactor performance and the hydrodynamics of EMBR was further elucidated relative to the current generation. The results of this study would benefit the design, operation and optimization of the EMBR for simultaneous energy recovery and wastewater treatment.

A combined system of microbial fuel cell and intermittently aerated biological filter for energy self-sufficient wastewater treatment

“…However, the issues surrounding MFC effluent quality have not yet been sufficiently addressed. MFC alone may not be a feasible avenue to meet stringent effluent quality requirements, hence requiring another step such as integration of MFC with membrane technology 5 or conventional treatment technology 6 to further purify the treated effluent. Furthermore, direct electricity generation is an integral characteristic of MFC.…”

Simultaneous effective carbon and nitrogen removals and phosphorus recovery in an intermittently aerated membrane bioreactor integrated system

“…Just as our previous reports 34 35 36 , utilization of cheap stainless steel mesh in this study, as an alternative to conventional microfiltration/ultrafiltration membrane can lower the MBR construction costs, increase the economical viability and promote the application of such processes 37 38 . In this mesh filter MBR, the filtration process was driven by gravity.…”

Impact of the Hydraulic Loading Rate on the Hydrodynamic Characteristics of an Anaerobic Fixed Bed Reactor Treating Cattle Slaughterhouse Wastewater

“…The long tail effect suggests the presence of dead zones or tracer diffusion into the reactor; thus, the larger the dead zone volume, the greater the tail area. Wang et al (2015) studied an electrochemical membrane bioreactor (EMBR) that has recently been developed for energy recovery and wastewater treatment. These authors observed that a long tail appeared in each RTD curve, especially at HRT values of 3.12 and 7.02 h, indicating a presence of stagnant or dead zones in the EMBR and the release of the tracer slow with flow stream in these regions.…”