Hydraulic optimization of membrane bioreactor via baffle modification using computational fluid dynamics

Xiaoxu Yan; Kang Xiao; Shuai Liang; Ting Lei; Peng Liang; Tao Xue; Kaichang Yu; Jing Guan; Xia Huang

doi:10.1016/j.biortech.2014.10.133

Hydraulic optimization of membrane bioreactor via baffle modification using computational fluid dynamics

Bioresour Technol. 2015 Jan:175:633-7. doi: 10.1016/j.biortech.2014.10.133. Epub 2014 Nov 4.

Authors

Xiaoxu Yan¹, Kang Xiao², Shuai Liang¹, Ting Lei¹, Peng Liang¹, Tao Xue³, Kaichang Yu³, Jing Guan³, Xia Huang⁴

Affiliations

¹ State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
² State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
³ Beijing Origin Water Technology Co., Ltd, Beijing 102206, China.
⁴ State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China. Electronic address: xhuang@tsinghua.edu.cn.

PMID: 25465790
DOI: 10.1016/j.biortech.2014.10.133

Abstract

Baffles are a key component of an airlift membrane bioreactor (MBR), which could enhance membrane surface shear for fouling control. In order to obtain an optimal hydraulic condition of the reactor, the effects of baffle location and size were systematically explored in this study. Computational fluid dynamics (CFD) was used to investigate the hydrodynamics in a bench-scale airlift flat sheet MBR with various baffle locations and sizes. Validated simulation results showed that side baffles were more effective in elevating membrane surface shear than front baffles. The maximum average shear stress was achieved by adjusting baffle size when both front and side baffles were installed. With the optimized baffle configuration, the shear stress was 10-30% higher than that without baffles at a same aeration intensity (specific air demand per membrane area in the range of 0-0.45m(3)m(-2)h(-1)). The effectiveness of baffles was particularly prominent at lower aeration intensities.

Keywords: Airlift membrane bioreactor; Baffle; Computational fluid dynamics; Hydrodynamics; Membrane surface shear.

MeSH terms

Bioreactors*
Equipment Design
Hydrodynamics
Membranes, Artificial
Stress, Mechanical
Waste Disposal, Fluid / instrumentation*

Substances

Membranes, Artificial