Yuan Wang

PhD Research Student

Contact Information: Room 922, Chemical Sciences Bldg The University of New South Wales Sydney, 2052, Australia Tel: +61-2-9385 9754 Fax: +61-2-9385 5966 E-mail: Click here

• Master of Science, Chemical Engineering (2003-2006) UNSW, Sydney, Australia
• Bachelor of Engineering (2001) Tianjin University, Tianjin, China

Membranes used in municipal membrane bioreactor (MBR) plants can be configured as flat sheet membranes or hollow fibre membranes. The hollow fibres can be mounted either horizontally or vertically. The membranes can be immersed in their own vessel or within the aerobic vessel. These various membrane configurations combine to give a unique reactor design. The design of MBRs requires knowledge of the biological reactions, membranes and hydrodynamics/mixing. However, current design methods usually assume each reactor vessel as a completely mixed reactor and the design is mainly based on biokinetic and membrane fouling considerations; hence the energy required to achieve complete mixing is usually overestimated.

5 MLD double deck flat sheet MBR located at Victor Harbour, South Australia

The mixing regimes of MBRs can be characterized using a fundamental chemical engineering approach – residence time distribution (RTD) analysis. The degree of mixing and membrane configuration affects the output response describing the system’s flow regimes and expressed by the RTD profiles. Another invaluable tool for assessing reactor hydrodynamics and its effect on mixing energy and volume requirements is computational fluid dynamics (CFD) modelling. CFD modelling formulates and solves the fundamental mass and momentum balance equations governing fluid flow using numerical techniques. CFD can numerically solve the hydrodynamics for a given reactor design. That is, it can predict the mixing behaviour of a reactor using certain reactor characteristics, such as the size and shape of reactor vessel and baffle walls, inlets and outlets positions, mixing energy inputs etc.

An example of CFD modelling: flat sheet MBR process flow stream lines coloured according to liquid velocity (m/s); Process units: 1. Bioselector, 2. Swing aerobic/anoxic zones, 3. Aerobic zones; Design aspects: a. Main inlets, b. Overflow weir, c. Underflow, d. Mixer, e. Aerator

• A/Prof Greg Leslie

• Y.Wang, K. W. Ong, M. Brannock and G. Leslie, Evaluation of membrane bioreactor performance via residence time distributions: effects of membrane configuration and mixing, Water Science & Technology, 57(3) (2008) 353–359
• Y. Wang, Sanly, M. Brannock and G. Leslie, Diagnosis of membrane bioreactor performance through residence time distribution measurements – a preliminary study, Desalination, in press
• Y. Wang, M. Brannock, G. Leslie, Membrane Bioreactors: Overview of the Effects of Module Geometry on Mixing Energy, Asia-Pacific Journal of Chemical Engineering, Special Issue of Membrane Reactors, Accepted
• M. Brannock, H. De Weever, Y. Wang, G. Leslie, Computational fluid dynamics simulations of MBRs: inside submerged versus outside submerged, Desalination, in press
• M. Brannock, Y. Wang, G. Leslie, Evaluation of Full-Scale Membrane Bioreactor Mixing Performance & the Effect of Membrane Configuration, Journal of Membrane Science, submitted
• M. Brannock, Y. Wang, G. Leslie, Mixing Characterisation of Full - Scale Membrane Bioreactors: CFD Modelling with Experimental Validation, Water Research, submitted

• Y. Wang, M. Brannock, G. Leslie, Hydrodynamic CFD Simulation of Mixing in Full-Scale MBRs with Field Experimental Validation, ICOM 2008, Honolulu, Hawaii, USA, 12-18 July 2008 2.
• Y. Wang, R. Sheikholeslami, Co-precipitation of calcium sulfate and calcium carbonate in seawater RO desalination unit, IDA World Congress on Desalination and Water Reuse, Singapore, 11-16 September, 2005