Overview of selected membrane interests Oxford, UK

1. Overview of selected membrane interests Oxford, UK Robert Field Dept of Engineering Science, University of Oxford, UK

2. Aims • General overview • Viscosity correction factors. • Particle rolling • Shear-induced diffusion Princeton , January 2011

3. Group Members • Small, growing dynamic group • ZangFengCUI • Robert FIELD • Nick HANKINS • Alex Lubansky • Ian THOMPSON Princeton , January 2011

4. Background • ZFC - The use of gas bubbling to enhance membrane processesJMS: 221 (2003) 1-35    • RWF - Critical and sustainable fluxes: Theory, experiments and applications JMS: 281 (2006) 42-69 • IPT - Identification and characterisation of bacterial populations of an in-use metal-working fluid by phenotypic and genotypic methodology International biodeterioration & biodegradation : 47 (2001)113-123 • AL - Rhelogy • NH - Removal of NH4+ ion from NH4Cl solution using clinoptilolite: A dynamic study using a continuous packed-bed column in up-flow mode Separation Science and Technology 39 (2004) 1347-1364 Princeton , January 2011

5. Aims • General overview and some current activities. • Viscosity correction factors • Particle rolling • Shear-induced diffusion Princeton , January 2011

6. Viscosity correction factor R.W. Field and P.Aimar “Ideal limiting fluxes in ultrafiltration” JMS 80, 1993, 107-115 Princeton , January 2011

7. Viscosity correction factor: continued R.W. Field ”A Theoretical Viscosity Correction Factor for Heat Transfer and friction in pipe flow” Chem Eng Sci 45, 1990, 1343 Princeton , January 2011

8. Aims • General overview and some current activities. • Viscosity correction factors. • Particle rolling • Shear-induced diffusion Princeton , January 2011

9. Modes of operation

10. Pure water flux Flux Strong form critical flux Weak form critical flux TMP Variation of TMP with flux: strong and weak forms of the critical flux The critical flux is that “flux below which a decline of flux with time does not occur; above it fouling is observed”.R.W. Field, D. Wu, J.A. Howell and B.B. Gupta, Critical flux concept for microfiltration fouling, J. Membr. Sci. 100 (1995), 259–272.

11. Physical basis for critical flux P. Bacchin, P. Aimar and R.W. Field “Critical and sustainable fluxes: Theory, experiments and applications” JMS 281, 2006, 42-69 Princeton , January 2011

12. Measuring critical flux When does the deviation from the clean water flux line occur? Is this the same point as the transition to irreversibility?

13. RETENTATE FEED MEMBRANE ∆P PERMEATE Multi-photon Microscope and Membrane Module • Crossflow Module • Feed Channel L = 37mm, W = 10mm, H = 0.5mm • Glass Cover-slip allows in-situ imaging of the membrane • Connected to a standard filtration circuit • Multi-photon Facts • Laser wavelength 800nm • Lens 60x • Best Resolution x,y,z 0.1μm, 0.1μm,0.5 μm, Full Details D Hughes, U.K. Tirlapur, R.W. Field, Z.F. Cui. In situ 3D characterization of membrane fouling by yeast suspensions using two-photon femtosecond near infrared non-linear optical imaging. J. Membrane Sci. 2006

14. Direct Observation Through the Membrane • H. Li, A.G. Fane, H.G.L. Coster, S. Vigneswaran, JMS paper • Fig 10 of the 2006 review of critical flux Princeton , January 2011

15. Particle rolling Determination of particle release conditions….single particle…model membrane Kuiper et al JMS (2000) 180, 15-28

16. Modes of operation

17. Terminology • Hermia1 introduced: • Where n=2 complete pore blocking • n=1.5 pore filling (standard) • n=1 incomplete pore blocking • n=0 cake formation • Field et al2 re-wrote it as • For CF this takes the form if 1. Hermia Trans IChemEng 60 (1982) 183-187 2. Field et al JMS 100 (1995) 259-272

18. Fouling: modelling removal term In simple terms, if the flux tends to a value of J* at long time, then the appropriate form of Equation (1) becomes: New starting point is: Princeton , January 2011

19. Aims • General overview and some current activities. • Viscosity correction factors. • Particle rolling • Shear-induced diffusion • Is it concentration dependent shear-induced diffusion or plain shear induced diffusion? Princeton , January 2011

20. Imaging of Cake Fouling Thick Cakes of Microspheres and Yeast Cells When cakes become thick multi-photon images can be taken of the upper layers of the cake. Cakes Viewed fromAbove 3D image b) c) a) Images show differences in cake composition and surface topology Scale Bar 20μm • 6μm microspheres, b) yeast cells, • c) Mixture of 6μm and 10 μm microspheres

21. Additional Aim: FO • Modeling Flux Performance of Double-skinned FO Membranes (Chuyang Tang, Qianhong She , Rong Wang, Robert Field, Anthony G. Fane) Princeton , January 2011

22. Psupport Js Jv Cdraw πdraw Cs/d πs/d Feed solution Draw solution Cfeed πfeed Cs/f πs/f x Skin on DS side Adraw , Bdraw Skin on FS side Afeed , Bfeed Additional Aim: FO Princeton , January 2011

23. Additional Aim: FO Princeton , January 2011

24. Flat sheet module Data logging computer Solenoid valve/time control Damper P2 Air rotameter P1 Compressed air Mass transfer in aerated “Kubota” systems Microprobes Princeton , January 2011 Fig.1 Schematic drawing of experimental module together with photograph

25. Mass transfer in aerated “Kubota” systems: effect of bubble size Effect of different nominal bubble volumes at the same frequency of 0.167 Hz Princeton , January 2011