Modeling and optimization of the forward osmosis process parameters selection, flux prediction and process applications

MODELING AND OPTIMIZATION OF THE FORWARD OSMOSIS PROCESS – PARAMETERS SELECTION, FLUX PREDICTION AND PROCESS APPLICATIONS TAN CHIEN HSIANG (B.Eng.(Hons.), NUS) A THESIS SUBMITTED FOR THE DEGREE OF PhD OF ENGINEERING DEPARTMENT OF CIVIL AND ENVIRONMENTAL ENGINEERING NATIONAL UNIVERSITY OF SINGAPORE 2011 ACKNOWLEDGEMENT Acknowledgement I wish to express my deepest appreciation and gratitude to my PhD advisor, Associate Professor Ng How Yong, for his invaluable guidance and encouragement throughout the entire course of the PhD degree. I would also like to extend my sincere appreciation to all research staff and students in the FO research group, especially, Dr. Duan Wei, Mr. Zhang Junyou and Ms. Venketeswari Parida, for their invaluable advice and kind assistance. Furthermore, I appreciate the assistance and cooperation of the following students, Mr. Tan Chun Lin, Ms. Choon Wen Bin, Mr. Melvin Tang Kai Yin and Ms. Yak Sin Wen (FYP students), Mr. Ng Yam Hui Terence, Ms. Zhang Jie and Ms. Cheryl Lin Kai Hui, (RP students). I also would like to accord my special thanks to all laboratory officers, Mr. S.G. Chandrasegaram, Ms. Tan Xiaolan, Ms. Lee Leng Leng, for their technical assistance and excellent laboratory work knowledge. In addition, I would like to acknowledge Dr. Lee Lai Yoke for her important inputs and advice. Finally, I would like to thank all my family members and friends, especially my parents, Zhang Jie and others who I did not mentioned here but had contributed greatly, for their patient support and encouragement for the entire course of my PhD study and research. I thank you all for being there for me whenever I need support! i TABLE OF CONTENTS TABLE OF CONTENTS Page Acknowledgement . i Table of Contents ii Summary . vi List of Tables . ix List of Figures xi List of Plates xviii LIST OF SYMBOLS . xx Chapter One – Introduction 1.1 Background 1.1.1 Membrane technology and its current trends . 1.1.2 Membrane technologies in water desalination and reclamation 1.1.3 The forward osmosis process . 12 1.2 Problem Statement 14 1.3 Research Objectives . 18 1.4 Organization of Thesis 21 Chapter Two – Literature Review . 24 2.1 Basic Principles of Forward Osmosis 25 2.2 Forward Osmosis Membrane and Modules . 28 2.2.1 Forward osmosis membrane 28 2.2.2 Forward osmosis membrane modules . 40 2.3 Concentration Polarization in Forward Osmosis . 43 2.3.1 External Concentration Polarization . 44 2.3.2 Internal Concentration Polarization . 47 2.4 Draw Solutions of Forward Osmosis 49 2.5 Proposed Applications of Forward Osmosis 55 2.5.1 Forward osmosis for seawater desalination . 55 2.5.2 Wastewater treatment and reclamation 60 2.5.3 Other applications 66 Chapter Three – Materials And Methods . 71 3.1 Introduction . 71 3.2 Forward Osmosis Theoretical Study and Modeling . 72 ii TABLE OF CONTENTS 3.3 Experimental Setups and Operating Conditions 72 3.3.1 The laboratory-scale forward osmosis system . 73 3.3.2 The laboratory-scale nanofiltration system 75 3.3.3 The laboratory-scale forward osmosis-membrane bioreactor with nanofiltration system 78 3.4 Membranes and Operating Orientations . 84 3.5 Chemicals and Solutions Used . 86 3.6 Measurements and Analytical Methods 88 3.6.1 Conductivity measurements . 88 3.6.2 Sampling methods 89 3.6.3 Total suspended solids and volatile suspended solid . 90 3.6.4 Chemical oxygen demand . 90 3.6.5 Total organic carbon . 91 3.6.6 Total nitrogen . 91 3.6.7 Ion chromatography . 91 3.6.8 Microscopic observations . 91 Chapter Four – Results And Discussion 93 4.1 Introduction . 93 4.2 The External and Internal Concentration Polarization 94 4.3 Theory – Modified Models to Predict Flux Behaviour in Forward Osmosis in Consideration of External and Internal Concentration Polarizations 98 4.3.1 Mass transfer coefficient for the external concentration polarization layer . 98 4.3.2 Impact of the internal concentration polarization layer 100 4.4 Results and Discussion – Modified Models to Predict Flux Behaviour in Forward Osmosis in Consideration of External and Internal Concentration Polarizations 104 4.4.1 Determination of pure water permeability, A 104 4.4.2 Osmotic pressure and diffusion coefficient as a fraction of NaCl concentration . 104 4.4.3 Impact of external concentration polarization on flux behaviour 107 4.4.4 Determination of K* and impact of internal concentration polarization on flux behaviour . 111 4.4.5 Modeling flux prediction with external and internal concentration polarization corrections . 115 4.4.6 Conclusion . 117 4.5 Theory – Revised External and Internal Concentration Polarization Models to Improve Flux Prediction in Forward Osmosis Process . 119 iii TABLE OF CONTENTS 4.5.1 Revised ECP model considering dilution (injection)/ suction and property (diffusivity) variation 121 4.5.2 Revised ICP model in FO modeling for different draw solutions 127 4.5.3 Flux prediction using revised ECP and ICP models in FO process . 128 4.6 Results and Discussion – Revised External and Internal Concentration Polarization Models to Improve Flux Prediction in Forward Osmosis Process 130 4.6.1 Determination of pure water permeability, A 130 4.6.2 Correlations of physical properties of draw solutions against solute concentrations . 131 4.6.3 Flux prediction in FO process with previous ECP and ICP models 133 4.6.4 Impact of revised ECP model on flux behaviour . 136 4.6.5 Impact of revised ICP model on flux behaviour 140 4.6.6 Flux prediction in FO process with revised ECP and ICP models 142 4.6.7 Conclusion . 146 4.7 Draw Solution Selection for a Novel Hybrid Forward Osmosis – Nanofiltration Process . 147 4.7.1 Forward osmosis tests on water fluxes for various draw solutions at varying concentration . 149 4.7.2 Selection of forward osmosis draw solutions based on forward osmosis testing for seawater desalination 152 4.7.3 Selection of forward osmosis draw solution based on nanofiltration testing for seawater desalination 155 4.7.4 Conclusion . 158 4.8 Hybrid Forward Osmosis – Nanofiltration Process for Seawater Desalination . 159 4.8.1 Performance of hybrid FO-NF process using bivalent draw solutions . 159 4.8.2 Pumping energy consumption for the hybrid FO-NF process for seawater desalination . 163 4.8.3 Conclusion . 166 4.9 Hybrid Forward Osmosis – Membrane Bioreactor for Domestic Wastewater Reclamation to Produce High Quality Product Water . 167 4.9.1 Computation fluid dynamics study to optimize FO-MBR membrane module design . 168 4.9.2 Effect of mean-cell residence times on laboratory-scale FO-MBR system without membrane cleaning . 172 4.9.3 Effect of mean-cell residence times on laboratory-scale FO-MBR system with backwash and chemical cleaning . 177 4.9.4 Conclusion . 189 iv TABLE OF CONTENTS Chapter Five – Conclusion And Recommendations . 191 5.1 Conclusion 191 5.2 Recommendations . 196 List of Publications 200 References . 202 v SUMMARY SUMMARY The forward osmosis (FO) process is a membrane process that makes use of the osmosis phenomenon for the transport of water from a feed solution to a draw solution across a highly-selective FO membrane. The driving force of this process is provided by the osmotic pressure difference between the feed and draw solution. More importantly, the FO process is recently explored as an alternative to other membrane processes. Apart from FO having low energy consumption, the FO membrane is considered to be of lower fouling propensity when compared to other membrane technologies. Other benefits of FO were also discussed in this thesis. Several challenges of the FO process were identified, including limited advancement on theoretical modeling and prediction of FO performance, lack of an ideal FO draw solution, limited data to evaluate the feasibility of FO applications, and lack of comprehensive analysis of energy and cost comparison with existing technologies. It is the objective of this thesis to investigate these challenges and systematically evaluate the feasibility of the FO process in water and wastewater treatment. In the first part of the study on FO modeling, the mass transfer coefficients derived from the boundary layer concept was used in the film theory model to describe the external concentration polarization (ECP) layer. A modified model for the internal concentration polarization (ICP) layer was proposed. It was shown that the revised models developed in this study could predict water fluxes and model both the ECP and ICP phenomenon for the FO process more accurately than the previous model proposed by other researchers. In the second part of the study on FO process modeling, water fluxes for the FO process using different draw solutes were predicted using revised FO models proposed in this study. Previously modified ECP vi SUMMARY model (developed in the first part of this study) can predict the flux behavior for the FO process accurately with NaCl or KCl as the draw solute only. When other draw solutes were considered, the effects of dilution/suction and property (diffusivity) variation were included in the revised ECP model, so as to improve the accuracy of prediction. The revised ICP model with the solute specific KS proposed in this study could improve the accuracy of the ICP effect because of the different degree of interactions of the different solutes with the porous matrix membrane material. Following work done on FO process modeling, further experiments were conducted to select the most appropriate draw solutions for the FO process, and at the same time a complementary reconcentration process was also proposed. Results obtained from laboratory-scale FO and NF tests suggest that both MgSO4 and Na2SO4 could be used as potential draw solutes for the hybrid FO-NF process. Also, the energy consumption of the post treatment NF process was low with an expected operating pressure of less than 40 bar, as opposed to seawater RO process that used 60 bar and above. With the appropriate draw solutions proposed, results from the laboratory-scale FO and NF tests in the next phase suggested that Na2SO4 could possibly be the most suitable draw solution for the proposed hybrid FO-NF process for seawater desalination. In order to produce good quality product water that meets the recommended TDS of the GDWQ from WHO, a hybrid FO-NF process with two-pass NF regeneration was proposed. Preliminary calculations suggested that the energy requirement of the FO-NF for seawater desalination is 2.29 kWh/m3, which was more than 25% lower than the RO process. Finally in the last phase, feasibility investigations were conducted on a hybrid FOMBR with NF post treatment process for domestic wastewater treatment. First, CFD vii SUMMARY simulation was used to understand the draw solution fluid flow within a plate-andframe FO module and modifications were conducted to fabricate a more effective module. A modified 6-chamber membrane module was designed and fabricated. A CFD simulation was conducted on this module and was found that it had good velocity profile contours. With the optimized membrane module, two separate tests were conducted to investigate the effect of different mean-cell residence time (MCRT) on FO-MBR operations (3-, 5-, and 10-day MCRT) and the effect of backwash and chemical cleaning to mitigate flux decline. Results from both studies indicated that mixed liquor conductivity increase had a large impact on flux decline as conductivity was linked to solute concentration that was further linked to the osmotic driving force. By normalizing the water flux, flux decline due to membrane fouling was studied. In addition, final permeate water quality indicated that the hybrid FO-MBR system (for all three MCRTs) had high organic removal, largely due to the non-porous FO membrane that was capable of retaining most of the solute within the mixed liquor. However, it was found that the final permeate had high concentrations of nitrate. Finally, recommendations for future studies with reference from the findings and conclusions obtained in this thesis were given. First, process parameters can be optimized and introduction of membrane spacers may aid in reducing ECP effects. Second, ICP effects can be mitigated by fabricating more appropriate FO membrane. Next, magnetic nanoparticles may be studied and considered for FO draw solution, ultimately reducing the energy consumption for solute recovery even further. Finally, further optimization of both hybrid FO-NF and FO-MBR is recommended for future studies. viii LIST OF TABLES LIST OF TABLES Table 1.1 Classification of some separation processes using physical and chemical properties of the components to be separated……………….5 Table 1.2 Classification of membrane with different barrier structures and their corresponding uses…………………………………………………….6 Table 1.3 Business market size for membrane technologies in 1998………… Table 1.4 Overview of available desalination technology………………… ….10 Table 3.1 Characteristics of influent wastewater obtained from Ulu Pandan WWRP……………………………………………………… …… .88 Table 4.1 Data calculated for the ICP layer developed using the revised ICP model…………………………………………………… …………113 Table 4.2 Coefficients of polynomial equations used for various physical properties of solutions that were used in this study……………… .132 Table 4.3 Revised KS values obtained for all draw solutes used in this study…………………………………………………………… ….143 Table 4.4 Average solute rejection of the FO membrane tested for the seven draw solutes investigated……………… ……………………………… 152 Table 4.5 Expected permeate water quality for a hybrid FO-NF process with two-pass NF regeneration…………… .……………………………163 ix CHAPTER FIVE – CONCLUSION AND RECOMMENDATIONS RECOMMENDATIONS complete system to determine its actual performance for seawater desalination. With this, a more complete energy analysis can then be conducted. e. With regards to the hybrid FO-MBR process, the studies conducted in this thesis had drawn numerous conclusions, especially on its flux performance, various operation parameters and final water quality. Looking at the final product water quality, it was observed that an elevated amount of nitrate existed in the product water. This showed that the FO-MBR with NF reconcentration had its limitation. Future studies should consider operating the FO-MBR in a pre-anoxic aerobic configuration for effective denitrification of the nitrates. As such, the viability of the biological process need to be further studied and to understand the impact of high conductivity (about 10,000 µm/cm range) on denitrification. Lastly, a complete energy analysis need to be worked out and compared with conventional MBR with RO system (comparing the same final product water quality) as this is one of the most important indication as to whether the hybrid FO-MBR system is a more viable system than current technologies. 199 LIST OF PUBLICATIONS AND PRESENTATIONS LIST OF PUBLICATIONS AND PRESENTATIONS Publications Tan, C.H., Ng, H.Y., Modified models to predict flux behaviour in forward osmosis in consideration of external and internal concentration polarization. J. Membr. Sci., 324, 2008, 209-219. Tan, C.H., Ng, H.Y., Modeling of external and internal concentration polarizaiton effect on flux behaviour of forward osmosis. Wat. Sci. Technol., 8, 2008, 533-539. Tan, C.H., Ng, H.Y., A novel hybrid forward osmosis – nanofiltration for seawater desalination: Draw solution selection and system configuration. Desal. Wat. Treatm., 13, 2010, 356-361. Tan, C.H., Ng, H.Y., Revised external and internal concentration polarization models to improve flux prediction in forward osmosis process. 2010, submitted. Presentations Tan, C.H., Ng, H.Y., Modeling of concentration polarization effect on flux behaviour of forward osmosis. Platform presentation at IWA World Water Congress, Vienna, Austria, 7-12 September 2008. Tan, C.H., Ng, H.Y., Modeling of concentration polarization effect for flux prediction of forward osmosis process. Poster presentation at 4th International Conference on Sustainable Water Environment, Singapore, 17-19 November 2008. Awarded best poster award. Tan, C.H., Ng, H.Y., A novel hybrid forward osmosis – nanofiltration (FO-NF) process for energy-efficient seawater desalination. Platform presentation at 18th 200 LIST OF PUBLICATIONS AND PRESENTATIONS KAIST-KU-NTU-NUS Symposium on Environmental Engineering, Daejeon, Korea, 16-19 June 2009. Awarded best presentation award. Tan, C.H., Ng, H.Y., A novel hybrid forward osmosis – nanofiltration (FO-NF) process for seawater desalination: Draw solution selection and system configuration. Platform presentation at 5th IWA Specialist Membrane Technology Conference for Water and Wastewater Treatment, Beijing, China, 1-3 September 2009. Tan, C.H., Ng, H.Y., A novel hybrid forward osmosis – nanofiltration process for seawater desalination: Evaluation of draw solution and energy consumption. Platform presentation at 3rd IWA ASPIRE conference, Taipei, Taiwan, 18-22 October 2009. Tan, C.H., Zhang, J.Y., Lee, L.Y., Duan, W., Ong, S.L., Ng, H.Y., Treatment of domestic wastewater using a hybrid forward osmosis membrane bioreactor (FO-MBR) process for water reclamation. Platform presentation at 19th KAIST-KU-NTU-NUS Symposium on Environmental Engineering, Kyoto, Japan, 27-30 June 2010. 201 REFERENCES REFERENCES Aaberg, R.J., Osmotic power. A new and powerful renewable energy source? Refocus, 4, 2003, 48-50. Achilli, A., Cath., T.Y., Marchand, E.A., Childress, A.E., The forward osmosis membrane bioreactor: A low fouling alternative to MBR processes. Desalination, 239, 2009, 10-21. Achilli, A., Cath, T.Y., Childress, A.E., Selection of inorganic-based draw solutions for forward osmosis applications. J. Membr. Sci., 364, 2010, 233-241. Alatiqi, I., Ettouney, H., El-Dessouky, H., Process Control in Water Desalination Industry: An Overview. Desalination, 126, 1999, 15-32. American Public Health Association. Standard methods for the examination of water and wastewater. 21st Ed. Washington, D.C.: American Public Health Association. 2005. Apaclara Limited, Technology, 2006, Electronic Source: http://www.apaclara.com/about.html Babu, B.R., Rastogi, N.K., Raghavarao, K.S.M.S., Effect of process parameters on transmembrane flux during direct osmosis. J. Membr. Sci., 280, 2006, 185-194. Baker, R.W., Membrane Technology and Applications, Wiley, West Sussex, 2004. Batchelder, G.W., Process for the demineralization of water. US Patent 3, 171,799, 1965. 202 REFERENCES Bhattacharya, S., DasGupta, S., De, S., Effect of solution property variations in cross flow ultrafiltration: a generalized integral approach, Separ. Purif. Technol., 24, 2001, 559-571. Castaldi, M., D’Errico, G., Paduano, L., Vitagliano, V., Transport properties of the binary-system glucose-water at 25 C. A velocity correlation study., J. Chem. Eng. Data, 43, 1998, 653-657. Cath, T.Y., Gormly, S., Beaudry, E.G., Flynn, M.T., Adams, V.D., Childress, A.E., Membrane contactor processes for wastewater reclamation in space Part Ι. Direct osmosis concentration as pretreatment for reverse osmosis. J. Membr. Sci., 257, 2005a, 85-98. Cath, T.Y., Adams, D., Childress, A.E., Membrane contactor processes for wastewater reclamation in space Π. Combined direct osmosis, osmotic distillation, and membrane distillation for treatment of metabolic wastewater. J. Membr. Sci., 257, 2005b, 111-119. Cath, T.Y., Childress, A.E., Elimelech, M., Forward Osmosis: Principles, Applications and Recent Developments. J. Membr. Sci., 281, 2006, 70-87. Cath, T.Y., Gormly, S., Beaudry, E.G., Adams, V.D., Childress, A.E., Membrane contactor processes for wastewater reclamation in space. I. Direct osmotic concentration as pretreatment for reverse osmosis. J. Membr. Sci., 257, 2005, 85-98. Cath, T.Y., Hancock, N.T., Lundin, C.D., Hoppe-Jones, C., Drewes, J.E., A multibarrier osmotic dilution process for simultaneous desalination and purification of impaired water. J. Membr. Sci., 362, 2010, 417-426. 203 REFERENCES Chang, Y.C., Myerson, A.S., The diffusivity of potassium chloride and sodium chloride in concentrated, saturated, and supersaturated aqueous solutions, AIChE J., 31, 1985, 890-894. Choi, Y, Choi, J., Oh, H., Lee, S., Yang, D.R., Kim, J.H., Toward a combined system of forward osmosis and reverse osmosis for seawater desalination. Desalination, 247, 2009, 239-246. Chou, S., Shi, L., Wang, R., Tang, C.Y., Qiu, C., Fane, A.G., Characteristics and potential applications of a novel forward osmosis hollow fiber membrane. Desalination, 261, 2010, 365-372. Cornelissen, E.R., Harmsen, D., de Korte, K.F., Ruiken, C.J., Qin, J., Oo, H., Wessels, L.P., Membrane fouling and process performance of forward osmosis membranes on activated sludge. J. Membr. Sci., 319, 2008, 158-168. Corry, B., Designing carbon nanotube membranes for efficient water desalination. J. Phys. Chem. B, 112, 2008, 1427-1434. Cussler, E.L., Diffusion: mass transfer in fluid system. Cambridge University Press, New York, 2nd ed, 1997, p. 142. Darwish, M.A., Al Asfour, F., Al-Najem, N., Energy consumption in equivalent work by different desalting methods: case study for kuwait, Desalination, 152, 2002, 83-92. De, S., Bhattacharya, P.K., Prediction of mass-transfer coefficient with suction in the applications of reverse osmosis and ultrafiltration, J. Membr. Sci., 128, 1997, 119-131. 204 REFERENCES De, S., Bhattacharya, P.K., Mass transfer coefficient with suction including property variations in applications of crossflow ultrafiltration, Separ. Purif. Technol., 16, 1999, 61-73. Desalination Markets 2005-2015, A Global Assessment and Forecast, Global Water Intelligence, 2005. Dore, M.H.I., Forecasting the Economic Costs of Desalination Technology. Desalination, 172, 2005, 207-214. Dova, M.I., Petrotos, K.B., Lazarides, H.N., On the direct osmotic concentration of liquid foods. Part I: Impact of process parameters on process performance. J. Food Eng., 78, 2007, 422-430. Dova, M.I., Petrotos, K.B., Lazarides, H.N., On the direct osmotic concentration of liquid foods. Part II: Development of a generalized model. J. Food Eng., 78, 2007, 431-437. Ebensperger, U., Isley, P., Review of the Current State of Desalination, Water Policy Working Paper 2005-2008, 2005. Elimelech, M., Yale constructs forward osmosis desalination pilot plant. Membrane Tech. 2007, 1, 7-8. Foreman, G. E. Spiral wound membrane module for direct osmosis separations. US Patent 4,033,878, 1977. Frank, B.S., Desalination of sea water. US Patent 3,670,897, 1972. Fritzmann, C., Lowenberg, J., Wintgens, T., Melin, T., State-of-the-art of Reverse Osmosis Desalination. Desalination, 216, 2007, 1-76. 205 REFERENCES Gekas, V., Hallström, B., Mass transfer in the membrane concentration polarization layer under turbulent cross flow: I. Critical literature review and adaptation of existing sherwood correlations to membrane operations, J. Membr. Sci., 30, 1987, 153-170. Gerstandt, K., Peinemann, K.V-., Skilhagen, S.E., Thorsen, T., Holt, T., Membrane processes in energy supply for an osmotic power plant. Desalination, 224, 2008, 6470. Ghiu, S.M.S., Carnahan, R.P., Barger, M., Permeability of electrolytes through a flat RO membrane in a direct osmosis study. Desalination, 144, 2002, 387-392. Glew, D.N., Process for Liquid Recovery and Solution Concentration, US Patent 3,216,930, 1965. Global Water Futures: Addressing Our Global Water Future. Center for Strategic and Internation Studies, Sandia National Laboratories, 2005. Gosting, L.J., A study of the diffusion of potassium chloride in water at 25 C with Gouy Interference Method, J. Am. Chem. Soc., 72, 1950, 4418. Gray, G.T., McCutcheon, J.R., Elimelech, M., Internal concentration polarization in forward osmosis: role of membrane orientation. Desalination, 197, 2006, 1-8. Hancock, N.T., Cath, T.Y., Solute coupled diffusion in osmotically drive membrane processes. Environ. Sci. Technol., 43, 2009, 6768-6775. Holloway, R.W., Childress, A.E., Dennett, K.E., Cath, T.Y., Forward osmosis for concentration of anaerobic digester centrate. Water Research, 41, 2007, 4005-4014. Hydration Inc., 2008, Electronic Source: http://www.htiwater.com/low/hydration_products.html 206 REFERENCES Hydration Technologies Inc. Forward osmosis pressurized device and process for generating potable water. US Patent 6,849,184, 2005. IDA Worldwide Desalting Inventory 2002, International Desalination Association, IDA, 2002. Ismail, A.F., Goh, P.S., Sanip, S.M., Aziz, M., Transport and separation properties of carbon nanotube-mixed matrix membrane. Sep. Purif. Technol., 70, 2009, 12-26. Jellinek, H.H., Masuda, H., Osmo-power. Theory and performance of an osmo-power pilot plant. Ocean engineering, 8, 1981, 103-128. Jia. Y.X., Li, H.L., Wang, M., Wu, L.Y., Hu, Y.D., Carbon nanotube: Possible candidate for forward osmosis. Sep. Purif. Technol., 75, 2010, 55-60. Jiao, B., Cassano, A., Drioli, E., Recent advances on membrane processes for the concentration of fruit juices: a review. J. Food Eng., 63, 2004, 303-324. Kessler, J.O., Moody, C.D., Drinking water from seawater by forward osmosis. Desalination, 18, 1976, 297-306. Kravath, R.E., Davis, J.A., Desalination of seawater by direct osmosis. Desalination, 16, 1975, 151-155. Laliberte, M., Model for calculating the viscosity of aqueous solutions, J. Chem. Eng. Data, 52, 2007, 321-335. Also see supplementary appendix. Lee, K.L., Baker, R.W., Lonsdale, H.K., Membranes for power generation by pressure-retarded osmosis. J. Membr. Sci., 8, 1981, 141-171. Lee, S., Boo, C., Elimelech, M., Hong, S., Comparison of fouling behavior in forward osmosis (FO) and reverse osmosis (RO). J. Membr. Sci., 365, 2010, 34-39. 207 REFERENCES Loeb, S., Norman, R.S., Osmotic power plants, Science, 189, 1975, 654-655. Loeb, S., Production of energy from concentrated brines by pressure-retarded osmosis. I. Preliminary technical and economic correlations, J. Membr. Sci., 1, 1976, 49-63. Loeb, S., Mehta, G.D., A two coefficient water transport equation for pressureretarded osmosis, J. Membr. Sci., 4, 1979, 351-362. Loeb, S., Titelman, L., Korngold, E., Freiman, J., Effect of porous support fabric on osmosis through a Loeb-Sourirajan type asymmetric membrane, J. Membr. Sci., 129, 1997, 243-249. Majumder, M., Ajayan, P.M., Carbon nanotube membranes: A new frontier in membrane science. Comp. Membr. Sci. Eng., 1.14, 2010, 291-310. Mallevialle, J., Odendaal, P.E., Wiesner, M.R., Water treatment membrane processes, McGraw-Hill, New York, 1996. Mehta, G.D., Loeb, S., Internal polarization in the porous substructure of a semipermeable membrane under pressure-retarded osmosis, J. Membr. Sci., 4, 1978, 261-265. Mehta, G.D., Loeb, S., Performance of permasep B-9 and B-10 membranes in various osmotic regions and at high osmotic pressures. J. Membr. Sci., 4, 1979, 335-349. McCormick, P., Pellegrino, J., Mantovani, F., Sarti, G., Water, salt, and ethanol diffusion through membranes for water recovery by forward (direct) osmosis processes. J. Membr. Sci., 325, 2008, 467-478. 208 REFERENCES McCutcheon, J.R., Elimelech, M., Influence of membrane support layer hydrophobicity on water flux in osmotically driven membrane processes. J. Membr. Sci., 318, 2008, 458-466. McCutcheon, J.R., McGinnis, R.L., Elimelech, M. A novel ammonia-carbon dioxide forward (direct) osmosis desalination process. Desalination, 174, 2005, 1-11. McCutcheon, J.R., McGinnis, R.L., Elimelech, M., Desalination by ammonia-carbon dioxide forward osmosis: Influence of draw and feed solution concentrations on process performance. J. Membr. Sci., 278, 2006, 114-123. McCutcheon, J.R., Elimelech, M., Influence of concentrative and dilutive internal concentration polarization on flux behavior in forward osmosis. J. Membr. Sci., 284, 2006, 237-247. McCutcheon, J.R., Elimelech, M., Modeling water flux in forward osmosis: Implications for improved membrane design. AIChE Journal, 53, 2007, 1736-1744. McGinnis, R.L., Osmotic desalination process. US Patent 6,391,205, 2002. McGinnis, R.L., Elimelech, M., Energy Requirements of Ammonia-Carbon Dioxide Forward Osmosis Desalination. Desalination, 207, 2007, 370-382. McGinnis, R.L., Elimelech, M., Global challenges in energy and water supply: the promise of engineered osmosis. Environ. Sci. Technol., 42, 2008, 8625-8629. Meeting the MDG Drinking Water and Sanitation Target: A Mid-term Assessment of Progress, UNICEF and WHO, 2004. Metha, G.D., Further results on the performance of present-day osmotic membranes in various osmotic regions. J. Membr. Sci., 10, 1982, 3-19. 209 REFERENCES Mi, B., Elimelech, M., Chemical and physical aspects of organic fouling of forward osmosis membranes. J. Membr. Sci., 320, 2008, 292-302. Mi, B., Elimelech, M., Organic fouling of forward osmosis membranes: Fouling reversibility and cleaning without chemical reagents. J. Membr. Sci., 348, 2010, 337345. Millennium Ecosystem Assessment, Ecosystems and Human Well-being: Synthesis. Island Press, Washington, D.C., 2005. Miller, D.G., Rard, J.A., Eppstein, L.B., Albright, J.G., Mutual diffusion coefficients and ionic transport coefficient Iij of MgCl2-H2O at 25 C, J. Phys. Chem., 88, 1984, 5739-5748. Mohammad, A.W., Hilal, N., Al-Zoubi, H., Darwish, N.A., Prediction of permeate fluxes and rejections of highly concentrated salts in nanofiltration membranes, J. Membr. Sci. 289, 2007, 40-50. Mulder, M., Basic principles of membrane technology. Kluwer Academic, Dordrecht, 1996. NanoMagnetics, Water purification, 2005, Electronic Source: http://www.nanomagnetics.com/water_purification.asp New family of forward osmosis membranes. Filtration & Separation, 47, 2010, 12. Ng, H.Y., Tang, W., Wong, W., Performance of forward (Direct) osmosis process: membrane structure and transport phenomenon. Environ. Sci. Technol., 40, 2006, 2408-2413. 210 REFERENCES Oasys Water commercialises FO membrane technology. Membrane Technology, June, 2010, and 16. Osmotek Inc., 2008, Electronic Source: http://www.rimnetics.com/osmotek.htm Projected Water Scarcity in 2025, Input for the World Water Vision, The Hague, IWMI, 2000. Petrotos, K.B., Quantick, P., Petropakis, H., A study of the direct osmotic concentration of tomato juice in tubular membrane – module configuration. I. The effect of certain basic process parameters on the process performance. J. Membr. Sci., 150, 1998, 99-100. Petrotos, K.B., Quantick, P., Petropakis, H., Direct osmotic concentration of tomato juice in tubular membrane – module configuration. II. The effect of using clarified tomato juice on the process performance. J. Membr. Sci., 171, 1999, 171-177. Petrotos, K.B., Lazarides, H.N., Osmotic concentration of liquid foods. J. Food Eng., 49, 2001, 201-206. Rard, J.A., Miller, D.G., The mutual diffusion coefficients of Na2SO4-H2O and MgSO4-H2O at 25 C from Rayleigh Interferometry, J. Soln. Chem., 8, 1979a, 755766. Rard, J.A., Miller, D.G., The mutual diffusion coefficients of NaCl-H2O and CaCl2H2O at 25 C from Rayleigh Interferometry, J. Soln. Chem., 8, 1979b, 701-716. Report of the Secretary-General, Road Map Towards the Implementation of the United Nations Millennium Declaration. United Nations General Assembly, 2001. 211 REFERENCES Sablani, S.S., Goosen, M.F.A., Al-Belushi, R., Wilf, M., Concentration polarization in ultrafiltration and reverse osmosis: a critical review. Desalination, 141, 2001, 269289. Sanitation and Hygiene Links to Health, Facts and Figures, WHO, 2005. Sourirajan, S., Reverse Osmosis, Academic Press, New York, 1970. Stache, K., Apparatus for transforming sea eater, brackish water, polluted water or the like into a nutritious drink by means of osmosis. US Patent 4,879,030, 1989. Stokes, R.H., The diffusion coefficients of eight uni-univalent electrolytes in aqueous solution at 25 C, J. Amer. Chem. Soc., 72, 1950, 2243-2247. Strathmann, H., Membrane Processes for Sustainable Industrial Growth, Membr. Technol., 113, 1999, 9-11. Su, J., Yang, Q., Teo, J.F., Chung, T.S., Cellulose acetate nanofiltration hollow fiber membranes for forward osmosis processes. J. Membr. Sci., 355, 2010, 36-44. (a) Su, J., Zhang, S., Chen, H., Chen, H., Jean, Y.C., Chung, T.S., Effects of annealing on the microstructure and performance of cellulose acetate membranes for pressureretarded osmosis processes. J. Membr. Sci., 364, 2010, 344-353. (b) Tang, W., Ng, H.Y., Concentration of brine by forward osmosis: Performance and influence of membrane structure. Desalination, 224, 2008, 143-153. Tang, C.Y., She, Q., Lay, W.C.L., Wang, R., Fane, A.G., Coupled effects of internal concentration polarization and fouling on flux behavior of forward osmosis membranes during humic acid filtration. J. Membr. Sci., 354, 2010, 123-133. 212 REFERENCES Ulbricht, M., Advanced Functional Polymer Membranes, Polymer, 47, 2006, 22172262. van den Berg, G.B., Rácz, I.G., Smolders, C.A., Mass transfer coefficients in crossflow ultrafiltration, J. Membr. Sci., 47, 1998, 25-51. Viet Bui, A., Nguyen, M.H., Prediction of viscosity of glucose and calcium chloride solutions, J. Food Eng., 62, 2004, 345-349. Wang, D., Meng, S., Yu, Z., Wang, X., Ando, M., Shintani, T., Separation performance of a nanofiltration membrane influenced by species and concentration of ions, Desalination 175, 2005, 219-225. Wang, K.Y., Chung, T.S., Qin, J.J., Polybenzimidazole (PBI) nanofiltration hollow fiber membranes applied in forward osmosis process. J. Membr. Sci., 300, 2007, 6-12. Wang, K.Y., Xiao, Y., Chung, T.S., Chemically modified polybenzimidazole nanofiltration membrane for the separation of electrolytes and cephalexin. Chem. Eng. Sci., 61, 2006, 5807-5817. Wang, K.Y., Chung, T.S., Polybenzimidazole nanofiltration hollow fiber for cephalexin separation, A.I.Ch.E. Journal, 52, 2006, 1363-1377. Wang, K.Y., Yang, Q., Chung, T.S., Rajagopalan, R., Enhanced forward osmosis from chemically modified polybenzimidazaole (PBI) nanofiltration hollow fiber membranes with a thin wall. Chem. Eng. Sci., 64, 2009, 1577. Wang, R., Shi, L., Tang, C.Y., Chou, S., Qiu, C., Fane, A.G., Characterization of novel forward osmosis hollow fiber membranes. J. Membr. Sci., 355, 2010, 158-167. 213 REFERENCES Water: A Shared Responsibility, Chapter 1: Living in a Changing World. nd World Water Development Report, UNESCO, 2006. Welty, J.R., Wicks, C.E., Wilson, R.E., Rorrer, G., Fundamentals of momentum, heat, and mass transfer. Wiley, 4th ed., p. 550-585, 2001. Xu, Y., Peng, X., Tang, C.Y., Fu, Q.S., Nie, S., Effect of draw solution concentration and operating conditions on forward osmosis and pressure retarded osmosis performance in a spiral wound module. J. Membr. Sci., 348, 2010, 298-309. Yaeli, J. Method and apparatus for processing liquid solutions of suspensions particularly useful in the desalination of saline water. US Patent 5,098,575, 1992. Yang, Q., Wang, K.Y., Chung, T.S., A novel dual-layer forward osmosis membrane for protein enrichment and concentration. Sep. and Pur. Technol., 69, 2009, 269-274. Yen, S.K., Haja N., F.M., Su, M., Wang, K.Y., Chung, T.S., Study of draw solutes using 2-methylimidazole-based compounds in forward osmosis. J. Membr. Sci., 364, 2010, 242-252. Yip, N.Y., Tiraferri, A., Philip, W.A., Schiffman, J.D., Elimelech, M., High performance thin-film composite forward osmosis membrane. Environ. Sci. Technol., 44, 2010, 3812-3818. Zhang, S., Wang, K.Y., Chung, T.S., Chen, H., Jean, Y.C., Amy, G., Wellconstructed cellulose acetate membranes for forward osmosis: Minimized internal concentration polarization with an ultra-thin selective layer. J. Membr. Sci., 360, 2010, 522-535. 214 [...]... permits Therefore, to aid in the global drive to achieve sustainable water resource, this thesis seeks to suggest the use of the forward osmosis (FO) process for the low cost production of clean drinking water and an alternative technology for the treatment of wastewater The FO process would then be optimized to address the needs of using this innovative technology with the careful selection of process parameters. .. measure of the driving force of water transported from a solution of low solute concentration across a membrane into a solution of high solute concentration Hence by calculating ∆π, it is then possible to determine the driving force of the osmosis process For almost five decades, osmosis has been studied for technological applications and is known as the forward osmosis (FO) or direct osmosis process. .. water price of 0.53 US$/m3 and that for the Tuas plant in Singapore, is below 0.5 US$/m3 (Fritzmann et al., 2007) However, thermal desalination processes still offer some advantages, for example, the ease of operation and production of better quality water, and these advantages need to be considered prior to the selection of the most effective desalination process Looking at the cost composition of a typical... discussion on the modeling and application of the FO process for seawater desalination and water reuse 1.1.3 The FO Process Osmosis is the diffusion of water through a partially permeable barrier from a solution of low solute concentration (high water potential) to a solution with high solute concentration (low water potential) The inherent energy of this natural process is known as the chemical potential,... pharmaceutical applications and even in power generation (Cath et al, 2006) Further review will be given in the next chapter FO process is similar to the more common reverse osmosis (RO) process in that both the processes utilize the transport of water across a semi-permeable membrane According to Fig 1.7, the FO process (Fig 1.7a) employs a negative ∆π for the transport of water from the feed side... represented 17% of the global population Of the 1.1 billion people, nearly two thirds of them live in Asia In sub-Sahara Africa, 42% of the population is still without improved water Between 2002 and 2015, the world’s population was expected to increase every year by 74.8 million people and the global demand for improved water source therefore shall increase concomitantly (WHO, 2005) However by 2025, the projected... operating cost greatly reduced with the introduction of energy recovery systems However, there is a limit as to the amount of energy that can be recovered from the operation Therefore, there are recently a greater interests in the study of other novel technologies, which are capable of producing high quality water at a small fraction of the energy cost compared to the RO desalination, that can ultimately... (Mulder, 1996) A classification of some separation processes in terms of the physical or chemical properties of the components to be separated is given in Table 1.1 A number of selections can be made on the possible separation principles for the separation of different components Table 1.1 – Classification of some separation processes using physical and chemical properties of the components to be separated... specifically the water potential, due to the difference in concentration of the two solutions In order to oppose the movement of water, osmosis may be countered by increasing the pressure (∆p) in the region of high solute concentration with respect to that in the low solute concentration region This is equivalent to the osmotic pressure of the 12 CHAPTER ONE – INTRODUCTION BACKGROUND solution The osmotic... selected The two criteria are: 1) separation must be feasible technically; and 2) separation must be feasible economically Economic feasibility, being more important among the two criteria, depends strongly on the value of the products isolated As such, the most practicable separation process is one that allows the achievement of the requirement of the separation at the lowest cost In many applications . MODELING AND OPTIMIZATION OF THE FORWARD OSMOSIS PROCESS – PARAMETERS SELECTION, FLUX PREDICTION AND PROCESS APPLICATIONS TAN CHIEN HSIANG (B.Eng.(Hons.), NUS) A THESIS SUBMITTED. It is the objective of this thesis to investigate these challenges and systematically evaluate the feasibility of the FO process in water and wastewater treatment. In the first part of the study. investigate the effect of different mean-cell residence time (MCRT) on FO-MBR operations ( 3-, 5-, and 10-day MCRT) and the effect of backwash and chemical cleaning to mitigate flux decline.