Physical Backwash Optimization in Membrane Filtration Processes: Seawater Ultrafiltration Case

Document Type : Research Paper


1 INSAT, university of Carthage, tunis, tunisia.

2 Department of Biological and Chemical Engineering, INSAT, university of Carthage, Tunis, Tunisia

3 issbat, university of Tunis EL Manar, tunis, tunisia

4 Biological and chemical engineering department, INSAT, University of Carthage, Tunis, Tunisia


Seawater ultrafi ltration (UF) as a pretreatment of reverse osmosis (RO) process in a thermal power plant was investigated using a 100 kDa hollow fi ber membrane. The choice of the UF physical backwash conditions remains arbitrary or ensuing from a sensibility study. As the optimum must take into account the factors interactions, we led a response surface study to analyze the eff ect of backwash interval BWI (30–90 min), backwash fl ow-rate BWF (10–34 L.min-1) and backwash duration BWD (15–45 s) on two responses: the Specific Flux Reduction (SFR) and the Net Water Production (NWP). Polynomial models describing the responses sensitivity with respect to the three variables were established to determine the optimal conditions corresponding to maximal NWP while assuring lowest fouling. Results showed that fouling is mainly controlled by BWI. For the NWP, all the variables are signifi cant especially their quadratic and interaction terms. Maximal NWP and low SFR can be reached at 30 min BWI, for a BWD and BWF ranges of [15-30 s] and [10-21 L.min-1], respectivel.

Graphical Abstract

Physical Backwash Optimization in Membrane Filtration Processes: Seawater Ultrafiltration Case


Main Subjects

[1] A.G. Pervov, A.P. Andrianov, R.V. Efremov, A.V. Desyatov, A.E. Baranov, A new solution for the Caspian Sea desalination: low-pressure membranes, Desalination 157 (2003) 377–384.
[2] L. Wang, X. Wang, K. Fukushi, Effects of operational conditions on ultrafiltration membrane fouling, Desalination 229 (2008) 181–191.
[3] J. Xu, G. Ruan, X. Chu, Y. Yao, B. Su, C. Gao, A pilot study of UF pretreatment without any chemicals for SWRO desalination in China, Desalination 207 (2007) 216–226.
[4] Y. Ye, L.N. Sim, B. Herulah, V. Chen, A.G. Fane, Effects of operating conditions on submerged hollow fibre membrane systems used as pre-treatment for seawater reverse osmosis, J. Membr. Sci. 365 (2010) 78–88.
[5] N.O. Yigit, G. Civelekoglu, I. Harman, H. Koseoglu, M. Kitis, Effects of various backwash scenarios on membrane fouling in a membrane bioreactor, Desalination 237 (2009) 346–356.
[6] M. Raffin, E. Germain, S.J. Judd, Influence of backwashing, flux and temperature on microfiltration for wastewater reuse, Sep. Purif. Technol. 96 (2012) 147–153.
[7] K.J. Hwang, C.S. Chan, K.L. Tung, Effect of backwash on the performance of submerged membrane filtration, J. Membr. Sci. 330 (2009) 349–356.
[8] E. Barbot, P. Moulin, Swimming pool water treatment by ultrafiltration–adsorption process, J. Membr. Sci. 314 (2008) 50–57.
[9] P.J. Smith, S. Vigneswaran, H.H. Ngo, R. Ben-Aim, H. Nguyen, A new approach to backwash initiation in membrane systems, J. Membr. Sci. 278 (2006) 381–389.
[10] C. Cojocaru, G. Zakrzewska-Trznadel, A. Jaworska, Removal of cobalt ions from aqueous solutions by polymer assisted ultrafiltration using experimental design approach. part 1: Optimization of complexation conditions, J. Hazard. Mater. 169 (2009) 599–609.
[11] J. Landaburu-Aguirre, E. Pongrácz, P. Perämäki, R. L. Keiski, Micellar-enhanced ultrafiltration for the removal of cadmium and zinc: Use of response surface methodology to improve understanding of process performance and optimization, J. Hazard. Mater. 180 (2010) 524–534.
[12] S.M.S. Shahabadi, A. Reyhani, Optimization of operating conditions in ultrafiltration process for produced water treatment via the full factorial design methodology, J. Sep. Purif. Technol. 132 (2014) 50- 61.
[13] J. Dasgupta, A. Singh, S. Kumar, J. Sikder, S. Chakraborty, S. Curcio, H.A. Arafat, Poly (sodium-4-styrenesulfonate) assisted ultrafiltration for methylene blue dye removal from simulated wastewater: Optimization using response surface methodology, J. Environ. Chem. Eng. 4 (2016) 2008–2022.
[14] A.W. Zularisam, A.F. Ismail, M.R. Salim, M. Sakinah, T. Matsuura, Application of coagulation–ultrafiltration hybrid process for drinking water treatment: Optimization of operating conditions using experimental design, J. Sep. Purif. Technol. 65 (2009) 193–210.
[15] J.P. Wang, Y.Z. Chen, Y. Wang, S.J. Yuan, H.Q. Yu, Optimization of the coagulation-flocculation process for pulp mill wastewater treatment using a combination of uniform design and response surface methodology, J. Water Res. 45 (2011) 5633–5640.
[16] X.S. Yi, W.X. Shi, S.L. Yu, X.H. Li, N. Sun, C. He, Factorial design applied to flux decline of anionic polyacrylamide removal from water by modified polyvinylidene fluoride ultrafiltration membranes, Desalination 274 (2011) 7–12.
[17] K. Guerra, J. Pellegrino, J.E. Drewes, Impact of operating conditions on permeate flux and process economics for cross flow ceramic membrane ultrafiltration of surface water, J. Sep. Purif. Technol. 87 (2012) 47–53.
[18] J. Paul Chen, S.L. Kim, Y.P. Ting, Optimization of membrane physical and chemical cleaning by a statistically designed approach, J. Membr. Sci. 219 (2003) 27–45.
[19] M. Pourabdollah, A. Torkian, M. Hosseinzadeh, A New Approach to Modeling Operational Conditions for Mitigating Fouling in Membrane Bioreactor, J. Water Environ. Res. 88 (2016) 2198-2208.
[20] G.G. Oriol, N. Moosa, R. Garcia-Valls, M. Busch, V. Garcia-Molina, Optimizing seawater operating protocols for pressurized ultrafiltration based on advanced cleaning research, J. Desal. Water Treat. 51 (2013) 384–396.