DOI QR코드

DOI QR Code

Hypochlorite treatment of polyamide membrane for improved reverse osmosis performance

  • Shao, P. (Energy, Mining and Environment (EME) Portfolio, National Research Council Canada) ;
  • Kurth, C.J. (NanoH2O Inc.)
  • Received : 2012.10.06
  • Accepted : 2013.02.05
  • Published : 2013.01.25

Abstract

The pH-dependent inter-conversion of the three free chlorine species ($Cl_2$, HOCl, OCl-) present in the aqueous hypochlorite solution was theoretically investigated. Each species was found overwhelmingly present in a characteristic pH range. Hypochlorite treatment of the polyamide membrane was carried out over these pH ranges and various membrane responses were observed. As pH is less than 8, membrane tends to be N-chlorinated by $Cl_2$ and HOCl, and N-chlorinated membrane showed reduced water permeance and salt rejection. As pH rises to 10-12, $OCl^-$ appears to be the dominating chlorine species. Membrane hydrolysis was found to well interpret the improved water permeance and salt rejection. When the pH is between 8-10, both N-chlorination and hydrolysis contribute to the response of the membrane, and the treated membrane showed improved salt rejection but reduced water permeation. Excessive hydrolysis occurred while the membrane was treated at pH 13 for the much stronger alkalinity.

Keywords

References

  1. Petersen, R.J. (1993), "Composite reverse osmosis and nanofiltration membranes (Review)", J. Membr. Sci., 83, 81-150. https://doi.org/10.1016/0376-7388(93)80014-O
  2. Nath, K. (2008), Membrane Separation Progresses, Prentice-Hall of India Private Ltd., New Delhi.
  3. Glater, J., Hong, S. and Elimelech, M. (1994), "The search for a chorine-resistant reverse osmosis membrane", Desalination, 95, 325-345. https://doi.org/10.1016/0011-9164(94)00068-9
  4. Glater, J., Zachariah, M.R., McCray, S.B. and McCutchan, J.W. (1983), "Reverse osmosis membrane sensitivity to ozone and halogen disinfectants", Desalination, 48, 1-16. https://doi.org/10.1016/0011-9164(83)80001-0
  5. Glater, J., Zachariah, M.R., McCray, S.B. and McCutchan, J.W. (1983), "Reverse osmosis membrane sensitivity to ozone and halogen disinfectants", Desalination, 48(1), 1-16. https://doi.org/10.1016/0011-9164(83)80001-0
  6. da Silva, M.K., Tessaro, I.C. and Wada, K. (2006), "Investigation of oxidative degradation of polyamide reverse osmosis membranes by monochloramine solutions", J. Membr. Sci., 282, 375-382. https://doi.org/10.1016/j.memsci.2006.05.043
  7. Dam, N. and Ogillby, P.R. (2001), "On the mechanism of polyamide degradation in chlorinated water", Helvetica Chimica Acta, 84, 2540-2549. https://doi.org/10.1002/1522-2675(20010919)84:9<2540::AID-HLCA2540>3.0.CO;2-0
  8. Gabelich, C.J., Frankin, J.C., Gerringer, F.W., Ishida, K.P., Suffet, I.H.(Mel) (2005), "Enhanced oxidation of polyamide membranes using monochloramine and ferrous iron", J. Membr. Sci., 258, 64-70. https://doi.org/10.1016/j.memsci.2005.02.034
  9. Shin, D.H., Kim, N. and Lee, Y.T. (2011), "Modification to the polyamide TFC RO membrane for improvement of chlorine resistance", J. Membr. Sci., 376, 302-311. https://doi.org/10.1016/j.memsci.2011.04.045
  10. Tang, C.Y., Kwon, Y.N. and Leckie, J.O. (2009), "Effect of membrane chemistry and coating layer on physiochemical properties of thin film composite polyamide RO and NF membranes: II, Membrane physiochemical properties and their dependence on polyamide and coating layers", Desalination, 242(1-3), 168-182. https://doi.org/10.1016/j.desal.2008.04.004
  11. Tang, C.Y., Kwon, Y.-N. and Leckie, J.O. (2007), "Probing the nano-and micro-scales of reverse osmosis membranes - A comprehensive characterization of physiochemical properties of uncoated and coated membranes by XPS, TEM, ATR-FTIR, and streaming potential measurements, J. Membr. Sci., 287, 146-156. https://doi.org/10.1016/j.memsci.2006.10.038
  12. Elimelech, M., Zhu, X.H., Childress, A.E. and Hong, S.K. (1997), "Role of membrane surface morphology in colloidal fouling of cellulose acetate and composite aromatic polyamide reverse osmosis membranes", J. Membr. Sci., 127, 101. https://doi.org/10.1016/S0376-7388(96)00351-1
  13. Tang, C.Y., Kwon, Y.N. and Leckie, J.O. (2009), "Effect of membrane chemistry and coating layer on physiochemical properties of thin film composite polyamide RO and NF membranes: I. FTIR and XPS characterization of polyamide and coating layer chemistry", Desalination, 242(1-30 ), 149-167. https://doi.org/10.1016/j.desal.2008.04.003
  14. Tessaro, I.C., da Silva, J.B.A. and Wada, K. (2005), "Investigation of some aspects related to the degradation of polyamide membranes: aqueous chlorine oxidation catalyzed by aluminum and sodium laurel sulfate oxidation during cleaning", Desalination, 181, 275-282. https://doi.org/10.1016/j.desal.2005.04.008
  15. Agus, E., Voutchkov, N. and Sedlak, D.L. (2009), "Disinfection by-products and their potential impact on the quality of water produced by desalination systems: A literature review", Desalination, 237, 214-237. https://doi.org/10.1016/j.desal.2007.11.059
  16. Shao, P. and Kurth, C.J. (2006), "Chlorination of polyamide membrane using bleach solutions", Technical Report, GEWPT.
  17. Soice, N.P., Maladono, A.C., Takigawa, D.Y., Norman, A.D., Krantz, W.B. and Greenberg, A.R. (2003), "Oxidtive degradation of polyamide reverse osmosis membrane: Studies of molecular model compounds and selected membranes", J. Appl. Polym. Sci., 90, 1173-1184. https://doi.org/10.1002/app.12774
  18. Ettori, A., Gaudichet-Maurin, E., Schrotter, J.-C., Aimar, P. and Causserand, C. (2011), "Permeability and chemical analysis of aromatic polyamide based membranes exposed to sodium hypochlorite", J. Membr. Sci., 375, 220-230. https://doi.org/10.1016/j.memsci.2011.03.044
  19. Rouaix, S., Causserand, C. and Aimar, P. (2006), "Experimental study of the effects of hypochlorite on polysulfone membrane properties", J. Membr. Sci., 277(1-2), 137-147. https://doi.org/10.1016/j.memsci.2005.10.040
  20. Mika, A.M., Childs, R.F. and Dickson, J.M. (2002), "Salt-separation and hydrodynamic permeability of a porous membrane filled with pH-sensitive gel", J. Membr. Sci., 206(1-2), 19-30. https://doi.org/10.1016/S0376-7388(01)00474-4
  21. Isabel, M., de Albani, D. and Arciprete, C. (1992), "A study of pore size distribution and mean pore size on unsupported gamma-alumina membranes prepared by modifications introduced in the alkoxide hydrolysis step", J. Membr. Sci., 69(1-2), 21-28. https://doi.org/10.1016/0376-7388(92)80164-F
  22. Hong, Z., Zhang, C., Gu, X., Jin, W. and Xu, N. (2011), "A simple method for healing nonzeolitic pore of MFI membranes by hydrolysis of silanes", J. Membr. Sci., 366(1-2), 427-435. https://doi.org/10.1016/j.memsci.2010.10.049
  23. Zhou, J., Childs, R.F. and Mika, A.M. (2005), "Calculation of the salt separation by negatively-charged gel-filled membranes", J. Membr. Sci., 260, 164-173. https://doi.org/10.1016/j.memsci.2005.03.028

Cited by

  1. Effects of DMSO and glycerol additives on the property of polyamide reverse osmosis membrane vol.74, pp.7, 2016, https://doi.org/10.2166/wst.2016.367