Malaysian Journal of Analytical Sciences Vol 22 No 1 (2018): 136 - 142

DESALINATION OF SEAWATER USING NEWLY FABRICATED NANOFILTRATION FLAT SHEET MEMBRANE

(Penyahgaraman Air Laut Menggunakan Rekaan Baru Membran Kepingan Rata Penapisan Nano)

Wan Syarizawani Wan Chik¹*, Mohd Johan Mohamed Ibrahim¹, Ramlah Mohd Tajuddin²

¹Faculty of Civil Engineering,

Universiti Teknologi MARA Cawangan Johor, Kampus Pasir Gudang, 85000 Segamat, Johor, Malaysia

²Faculty of Civil Engineering,

Universiti Teknologi MARA, 40450 Shah Alam, Selangor, Malaysia.

*Corresponding author: zawani9681@johor.uitm.edu.my

Received: 4 December 2016; Accepted: 1 December 2017

Abstract

Desalination is one of the technologies to produce clean water for drinking, irrigation, industrial and development. Generally desalination can be classified based on their separation mechanisms which are thermal and membrane based desalination. In this study the newly fabricated nanofiltration membrane was used to identify their performance in desalination process. The material chosen in this study is polysulfone (PSf), N-methyl-2-pyrolidon (NMP) and polyvinylpyrrolidone (PVP). The dope solution composition was determined by using titration method. The membrane compositions are 20:1:79, 20:2:78, 20:3:77 and 20:4:76 (weight ratio) for PSf/PVP-1%, PSf/PVP-2%, PSf/PVP-3% and PSf/PVP-4% respectively. The polysulfone membrane was fabricated by wet phase inversion method. The aims of this research are to investigate the effect of different PVP concentrations in material composition on membrane morphology, membrane fluxes and seawater rejection. The results observed by SEM show the membrane composition PSf/PVP-1% has lower pore size with average pore size 8.4 nm while PSf/PVP-4% has highest pore size. Membrane PSf/PVP-1% has highest rejection (5.7%) and lower flux (2.43 L/cm².hr) while PSf/PVP-4% has highest flux (6.44 L/cm².hr) and lower rejection (0.87%). It is related with PVP contents in the membrane solution. In conclusion, increase PVP concentration will increase pore size, therefore it will increase flux while the rejection will decrease.

Keywords: membrane based desalination, nanofiltration, polysulfone, polyvinylpyrrolidone

Abstrak

Penyahgaraman adalah salah satu teknologi untuk menghasilkan air bersih untuk minuman, pengairan, perindustrian dan pembangunan. Secara umumnya penyahgaraman boleh dikelaskan berdasarkan mekanisme pengasingan iaitu penyahgaraman berdasarkan terma dan membran. Dalam kajian ini membran penapisan nano yang baru direka telah digunakan untuk mengenal pasti prestasi dalam proses penyahgaraman. Bahan dipilih dalam kajian ini adalah polisulfon (PSf), N-metil-2-pirolidon (NMP) dan polivinilpirolidon (PVP). Komposisi cecair larutan yang telah ditentukan adalah menggunakan kaedah titratan. Komposisi membran yang digunakan ialah 20:1:79, 20:2:78, 20:3:77 dan 20:4:76 (nisbah berat) untuk PSf/PVP-1%, PSf/PVP-2%, PSf/PVP-3% dan PSf/PVP-4%. Membran polisulfon dihasilkan melalui kaedah fasa penyongsangan basah. Tujuan kajian ini adalah untuk mengkaji kesan kepekatan PVP berbeza dalam komposisi bahan morfologi membran, fluks membran dan penyingkiran air laut. Keputusan dipatuhi oleh SEM menunjukkan membran komposisi PSF/PVP-1% mempunyai saiz liang yang lebih kecil dengan purata saiz liang 8.4 nm manakala PSF/PVP-4% mempunyai saiz liang terbesar. Membran PSF/PVP-1% mempunyai penyingkiran tertinggi (5.7%) dan fluks yang lebih rendah (2.43 L/cm2.hr) manakala PSF/PVP-4% mempunyai fluks tertinggi (6.44 L/cm2.hr) dan penyingkiran yang lebih rendah (0.87%). Ia berhubungkait dengan kandungan PVP dalam larutan membran. Kesimpulannya, peningkatan kepekatan PVP akan meningkatkan saiz liang, oleh itu ia akan meningkatkan fluks manakala penyingkiran akan berkurangan.

Kata kunci: penyahgaraman berdasarkan membran, penapisan nano, polisulfon, polivinilpirolidon

References

1. Ioannis, C., Karagiannis, P. and Soldatos, G. (2008). Water desalination cost literature: Review and assessment. Desalination, 223: 448-456.

2. Misdan, N., Lau, W. J. and Ismail, A. F. (2012). Seawater reverse osmosis (SWRO) desalination by thin-film composite membrane-current development, challenges and future prospects. Desalination, 287: 228-237.

3. Altaee, A., Zaragoza, G. and Tonningen, H. R. V. (2014). Comparison between forward osmosis-reverse osmosis and reverse osmosis processes for seawater desalination. Desalination, 336: 50-57.

4. Fang, Y., Bian, L., Bi, Q., Li, Q. and Wang, X. (2014). Evaluation of the pore size distribution of a forward osmosis membrane in three different ways. Journal of Membrane Science, 454: 390-397.

5. Zhao, S., Wang, Z., Wei, X., Tian, X., Wang, J., Yang, S. and Wang, S. (2011). Comparison study of the effect of PVP and PANI nanofiber additives on membrane formation mechanism, structure and performance. Journal of Membrane Science, 385-386: 110-122.

6. Chakrabarty, B., Ghoshal, A. K. and Purkait, M. K. (2008). Preparation, characterization and performance studies of polysulfone membranes using PVP as an additive. Journal of Membrane Science, 315: 36-47.

7. Song, H. J. and Kim, C. K. (2013). Fabrication and properties of ultrafiltration membranes composed of polysulfone and poly (1-vinypyrrolidone) grated silica nanoparticles. Journal of Membrane Science, 444: 318-326.

8. Derya, Y. and Koseoglu, L. (2013). The determination of performances of polysulfone (PS) ultrafiltration membranes fabricated at different evaporation temperatures for the pretreatment of textile wastewater. Desalination, 316: 110-119.

9. Sener, T., Okumus, E., Gurkan, T. and Yilmaz, T. (2010). The effect of different solvents on the performance of zeolite filled composite prvaporation membranes. Desalination, 261: 181-1185.

10. Yoo, S. H., Kim, J. K., Jho, J. Y., Won, J. and Kang, Y. S. (2004). Influence of the addition of PVP on the morphology of asymmetric polyimide phase inversion membranes: effect of PVP molecular weight. Journal of Membrane Science, 236: 203-207.

11. Zhao, S., Wang, Z., Wei, X., Tian, X., Wang, J., Yang, S. and Wang, S. (2011). Comparison study of the effect of PVP and PANI nanofiber additives on membrane formation mechanism, structure and performance. Journal of Membrane Science, 385-386: 110-122.

12. Zhang, P. Y., Wang, Y. L., Xu, Z. L. and Yang, H. (2011). Preparation of poly(vinybutyral) hollow fiber ultrafiltration membrane via wet spinning method using PVP as additive. Desalination, 278: 186-193.

13. Dieling, Z., Jian, Z., Kang, L. and Tai, S. (2017). Fluorographite modified PVDF membranes for seawater desalination via direct contact membrane distillation. Desalination, 413: 119-126.

14. Han, J., Yang, D., Zhang, S. and Jian, X. (2009). Effect of dope compositions on the structure and performance of PPES hollow fiber ultrafiltration membranes. Journal of Membranes Science, 345: 257-266.

15. Guan, R., Dai, H., Li, C., Liu, J. H. and Xu, J. (2006). Effect of casting solvent on the morphology and performance of sulfonated polyethersulfone membranes. Journal of Membrane Science, 277: 148-156.

16. Hu, D., Xu, Z. L., Wei, Y. M. and Liu, Y. F. (2014). Poly(styrene sulfonic acid) sodium modified nanofiltration membranes with improved permeability for the softening of highly concentrated seawater. Desalination, 336: 179-186.

17. Alireza, Z., Ahmad, R. and Mathias, U. (2017). Nano-sized metal organic framework to improve the structural properties and desalination performance of thin film composite forward osmosis membrane. Journal of Membrane Science, 531: 59-67.

18. Baker, R.W. (2004). Membrane technology and application. Membrane technology and research. John Wiley & Son Inc.: pp. 17-81.