Determination of the optimum filtration conditions in pretreatment of seawater desalination by reverse osmosis

역삼투법 해수담수화 전처리 여과공정의 최적조건

  • Received : 2009.01.22
  • Accepted : 2009.03.30
  • Published : 2009.04.15

Abstract

This study examines the optimum filtration conditions in pretreatment of seawater desalination by reverse osmosis. For this purpose, Masan bay seawater is treated through a gravity filter column while $FeCl_3$ is added as coagulant. The conditions of coagulantd osage, media depth, filtration rate, and backwash time are evaluated. The study results show that the filtrate quality improved with increasing coagulant dosage, but head loss rapidly increased. After 4mg/L, the unit filter run volume reduced to less than $200m^3/m^2$. Considering the head loss development, 4mg/L is determined as the optimum dosage. The better filtrate qualities are obtained with depth of 100cm than that of 80cm. The two stage filtration, which outperformed the single stage filtration, is suggested for treatment of Masan bay. The filtration rate of 5m/h is decided as the optimum condition considering the head loss development. At 10m/h, the filtrate quality deteriorated even though the extent was minimal, and head loss increased rapidly. The backwash time of 10 min is decided appropriate.

Keywords

Acknowledgement

Supported by : 건설교통부

References

  1. 해양수산부고시 제2005-61호 (2005) 해양환경공정시험방법개정고시(안)
  2. 한국상하수도협회 (2004) 상수도시설기준: 여과
  3. ASTM. (1995) A Standard Test Method for Silt Density Index (SDI) of water, D4189-95
  4. Aziz, P.K.A., Ibrahim A., Mohammad A., Green T.N., Dalvi, A.G., and Javeed M.A. (2000) Effects of environment on source water for desalination plants on the eastern coast of SaudiArabia, Desalination, 132, pp.29-40 https://doi.org/10.1016/S0011-9164(00)00132-6
  5. Bonneyle, V., Sanz, M.A., Durand J., Plasse L., Gueguen, F., and Mazouine, P. (2004) Reverse osmosis on open intake seawater: pretreatment strategy, Desalination, 167, pp.191-200 https://doi.org/10.1016/j.desal.2004.06.128
  6. Brehant, A., Bonnelye, V., and Perez, M. (2002) Comparison of MF/UF pretreatment with conventional filtration prior to RO membranes for surface seawater desalination, Desalination,144,pp.353-360 https://doi.org/10.1016/S0011-9164(02)00343-0
  7. Cleasby, J.L., Dharmarajah, A.H., Sindt, G.L., Baumann, E.R. (1989) Designand Operation Guidelines for Optimization of the High-Rate Filtration Process: Plant Survey Results, American Water Works Association Research Foundation, Co
  8. Cleasby, J.L., Dharmarajah, A.H., Sindt, G.L., Baumann, E.R. (1992) Designand Operation Guidelines for Optimization of the High-Rate Filtration Process: Plant Demonstration Studies, American Water Works Association Research Foundation, Co
  9. Ebrahim, S.H., Abdel-Jawad, M.M., Safar, M. (1995) Conventional pretreatment system for the Doha reverse osmosis plant: Technical and economic assessment, Desalination, 102, pp.179-187 https://doi.org/10.1016/0011-9164(95)00052-4
  10. Fair, G.M., Geyer J.C., Okun D.A. (1968) Water and Wastewater Engineering (Vol2) New York, John Wiley & Sons, Inc
  11. Fuller, G.W. (1989) The Purification of the Ohio River Water at Louisville, Kentucky, New York: D. Van Nostrand C
  12. Glueckstern, P, Priel, M., and Wilf, M. (2002) Field evaluation of capillary UF technology as a pretreatment for large seawater RO systems, Desalination, 147, pp.55-62 https://doi.org/10.1016/S0011-9164(02)00576-3
  13. van Hoof, S.C.J.M., Minnery, J.G., and Mack, B. (2001) Dead-end ultrafiltration as alternative pre-treatment to reverse osmosis in seawater desalination: a case study, Desalination, 139, pp.161-168 https://doi.org/10.1016/S0011-9164(01)00306-X
  14. Isaias, N.P. (2001) Experience in reverse osmosis pretreatment, Desalination, 139, pp.57-64 https://doi.org/10.1016/S0011-9164(01)00294-6
  15. Kawamura, S. (1991) Integrated Design of Water Treatment Facilities, John Wiley & Sons, Inc, New York
  16. Kim, S.H., Yoon, J.S., and Yoon, C.H. (2006) Evaluation of MF system performance as pretreatment for RO seawater desalination through pilot plant operation, Water Science & Technology: Water Supply, 6(4), pp.163-169 https://doi.org/10.2166/ws.2006.746
  17. Kim, S.H., Kim, H.K., Moon, B.H., Seo, G.T., and Yoon, C.H. (2006) Effects of addition sequence and rapid mixing conditions on use of dual coagulants, Water Science & Technology, 53(7), pp.87-94 https://doi.org/10.2166/wst.2006.211
  18. Mitrouli, S.T., Yiantsios, S.G., Karabelas, A.J., Mitrakas, M., Follesdal, M., Kjolseth, P.A. (2008) Pretreatment for desalination of seawater from an open intake by dual-media filtration: pilot testing and comparison of two different media, Desalination, 222, pp.24-37 https://doi.org/10.1016/j.desal.2007.02.062
  19. Moch, I. (2002) A 21s tcentury study of global SWRO operating and capital costs, IDA
  20. O'Melia, C.R. (1985) Practices, Pretreatment, and Filtration, Journal of the Environment Engineering Division, ASCE, 111(6), pp.874-884
  21. Xu, J., Ruan, G., Chu, X., Yao Y., Su, B., Gao, C. (2007) A pilot study of UF pretreatment without any chemicals for SWRO desalination in China, Desalination, 207, pp.216-226 https://doi.org/10.1016/j.desal.2006.08.006
  22. Shahalam, A.M., Al-Harthy, A., and Al-Zawhry, A. (2002) Feed water pretreatment in RO systems: Unit processes in the Middle East, Desalination, 150, pp.235-245 https://doi.org/10.1016/S0011-9164(02)00979-7
  23. Tenzer, B., Adin, A., and Priel, M. (1999) Seawater filtration for fouling prevention under stormy conditions, Desalination,125,pp.77-88 https://doi.org/10.1016/S0011-9164(99)00125-3
  24. Wolf, P.H., Siverns, S., and Monti, S. (2005) UF membranes for RO desalination pretreatment, Desalination, 182, pp.293-300 https://doi.org/10.1016/j.desal.2005.05.006
  25. Yao, K.M. (1968) Influence of Suspended Particle Size on the Transport Aspect of Water Filtration, Ph.D. dissertation, Dept. of Environmental Sciencesand Engineering, Univ. of North Carolina, Chaper Hill, N.C
  26. Yao, K.M., Habibian, M.T., and O’Melia, C.R. (1971) Water and Wastewater Filtration: Conceptsand Application, Environmental Science and Technology, 5, pp.1105-1112 https://doi.org/10.1021/es60058a005