Browse > Article

Reduction of Cake Resistance by Floc Reaggregation in a Membrane-Feed-Pipe  

KIM, Taeyoung (KAIST 건설 및 환경공학과)
PARK, Heekyung (KAIST 건설 및 환경공학과)
Publication Information
Journal of Korean Society of Water and Wastewater / v.21, no.6, 2007 , pp. 717-726 More about this Journal
Abstract
Fully-grown flocs in a mixing tank of membrane filtration with dead-end membrane are ruptured while passing through a pump and the ruptured flocs are aggregated again in a Membrane-Feed-Pipe (MFP). To look at more details, this study tries to relate the reaggregation to a parameter of mixing intensity in MFP, i.e., G-value. The G-value is a function of Reynolds number, pipe diameter, friction factor and average velocity in MFP. To deal with polydispersity condition, we develop a representative particle size called in this study EDPD (Effective Diameter for Polydispersity condition in Dead-end filtration). The experimental results show that as the G-value increases, the EDPD decreases and also the cake resistance increases. Through comparison between EDPD and cake resistance, these results show that cake resistances are controlled by reaggregation phenomenon in MFP. The effect of detention time in MFP, however, does not affect the reaggregation of the broken flocs as G-values are increased.
Keywords
Reaggregation; G-value; Detention time; Membrane-Feed-Pipe; Cake resistance;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
연도 인용수 순위
1 M.M. Clark (1985) Critique of camp and stein's rms velocity gradient, J. Emnron. Eng., 116(6), pp. 741-754
2 Graber, S.D. (1994) A critical review of the use of the Gvalue (RMS velocity gradient) in environmental engineering, Dev Tbeor. Appl. Mech., 17, pp. 533-556
3 Kim, S., Cho, S.H., and Park, H. (2002) Reduction of cake layer by re-aggregation in coagulation-crossflow microfiltration process, Water Sci. and Technol.: Water Supply, 2(5-6), pp. 329-336
4 Kim, S., Park, N., Kim. T., Park, H. (2007) Reaggregation of floes in coagulation-cross-flow microfiltration, J. Environ. Eng., 133(5), pp. 507-514   DOI   ScienceOn
5 Soffer, Y., Ben, A.R., and Adin, A. (2000) Membane for water reuse: effect of pre-coagulation on fouIing and selectivity, Water Sci. Technol., 42(1-2), pp. 367-372   DOI
6 Yukselen, M.A., Gregory J. (2004) The effect of rapid mixing on the break-up and re-formation of floes, J. Chemi Technol Biotechnol., 79, pp. 782-788   DOI   ScienceOn
7 Altmann, J. and Ripperger, S. (1997) Particle deposition and layer formation at the crossflow microfiltration, J. Mem. Sci., 124, pp. 119-128   DOI   ScienceOn
8 Wiesner, M.R., Clark, M.M., and Mallenvialle, J. (1989) Membrane filtration of coagulated suspensions. J. Environ. Eng., 115(1), pp. 20-40   DOI   ScienceOn
9 M.M. Clark, and J.R.V. Flora (1991) Floc restructuring in varied turbulent mixing, J. colloid and interface sci., 147(2), pp. 407 -421   DOI   ScienceOn
10 Kim, S. (2003) Characteristics and control of cake formation in crossflow microfiltration at polydisperse condtion, Ph.D. thesis, Dept. of Civil and Environmental Engineering, KAIST, Daejeon, South Korea
11 R.J. Latimer, Appiah Amirtharajah (1998) Pilot scale comparison of static mixers and backmix reactors for coagulation, AWWA Annual Conference, pp. 705-740
12 Kim, S., and Park, H. (2005) Effective diameter for shearinduced diffusion for characterizing cake formation in crossflow microfiltration at polydisperse conditions, J. Environ. Eng., 131(6), pp. 865-873   DOI   ScienceOn
13 Godfrey, J.C., Amirtharajah, M.M. Clark (1991) Mixing in coagulation and flocculation, AWARF. Denver
14 Lee, J.D., Lee, S.H., Jo, M.H., Park, P.K., Lee, J.H., Kwak, J.W. (2000) Effect of coagulation conditions on membrane filtration characteristics in coagulation-microfiltration process for water treatment, Environ. Sci. Technol., 34, pp. 3780-3788   DOI   ScienceOn
15 Yukselen, M.A., and Gregory, J. (2002) Breakage and Reformation of Alum flocs, Environ. Eng., Sci., 19(4), pp. 229-236   DOI   ScienceOn
16 Kwon, D.Y. (1998) Experimental investigation on Critical flux in cross-flow microfiltration, Ph.D. thesis, Faculty of Engineering and Environmental Engineering Group, Univ. of Technology, Sydney, Australia
17 Smoluchoski, M. (1917). Versuch einer mathematischen Theorie der Koagulationskinetic kolloider L sungen, Z. Phys. Chem., 92, pp. 129-168
18 MaLaughlin J.B. (1993) The lift on a small sphere inwallbounded linear shear flows, J. Fluid Mech., 246, pp. 249-265   DOI
19 Mehmet A. Y., John G. (2004) The effect of rapid mixing on the break-up and re-formation of floes, J. Chemi Technol Biotechnol., 79, pp. 782-788   DOI   ScienceOn
20 S. Casey Jones, Fotis Sotiropoulos, and Appiah Amirtharajah. (2002) Numerical modeling of helical static mixers for water treatment, J. Environ. Eng., 128(5), pp. 431-440   DOI   ScienceOn