Fouling behaviour during ultrafiltration of skim latex / Ho Kar Wei

• Main Author: Ho, Kar Wei
• Format: Thesis
• Published: 2013
• Subjects: T Technology (General); TA Engineering (General). Civil engineering (General)
• Online Access: http://studentsrepo.um.edu.my/8613/6/HO_KAR_WEI_%2D_Fouling_Behavior_during_ultrafiltration_of_skim_latex.pdf; http://studentsrepo.um.edu.my/8613/
• Institution: Universiti Malaya

Natural field latex with about 30% dry rubber content (DRC) needs to be further concentrated to about 60% DRC for further downstream processing into a variety of products. A large volume of skim latex (consists of 6-8% DRC) is produced as byproduct during centrifugation of natural field latex. Membrane separation process can be used to recover the skim rubber particles as well as the by-product serum from the skim latex stream leading to zero discharge. Current practice requires a wastewater treatment plant to treat the waste to meet the legal requirement before discharging to the environment. As such a study has been initiated to gain an understanding of the fouling behavior of skim latex in terms of permeate flux and fouling resistances during the ultrafiltration of skim latex in order to increase membrane life as well as optimizing cleaning procedure. A bench scale crossflow ultrafiltration unit using single channel tubular ceramic membrane with pore size 0.05μm was used in this study. The effect of operating conditions, i.e. crossflow velocity (1.3 cm/s to 4.6 cm/s) and transmembrane pressure (0.3 bar to 1.0 bar) were investigated. The overall filtration performance showed a similar trend, i.e. initial permeates fluxes start up high and then decreases rapidly. Finally, permeate flux attained pseudo steady state where permeate flux was almost constant at this stage. At crossflow velocity 4.6cm/s, initial permeate flux and permeate flux at pseudo steady state decreased with the increase in transmembrane pressure. At crossflow velocity 1.3 cm/s, permeate flux at pseudo steady state is reduced by about 38% as transmembrane pressure increased from 0.6 bar to 1.0 bar. However, permeate flux at pseudo steady state is increased drastically (263%) as transmembrane pressure increased further to 1.3 bar. This behavior occurred due to the change in the microstructure of fouled membrane as shown in scanning electron microscope images. Keywords: Ultrafiltration; skim latex; ceramic membrane; fouling