CROSS-HOW FILTRATION OF LATEX EMULSION ON A PILOT-SCALE USING ORGANICAND INORGANIC MEMBRANES WITH DIFFERENT CUTOFF VALUES

The aim of the following project was to increase the concentration of a ca. 1 wt% styrene butadiene latex emulsion (also termed 'white-water streams') resulting from industrial production using cross-flow filtr ation, and to investigate the process performance using different type s of membranes. The permeate flux Lie in the range 2.36x10(-5)-0.14x10 (-5) m s(-1) when the emulsion was concentrated up to similar to 40 wt %. Although three different membrane types, one organic and two inorga nic, with varying cut-off values (20 000, 50 000 and 0.2 mu m) were us ed, no significant differences in average permeate flow were observed. The concentration of the latex emulsion was seen to have the greatest effect on the permeate flux, and with increasing concentration, the f lux was observed to drop to similar to 0. In contrast to this, during continuous testing over a period of nearly two months, using two emuls ions of 15 wt% and 1 wt%, respectively, the permeate flow rate remaine d practically stable.