Influence of pH and surfactants on ultrafiltration membranes during treatment of bleach plant effluent

The influence of pH and surfactants during treatment of E-stage effluent was studied. Three tubular ultrafiltration membranes were used in the experiment. The flux of the three membranes was at its highest level at the normal, high pH, of the effluent. In this experiment the densest membrane showed the greatest flux decrease, while the most ouen membrane was either unaffected bv variations in ph or experienced a more moderate decrease. The flux after treatment with a nonionic surfactant could be restored by cleaning with a commercial cleaning agent, but it was not possible to restore the initial flux when a cationic surfactant had been added to the effluent. The role of cleaning during membrane treatment is also discussed.