Ultrafiltration of bleach plant effluent

An up-to-date evaluation of capacity and retention of new membranes with regard to bleach plant effluents has been made. The results from a trial of seven reverse osmosis, ultrafiltration and microfiltration membranes are reported. The trial has even included membranes not yet commercially available. The trial has demonstrated that some of the tested membranes could probably combine a satisfactory flux and an acceptable retention. A rough estimate of the costs shows that treatment of the E-stage effluent with ultrafiltration could be performed within a total cost of approximately 25 SEK per tonne of pulp.