Abstract

The work reported refers to the application of ultrafiltration to spent unhairing liquors from a low production scale Portuguese tannery. dealing mainly with sheepskins. A set of trials with an ultrafiltration pilot were carried out aiming to studs’ the continuous recycling of permeate and the evaluation of total savings. Although good savings were attained ( 67Y (‘or water. 58 for suiphide and 53 (‘or lime), a fair average permeate flux was obtained (38 litres r2n hour). Because of the capital and operational costs associated with membrane technologies the obtained results showed that good practical permeate fluxes (higher than 40 litres r2n hour) and process volumes higher than 10 r3n day are important conditions for the economic viability of’ the process.