Enzymatic membrane reactor for eco-friendly goat skin unhairing.

A new approach is proposed in order to solve current problems in the dehairing process. An enzymatic agent was used as an alternative to conventional chemical dehairing methods. Ultrafiltration of the enzymatic dehairing bath was carried out during the unhairing operation thus creating an enzymatic membrane reactor for the production of dehaired skins. The operating system, analytical measurements and microscopical observations on the treated skins in comparison with the control group (lime-sulphide process) are reported and discussed. The results obtained show the possibility to reduce the environmental impact caused mainly by the aqueous stream coming from conventional dehairing. Other advantages obtained using the coupled enzymatic/UF system were: control of enzyme action; reduction of sulphide requirement; easy recovery of hair with consequent reduction of polluting load and of cleaning-up costs; the possibility of reusing the recovered hair; simplification of wastewater cleaning-up processes; increased opening-up of the fibre structure and production of softer leather; plus the possibility of avoiding the bating operation, thus obtaining savings in terms of time, work, water and chemicals.