Proceedings

Abstract

The production of leather from hides generates waste water which contains fat, proteins and chemicals. The waste water must be biochemically treated in a subsequent waste water treatment plant. The disposal of the biomass as a mixture of primary and waste activated sludge is burdened with high cost for Cr removal or incineration with on-line CrO4-scrubbing. A benefit of high dry solids dewatering is that if the solids content in the filter cake exceeds DS > 40 % the incineration could run without additional external fuel.

The evaluation of bench marking showed, that the Bucher press system achieves the best drainage / dewatering results and the minimum of filter cake for reworking and disposal. The economic analysis showed a short return on investment and the installation of the Bucher system was approved.

The new technology was implemented into the tannery’s infrastructure with the usual minor adaptations which were solved in cooperation with customer’s and supplier’s staff at acceptable cost.