A process for the manufacture of wet blue chrome tanned hide with no discharge of liquid effluent or toxic solid waste comprises the steps of taking the composite spent liquors obtained from the liming, deliming and pickling operations to an Internal ETP; treating the said composite liquors with a culture of microorganisms, such as herein described, producing bacterial proteases (en/ymes) and bringing the pH to 8 . 5 to 9 . 5. Thereafter, the resultant is recycled for the soaking operation; the spent liquor, obtained after the soaking operation, is evaporated to dryness. The chrome is recovered from the spent liquor, obtained after the chrome tanning and finishing operation, in a CRP, for re-use, the supernatant liquor, after such recovery, being reused for the pickling operation, The wash liquor obtained before deliming and a part of the wash liquor obtained after deliming is taken for carrying out the liming operation. The left over part of the wash liquor obtained after deliming together with tannery spillages and yard cleaning water are taken to an Extemal ETP for treatment and evaporation to dryness. Biogas is generated from the fleshings, by methanisation, to serve as a fuel.
展开▼
