Objective
The global leather industry has little knowledge about alternatives to chrome tanning. All scientific solutions for chrome minimising in tannery sewage does not currently reach the low level in chromium contents which is prescribed for chromium derivation.
The aim of the project is to avoid emissions in production processes, to reduce waste, to retain substance quantities and finally to create a closed-loop recycling system for the leather industry.
All the waste water of the company Südleder is composed of three component flows. These are sent to a company, which owns a waste water treatment plant, to be cleaned and pre-treated.
The alkaline component flow is separately collected and fed into the waste water treatment plant by a pressure pipeline with added oxygen. The sulphide oxidation only takes place in this pressure pipeline so that the water flow retains its alkalinity and odour emissions do not occur. The alkalinity of the water can be used to precipitate the chrome in the waste water treatment plant.
The acidic component of the sewage contains chrome and is collected separately to be purified in the treatment plant. After this purification, the chrome is totally separated from the water and recycled. The water returns to the production cycle.
The next step involves an innovative separation of soluble proteins from the desulphurated sewage. It is then treated together with untanned remnant materials of leather manufacturing in a biogas plant where energy can be reclaimed, sludge reduced, and quantities of remnant materials to be recycled are also minimised.
Topic(s)
Data not availableCall for proposal
Data not availableFunding Scheme
CSC - Cost-sharing contractsCoordinator
95111 Rehau
Germany