Division 6
United Kingdom
In order to reduce the pollutant load in the waste water before effluent treatment arising from the tanyard process steps, BAT is to use an appropriate combination of the techniques given below.
| Technique | Description | Applicability | |
|---|---|---|---|
| a | The use of short floats | Short floats are reduced amounts of process water. When less water is present, the quantity of process chemicals which is discarded unreacted is reduced. | This technique cannot be applied for the processing of calfskins. Applicability is also limited to:
|
| b | Maximising the uptake of chromium tanning agents | Optimisation of the operating parameters (e.g. pH, float, temperature, time, and drum speed) and the use of chemicals to increase the proportion of the chromium-tanning agent taken up by the hides or skins. | Generally applicable. |
| c | Optimised vegetable-tanning methods | Use of drum tanning for part of the process. Use of pretanning agents to aid penetration of vegetable tannins. | Cannot be applied in the production of vegetable-tanned sole leather. |