Pages 220–225
Abstract
Research summary supplied by the authors
The pollution of Pretanning operations of tanneries is of high concern. The search of technologies to reduce the consumption, time and cost of chemicals in leather manufacturing process can reduce the environmental impact. Deliming is an important step in beamhouse process sequence that follows the liming operation. During liming, the hides and skins are treated with calcium hydroxide (lime) and sodium sulphide to encourage the fibre swelling, plumping and unhairing, but along with this operation the system is reached in a high pH (typically above 12.5) region. The regular deliming process with Ammonium salts tries to minimize this high alkalinity slowly and steadily, bringing the pH down to a more neutral range suitable for following operations like bating and pickling. The consequence of conventional deliming operation is the production of ammoniacal nitrogen, which is toxic and dangerous for our environment. The application of a carefully selected buffering system, such as sodium acetate and acetic acid, is essential to control the pH and also reduce the pollutional load. Keyword – Elimination of Ammonia – Nitrogen from Beamhouse, Sodium Acetate and Acetic Acid buffer