Cleaner Technology Approach In Leather Pickling Process Using Curing Salt And Sulfonic Acid: In Ase Of Bahir Dar Tannery

Kefale GY, Kassa MM, Fikadu RA and Wodag AF

Published on: 2022-08-20

Abstract

Cleaner technology refers to measures taken to reduce or eliminate at the source of production any pollution. Pickling is a process in leather processing which is used to prepare pelt for tanning by stopping enzymatic bating and adjust acidity and pH or its water content for subsequent process. Sodium chloride is a common salt used during curing for preservation and leather pickling to prevent excessive acidic swelling and finally discharged with in waste water after processing. However, the presence of salt at large amount in the discharge waste water of tanneries highly affects the salinity of the fertile soil which intern reduces the agricultural productivity of the land. Thus, the problem of toxic chloride effluent discharge can be reduced by desalted and purified the curing salt to use it in pickling operation with that of sulphonic acids that creates an eco-friendlier environment. This study was conducted to determine the effectiveness of purified dedusted salt usage in pickling operation with sulphonic acid as a cleaner technology approach. Cured sheep skins were taken by purposive sampling method to generate dusted salt sticking to the skin surface by shaking manually.  The salt generated by desalting is diluted, filtered and treated bactericide with charcoal to remove contaminations and impurities. The study found that the physical properties obtained contain 107, 101, 89, 93, and 105-degree centigrade shrinkage temperature, 80.83, 79.86, 63.88, 67.83 and 71.44 N/mm2 tensile strength, 67.23, 48.26, 45.685, 48.158 and 49.305 N/mm tear strength, and 45.7, 32.5, 23.1, 32.7 and 30.8 (%) of elongation respectively. This showed that the first sample has better physical properties than other experimental samples produced with different proportion purified salt and sulphonic acid. In conclusion, this study found that the pickling with 4% purified salt and 3% sulphonic acid can effectively substitute the conventional method of leather pickling process with creating eco-friendlier environment.