Preparation of Gelatin from Chrome-tanned Leather Pretreated with Lime Soak

Abstract

A modified method for preparing gelatin from chrome-tanned leather pretreated with lime soak is proposed to improve the polluted sewage from leather industry. After liming for 3days, washing and pH adjustment, the limed leather was subjected to gelatin extraction for 3 h at 70°C. Gelatin was obtained in 40% yield and its quality was good: Viscosity 158 mp, gel strength 415 g, chromium 30∼70 ppm, calcium 0.8∼20. %. The chromium(III)content in the liming solution and wash water was less than 0.1 ppm and chromium(VI) was not detected.