Abstract

Carboxylated collagen fibre (CCF) was prepared using glyoxylic acid modified collagen fibre which was extracted from fresh pigskin, the prepared CCF was used as an adsorbent to treat trivalent chromium ions (Cr(III)) in wastewater (Cr-CCF). Alkali-enzyme hydrolysis was used to extract collagen protein from the CCF after the adsorption of Cr(III) to obtain chromium-containing collagen hydrolyzate (Cr-CCH). Fourier transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC) were employed to analyse the structure and relative molecular mass distribution of the collagen in Cr- CCH. The Cr(III) content was determined by diphenylcarbazide spectrophotometry. The optimal hydrolysis conditions were optimised by single factor experiments with the collagen extraction rate as the index. Finally, sheep and sturgeon wet-blue was chosen to evaluate the retanning efficiency of Cr- CCH. The satisfactory sensory and mechanical properties of the finished leather demonstrated that Cr-CCHcou ld become a good candidate as a retanning agent, which not only satisfied performance requirements for finished leather, but also achieved recycling of resources.