Mengistu Ashagrie, Angassa Kenatu, Tessema Israel, Andualem Getaneh, Yiheyes Bereket, Berhane Daniel, Abewaa Mikiyas, Kassie Mulat, Telay Berhanu
The Federal Democratic Republic of Ethiopia Manufacturing Industry Development Institute, P.O. Box 1180, Addis Ababa, Ethiopia.
Department of Environmental Engineering, College of Biological and Chemical Engineering, Sustainable Energy Center of Excellence, Addis Ababa Science, and Technology University, P.O. Box 16417, Addis Ababa, Ethiopia.
Heliyon. 2024 Jul 3;10(13):e34049. doi: 10.1016/j.heliyon.2024.e34049. eCollection 2024 Jul 15.
Hair burning unhairing and dampening of tannery wastes during the hair-saving unhairing process are becoming significant problems in the tanning industry. Therefore, this research article focuses on the extraction of keratin hydrolysate (KH) and its application as a chrome exhaust aid and keratin filler in leather manufacturing process. The structure, morphology and functional groups of the extract were examined using X-Ray Diffractometer (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectrometer (FTIR), respectively. To study and contrast the degree of improvement in chromium uptake, the KH solution was applied both before tanning on the pickled pelt and after tanning during basification. The thermal stability, physical strength characteristics and organoleptic properties of the leathers obtained were characterized. Furthermore, the environmental impact of the tanning system was assessed through a comparative analysis of the spent liquors. Finally, experimental retanning process was conducted to replace the commercial protein filler (Celatan F: 50, 75, and 100 %) with KH solution, with concurrent processing of control leather using conventional chrome tanning agent at 6 % dosage of chromium. The FTIR analysis of the extract confirmed the presence of alkyl side chains of amino acids as well as carboxylic, amide, carboxyl group and aldehyde functional groups at 1400-1700 cm,3,303.46 cm,3270 cm and 2752 cm, respectively. XRD spectrum showed two diffraction peaks at 2 theta values of 9.36° and 21.16°, respectively. Leathers with improved mechanical strength, organoleptic properties and thermal stability were obtained with 100 % substitution of Celatan F at pH 6 and 10 % chromium dosage. It was also discovered that the shrinkage temperature of the experimental leather was enhanced to more than 105 °C. Environmental impact evaluation on the spent liquor showed that the complete replacement of Celatan F with KH solution brought about a notable decrease in COD and TDS in the spent liquor. The extraction and application of tannery hair waste-based keratin hydrolysate as an efficient, environmentally friendly chrome exhaust aid and keratin filler has been attempted and established in this research article.
在保毛脱毛过程中，制革废弃物的毛发燃烧、脱毛及润湿性问题正成为制革行业的重大难题。因此，本文着重研究角蛋白水解物（KH）的提取及其在皮革制造过程中作为铬鞣废液助剂和角蛋白填充剂的应用。分别使用X射线衍射仪（XRD）、扫描电子显微镜（SEM）和傅里叶变换红外光谱仪（FTIR）对提取物的结构、形态和官能团进行了检测。为研究和对比铬吸收的改善程度，KH溶液在鞣制前应用于浸酸皮，在碱化过程中应用于鞣制后。对所得皮革的热稳定性、物理强度特性和感官性能进行了表征。此外，通过对废液的对比分析评估了鞣制系统对环境的影响。最后，进行了实验复鞣工艺，用KH溶液替代商业蛋白填充剂（Celatan F：50%、75%和100%），同时使用6%铬用量的传统铬鞣剂对对照皮革进行处理。提取物的FTIR分析证实，在1400 - 1700 cm、3303.46 cm、3270 cm和2752 cm处分别存在氨基酸的烷基侧链以及羧基、酰胺基、羰基和醛基官能团。XRD谱图在2θ值分别为9.36°和21.16°处显示出两个衍射峰。在pH值为6和铬用量为10%的条件下，用100%的Celatan F替代后，获得了机械强度、感官性能和热稳定性得到改善的皮革。还发现实验皮革的收缩温度提高到了105℃以上。对废液的环境影响评估表明，用KH溶液完全替代Celatan F可使废液中的化学需氧量（COD）和总溶解固体（TDS）显著降低。本文尝试并确立了以制革毛发废弃物为基础提取角蛋白水解物，并将其作为一种高效、环保的铬鞣废液助剂和角蛋白填充剂的方法。
