Conca Silvia, Gatto Vanessa, Samiolo Riccardo, Giovando Samuele, Cassani Andrea, Tarabra Elisa, Beghetto Valentina
Crossing S.R.L., Viale Della Repubblica 193/B, Treviso, 31100 Italy.
CRCF Srl for Silvateam Spa, Via Torre 7, San Michele Mondovì, 12080 Italy.
Collagen Leather. 2024;6(1):28. doi: 10.1186/s42825-024-00171-9. Epub 2024 Sep 2.
Vegetable tannins are environmentally friendly tanning agents. However, they generally impart a dark colour to the tanned leather and highly contribute to the organic load in wastewaters. In this study, we employed a purification protocol separately on chestnut tannin (CT) and sulfited quebracho tannin (QT) to obtain the purified fractions (PCT and PQT). These samples were characterised by GPC, H NMR, C NMR, FT-IR, and HPLC-DAD techniques and applied for tanning tests. Through the purification process, non-tannin components and smaller molecules such as gallic acid, glucopyranose, and catechin were effectively removed from CT and QT, which consequently led to the reduced moisture content, pH value, and lighter colour of purified fractions. The crust leathers processed with PCT and PQT showed desirable light shades. Moreover, the organic loads in PCT and PQT tanning wastewater were reduced by 13.5% and 19.1%, respectively, when compared to those in traditional CT and QT tanning wastewater. Additionally, the physical and mechanical characteristics of crust leathers processed with PCT and PQT were comparable to those processed with CT and QT. Thus, purification of vegetable tannins may serve as a feasible strategy for producing light-colored vegetable-tanned leather while minimizing organic pollutant discharge during the vegetable tanning process.
The online version contains supplementary material available at 10.1186/s42825-024-00171-9.
植物单宁是环境友好型鞣剂。然而，它们通常会使鞣制后的皮革颜色变深，并对废水中的有机负荷有很大贡献。在本研究中，我们分别对栗木单宁（CT）和亚硫酸化坚木单宁（QT）采用了一种纯化方案，以获得纯化级分（PCT和PQT）。这些样品通过凝胶渗透色谱（GPC）、核磁共振氢谱（¹H NMR）、核磁共振碳谱（¹³C NMR）、傅里叶变换红外光谱（FT-IR）和高效液相色谱-二极管阵列检测（HPLC-DAD）技术进行了表征，并应用于鞣制试验。通过纯化过程，从CT和QT中有效去除了非单宁成分以及小分子，如没食子酸、吡喃葡萄糖和儿茶素，这使得纯化级分的水分含量、pH值降低，颜色变浅。用PCT和PQT处理的坯革呈现出理想的浅色。此外，与传统CT和QT鞣制废水相比，PCT和PQT鞣制废水的有机负荷分别降低了13.5%和19.1%。此外，用PCT和PQT处理的坯革的物理和机械性能与用CT和QT处理的相当。因此，纯化植物单宁可作为一种可行的策略，用于生产浅色植物鞣革，同时在植物鞣制过程中最大限度地减少有机污染物排放。
在线版本包含可在10.1186/s42825-024-00171-9获取的补充材料。
