制革污泥生物淋滤液组份特征及对鞣革质量的影响

Components in bioleachate from tannery sludge and their effects on leather quality

利用ICP-AES、FT-IR及凝胶色谱等测定方法对制革污泥生物淋滤液的成分进行了系统分析,并采用鞣制试验对淋滤液在浸酸、铬鞣中的应用进行了尝试.研究结果表明,制革污泥生物淋滤液含有较高浓度的Cr3+、Fe3+、Ca2+、Na+、Mg2+、K+离子及其它一些微量金属,对鞣革质量产生明显影响的主要是Fe3+离子;鞣革质量的降低主要表现在无鞣性金属离子在蓝皮中的富集,从而影响蓝皮的吸铬量;鞣制处理中仅仅通过pH调整难以达到不同金属间的分离.淋滤液中可溶性有机物的TOC浓度一般低于1000mg·L-1,主要是多糖类、脂肪族或芳香族羧酸类化合物;废水和淋滤液中DOM的平均分子量主要分布在1923和147两个范围,其质量分数分别占74.1%和25.7%;可溶性有机物一般对鞣革的收缩温度Ts和铬含量不产生明显影响,但可导致鞣后皮色加深.

The components of bioleaehate derived from tannery sludge were analyzed by the methods of ICP-AES, FT-IR and gel chromatogram, etc. The experiments were then conducted to explore the application of the bioleachate in picking and tanning processes of tannery industry. The results showed that the bioleachate contained high level of Cr^3＋ , Fe^3＋ , Ca^2＋ , Na^＋ , Mg^2＋ , K^＋ and low concentrations of trace metals. Fe^3＋ and other metal ions, which have little tanning capability, were taken in the hide when Cr^3＋ was absorbed during tanning process and affected obviously the hide quality. It was difficult to make a complete separation among these metals just by adjusting pH during the picking and tanning process. The dissolved organic matter （DOM） in the bioleachate was composed of amylose, acyclic and aromatic carboxylic acid etc. And they could be mainly divided into two groups, with an average molecular weight and the content equal to 1923,147 and 74.1% , 25 % , respectively. The TOC value was detected to be less than 1000mg·L^-1. Generally, DOM have little effect on the Ts （shrinkage temperature） and Cr absorption, but it will darken the tanned hides.