制革厂固、液副产物的处理

制革工艺将原料皮变成革,属于典型的工业领域,在工艺处理过程中要考虑产生的固、液副产物对环境尤其是水和土壤的污染。制革的固、液副产物分别是铬屑和含铬废液。为了减少蛋白原料的损失以及降低循环废液铬复合物的含量,循环的固体副产物(铬屑)通过酶水解可以达到既经济又环保的处理过程。产生的溶于水的水解产物,可以作为肥料的有效成份、涂层材料以及用于胶粘剂混合物中的添加剂、耐腐蚀的材料等。液体副产物(鞣液)中的有用固体残留物,通过酶水解,可以降低废液中的铬含量。去铬要求废液中的铬吸附在铬泥上,这种处理方法高效、简单,投资少,并且去铬液对环境的危害也小得多。

TREATMENT OF SOLID AND LIQUID TANNERY BY-PRODUCTS

The tanningindustry processes raw hides and converts theminto leather.The tanningindustry belongs to typical industrial branches which during the technological process produceconsiderable quantities of liquid and solid by-products contributing to polluting the environment,particularly water and soil.The solid tanned by-products contain chromiumand by-product liq-uors contain residual chromium.In order to prevent loss of protein material and chrome com-pounds were focused on recycling liquid and solid by-products.Recycling of solid by-products(chrome-tanned leather shavings) was realizedthrough enzymatic hydrolysis whichis an econom-ically and ecologically acceptable process.Water soluble hydrolysate is thus produced,usable asfertilizer components,coating material,as an additive into adhesives mixtures,corrosioninhibi-tor etc.Recycling of liquid by-products(spent tanning liquors) utilizes solid residue,producedthrough enzymatic hydrolysis of chrome-tanned leather shavings,to reduce chromiumcontent inliquor.The principle of dechromation consists in sorption of chrome fromspent liquor to chromesludge andis characterized by very high efficiency,si mplicity and lowinvest ment requirements.Dechromed liquor poses a muchless hazard for the environment.