制革废水中的氯离子含量及来源分析

Chloride Ion Content in Wastewaters of Leather Making Processes and Analysis of its Origin

测定了常规牛皮制革工艺中各工序废水中的氯离子浓度,分析了氯离子的分布特点及其来源。结果表明,制革过程每个湿操作工序的废水中都含有氯离子,其中原料皮水洗、预浸水-水洗、主浸水、浸酸和铬鞣-水洗工序废水中氯离子浓度较高。制革废水的氯离子大约60%来源于原料皮的防腐保存用盐,40%来源于浸水和浸酸工序加入的食盐,这些食盐的输入会导致制革综合废水中的氯离子浓度大3 g/L。基于测试结果,提出了削减制革过程氯离子排放的技术建议。

Content of chloride ion in wastewaters of leather making processes was determined, and the distribution and source of chloride ion in the wastewaters were analyzed. The results indicated that all the processing operations in water generated chloride ion containing wastewaters, while the chloride ion content in the wastewaters of raw hide washing, pre- soaking-washing, soaking, pickling, chrome tanning-washing operations were remarkably higher. Approximately, 60% of chloride ion in tannery wastewater came from the salt used for raw hide preservation, and other 40% was introduced in soaking and pickling processes, where about 3% and 7% salt were employed, respectively. The input of salt from these o- rigins led to a high chloride ion concentration in tannery combined wastewater （〉3 g/L）. On the basis of the results, some technologies that may considerably reduce chloride ion concentration in tannery wastewater were suggested.