牛仔布染色废水中的靛蓝回收技术研究

文章研究了从牛仔布染色废水中回收靛蓝染料的方法。取自常州某印染厂的染色废水中,其靛蓝含量为249.6mg/L。经预处理-晶体再析-膜回收处理工艺,成功的回收了废水中的靛蓝染料。首先通过显微镜观察、统计废水中的纤维和颗粒大小,选用聚丙烯无纺布PP25预处理,过滤除去废水中的纤维及大颗粒杂质;然后加酸调节pH值至6,鼓空气氧化30min,将隐色体靛蓝氧化为氧化态的固体靛蓝析出,后调pH至4,有效削弱表面活性剂的增溶作用,实现靛蓝晶体再析,同时破坏废水中的胶体物质,减轻后续分离过程中对膜的污染;处理过后的靛蓝染色废水经PE微滤膜过滤,靛蓝染料可全部截留。膜孔径0.2μm,所得靛蓝含量达50.17%,出水在660nm波长下的吸光度为0.02,色度、浊度分别降低99.2%和99.5%,COD去除率达80.6%。该工艺回收靛蓝染料的同时,废水水质有很大程度的改善,减轻了废水的后处理负担。

Reclaiming Indigo from Dyeing Effluents of Jean-cloth Production

Dyeing wastewater samples from a jean-cloth manufacturing factory are treated in a laboratory scale with a purpose to reclaim indigo from the wastewater. The wastewater, with indigo concentration of 249.6mg/L, has been processed through pretreatment of filtration to remove fiber and other particles, and then crystallization of indigo blue and finally using micro-filtration to recover indigo dye. PE membrane micro-filtration, pore size of 0.2μm, used in the experiment can almost completely recover the dye with 50.17% of indigo crystals content in the filter cake. As to the wastewater, pollution parameters in terms of colority, turbidity and COD decrease by 99.2%, 99.5 and 80.6% respectively.