Electrolyte Effects on Hydrolyzed Reactive Dye Binding to Quaternized Cellulose

eactive dyes make up an increas- R ing proportion of the dyes used on r ellulosic fibers by the textile dyeing;;idustry. With 5-60 % of the applied reactive dye ending up in dyehouse wastewater, the need for a cost effec-tive color removal process is essential.' Reactive dyes pose a particularly dif-ficult problem because of their high water solubility and resistance to bio-1 og i cal an d c h em i cal d egra da t i on. 'J Reactive dyes are typically applied in-:~lutions of high salt concentration r; i i t l at high pH. adding to tlic trcatnicnt problem. Ion cxc:liangc: systcms havc: h t t m dismisstd or ignorctd as ii v i i i b l c toc:h-nology for t l l c trctatmttnt of ' tlyo-con-taining c:ffluc:nts, perhaps I)i:c:ausc! i t is thought that ion oxc:hangt!rs muld not accomodalc tlic uridcly tfivwsc: d!~c:s L SSTRACT The presence of fiber-reactive dye hydrolysis products in dyehouse effluents poses a difficult wastewater treatment problem. Although conventional ion-exchange resins can be used to remediate reactive dye-containing effluents, regeneration of resin exchange capacity can require the use of cqanic solvents, substantially increasing the cost of the treatment process. This study shows that quaternized cellulose can remove reactive dye hydrolysis products from effluent, largely unhindered by typical dyebath concentrations of electrolytes. Furthermore, the dye adsorption capacity of the quaternized cellulose can be regenerated by base treatment {aqueous NaOH). Quaternized cellulose offers economic advantages over other ion-exchange systems in decolorization of dyehouse wastewater