Decolorization of BF Cibacete Blue (CB) and Red Solophenyle 3BL (RS) Using Aluminum Sulfate and Ferric Chloride

Abstract

Coagulation process is largely applied for dye removal from textile wastewater treatment. This research aims to focus on implied mechanisms through coagulation of such wastewater. In this work, jar tests are performed to assess the coagulation process as a technique to treat synthetic solutions containing two textile dyes: BF cibacete blue (CB) and red solophenyle 3BL (RS). The effects of operational parameters such as coagulant type (FeCl3 and Al2 (SO4)3. 18H2O (alum)) and dose, initial pH, and dye concentration are studied. For a fixed 15 mg/L concentration of the two dyes, the FeCl3 optimal doses are found to 80 and 20 mg/L for RS and CB with removal rates of 65 and 89%, respectively. Regarding alum, discoloration is achieved at 44 and 77% for CB and RS with optimal doses of 80 and 40 mg/L, respectively. Similar efficiency trends are also obtained for a 50 mg/L concentration of the two dyes. The involved coagulation mechanisms are: charge neutralization followed by precipitation of the insoluble dye-coagulant complexes, and their adsorption into the Al or Fe hydroxides. It would be interesting to follow a real effluent application on the textile industry possibly containing the two dyes tested in this work.