STATISTICAL DESIGN FOR THE REMOVAL OF BASIC RED 46 USING REGENERATED FULLER EARTH AS AN ALTERNATIVE MATERIAL STATISTICAL DESIGN FOR THE REMOVAL OF BASIC RED 46 USING REGENERATED FULLER EARTH AS AN ALTERNATIVE MATERIAL

Abstract

Several non-conventional materials have been evaluated in recent years as adsorbents for the treatment of colored effluents from the textile industry. Fuller's earth (FE), which is composed of various minerals, has shown a high capacity for removal of different cationic dyes. However, basic red 46 (RB46), widely used in dyeing processes, has not been studied on this material. In this study, we evaluated the best conditions for achieving the greatest removal of RB46 on FE through a statistical design of experiments using the batch system. The variables analyzed were adsorbent dosage, dye concentration, and contact time. The final concentration of the dye was quantified by UV-Vis spectrophotometry. A 23 factorial design and its further optimization through a central composite surface design allowed us to achieve a maximum removal of 99.07% at a concentration of 35.0 mgL-1, a dosage of 1.1 gL-1, and a contact time of 8h with an adjusted correlation coefficient of 96.79%. FE is an excellent material for RB46 removal since it requires a lower dosage for high concentrations of the dye compared with dosages reported for other adsorbents.