Untreated clay with high adsorption capacity for effective removal of C.I. Acid Red 88 from aqueous solutions: Batch and dynamic flow mode studies

Batch and dynamic flow adsorption studies were carried out using natural clay for the removal of Acid Red 88 (AR88) dye from aqueous solutions. Adsorption conditions were examined with respect to initial pH, adsorbent amount, contact time, initial dye concentration, column i.d. and flow rate. Adsorption process was better described by the pseudo-second-order kinetic and Langmuir isotherm models. SEM and zeta potential analysis were used to characterize the adsorbent material. 98.10 +/- 0.34% of dye could be removed in 15 min at pH 2.0 in the batch mode. The adsorbent exhibits very high rnonolayer dye binding capacity of 1133.10 mg g(-1) which was comparable to or higher than those of many sorbent materials. Our results indicate that the suggested natural and low-cost adsorbent material may be useful for the effective removal of contaminating acid dyes. (C) 2010 Elsevier B.V. All rights reserved.