DESALINATION AND WATER TREATMENT, cilt.54, ss.2023-2035, 2015 (SCI-Expanded)
The dye sorption of Basic Yellow 28 (BY 28) in an adsorption process was optimized by varying three independent factors (initial pH, temperature, and ionic strength) using a central composite design, which is an experimental design that is useful in response surface methodology. The quantitative relationship was measured between the amount of the adsorbed dye (q, mg g(-1)) and the economical adsorbent, sepiolite, and the effect of initial pH, temperature, and ionic strength on the adsorption process was evaluated using the quadratic model. The model adequacy was tested by the analysis of variance, and the model was shown to be highly significant. The model showed that each of the independent factors was significant at the 5% significance level, revealing that the dye adsorption in the aqueous solution was affected by all three factors that were studied. The predicted maximum amount of adsorbed dye (31.54 mg g(-1)) was found using a solution pH of 6, a temperature of 25 degrees C, and an ionic strength of 0.00 mol L-1 within 30 min of contact time with the sepiolite. The activation energy was 19.11 J mol(-1) for the adsorbed dye onto the sepiolite. The pseudo-second-order kinetic model appears to be the most efficient in describing the adsorption kinetics that were obtained from 20 to 60 degrees C.