Full factorial experimental design analysis of reactive dye removal by carbon adsorption

Abstract

The objective of this study was to investigate the removal of Remazol Yellow dye from aqueous solutions by adsorption on activated carbon prepared by chemical activation of sunflower seed cake. It was found that the carbon content of biomass increases up to 65.12% after activation and carbonization processes. The maximum percentage dye removal was obtained as 82.12% with 0.4 g/50 mL adsorbent dosage at 313 K. The Langmuir model showed the best fit with equilibrium isotherm data. The interactions were evaluated with respect to both pseudo-first-order and pseudo-second-order reaction kinetics. The adsorption process was found to follow the pseudo-second-order model. To optimize the operating conditions, the effects of pH, adsorbent dosage, and initial dye concentration were investigated by full factorial experimental design method; adsorbent dosage was found as the most significant factor with P=0.02 lower than 95% confidence level. The obtained results are very promising since (i) the utilization of sunflower seed cake activated carbon (SSCAC) played a critical role in the adsorption of dye; (ii) sunflower seed cake was an intriguing, low-cost, and easily available material. It can be an alternative adsorbent precursor for more expensive adsorbents used for Remazol Yellow (RY) removal. © 2013 N. Özbay et al.