Removal of Cibacron Brilliant Yellow 3G-P Dye from Aqueous Solutions Using Coffee Husks as Non-Conventional Low-Cost Sorbent

The purpose of this research is to establish the experimental conditions for removal of Cibacron Brilliant Yellow 3G-P dye (CBY) from aqueous solutions by sorption onto coffee husks as a low-cost sorbent. The effects of various experimental parameters (e.g. initial CBY dye concentration, sorbent mass, pH, temperature) were examined and the optimal experimental conditions were determined. The results indicated that the removal of the dye was pH dependent and at initial pH of 2, the dye was removed effectively. The CBY dye sorption data were fitted to Langmuir, Freundlich, Temkin and Dubinin-Radushkevich equilibrium models. The maximum sorption capacity of CBY dye ions onto coffee husks increased from 24.04 to 35.04 mg g when the temperature was increased from 293 to 313 K. The calculated sorption thermodynamic parameters including ΔG, ΔH, and ΔS indicated that the CBY dye sorption onto coffee husks is a spontaneous, endothermic and mainly physical in nature. Keywords—Coffee husks, equilibrium, reactive dyes, sorption.