Adsorption of Rhodamine B Dye on Elaeis guineensis Frond Fiber

Abstract

Adsorption of Rhodamine B (RB) dye was investigated using raw Elaeis guineensis frond fiber (EGFF). Experiments were performed using face centered composite statistical design with six input parameters namely pH (2-10), agitation speed (150-300 rpm), initial dye concentration (100-500 mg/L), temperature (27-80°C), contact time (10-40 min), and adsorbent dosage (0.5-1.5 g). Particle size of < 45 μm was taken as a fixed input parameter. Regression analysis showed good fit of the experimental data to the second-order polynomial model with coefficient of determination (R2) value of 0.99 and 0.98 for color removal and chemical oxygen demand (COD) reduction, respectively. Two optimum operating conditions for the adsorption of RB were found using RSM, resulted in > 99% of color removal and > 97% of COD reduction. The adsorption process was rapid and fitted to the pseudo-second-order kinetic model, while equilibrium data were favorably described by the Langmuir isotherm. The adsorbent showed excellent reusability with 0.1 M NaOH solution as desorbing agent. The findings make EGFF a promising and low-cost adsorbent for the removal of RB from aqueous solutions.