Response surface methodology optimization of dye adsorption by palm fatty acid distillate adsorbent

Abstract This work is aimed to optimize the methylene blue and congo red removal by adsorbent produced by palm fatty acid distillate. The adsorbent was characterized for surface morphology, surface functional groups, elemental composition and textural properties. The adsorption was studied at varying concentrations, contact times, temperatures, and solution pH. The Box-Behnken Design (BBD) combined with the Response Surface Methodology (RSM) was developed on the basis of experimental results to optimize the adsorption conditions. The ANOVA results indicate the high precision of the model to represent the adsorption data as the p-value was < 0.05. Also, the significant R 2 value of greater than 0.9 and large F-value show that the model is valid for the present work The results of the RSM optimization indicate that the optimal conditions to attain a 47.8 mg/g methylene blue capacity are concentration of 100 mg/L, temperature of 70 °C, contact time of 18 h and pH 6, while for congo red, the capacity of 189 mg/g was achieved under the concentration of 300 mg/L, temperature of 70 °C, contact time of 15 h and pH 6. Finally, statistical significance was shown for the linear model, and the current work demonstrates that the adsorbent can be utilized for adsorption of methylene blue and congo red.