Synthesis of mesoporous silica with ricinoleic methyl ester (Ricinus communis) as a template for adsorption copper (II) with optimizing Box-Behnken design

Abstract

Mesoporous silica has been synthesized with ricinoleic methyl ester (Ricinus communis) as a template. Fourier-transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), and N2 adsorption were used to characterize the adsorbent. The Response Surface Methodology (RSM) was used to optimize the adsorption of copper (II). As seen in the results, there was a good correlation between the values found in experiments and the values predicted by the quadratic model (P < 0.05). Increasing the reaction time and adsorbent dosage improved the process efficiency. Using variance analysis (ANOVA) to compare the collected data, the best conditions were found at a pH of 7.22, a concentration of Cu2+ of 57.08 ppm, an adsorbent dose of 0.10 g, and a time of 53.95 min. The Cu2+ adsorption efficiency under these conditions was 82.36%. The percentage removal for Cu2+ adsorption of mesoporous silica with variations of Cu2+ concentration 20 ppm, 30 ppm, 40 ppm, 50 ppm, 60 ppm, 70 ppm, and 80 ppm obtained were 93.00%, 89.33%, 88.60%, 90.00%, 88.70%, 88.74%, and 81.25%. The percentage removal for Cu2+ adsorption of mesoporous silica of Cu2+ concentration 50 ppm with variations time 30 min, 40 min, 50 min, 60 min, 70 min, 80 min, and 90 min were obtained 89.00%, 89.20%, 89.40%, 89.60%, 89.80%, 89.80%, and 89.80%. The Cu2+ adsorption experiment data best fit the Langmuir isotherm model, and the removal followed the pseudo-second-order kinetic model (R2 = 0.99). MSEM-A could absorb the maximum amount of Cu2+ was 87.03 mg/g.

Keywords

• Adsorption
• Copper (II)
• Mesoporous silica
• Surface response methodology