Comparison of Conventional and Ultrasonic-Assisted Adsorption Processes by Using H3PO4 Activated Cypress Tree Cone for Methylene Blue Removal

Abstract

Recycling agricultural waste, such as corn cobs, tree cones or grape stalks, contributes to converting waste into a new resource by encouraging the development of the circular economy. In this study, colour removal efficiency of H3PO4 activated cypress tree cone (H3PO4-CTC) from Methylene Blue (MB) (C16H18N3SCl) was investigated by using conventional and ultrasonic-assisted adsorption processes. The properties of the prepared H3PO4-CTC adsorbent were obtained by SEM-EDX and FTIR analysis, and the optimum pH and adsorbent dose effect on MB adsorption was determined. Kinetic and isotherm models were presented for conventional and ultrasonic-assisted adsorption processes under optimum conditions. The removal of MB was found favourable at conventional and ultrasonic-assisted adsorption processes. Comparing the Freundlich isotherm, the Langmuir isotherm was also found to fit the experimental data more. According to the Langmuir isotherm, qmax values were obtained as 3.87 and 4.50 mg/g, respectively, by conventional and ultrasonic-assisted adsorption processes. It was also determined that MB removal was over 90% in the first two uses of H3PO4-CTC. In the study, it was observed that H3PO4 activated cypress tree cone could be used as a low-cost adsorbent in MB adsorption, and it was also seen that MB adsorption could be increased with the ultrasonic adsorption process compared to the conventional adsorption process.