Investigation of rice husk-derived activated carbon and its application

Abstract

Activated carbon derived, which is used for the adsorption of the organic dye methylene blue (MB) was synthesised from rice husk through a carbonisation process, followed by activation using sodium hydroxide (NaOH) at varying concentrations, complemented by treatments with nitric acid and citric acid to enhance porosity and increase the surface area. Characterisation via Scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) analysis revealed a significant increase in surface area from 55.47 to 300.20 m²/g after the activation process. Fourier transform infrared spectroscopy (FT-IR) analysis demonstrated pronounced absorption bands in the 2000 to 400 cm^-¹ range, indicative of the functional groups characteristic of activated carbon. The MB adsorption efficiency of the derived material was influenced by the NaOH concentration utilised during activation, in addition to the pH and initial MB concentration in the solution. The sample activated with 0.3 M NaOH and with citric acid exhibited the greatest adsorption capacity, achieving up to 200 mg/g for MB. These findings highlight the material's potential applicability as a highly effective adsorbent for removing organic dye MB in textile wastewater treatment processes.