Activated Carbon Aerogel Derived from Durian Rind Endocarp for High-Efficiency Methylene Blue Adsorption

Abstract Transforming agricultural residues into high-value engineering carbon aerogels provides a sustainable strategy for mitigating the environmental burden arising from improper disposal of these wastes. A viable strategy for producing adsorbent materials for wastewater treatment is directly converting biomass into carbon aerogel. This study has successfully produced three-dimensional carbon aerogel (CA-900) from durian rind using a hydrothermal and pyrolysis procedure followed by CO 2 activation at 900 °C. In addition, the ACA-900 exhibited a remarkable adsorption for methylene blue dye (pH 6.88 at 30 °C) and followed a pseudo-second-order model (k 2 = 0.766 g mg −1 min −1 following the chemisorption mechanism. At the same initial concentration (25 ppm), the ACA-900 adsorbs methylene blue rapidly at an equilibrium adsorption capacity of 24.84 mg g −1 in only 15 minutes, while it takes the CA-900 more than 120 minutes to reach equilibrium at 17.18 mg g −1 . The results indicate a viable, sustainable pathway to valorize abundant biowaste into a multifunctional adsorbent material via a nontoxic, environmentally benign fabrication process.