Development of Sustainable Adsorbent for Cationic Dye Removal: A Fresh Start for Waste Valorization

Abstract

Industrial wastewater treatment has been a serious global issue in recent decades, and waste management necessitates the invention of new, costeffective method. There is a massive demand for potential wastewater purification methods using eco-friendly, low-cost materials. Adsorption is the most affordable, reliable, and quickly operational wastewater treatment method. In the 21st century, a rising demand for environmentally friendly porous geopolymer adsorbents may be produced from industrial waste via the circular economy concept. This work prepares a cost-effective, porous, shaped, waste-based adsorbent to remove cationic dyes from wastewater efficiently. Using the injection solidification process, the geopolymer slurry was injected drop by drop into the PEG-600 medium using a syringe. The bead-shaped adsorbents are then cleaned and dried. Standard techniques (FTIR, XRF, XRD, BET, Raman, ICP-OES, and SEM-EDX) were used to characterize the adsorbents. Geopolymer beads exhibited good adsorption capacity for Methylene Blue (MB), Crystal violet(CV), and Malachite Green(MG), with optimal adsorption capacities reaching 22.60 mg/g, 12.31 mg/g, and 36.67 mg/g, respectively. The adsorption kinetics and isotherm were studied to explain the factors affecting the adsorption mechanism and how the geopolymer's unique ion exchange capabilities generally enabled it to adsorb dyes. After 4 cycles of adsorption tests still beads are stable and efficient to adsorb dyes. The study thoroughly examines the adsorbent features, including the stability, regeneration and desorption process.