Microwave‐Assisted Synthesis of Biopolymer Based Alkali‐Activated Fly Ash Beads for Cationic Dye Removal: A Statistical Physics Modeling Approach

ABSTRACT This study investigates the novel microwave‐assisted synthesis of a Chitosan‐based Alkali Activated Fly Ash (CS@AAFA) composite beads to remove Malachite Green (MG). The synthesized materials were evaluated using FTIR for identifying the presence of functional groups, XRD for elemental composition and crystallinity, FEG‐SEM for micro & nano surface structures and point zero charge. The MG dye removal experiments were conducted with a 617 nm wavelength by UV–Vis spectrophotometer. Adsorption parameters such as initial concentration (50–150 mg L −1 ), contact time (0–150 min), dose (0.5–4 g L −1 ), and pH (2–12) were investigated. The most favorable (91.8%) removal was observed at 27°C, 10 pH and 50 mg L −1 MG concentration at a 2 g L −1 dose of adsorbent. The isotherm, kinetic and statistical physics models indicate Langmuir type physiosorption with multilayer adsorption capacity of 65.1 mg g −1 . The field potential of the adsorbents was investigated through ionic strength and dye mixtures, ensuring the best adsorption onto the CS@AAFA composite surface. The adsorption mechanism suggests electrostatic interaction, hydrogen bonding, π–π stacking, n–π stacking and pore filling. The present investigation provides rapid synthesis and removal of MG dye using synthesized low‐cost adsorbent with potential applicability in wastewater treatment.