<p>The composite of mullite/ZnₓCo₁₋_xFe₂O₄ ferrite, where (x = 0.15, 0.3, 0.45), demonstrates a high efficiency in removing malachite green (MG) dye from aqueous solutions. The experimental studies revealed that the prepared composite adsorbent achieves &gt;90% malachite green removal efficiency under pH 7, composite dosage (0.05 g/L), and contact time 0–80 min. (at 0, 3, 6, 15, 25, 40, 60, 80 min intervals). Characterization via XRD and FTIR confirms the presence of mullite and ferrite in composite samples. The adsorption method was used to study the removal of malachite green dye using mullite and the prepared mullite-ferrite composites at a 50% addition ratio. The results showed an increase in the removal efficiency when ferrite was added to mullite, and this increase was improved by increasing the zinc content in cobalt ferrite. The equilibrium adsorption capacity for mullite and the composites were extracted by studying the MG dye adsorption at different times. A quasi-first- and second-order kinetic model was used to calculate the equilibrium adsorption capacity. Adsorption kinetics follow the pseudo-second-order model, indicating chemisorption-dominated mechanisms. The quasi-second-order kinetic model’s results were in good agreement with the experimental, which indicated that the cobalt zinc ferrite increased in tandem with the adsorption efficiency.</p> Graphical Abstract <p></p>