Synthesis and Application of Manganese Dioxide Nanoparticles for Removal of Cationic Dyes from Water

In this research, MnO2 nanoparticles were prepared via chemical redox reactions. Then it was used for removal of the cationic dye of malachite green in an equilibrium batch system. SEM and XRD techniques were used for surface morphology and crystallinity characterization. For the determination of optimum adsorption conditions, the effect of different parameters including pH, initial concentration of dye, contact time, temperature, and adsorbent dosage were investigated. Freundlich and Langmuir adsorption isotherms were employed for the treatment of adsorption data and pseudo-first and second-order of kinetics used for kinetics study. The thermodynamic study indicated that the sorption is an endothermic spontaneous process accompanied by disorder increase. It was found that the adsorption data fit well with Pseudo-second order kinetics and the maximum sorption capacity was 275- 280 mg/g. Desorption study also was carried out and the exhausted adsorbent can be easily regenerated for frequent use.