Application of polyaniline impregnated mixed phase Fe2O3, MnFe2O4 and ZrO2 nanocomposite for rapid abatement of binary dyes from aqua matrix: response surface optimisation

Abstract

ABSTRACT Wastewater loaded with toxic dyes causes serious environmental problems because of their high toxicity and needs to be treated before their disposal. In this research, mixed phase of Fe2O3, MnFe2O4 and ZrO2 nanocomposite was impregnated onto polyaniline to prepare a new nanocomposite (Fe-Mn-Zr/PANI-NC). The produced nanocomposite was utilised to adsorb methyl orange (MO) and eosin yellow (EY) dyes from binary dye solution. The response surface methodology (RSM) based optimisation showed that MO and EY dyes can be removed with ~98% efficiency under optimal experimental conditions. The adsorption process was quick in the wide solution pH range from 2.0 to 5.0 and the equilibrium was achieved within 5 min of reaction at solution pH 5.0. The adsorption process was mainly driven by strong electrostatic attraction and π-π interaction between dye molecules and Fe-Mn-Zr/PANI-NC. Kinetic study reveals the applicability of the pseudo-second-order and intra-particle diffusion model and the maximal adsorption capacity of Fe-Mn-Zr/PANI-NC was computed using the Langmuir isotherm model and found to be 217.39 mg/g for MO dye and 117.65 mg/g for EY dye. Therefore it can be concluded that Fe-Mn-Zr/PANI-NC can be a potential adsorbent for MO and EY dye remediation from wastewater due to high adsorption capacity, short equilibrium time, high reusability and adsorption favourability in a wide range of solution pH.