Design and synthesis of Zn0.3Fe0.45O3 nanoparticle for efficient removal of Congo red dye and its kinetic and isotherm investigation

Abstract

Zn0.3Fe0.45O3 bimetallic oxide nanoparticle (ZnFeBONp) was synthesized and characterized by FESEM, EDS, XRD, BET, TEM and FT-IR techniques with the aim of exploring its application for removing of Congo red dye from waste samples. The effects of pH, contact time, adsorbent dosage and dye concentration on the removal of dye were investigated and optimized as pH 6.5, 40 min contact time, 0.2 g adsorbent dose for 20 ppm dye. Results indicated that the synthesized adsorbent could effectively remove high concentrations of dye in a short contact time. Isotherm modeling revealed that the Langmuir isotherm could better describe the adsorption of the dye on the ZnFeBONp as compared to other models. The qmax up to 333.33 mg g−1. The results showed that the adsorption system followed the Ho and McKay equations for the entire adsorption. Kinetics of Congo red adsorption on ZnFeBONp best fit with the pseudo-second-order model. Because of the high-specific surface area and nano-scale particle size, ZnFeBONp indicated favorable adsorption behavior for dye.