Kinetics, isotherms and thermodynamic modelling of reactive blue 52 and reactive orange 107 dyes from aqueous solution using PANI-CoCl2 as adsorbent

Abstract

In this work decolourisation of organic dyes such as Reactive Blue 52 and Reactive Orange 107 from aqueous solution by PANI-CoCl₂ composite have been studied. Polyaniline (PANI) is a viable conducting polymer because of its unique proton dopability, excellent redox recyclability, chemical stability, variable electrical conductivity, low cost and ease of synthesis. The morphology of PANI-CoCl₂composite have been characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. It is also shown that many factors affected the adsorption rate, such as adsorbent mass, contact time, variation of pH, agitation speed, dye concentration and temperature. The capacity of the adsorbent is tested using recyclability process. Adsorption of Reactive Blue 52 and Reactive Orange 107 by PANI-CoCl₂follows pseudo-second-order kinetics and the best-fit isotherm is the Langmuir model which is confirmed by using correlation coefficients in ANOVA technique. The thermodynamic parameters like changes in free energy, enthalpy and entropy have been also calculated.