Equilibrium, kinetic and thermodynamic studies of congo red biosorption from textile wastewater using spathodea campanulata leaves

Abstract

The aim of the present study is to remove Congo red (CR) dye from their Textile wastewater using Spathodea campanulata leaves powder as biosorbent in a batch study. The variables covered in a batch study were contact time, solution pH, initial CR dye concentration, biosorbent dosage, the average particle size of the biosorbent and temperature. The kinetic and isotherm studies of biosorption of CR dye onto Spathodea campanulata biosorbent was investigated using various kinetic pseudo-first-order, pseudo-second-order and isotherm models (Langmuir, Freundlich, Temkin). The experimental data of biosorption of the dye onto the Spathodea Campanulata biosorbent fitted well with the Langmuir isotherm model. The isotherm reveals that the biosorption of the dye onto Spathodea Campanulata biosorbent was favorable. Thermodynamic parameters such as Gibbs free energy, enthalpy change and entropy change were also estimated for the biosorption of CR dye. The thermodynamic studies indicated that the biosorption of Congo red dye onto Spathodea campanulata biosorbent was spontaneous, feasible and endothermic.