Batch and fixed bed adsorption study for the removal of Drimarine Black CL-B dye from aqueous solution using a lignocellulosic waste: A cost affective adsorbent

The present study investigated the removal of Drimarine Black CL-B dye from aqueous solution using untreated, hydrochloric acid treated and immobilized peanut husk. Batch studies were conducted for equilibrium, kinetic and thermodynamic modeling on the removal of Drimarine Black CL-B dye. The operating variables studied were initial dye concentration, biomass dose, contact time, solution pH and temperature. Results showed that the pH value of 1 was favorable for the maximum removal of the dye. The biosorption data have been analyzed using Langmuir, Freundlich, Dubinin-Radushkevich (D-R), Temkin and Harkins Jura isotherms. The isothermal data for biosorption followed the Langmuir model for untreated; hydrochloric acid treated and immobilized peanut biomass. The kinetic data followed the pseudo-second-order kinetic model for untreated, hydrochloric acid treated and immobilized peanut husk. Thermodynamic parameters like enthalpy, entropy and Gibbs free energy changes were also calculated and it was observed that the biosorption of Drimarine Black CL-B dye on untreated, hydrochloric acid treated and immobilized peanut husk was a spontaneous process. Breakthrough capacities were also investigated in column mode. Effect of bed height, flow rate and initial dye concentration were investigated in column study. Thomas and Bed Depth Service Time (BDST) models were also applied on the experimental data. FT-IR study was done to get information about the presence of different functional groups like hydroxyl, carboxyl and amino on the surface of peanut husk. The results indicated that peanut husk could be used to treat dye containing effluents.