Adsorptive removal of Rhodamine B (dye) using low cost adsorbents

Abstract

Dyes are widely used in several industries like textile, dyeing, paper and pulp, tannery, paint industries etc. and these are emitting to environment in the form of liquid effluent, which is a matter of global concern. Their classification can be done based on their usage, group and solubility. Various treatment processes used for the removal of dyes include adsorption, microbial degradation, wet air oxidation, ion exchange etc. Low cost adsorbents are available option for dyes removal from aqueous effluents. However, high cost of commercial adsorbents like activated carbon and others, material are losses during their usage, but by regeneration pose can be a best utilization of costlier adsorbent. Four different adsorbents were self-prepared in laboratory from Aegle marmelos (Bael) Shell, abrus precatorius seed, azadirachta indica (neem) seed and Mahua seed, which are all raw biomass. The adsorbents were characterized for BET surface area, point of zero charge, CHNS, TGA, SEM, FTIR etc. Rhodamine B (RhB) basic dye, removal from the wastewater using adsorbents, activated mahua seed carbon(AMC) and activated neem seed carbon(ANC) among four self-prepared adsorbents. Here batch studies were conducted to evaluate the effect of adsorbent dose, contact time, pH, initial concentration at 25 0C.The equilibrium adsorption data of RhB (dye) on adsorbent were analysed by the Langmuir, Freundlich and Temkin isotherm models. The isotherm data were well described by the Freundlich isotherm model. Pseudo-first-order, pseudo-second-order models were used to analyze the kinetic data obtained at different concentrations. The adsorption kinetics was well described by the pseudo-second-order kinetic model. For RhB-AMC and RhB-ANC system maximum adsorption capacity were found to 39.683 mg/g and 15.152 mg/g respectively at 650C.Adsorption experiment has carried out to show that maximum adsorption and it observed in acidic medium for AMC and basic medium for ANC.