Equilibrium and Thermodynamic Studies for the Removal of Anionic Congo Red Dye by Carpobrotus Edulis Plant as Low-Cost Biomaterial

Abstract

Organic synthetic dyes are widely used in textile industry. The presence of dyes in the effluents is a major concern due to their effect on health and environment. Thus, these pollutants must be removed from wastewaters by appropriate treatments before their evacuation. In this regard, much attention has recently been paid to dried plants as low cost biomaterials. In the present study, we aimed to investigate the removal of Congo red dye (CR) from aqueous solutions by Carpobrotus edulis plant as natural adsorbent using batch adsorption technique at room temperature. The effect of contact time, pH, dye concentration, and adsorbent dose on the removal of dye was also studied. The experimental data were analyzed by using mathematical models to determine the thermodynamic parameters. The negative values of free energy change indicated the spontaneous nature of the adsorption and negative value of enthalpy change suggested the exothermic nature of the adsorption process. The characterization of the dried plant was studied by using different methods such as; BET method, SEM‐EDX and Elemental analysis techniques. Overall the results of the present study show that C. edulis plant can be successfully used for removal of anionic textile dyes from industry effluents.