Removal of Congo red and Rhodamine B dyes from aqueous solution by raw Sarolangun bentonite: Kinetics, equilibrium and thermodynamic studies

Water pollution due to the existence of colored substance in the waterbody has become a major environmental issue nowadays. In this work, the raw bentonite grounded from Sarolangun has been utilized as a natural abundant adsorbent material for removal of Congo red and Rhodamine B dye from aqueous solution. The raw bentonite was characterized by XRD, FT-IR, and XRF. The results showed that the raw bentonite was mainly composed of montmorillonite mineral. The effect of some operational parameters including contact time, initial dye concentration, and temperature. The kinetics, equilibrium, and thermodynamic adsorption was also systematically investigated. The results indicated that the adsorption of both Congo red and Rhodamine B on the raw bentonite was best fitted with pseudo-second-order kinetics model. The adsorption isotherm study indicated that the adsorption process was well described by Freundlich isotherm model, and the adsorption thermodynamic investigation revealed that the adsorption process of the both dyes was spontaneous and an exothermic process. These finding showed that the raw Sarolangun bentonite has promising properties to be a good low-cost adsorbent for dyes removal.Water pollution due to the existence of colored substance in the waterbody has become a major environmental issue nowadays. In this work, the raw bentonite grounded from Sarolangun has been utilized as a natural abundant adsorbent material for removal of Congo red and Rhodamine B dye from aqueous solution. The raw bentonite was characterized by XRD, FT-IR, and XRF. The results showed that the raw bentonite was mainly composed of montmorillonite mineral. The effect of some operational parameters including contact time, initial dye concentration, and temperature. The kinetics, equilibrium, and thermodynamic adsorption was also systematically investigated. The results indicated that the adsorption of both Congo red and Rhodamine B on the raw bentonite was best fitted with pseudo-second-order kinetics model. The adsorption isotherm study indicated that the adsorption process was well described by Freundlich isotherm model, and the adsorption thermodynamic investigation revealed that the adsorption process of ...