Removal of Dyes from Wastewater by Adsorption Using Modified Boron Enrichment Waste: Thermodynamic Criteria

In this study, Methylene Blue (MB) and Malachite Green (MG) removal from synthetic wastewaters using modified boron enrichment waste by adsorption process were aimed. Boron enrichment waste was modified with acid and ultrasound together. The boron enrichment process waste could be used as an effective adsorbent due to its constituents including ulexite, calcite, dolomite, zeolite and some clays . About 84% MB and 80% MG removal were obtained by modified boron enrichment waste (MBEW) at optimum equilibrium conditions (Contact time: 20-10 min., adsorbent dose: 625-375 mg/L, pH: 11-10, shaking speed: 200 rpm and temperature: 25 0 C) respectively. Besides, the thermodynamic parameters, such as Δ G ◦ , Δ H ◦ and Δ S ◦ were also calculated. Thermodynamic (negative ∆G values) study indicates that the adsorption of dye is feasible, and spontaneous in nature. Thermodynamic study demonstrates the spontaneous and endothermic nature of sorption process due to negative values of free energy change and positive value of enthalpy change, respectively. All the studied results showed that the modified enrichment waste could be used as effective adsorption material for the removal of methylene blue and malachite green from aqueous solutions.