Background: The presence of quantities of dye chemicals in the textile industry effluent is clearly visible and harmful environmental impacts caused by chemical compounds are also as a noticeable challenge. Regarding this issue, control of the pollution has been considered.
Methods: In this study, an absorbent of Sodium Montmorillonite modified by Methylene Blue dye was used to remove Brilliant Red dye from the textile effluent. All batch experiments were carried out in 250mL of solution of 640 mg/L Methylene Blue with 2g of adsorbent and performed on a shaker with a shaking of 120 rpm; the precipitate was placed in an oven at 60◦C for 24 hours. The effective parameters on the adsorption including: pH, absorbance dose, dye concentration and contact time were optimized by using both one factor at a time technique and Central Composite Design method by designing 30 experiments with four variables (n= 4) and two levels (low (-) and high (+)).
Results: The optimal values of the influencing parameters such as pH, absorbance dose, dye concentration and contact time were determined at 6, 0.3 g, 80 mg/L and 60 min with an approximate 92% removal percentage, respectively. The results illustrated that the process was more consistent with Langmuir adsorption isotherm and pseudo-second kinetics equation.
Conclusion: The adsorption behaviors of the modified absorbent showed that the adsorption kinetics and isotherms were in good agreement with pseudo-second-order equation and the Langmuir equation, respectively. The potential for regeneration and reuse of the modified absorbent was proved by the desorption studies.