Study of adsorption isotherms and adsorption kinetics of reactive blue 19 dye from aqueous solutions by multi -wall carbon nanotubes

The Colors are classified as complex toxic organic materials, which are considered as the most important pollutants from the textile wastewater. This study aimed to investigate the feasibility of multi-walled carbon nanotubes use as adsorbents for the adsorption of Reactive Blue 19 from aqueous solutions and examined adsorption isotherms and adsorption kinetics. This experimental study was performed discontinuously and studied the effects of the different parameters including contact time, pH, mixing intensity, the initial concentration of the dye, and nanotubes dose on the dye removal of Reactive Blue 19. Experimental data were evaluated with Freundlich and Langmuir isotherm models for adsorption equilibrium and different isotherm models for kinetics of absorption were analyzed by comparing the total number coefficient of samples by the software. The results showed that the maximum adsorption capacity of reactive blue 19 on multi-wall carbon nanotubes was found to be 7.546 mg/gr in optimal condition. The maximum absorbance in the first 60 min was obtained 3 hrs. By increasing the adsorbent dose from 0.04 to 0.08 g on 100 ml at the initial concentration, removal randoman for Reactive Blue 19 solution 25 mg/L, the dye removal efficiency was increased from 69.3% to 89.5%. At the optimized pH 4, optimal contact time 3 hrs, the dye removal efficiency was increased from 80.5% to 89.5% while the initial concentration of color was decreased from 75 to 25 mg/L. Due to the small size, high surface area, regulatory network and Cristal form of unique, high reactivity, and the remarkable function of multi-wall carbon nanotubes as adsorbents for the removal of organic pollutants from water solutions, the results showed that the multi-walled carbon nanotubes are effective adsorbents for the dye removal for reactive blue 19.