Investigation of Reactive Blue 21 Dye Removal Using Multi-Wall Carbon Nanotubes: Isotherm and Kinetics

Objectives: Increasing use of colored materials in various industries and their discharge into the environment through industrial wastewater, can create many problems for humans and other beings. In the present study, the effect of removing Reactive Blue 21 (RB 21) dye using Multi-Wall Carbon Nanotubes (MWCNTs) as adsorbent is studied.Materials & Methods: The research was carried out on a laboratory scale and in a discontinuous system. Factors affecting dye removal such as pH, adsorption dose, concentration of dye and contact time were investigated. Also two Langmuir and Freundlich isotherms were studied in different concentrations of dye. UV-visible spectrophotometer was used to determine the dye removal. It should be noted that all experiments were carried out at 25°C.Results: Regarding the results in an environment with pH=3, in 30 minutes time, with 0.05 g/L of adsorbent (MWCNTs) to remove 50 mL of RB 21 dye with a concentration of 40 ppm, the best adsorption and maximum dye removal was obtained as 81%.Conclusion: According to the results of the experiments, it was found that MWCNTs are very suitable for comparison with other synthetic adsorbents used to remove RB 21 dye.