The Journal of

Introduction: Dye effluents of some industries include many toxic, carcinogenic, and mutagenic compounds; therefore, colored contaminants of such industries should be carefully treated using an appropriate method before discharging wastewater to the environment. This study aimed to evaluate the performance of Multi-Walled Carbon Nanotubes (MWCNT_S) as an effective adsorbent in removing Acid Black 1 (AB1) from colored wastewater.

Methods: This laboratory study was conducted in the batch system and MWCNT_S was used as an adsorbent to remove AB1 dye. The effect of various factors influencing dye removal, such as adsorbent dose, initial dye concentration, contact time, and pH investigated in this study.

Results: The results showed that pH=3 was the best pH for dye removal and the equilibrium time for AB1 dye adsorption on MWCNT_S was 60 minutes. As dye concentration increased, dye removal rate decreased. Besides, increasing the amount of adsorbent increased the dye removal efficiency and at the adsorbent dose of 600 mg/L, dye removal efficiency was 98.86% and 94.62% for 30 and 50 mg/L dye concentrations, respectively. Also, AB1 dye removal followed Langmuir isotherm and Pseudo-second-order kinetic models.

Conclusion: The results of adsorption studies showed that by increasing the contact time and the adsorbent dose and reducing the pH, dye removal efficiency was also increased. In addition, MWCNT_S could be used as an efficient adsorbent for decolorization of azo dyes from wastewater.