Application of oxidized multiwall carbon nanotubes as a novel adsorbent for removal of Acid Red 18 dyefrom aqueous solution

Synthetic dyes are widely used in various industries. Discharging waste water containing dyes causes serious environmental problems because of its high toxicity and possible accumulation in the environment. The present work focuses on removal of anionic dye (Acid Red 18) by oxidized multiwall carbon nanotubes (o-MWCNT) from aqueous solution. In this experimental study the effect of various parameters such as contact time, solution pH, adsorbent dosage and initial dye concentration were studied. The final dye concentration was read by UV–Vis spectroscopy at maximum wavelength 506 nm. Adsorption data were analyzed using Langmuir, Freundlich and Temkin adsorption isotherms. the results of this study showed that, by increasing contact time and adsorbent dosage dye removal percentage increases but by increasing solution pH and initial dye concentration dye removal percentage decrease. The adsorption of Acid Red 18 dye complies with Langmuir isotherm (R2= 0.995) model. The results of this study indicate that oxidized multiwall carbon nanotubes can be used as an effective adsorbent for the removal of dyes.