acid violet 17 dye decolorization by multi-walled carbon nanotubes from aqueous solution

Background: dyes can cause many problems in environment. therefore, removal of these contaminants before discharging wastewater to environment can reduce the environmental hazards. adsorption is one of the usual processes for decolorizing from wastewater. nanotubes are new adsorbents that can adsorb different compounds. this work aimed to investigate acid violet 17 dye removal by adsorption using multiwalled carbon nanotubes as adsorbent from aqueous solution.methods: this experimental study was conducted in the batch mode and to investigate effects of parameters such as contact time, initial concentration of dye, ph and multiwalled carbon nanotubes dose on decolorization process.results: results showed that the maximum dye decolorization was achieved in 3 hours. with increasing adsorbent dose, the removal efficiency was increased up to 95.9%. it was found that the maximum adsorption capacity of multiwalled carbon nanotubes occurred in acidic ph conditions. with decreasing the initial concentration of dye, removal efficiency increase up to 83.4%. adsorption equations were described by freundlich isotherm and pseudosecond order kinetic.conclusion: the optimal conditions for decolorization efficiency ware equilibrium time of 3 hours, ph of 4, and nanotube dose of 0.4 g /l. the high r2 value of greater than 0.90 obtained showed that the experimental data agreed well with freundlich isotherm and pseudosecond order kinetic models.