Using Carbon Nanotubes to Remove Benzene and Toluene from Aqueous Solutions

The removal of ethylbenzene and xylene at a concentration of 10 mg/l from aqueous solutions by single- and multi-walled carbon nanotubes (SWCNT and MWCNT, respectively) and hybrid carbon nanotubes (HCNT) was evaluated at a nanomaterials dose of 1 g/l, a contact time of 10 minutes, and a pH 7. Synthetic samples were analyzed by gas chromatography/mass spectrometry (GC/MS). In order to analyze the data, design of experiment (DOE) was applied. The equilibrium amounts (qe) (mg/g) using SWCNT (ethylbenzene: 9.97 mg/g and xylene: 10 mg/g) were higher than using MWCNT and HCNT. Xylene was adsorbed more than ethylbenzene due to its better water solubility and lower molecular weight. It is concluded that recycling by heating at 105 ± 2ºC, used for the first time in this study, cause better adsorption performance for carbon nanotubes. In addition, the SWCNTs can effectively adsorb ethylbenzene and xylene from water and can thus be used as efficient adsorbents to purify waters and wastewaters polluted by petrochemicals.