Removal of Trichloroethylene from water by adsorption on to multiwall carbon nanotubes

ABSTRACT

Groundwater recourses may be contaminated with trichloroethylene [TCE] which is used in electronic, electric, dry cleaning and other similar industries and often treated by air stripping, which TCE in its vapor form is stripped from groundwater by air and is emitted into the atmosphere without any additional treatments. Carbon nanotubes are expected to play an important role in sensing, pollution treatment and separation techniques. In this study adsorption of trichloroethylene on multiwall carbon nanotubes has been investigated. The effect of contact time, pH, initial concentration of trichloroethylene and temperature on its adsorption were investigated. Adsorption isotherms and related constants were also determined. Results showed that contact times to reach equilibrium changed from 30 min [for 150 microg/L initial concentration] to 10 min [for 600 microg/L concentrations] at 25 [degree sign]C; the equilibrium times in 40[degree sign] C were 40 min and 15 min, respectively. Multi-wall carbon nanotubes showed to act as a good adsorbent for TCE in a wide range of pH=[3-9]. For pH>9, adsorption decreased due to ionization of oxygen-containing groups. Adsorption test results revealed that TCE adsorption on the studied adsorbents could be better described by Freundlich isotherm