Study of the Adsorptive Removal of 1,2,3-Trichlorobenzene from Water Using Multi-wall Carbon Nanotubes

Three kinds of multi-walled carbon nanotubes(MWNTs) with different diameters were tested for the adsorption of 1,2,3-trichlorobenzene(TCB) from water.Results showed that the adsorption quantity of the tested TCB increased with the decrease of the diameter of MWNTs.Further experiments demonstrated that it took only 150 min for MWNT(L-8) to attain equilibrium,and the maximal adsorption capacity was 77.5mg/g.The adsorption kinetics and isotherm could be well described with a pseudo-second-order rate model and Freundlich isotherm respectively.The adsorption thermodynamics of 1,2,3-Trichlorobenzene on the MWNT(L-8) was carried out at 278 K±1 K,288 K±1 K,298 K±1 K,respectively.And the thermodynamic parameters,such as equilibrium constant(K0),standard free energy changes(ΔG0),standard enthalpy change(ΔH0) and standard entropy change(ΔS0),were obtained,indicating that the adsorption of the TCB on the MWNT was spontaneous and endothermic.The fact that the variation of pH from 2 to 11 had little effect on the TCB adsorption on the MWNT showed that the H bond between TCB and MWNT did not play much role,while the π electronics on the surface of MWNTs and TCB benzene ring might be coupled and acted as a strong adsorption force.