Abstract
PURPOSE: The present study aimed to investigate the effect of humic acid (as a NOM model) on the adsorption capacity of MWCNT. METHODS: Ethyl benzene and toluene were removed from aqueous solution and adsorbed on multi walled carbon nanotubes in batch adsorption experiments at the presence of different concentrations of humic acid. RESULTS: The results showed that the highest adsorption of multi walled carbon nanotubes was 72 mg/g for ethyl benzene and 35 mg/g for toluene in an aqueous solution without humic acid. Langmuir isotherm model and pseudo-second-order kinetic model were the predominant models of adsorption process. Pre-loading of humic acid on MWCNT reduced the adsorption capacity of MWCNT from 14 mg/g to 8 mg/g for toluene and from 25 mg/g to 10 mg/g for ethyl benzene, when the experiments were conducted with MWCNT pre-loaded by humic acid from 0 to 30% . CONCLUSIONS: The batch adsorption experiments showed that the presence of dissolved humic acid in the aqueous environment slightly affected the adsorption of ethyl benzene and toluene by MWCNT but, Pre-loading of humic acid on MWCNT could reduce the adsorption capacity of multi walled carbon nanotubes.