Main content area

Coadsorption of Cu and sulfamethoxazole on hydroxylized and graphitized carbon nanotubes

Wu, Di, Pan, Bo, Wu, Min, Peng, Hongbo, Zhang, Di, Xing, Baoshan
The Science of the total environment 2012 v.427-428 pp. 247-252
adsorption, antibiotics, carbon nanotubes, heavy metals, metal ions, pH, sorbates, sulfamethoxazole
Because of their various functional groups, antibiotics may complex with heavy metals and thus the environmental behaviors of both antibiotics and heavy metals may be altered. Noticing the experimental flaws of the previous studies, this study used Cu²⁺ and sulfamethoxazole (SMX) as model sorbates and carbon nanotubes (CNTs) as model sorbents to investigate the coadsorption of Cu and SMX. Combining the results of binary interaction experiments, we concluded that Cu and SMX preferentially occupy different types of CNT sorption sites at pHs 1.0 and 3.5, showing no apparent sorption change with the presence of coadsorbates. However, at pH 6.5, ternary complexes of Cu–SMX–CNTs and SMX–Cu–CNTs may be formed depending on Cu²⁺ concentrations. XPS data provided further support for the adsorption of both Cu and SMX on CNTs. These results indicated that the environmental behavior of antibiotics should be evaluated with careful consideration of the rule of metal ions.