Kinetics and isotherms of oxytetracycline adsorption on beta-cyclodextrin/carboxymethylcellulose hydrogel films

Oxytetracycline (OTC), widely used as an antibiotic substance in aquaculture, has an adverse effect on environmental and public health. The aim of this paper was to demonstrate that OTC can be removed by hydrogel films composed of beta-cyclodextrin/carboxymethylcellulose (beta-CD/CMC) with esterification-crosslink method. Oxytetracycline adsorption experiments were performed with an initial pH of 1-12 and an initial concentration of 10-500 mg/L. The experimental data were fitted with Langmuir and Freundlich isotherms and compared using linear and nonlinear models. The experimental results indicate that OTC's adsorption capacity depends on the active beta-cyclodextrin content. The optimal pH was around 8.