Sorption Behavior of Dicloxacillin in Zeolites Modified with a Cationic Surfactant at Different pH

Abstract

In the present work, a natural zeolite was first treated with a sodium chloride salt and subsequently modified with different cetyltrimethylammonium bromide (CTAB) concentrations for dicloxacillin removal. All the employed materials are characterized by several analytical techniques. Antibiotic sorption behavior was evaluated according to diverse parameters such as the effect of contact time, initial concentration, and pH by a batch system. Experimental results showed that the cationic surfactant treatment benefited dicloxacillin sorption. Kinetic results indicated that the equilibrium time was reached at 54 h and a maximum adsorption capacity of 1.072 and 1.051 mg/g for both modified zeolites at 25 mmol/L and 50 mmol/L, respectively. According to the kinetic data, the pseudo-secondorder model adjust the best. Obtained adsorption equilibrium results, adsorption isotherms adjust well to the linear model for both adsorbents with both materials, indicating a partition mechanism. Dicloxacillin species present at different pH values and the net surface charge of the modified adsorbents influence the adsorption process.