Removal of Tetracycline from Aqueous Solutions Using Modified Pyrolytic Coke Adsorbent Systems

Abstract

Pharmaceuticals are widely used in the treatment of diseases, and among them, antibiotics are the most widely used group of drugs. The presence of these compounds in the environment is a serious threat to global health. Common methods of removing antibiotics are photocatalytic processes, advanced oxidation, ozonation, and the use of sorbents. Adsorption processes are the most suitable option for removing drug compounds from aqueous media due to their high efficiency, simple system design, easy implementation and cost-effectiveness. The aim of this study was to use a new method to achieve a high removal rate of tetracycline antibiotics from aqueous solution, using a modified pyrolytic coke adsorbent and to optimize the adsorption process. The properties and characteristics of the adsorbents were determined by SEM, XRD, FTIR, BET and EDX analyses. At ambient temperature (25 ℃) the influence of effective factors such as adsorbent dose, solution pH, contact time and initial contaminant concentration were investigated. Based on the results, it was found that the optimal and maximum adsorption of tetracycline was occurred at pH=5, absorbent dose of 3 g/L, the initial concentration of 50 mg/L and the contact time of 90 minutes. This rate was equal to 96.32 percent. The results of FTIR analyses showed that the uptake of tetracycline by positive amine-NH groups was done at the adsorbent level. Also, the adsorption process of tetracycline by the modified adsorbent followed the Temkin adsorption isotherm model and the pseudo-second-order adsorption kinetics model.

Keywords

• pyrolytic coke
• tetracycline
• adsorption
• aqueous solution
• modified coke