Investigating Removal Efficiency of Tetracycline Antibiotic from Aqueous Solutions Using Nanoclay Adsorbent and Study of Effective Parameters, Kinetic Models, and Adsorption Isotherms

Pharmaceutical contaminants are one of the most important environmental problems that must be cleared of aqueous environments before they enter the environment. Adsorption method is operationally easy and cost-effective if the adsorbent is not expensive. The purpose of this study is optimization the process of removal of tetracycline from aqueous solutions by nanoclay adsorbent and investigation the kinetics and adsorption isotherms. In this study, after preparing the nanoclay, optimization of parameters was done with Design Expert software. The parameters effect of pH, initial concentration and amount of adsorbent were investigated and SEM, XRD and FTIR analyzes were done to identify nanoclay properties. The optimal values ​​of parameters were pH equal to 9.5, adsorbent amount equal to 1.2 g and initial concentration equal to 21.15 mg /l at 25 °C, time of 30 min and stirring speed of 1000 rpm. The study of kinetic models and equilibrium isotherms showed that the adsorption follows the Pseudo-second Order (R2=0.999(   and   the Langmuir model, respectively. Under optimal condition, nanoclay as a low cost and environmentally friendly adsorbent has a good ability to adsorb tetracycline from aqueous solutions.