Evaluation the efficiency of magnetic-metallic chitosan nanocomposite adsorbent in the removal of tetracycline antibiotic from aqueous solutions

Antibiotics are considered due to health and environmental problems and therefore they counted as a major threat to human health. The aim of this study was to determine the absorption efficiency of magnetic-chitosan nanocomposite in the removal of antibiotic tetracycline from aqueous solutions.

In this study, the experiments were performed by spectrophotometer. The magnetic-chitosan nanocomposite were considered as an antibiotic adsorbent which its adsorption efficiency was measured by changing the variables such as temperature, time, PH, dosage of magnetic-chitosan nanocomposite, concentration of tetracycline, concentration of interactive ions of chlorine, sulfate and carbonate. Synthesis of magnetic-chitosan nanocomposite was based on co-precipitation method. The Freundlich, Langmuir and Temkin isotherms were used to determine the isotherm and the absorption kinetics.

The results showed that the best antibiotic removal efficiency was obtained at pH = 6. The highest removal efficiency was obtained at 90 minutes and equal to 91.23%. Moreover, the removal efficiency of tetracycline was significantly reduced in alkaline pH. Also, by increasing the absorbent dose from 0.1 g/L to 0.5 g/L, the removal efficiency of the pollutant increased from 72.24% to 90.22% at 90 minutes. In addition, with an increase in pollutant concentration between 5-30 mg/L, the removal efficiency of the pollutant decreased from 93.4% to 53.7%. In order to study the thermodynamics of the tetracycline pollutant absorption process by magnetic-chitosan nanocomposite, the removal efficiency of the pollutant dropped from 91.23% to 45.1% at 20, 30 and 45 degrees of Celsius. The presence of interfering ions has a decreasing effect on the removal efficiency of tetracycline, which the removal efficiency were reduced from 91.23% at 90 minutes (in the absence of ions) to 70.16% (for chlorine ion), 65.96% (for ion Carbonate) and 54.2% (for sulfate ions).
               

Finally, the use of magnetic- chitosan nanocomposite adsorbent is recommended in the removal of antibiotic tetracycline.