Oxytetracycline Adsorption from Aqueous Solutions on Commercial and High-Temperature Modified Activated Carbons

The aim of the work was to evaluate the possibility of using commercial and modified activated carbons for the removal of oxytetracycline from aqueous solutions. The kinetics and statics of adsorption as well as the effect of the activated carbon dose and solution pH on the efficiency of the oxytetracycline adsorption were analyzed. Based on the study of oxytetracycline adsorption isotherms, the activated carbons were ranked in the following order: F-300 > WG-12 > Picabiol > ROW08 > WACC 8 x 30 > F-100 > WAZ 0.6-2.4. The most effective activated carbons were characterized by large specific surfaces. The best matching results were obtained for: Redlich-Peterson, Thot and Jovanovic models, and lower for the most frequently used Freundlich and Langmuir models. The adsorption proceeded better from solutions with pH = 6 than with pH = 3 and 10. Two ways of modifying activated carbon were also assessed. A proprietary method of activated carbon modification was proposed. It uses the heating of activated carbon as a result of current flow through its bed. Both carbons modified at 400 degrees C in the rotary kiln and on the proprietary SEOW (Joule-heat) modification stand enabled to obtain adsorbents with higher and comparable monolayer capacities. The advantage of the proposed modification method is low electricity consumption.

Automated summary

This study evaluated the potential of using commercial and modified activated carbons for the removal of oxytetracycline from aqueous solutions. The activated carbons with larger specific surfaces showed better effectiveness, especially with adsorption from solutions at pH 6. Both methods of modifying activated carbon led to the production of adsorbents with higher monolayer capacities. The proposed modification method also boasted low electricity consumption.