The adsorption mechanisms and the effect of Oxytetracycline (OTC) onto activated sludge were studied.
The results show that the adsorption of Oxytetracycline (OTC) onto activated sludge was coincident with
the Langmuir, Freundlich and Temkin isotherm models. The Freundlich model had the best fit which suggested
that chemical adsorption mechanism was dominant. The influences including pH and metal ions
on the OTC were examined. It was demonstrated that the adsorption process was highly pH-dependant,
which indicate that cationic exchange mechanisms may play an important role in the adsorption process.
Na+, K+, Ca2+, Mg2+ and Cd2+ ions more or less inhibited the adsorption of OTC on activated sludge while
Cu2+ enhanced the adsorption ability. The phenomenon may reflect the result that a surface complexation
mechanism could involved in the adsorption.