Removal mechanism of oxytetracycline by nano Ni/Fe bimetallic

The removal mechanism of oxytetracycline (OTC) by nanoscale Ni/Fe bimetallic was studied with a batch experimental series. The influences of solution pH, bimetallic dosage and reaction temperature on adsorption kinetics were evaluated and also formation of transformation products was determined. The results showed that the effect of pH on OTC removal was significant and increasing the dosage of Ni/Fe resulted in slight increase of removal efficiency. The kinetics of adsorption fitted well pseudo-second-order model. The maximum adsorption capacity calculated by the Langmuir model was 588 mg/g of OTC on Ni/Fe. The main transformation product was β-Apo-OTC as OTC transformation products which also quickly sorbed onto Ni/Fe. The removal mechanism of OTC by Ni/Fe was mainly due to the adsorption rather than the degradation process. Keywords: oxytetracycline, removal mechanism, transformation product, Ni/Fe bimetallic.