Removal of tetracycline and oxytetracycline by microscale zerovalent iron and formation of transformation products

Abstract

The main objective of this study was to determine the removal mechanism of tetracycline (TC) and oxytetracycline (OTC) by microscale zerovalent iron (mZVI) and the formation of transformation products during their removal studies. Solution pH, iron dose, and reaction temperature were studied with a batch experimental series in order to evaluate the removal efficiency of TC and OTC and the adsorption kinetics. The results showed that pH was a key factor in removing both tetracycline compounds, although increasing the temperature and iron dose enhanced their removal efficiency. The optimal pH was similarly found as 3 for both tetracycline and oxytetracycline. The kinetics of adsorption fitted the pseudo-second-order model perfectly. The adsorption data was interpreted by the Langmuir model with the maximum adsorption capacity of 23.98 and 34.01 mg g(-1) (60 °C) of TC and OTC on mZVI, respectively. The main transformation product was 4-epi-tetracycline for TC which quickly sorbed onto mZVI within 15 min. β-Apo-OTC and α-Apo-OTC were found as OTC transformation products. The removal mechanism of TC and OTC using mZVI surface was due to the adsorption rather than the degradation process.

Removal of tetracycline antibiotics from aqueous solution by amino-Fe (III) functionalized SBA15

“…The values of 1/n were less than 1.0 for all TCs, suggesting that the adsorbent was favorable for the removal of TCs from aqueous solution [23]. It was reported that the sorption capacity of TCs on magnetic porous carbon, microscale zerovalent iron, cross-linked chitosan and hydrophilic molecularly imprinted polymers were 53 mmol kg −1 [1], 49 mmol kg −1 [17], 43 mmol kg −1 [30], and 23-54 mmol kg −1 , respectively [24]. The current results clearly indicate that the Fe-N,N-SBA15 sorbent developed in this study has great potential for removal of antibiotics from aqueous environments.…”

“…Barbooti et al found that the ferric ions in clay could form stable complexes with OTC, improving the adsorption characteristics [15]. Özge Hanay et al proved that increasing iron dose enhanced TC and OTC removal efficiency [17]. Raquel et al also confirmed that the surface complexation mechanism could be described by the interaction of divalent anion species of OTC with the iron oxide surface [18].…”

Iron-incorporated mesoporous silica for enhanced adsorption of tetracycline in aqueous solution

“…12,24 However, most of these materials have relatively low surface area and the numbers of useful active sites are limited. Therefore, we propose to incorporate iron into a framework of mesoporous silica materials to overcome the difficulties mentioned above.…”

Oxytetracycline removal from water by novel microbial embedding gel beads

“…Oxytetracycline (OTC), as one kind of typical tetracyclines, is widely used in clinical treatment and livestock industry, and as growth promoter due to its broad spectrum of activity and low cost [1]. Residues of antibiotics have been detected in surface water, sediment, soil and other environments.…”