Photochemical mineralization of amoxicillin medicinal product by means of UV, hydrogen peroxide, titanium dioxide and iron

ABSTRACT

In the present study, the photochemical degradation of amoxicillin and total organic carbon (TOC) removal in pharmaceutical aqueous solutions was studied using UV irradiation, titanium dioxide, hydrogen peroxide and iron in a batch photoreactor operated for 120–150 min. The effect of the initial concentrations of the target compound, hydrogen peroxide and ferric ions and of their combination was examined. It was found that under direct UV photolysis, considerable TOC removals were obtained only when the initial concentration of amoxicillin (AM) was below 100 mg/L. For initial concentration of AM 250 mg/L, the TOC removals achieved were of no practical use (below 5%). The TOC removals achieved in the presence of TiO₂ were lower than 20% in all cases. In the presence of hydrogen peroxide in the range of 12.2–146.9 mmol/L and initial AM concentration 250 mg/L, for increasing H₂O₂ concentrations higher TOC removals were achieved up to the concentration of 73.4 mmol/L H₂O₂. The presence of even very small amounts of Fe(III) in the solution resulted in significantly increased TOC removals; 2.2 times higher than without Fe(III) after 120 min. Fe(III) presence accelerated dramatically the process during the first 60 min. The origin of Fe(III) ions was not important since practically the same results were obtained whether FeCl₃ or Fe(NO₃)₃ was used as source of ferric ions. Adjusting the initial concentrations of AM, Fe(III) and H₂O₂, TOC removals above 90% were achieved.

GRAPHICAL ABSTRACT

KEYWORDS:

• Η₂Ο₂
• antibiotic pollution
• UV irradiation
• photo-Fenton
• Fe(III)

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Social Policy Grant of Nazarbayev University (Nur-Sultan, Kazakhstan).