Oxidation of aqueous pharmaceuticals by pulsed corona discharge

Abstract

Oxidation of aromatic compounds of phenolic (paracetamol, beta-oestradiol and salicylic acid) and carboxylic (indomethacin and ibuprofen) structure used in pharmaceutics was studied. Aqueous solutions were treated with pulsed corona discharge (PCD) as a means for advanced oxidation. Pulse repetition frequency, delivered energy dose and oxidation media were the main parameters studied for their influence on the process energy efficiency. The PCD treatment appeared to be effective in oxidation of the target compounds: complete degradation of pollutant together with partial mineralization was achieved at moderate energy consumption; oxidation proceeds faster in alkaline media. Low-molecular carboxylic acids were identified as ultimate oxidation by-products formed in the reaction.

Elucidation of the degradation pathways of sulfonamide antibiotics in a dielectric barrier discharge plasma system

“…[28,29,39], and it has been well known that inorganic ions such as NO 3 À , NH 4 + and SO 4 2À are generated by cleavages of bonds containing N and S atoms during the oxidation treatment [19,40,41]. The toxicity of degradation byproducts may be a matter of concern.…”

“…They found that among various reactive species ozone played a major role in the degradation of antibiotics. Pulsed corona discharge plasma as a means for advanced oxidation has also been applied to the oxidation of aqueous pharmaceuticals [28,29]. The authors reported that this method is effective in the oxidation of pharmaceuticals and ultimate oxidation byproducts are low-molecular carboxylic acids.…”

Degradation in chlorinated water of the UV filter 4-tert-butyl-4′-methoxydibenzoylmethane present in commercial sunscreens

“…[2] The increased production and use of UV filters has led to increased inputs into the environment and this fact prompted UV filters to be considered environmental pollutants in the same group of emerging pollutants classified as pharmaceuticals and personal care products. [3][4][5][6][7] UV filters may enter the environment through direct and indirect *Corresponding author. Email: jcsilva@fc.up.pt sources.…”

Mineralization of paracetamol in aqueous solution with advanced oxidation processes

“…[20,21] Hazard quotient effects of paracetamol were determined to be greater than unity suggesting potential ecological risks [22] and it is persistent on hydrolytic or microbial degradation. [23] Paracetamol is removed from water by several ways which include ozonation, [24] [24,25] photocatalytic degradation, [26][27][28][29][30] electrochemical methods, [31][32][33] pulsed corona discharge [34] and chlorination. [19] Paracetamol is mainly removed from water using such methods but persistent toxic intermediates are still present.…”