Sulfaquinoxaline Oxidation and Toxicity Reduction by Photo-Fenton Process

• Published in: International journal of environmental research and public health Vol. 18; no. 3; p. 1005
• Main Authors: Urbano, Vanessa Ribeiro, Maniero, Milena Guedes, Guimarães, José Roberto, Del Valle, Luis J, Pérez-Moya, Montserrat
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 23-01-2021; MDPI
• Subjects: Antibiotics; Bacteria; Biodegradation; Biological activity; Coliforms; Design of experiments; E coli; Experimental design; Gram-positive bacteria; Hydrogen Peroxide; Hydrogen-Ion Concentration; Iron; Laboratories; Mineralization; Oxidation; Oxidation-Reduction; Pilot plants; Radiation; Sulfaquinoxaline; Toxicity; Water analysis; Water Pollutants, Chemical - analysis; Water sampling; Spain; toxicity; mineralization; oxidations; sulfaquinoxaline; photo-Fenton; advanced oxidation process; experimental design; emerging contaminants
• ISSN: 1660-4601; 1661-7827; 1660-4601
• DOI: 10.3390/ijerph18031005

Sulfaquinoxaline (SQX) has been detected in environmental water samples, where its side effects are still unknown. To the best of our knowledge, its oxidation by Fenton and photo-Fenton processes has not been previously reported. In this study, SQX oxidation, mineralization, and toxicity (
and
bacteria) were evaluated at two different setups: laboratory bench (2 L) and pilot plant (15 L). The experimental design was used to assess the influence of the presence or absence of radiation source, as well as different H
O
concentrations (94.1 to 261.9 mg L
). The experimental conditions of both setups were: SQX = 25 mg L
, Fe(II) = 10 mg L
, pH 2.8 ± 0.1. Fenton and photo-Fenton were suitable for SQX oxidation and experiments resulted in higher SQX mineralization than reported in the literature. For both setups, the best process was the photo-Fenton (178.0 mg L
H
O
), for which over 90% of SQX was removed, over 50% mineralization, and bacterial growth inhibition less than 13%. In both set-ups, the presence or absence of radiation was equally important for sulfaquinoxaline oxidation; however, the degradation rates at the pilot plant were between two to four times higher than the obtained at the laboratory bench.