Photo-Fenton decomposition of β-blockers atenolol and metoprolol; study and optimization of system parameters and identification of intermediates

• Published in: Chemosphere (Oxford) 2014-07, Vol.107, p.180-186
• Main Authors: Veloutsou, S., Bizani, E., Fytianos, K.
• Format: Article
• Language: English
• Subjects: Adrenergic beta-Antagonists - chemistry; Adrenergic beta-Antagonists - isolation & purification; Advanced oxidation processes (AOPs); Applied sciences; Atenolol; Atenolol - chemistry; Atenolol - isolation & purification; Biological and physicochemical phenomena; Exact sciences and technology; Hydrogen Peroxide - chemistry; Iron - chemistry; Kinetics; Metoprolol; Metoprolol - chemistry; Metoprolol - isolation & purification; Natural water pollution; Pharmaceuticals; Photo-Fenton reaction; Photolysis; Pollution; Water Pollutants, Chemical - chemistry; Water Pollutants, Chemical - isolation & purification; Water treatment and pollution
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2013.12.031

•Photo-Fenton system is highly effective in atenolol and metoprolol’s degradation.•Initial compounds degradation and mineralization on longer irradiation is achieved.•A CCD analysis proved iron’s concentration the parameter with the greatest impact.•Toxicity evaluation proved initial compounds and intermediates as moderately toxic.•Atenolol’s and metoprolol’s degradation products were detected using LC/MS-MS. Active pharmaceutical compounds reach the wastewater treatment plants mainly through excretion and improper disposal, and, because of insufficient treating methods, they end up to surface water or even potable water in some cases. Atenolol and metoprolol are β-blockers, members of cardiovascular pharmaceuticals group. They are generally used in the treatment of disorders such as hypertension, angina and arrhythmias. They have been in long-term use in Europe and North America, and they have also been detected in the aquatic environment. In this study the degradation of atenolol and metoprolol in aqueous solutions by means of the photo-Fenton reaction was investigated. The purpose of this study was: (i) to investigate the influence of the concentrations of iron and hydrogen peroxide, by means of central composite design, (ii) to study the degradation kinetics in aqueous solutions, (iii) to evaluate the mineralization and the toxicity evolution of the target compounds and (iv) to identify the degradation products. It has been found that increase of iron and hydrogen peroxide concentration accelerate the degradation of atenolol and metoprolol, while the kinetics of the process can be characterized as pseudo-first order. In general the photo-Fenton method has proved to be effective in decomposing and mineralizing the target compounds. The determination of the by-products formed during the degradation using LC-MS/MS equipment and the evaluation of the toxicity of the treated solution in different stages of the process would offer significant, innovative information regarding the treatment of water and wastewater containing active pharmaceutical compounds, especially of the β-blocker group.