|Keywords||Fenton reaction, Fenton-like reaction, MTBE, degradation, by-products|
|Abstract||After it has been demonstrated in many studies that MTBE removal by conventional remediation technologies is costly and ineffective, attention has been drawn to advanced oxidation processes. This motivated us to undertake a study of the degradation of MTBE and its by-products by Fenton and Fenton-like process. The present work was carried out to experimentally explore the characteristics of oxidation, which would leads to the development of a mechanism that describes the influence of chloride and sulfate ions on Fenton and Fenton-like reactions. The obtained results demonstrated that oxidation of MTBE and its by-products by Fenton and Fenton-like systems is effective in both cases, but also sensitive to the presence of inorganic ions. Perchlorate ions do not form complexes with iron species and are not reactive towards hydroxyl radicals. In contrast, chloride and sulfate ions were found to form complexes with iron and less reactive inorganic radicals than OH•. These phenomena lead to a decrease of the active iron species, hydroxyl radicals concentration and in the end the decrease in the rate of organic matter oxidation. At the initial stage of Fenton–like reaction and second stage of Fenton reaction, the iron species are in ferric form which indicates that a complex reaction might be the primary cause of inhibition of Fenton and Fenton-like reaction. Additionally, the inhibiting effect of anions on the rate of conversion of MTBE depends on scavenging of OH• radicals. In contrast to MTBE, the concentrations of its by-products were lower in the presence of chloride and sulfate than in the presence of perchlorate. Other factors that influence the difference of oxidation between MTBE and its by-products also likely exist. The amount of hydrogen peroxide as well as iron added in the reaction mixture were also considered as the factors that increased the effect of MTBE oxidation in the presence of chloride ions. When the concentration of iron increased, the concentration of MTBE as well as by-products decreased in both systems. Based on these data, a great amount of ferrous ions rather than hydrogen peroxide can reduce the inhibition originating from chloride ions if the initial iron concentration is too low to overcome the complex effect.|
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|Name||Affiliation||Home page||Total pubs|
|Siedlecka EM||Faculty of Chemistry, University of Gdansk, ul. Sobieskiego 18, PL-80-952 Gdansk, Poland||1|
|Stepnowski P||Faculty of Chemistry, University of Gdansk, ul. Sobieskiego 18, PL-80-952 Gdansk, Polandemail@example.com||4|
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