Effect of flow breakers on the VUV photolysis of aqueous solution of coumarin
Vacuum ultraviolet (VUV) photolysis is one of the Advanced Oxidation Processes (AOPs) for the elimination of trace pollutants from water and air. During VUV photolysis reactive species (mainly H and OH) can be generated directly from water without the addition of any chemicals. The penetration dep...
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| Dokumentumtípus: | Könyv része |
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2019
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| Sorozat: | Proceedings of the International Symposium on Analytical and Environmental Problems
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| Kulcsszavak: | Analitikai kémia |
| Online Access: | http://acta.bibl.u-szeged.hu/64863 |
| Tartalmi kivonat: | Vacuum ultraviolet (VUV) photolysis is one of the Advanced Oxidation Processes (AOPs) for the elimination of trace pollutants from water and air. During VUV photolysis reactive species (mainly H and OH) can be generated directly from water without the addition of any chemicals. The penetration depth of VUV radiation in water is very small, only 0.04 mm, so reactive species form and react with organic compounds and dissolved O2 in this extremely thin layer. Carbon centered radicals can react at a longer distance from the light source, and their fast reaction with dissolved O2 results in an O2 poor layer, wider than the photo reaction zone. Consequently VUV irradiated solution is an extremely inhomogeneous system. To reduce the inhomogeneity of the VUV irradiated aqueous solution flow breakers (PTFE rings) were used to enhance the mass transfer into the zone determined by the reactions of primary, carbon centered and peroxyl radicals. Coumarin and its hydroxylated byproduct, the umbelliferone (7-hydroxy-coumarin) were used as model compounds. The effects of the PTFE rings on the transformation rate of coumarin and formation rate of umbelliferone were investigated in O2-saturated and O2-free solutions. The detailed investigation of the concentration effect of both dissolved O2 and coumarin is also reported in this work. |
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| Terjedelem/Fizikai jellemzők: | 307-311 |
| ISBN: | 978-963-306-702-4 |