Comparative study on heterogeneous and homogeneous catalytic ozonation efficiency in micropollutants' removal
Catalytic ozonation was applied for the removal of small concentrations (4 μM) of micropollutants benzotriazole, carbamazepine, p-CBA from aqueous solutions at pH 7. These compounds present different physicochemical characteristics and different kinetic rate constants, when reacting with ozone or hy...
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| Format: | Article |
| Language: | English |
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IWA Publishing
2021-12-01
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| Series: | Aqua |
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| Online Access: | http://aqua.iwaponline.com/content/70/8/1121 |
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| author | S. Psaltou E. Kaprara M. Mitrakas A. Zouboulis |
| author_facet | S. Psaltou E. Kaprara M. Mitrakas A. Zouboulis |
| author_sort | S. Psaltou |
| collection | DOAJ |
| description | Catalytic ozonation was applied for the removal of small concentrations (4 μM) of micropollutants benzotriazole, carbamazepine, p-CBA from aqueous solutions at pH 7. These compounds present different physicochemical characteristics and different kinetic rate constants, when reacting with ozone or hydroxyl radicals in the ranges of <0.15–3 × 105, 5.2 × 109, and 8.8 × 109 M−1s−1, respectively. Calcite was used as heterogeneous catalyst and its catalytic activity evaluated, by applying (and optimized) different experimental conditions (i.e., pH, temperature, ozone concentration), concerning the removal efficiency of p-CBA. Study of micropollutants' removal showed all examined organic compounds can be sufficiently removed by application of catalytic ozonation either by use of calcite, or by presence of Co(II) or Fe(II) (applied as homogeneous catalysts), while the optimum catalyst between them was found to be calcite. Carbamazepine with kO3 = 3 × 105 M−1s−1 can be easily removed, even by application of single ozonation, while benzotriazole and p-CBA resulted in 50% and 68.2% higher removal after application of catalytic ozonation within 3 min of oxidation reaction, due to acceleration of hydroxyl radicals' production by presence of calcite in the ozonation system. The contribution of hydroxyl radicals in removal of all three micropollutants was evaluated by extraction of Rct and f•OH parameters. HIGHLIGHTS
Benzotriazole, carbamazepine and p-CBA were successfully removed by catalytic ozonation.;
Among examined catalysts calcite was defined as the best one.;
The removal of micropollutants is based on the mechanism of radicals’ production.;
Benzotriazole removal was in best agreement with the 1st order kinetic model.;
The kinetic model of p-CBA depended on the applicable catalyst.; |
| first_indexed | 2024-04-11T20:03:23Z |
| format | Article |
| id | doaj.art-444fa6f095914c8c89d1cc92a2364787 |
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| issn | 2709-8028 2709-8036 |
| language | English |
| last_indexed | 2024-04-11T20:03:23Z |
| publishDate | 2021-12-01 |
| publisher | IWA Publishing |
| record_format | Article |
| series | Aqua |
| spelling | doaj.art-444fa6f095914c8c89d1cc92a23647872022-12-22T04:05:27ZengIWA PublishingAqua2709-80282709-80362021-12-017081121113410.2166/aqua.2021.067067Comparative study on heterogeneous and homogeneous catalytic ozonation efficiency in micropollutants' removalS. Psaltou0E. Kaprara1M. Mitrakas2A. Zouboulis3 Laboratory of Chemical and Environmental Technology, Department of Chemistry, Aristotle University, Thessaloniki 54124, Greece Laboratory of Analytical Chemistry, Department of Chemical Engineering, Aristotle University, Thessaloniki 54124, Greece Laboratory of Analytical Chemistry, Department of Chemical Engineering, Aristotle University, Thessaloniki 54124, Greece Laboratory of Chemical and Environmental Technology, Department of Chemistry, Aristotle University, Thessaloniki 54124, Greece Catalytic ozonation was applied for the removal of small concentrations (4 μM) of micropollutants benzotriazole, carbamazepine, p-CBA from aqueous solutions at pH 7. These compounds present different physicochemical characteristics and different kinetic rate constants, when reacting with ozone or hydroxyl radicals in the ranges of <0.15–3 × 105, 5.2 × 109, and 8.8 × 109 M−1s−1, respectively. Calcite was used as heterogeneous catalyst and its catalytic activity evaluated, by applying (and optimized) different experimental conditions (i.e., pH, temperature, ozone concentration), concerning the removal efficiency of p-CBA. Study of micropollutants' removal showed all examined organic compounds can be sufficiently removed by application of catalytic ozonation either by use of calcite, or by presence of Co(II) or Fe(II) (applied as homogeneous catalysts), while the optimum catalyst between them was found to be calcite. Carbamazepine with kO3 = 3 × 105 M−1s−1 can be easily removed, even by application of single ozonation, while benzotriazole and p-CBA resulted in 50% and 68.2% higher removal after application of catalytic ozonation within 3 min of oxidation reaction, due to acceleration of hydroxyl radicals' production by presence of calcite in the ozonation system. The contribution of hydroxyl radicals in removal of all three micropollutants was evaluated by extraction of Rct and f•OH parameters. HIGHLIGHTS Benzotriazole, carbamazepine and p-CBA were successfully removed by catalytic ozonation.; Among examined catalysts calcite was defined as the best one.; The removal of micropollutants is based on the mechanism of radicals’ production.; Benzotriazole removal was in best agreement with the 1st order kinetic model.; The kinetic model of p-CBA depended on the applicable catalyst.;http://aqua.iwaponline.com/content/70/8/1121advanced oxidation processescatalystscatalytic ozonationmicropollutantsrct valuewater treatment |
| spellingShingle | S. Psaltou E. Kaprara M. Mitrakas A. Zouboulis Comparative study on heterogeneous and homogeneous catalytic ozonation efficiency in micropollutants' removal Aqua advanced oxidation processes catalysts catalytic ozonation micropollutants rct value water treatment |
| title | Comparative study on heterogeneous and homogeneous catalytic ozonation efficiency in micropollutants' removal |
| title_full | Comparative study on heterogeneous and homogeneous catalytic ozonation efficiency in micropollutants' removal |
| title_fullStr | Comparative study on heterogeneous and homogeneous catalytic ozonation efficiency in micropollutants' removal |
| title_full_unstemmed | Comparative study on heterogeneous and homogeneous catalytic ozonation efficiency in micropollutants' removal |
| title_short | Comparative study on heterogeneous and homogeneous catalytic ozonation efficiency in micropollutants' removal |
| title_sort | comparative study on heterogeneous and homogeneous catalytic ozonation efficiency in micropollutants removal |
| topic | advanced oxidation processes catalysts catalytic ozonation micropollutants rct value water treatment |
| url | http://aqua.iwaponline.com/content/70/8/1121 |
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