Oxidation of Herbicides in Groundwater by the Fenton Process: A Realistic Alternative for O3/H2O2 Treatment? |
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Authors: | G F Upelaar R T Meijers R Hopman J C Kruithof |
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Affiliation: | Kiwa N.V., Research And Consultancy , Water Treatment And Distribution Department , P.O. Box 1072, 3430 BB, Nieuwegein, The Netherlands |
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Abstract: | Oxidation with O3/H2O2 and Fe2+/H2O2 are optional for the degradation of herbicides and pesticides in water. The choice of which process will be applied depends upon the degree of degradation of organic micropollutants and the process conditions related to the formation of oxidation by-products, and also on the total costs and the safety and reliability of the process. Under real conditions, atrazine and some phenylureaherbicides were oxidized with O3/H2O2. Comparable experiments under conditions of different pH, iron and DOC content were performed with Fe2+/H2O2, in order to gain information on the influence of these parameters. The oxidation results of both processes as well as the formation of bromate as one of the oxidation by-products are described. It was found that 80% of atrazine and >99% of some phenylureaherbicides could be degraded with O3/H2O2 at pH 7.8 (H2O2/O3 ratio 3.7 g/g). Under these conditions, bromate was formed up to 5 μg/1. Comparable results were obtained with Fe2+/H2O2 at a pH value of 5.5, whereas the formation of bromate was kept below 0.2 μg/L. |
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Keywords: | Ozone Fenton's Reagent Advanced Oxidation Processes Phenylureaherbicides Atrazine Hydrogen Peroxide Bromate Adsorption Flocculation Ground Water |
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