Efficiency and energy requirements for the transformation of organic micropollutants by ozone, O₃/H₂O₂ and UV/H₂O₂

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• 作者：Ioannis A. Katsoyiannis^a ; Silvio Canonica^a ; Urs von Gunten^a ; ^b ; ^{vongunten@eawag.ch"" rel=""nofollow}
• 关键词：Oxidation ; Energy ; Ozonation ; O₃/H₂O₂ ; UV/H₂O₂ ; Scavenging rate ; Micropollutants
• 刊名：Water Research
• 出版年：2011
• 出版时间：July 2011
• 年：2011
• 卷：45
• 期：13
• 页码：3811-3822
• 全文大小：445 K

文摘

The energy consumptions of conventional ozonation and the AOPs O₃/H₂O₂ and UV/H₂O₂ for transformation of organic micropollutants, namely atrazine (ATR), sulfamethoxazole (SMX) and N-nitrosodimethylamine (NDMA) were compared. Three lake waters and a wastewater were assessed. With p-chlorobenzoic acid (pCBA) as a hydroxyl radical (^•OH) probe compound, we experimentally determined the rate constants of organic matter of the selected waters for their reaction with ^•OH (k_OH,DOM), which varied from 2.0 × 10⁴ to 3.5 × 10⁴ L mgC⁻¹ s⁻¹. Based on these data we calculated ^•OH scavenging rates of the various water matrices, which were in the range 6.1–20 × 10⁴ s⁻¹. The varying scavenging rates influenced the required oxidant dose for the same degree of micropollutant transformation. In ozonation, for 90 % pCBA transformation in the water with the lowest scavenging rate (lake Zürich water) the required O₃ dose was roughly 2.3 mg/L, and in the water with the highest scavenging rate (Dübendorf wastewater) it was 13.2 mg/L, corresponding to an energy consumption of 0.035 and 0.2 kWh/m³, respectively. The use of O₃/H₂O₂ increased the rate of micropollutant transformation and reduced bromate formation by 70 % , but the H₂O₂ production increased the energy requirements by 20–25 % . UV/H₂O₂ efficiently oxidized all examined micropollutants but energy requirements were substantially higher (For 90 % pCBA conversion in lake Zürich water, 0.17–0.75 kWh/m³ were required, depending on the optical path length). Energy requirements between ozonation and UV/H₂O₂ were similar only in the case of NDMA, a compound that reacts slowly with ozone and ^•OH but is transformed efficiently by direct photolysis.