Hydrogen peroxide enhanced photocatalytic oxidation of microcystin-LR using titanium dioxide
Hydrogen peroxide enhanced photocatalytic oxidation of microcystin-LR using titanium dioxide
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DOI：
10.1016/s0926-3373(99)00121-6
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发表时间：
2000-02-21
影响因子：
22.1
通讯作者：
Robertson, PKJ
中科院分区：
文献类型：
--
作者：
Cornish, BJPA;Lawton, LA;Robertson, PKJ
饮用水源中存在的蓝藻毒素对人类健康构成相当大的威胁。传统的水处理系统已被证明不可靠的去除这些毒素，因此，新的技术已被研究。以前的工作表明，TiO 2纳米粒子有效地破坏水溶液中的微囊藻毒素-LR，但检测到无毒的副产物。它已被证明，光催化反应增强了利用替代电子受体。我们在这里报告增强的光催化降解微囊藻毒素-la后，加入过氧化氢的系统。有人还发现，过氧化氢与紫外线照射单独是能够分解微囊藻毒素-LR，虽然在一个慢得多的速度比发现二氧化钛。当使用TiO 2/UV/H2 O2系统时，没有发现HPLC可检测的副产物，表明该方法比单独的TiO 2/UV更有效。然而，结果表明，只有18%的矿化发生与TiO 2/UV/H2 O2系统，因此无法检测的副产物必须仍然存在。在较高浓度下，过氧化氢被发现与微囊藻毒素-LR竞争催化剂上的表面位点，但在较低的过氧化物浓度下，这种竞争性吸附没有观察到。毒性研究表明，无论是在存在和不存在的H2 O2的微囊藻毒素溶液的解毒。这些结果表明，过氧化氢大大提高了微囊藻毒素-LR的光催化氧化。（C）2000 Elsevier Science B. V.保留所有权利。
Cyanobacterial toxins present in drinking water sources pose a considerable threat to human health. Conventional water treatment systems have proven unreliable for the removal of these toxins and hence new techniques have been investigated. Previous work has shown that TiO2 photocatalysis effectively destroys microcystin-LR in aqueous solutions, however non-toxic by-products were detected. It has been shown that photocatalytic reactions are enhanced by utilisation of alternative electron accepters. We report here enhanced photocatalytic degradation of microcystin-la following the addition of hydrogen peroxide to the system. It was also found that hydrogen peroxide with UV illumination alone was capable of decomposing microcystin-LR although at a much slower rate than found for TiO2. No HPLC detectable by-products were found when the TiO2/UV/H2O2 system was used indicating that this method is more effective than TiO2/UV alone. Results however indicated that only 18% mineralisation occurred with the TiO2/UV/H2O2 system and hence undetectable by-products must still be present. At higher concentrations hydrogen peroxide was found to compete with microcystin-LR for surface sites on the catalyst but at lower peroxide concentrations this competitive adsorption was not observed. Toxicity studies showed that both in the presence and absence of H2O2 the microcystin solutions were detoxified. These findings suggest that hydrogen peroxide greatly enhances the photocatalytic oxidation of microcystin-LR. (C)2000 Elsevier Science B.V. All rights reserved.