Hexavalent chromium removal using metal oxide photocatalysts
Hexavalent chromium removal using metal oxide photocatalysts
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DOI：
10.1016/j.apcatb.2015.04.047
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发表时间：
2015-10-01
影响因子：
22.1
通讯作者：
Chan, Candace K.
中科院分区：
文献类型：
--
作者：
Cheng, Qian;Wang, Chengwei;Chan, Candace K.
光催化是一种很有吸引力的去除水中六价铬（Cr（VI））的处理方法。到目前为止，Cr（VI）的光催化还原主要是使用TiO 2光催化剂在酸性水溶液中进行研究。在这里，我们研究使用氧化锌（ZnO），三氧化钨（WO 3）和钽酸钠（NaTaO 3），金属氧化物，显示出良好的其他光催化反应，如水分解，以及二氧化钛（TiO 2，赢创P90）的活性去除Cr（VI）。在合成的中性和碱性水，以及在冷却塔排污水中，使用这些光催化剂的去除Cr（VI）的效率进行了研究。还研究了水处理过程中使用的几种添加剂对Cr（VI）去除率的影响。对于NaTaO 3，柠檬酸被发现有一个不利的影响，铬（VI）的去除，而甲酸钠，氯化铵，和亚硫酸钠是有益的。虽然单独的亚硫酸盐可以化学还原Cr（VI），但亚硫酸盐与光催化剂组合导致在10分钟内使用SO 32-/Cr（VI）比>35在pH值类似于8的溶液中更快和完全去除Cr（VI）。NaTaO 3被发现显示最高的Cr（VI）去除率的光子的基础上，在pH 3和亚硫酸钠的存在下，而ZnO和TiO 2在pH 7和冷却塔排污水表现出最好的性能。(C)2015 Elsevier B. V.版权所有。
Photocatalysis is an attractive treatment method for removing hexavalent chromium (Cr(VI)) from water. Thus far, photocatalytic reduction of Cr(VI) has been investigated mostly using TiO2 photocatalysts in acidic water solutions. Here we investigate Cr(VI) removal using zinc oxide (ZnO), tungsten trioxide (WO3), and sodium tantalate (NaTaO3), metal oxides that display good activity for other photocatalytic reactions such as water splitting, as well as titanium oxide (TiO2, Evonik P90). The efficiency for Cr(VI) removal using these photocatalysts was investigated in synthetic neutral and alkaline water, as well as in cooling tower blowdown water. The effect of several additives used in water treatment processes on the Cr(VI) removal rate was also studied. For NaTaO3, citric acid was found to have a detrimental effect to Cr(VI) removal, while sodium formate, ammonium chloride, and sodium sulfite were beneficial. While sulfite alone could chemically reduce Cr(VI), sulfite in combination with a photocatalyst resulted in faster and complete removal of Cr(VI) in 10 min using a SO32-/Cr(VI) ratio >35 in pH similar to 8 solutions. NaTaO3 was found to display the highest Cr(VI) removal rates on a photon basis at pH 3 and in the presence of sodium sulfite, while ZnO and TiO2 showed the best performance in pH 7 and cooling tower blowdown water. (C) 2015 Elsevier B.V. All rights reserved.