铁(氢)氧化物矿物对有机污染物的光催化氧化作用

对水溶液中(氢)氧化铁的光催化氧化反应的发展与机理研究进行了总结,着重对近十年来应用针铁矿／过氧化氢进行光催化氧化环境中有机物的研究进展及其环境矿物学意义作了概述和探讨。采用天然生物矿化的纳米针铁矿／过氧化氢以偶氮染料甲基橙为光解模型物进行了光催化氧化的初步研究,结果表明铁细菌形成的针铁矿具有降解生物难降解的有机污染物的能力。在甲基橙溶液初始浓度为30mg／L,铁细菌矿化的针铁矿用量2．5g／L,反应体系H2O2的初始浓度97mmol／L,pH值为6．92,15W紫外灯照射2h后,甲基橙浓度可降低33％。

PHOTOCATALYSIS OF ORGANIC CONTAMINANTS BY IRON (HYDR) OXIDE MINERALS IN WATER

Geosurface environment, as an "organic earth system" with natural self-purification function,possesses natural photocatalysis of organic substances by using solar energy. It is of great significance in enviromineralogy and advanced photocatalytic materials investigations involving photocatalytic reaction of iron (hydro)oxide minerals (HOIM) with organic contaminants (OC) in natural water phases. The progress and photocatalytic mechanism of HOIM/ H_2O_2 in water have been reviewed in this paper, especially, the applications of synthetical and natural goethite to photocatalytic treatment of OC in the last decade are summarized and discussed from the viewpoint of enviromineralogy. Moreover, photocatalysis of methyl orange (MC) as a model compound in biomineralized goethite (BG)/ H_2O_2 slurry and the fluorescence emission spectrum of BG have been studied for the first time. Photocatalysis efficiency of MC in neutral aqueous solution after 2 hours' (15 W) UV irradiation is about 33% when the initial concentration of MC, H_2O_2 and BG are (30 mg)/L, (97 mmol/L) and (2.5 g/L), respectively.