铁氧化物/草酸/UVA体系中2-硫醇基苯骈噻唑的光化学降解  

Photodegradation of 2-Mercaptobenzothiazole in the Iron Oxides/Oxalic Acid/UVA System

作　　者：刘承帅[1] 高原雪[2] 李芳柏[2] 雷静[2] 张干[1] 匡耀求[1] 

机构地区：[1]中国科学院广州地球化学研究所,广东广州510640 [2]广东省生态环境与土壤研究所广东省农业环境综合治理重点实验室,广东广州510650

出　　处：《催化学报》2006年第2期139-145,共7页

基　　金：国家自然科学基金(20377011);广东省自然科学基金重点项目(036533)资助

摘　　要：用水热法合成纯-ΓFEOOH粉末,然后分别在250,320,420和520℃下煅烧得到IO-250等4种铁氧化物.XRD结果表明,煅烧后得到的IO-250和IO-320为-ΓFE2O3和-ΑFE2O3混合相,IO-420和IO-520为纯-ΑFE2O3相.N2吸附结果表明,随煅烧温度升高,铁氧化物比表面积减小.铁氧化物与草酸悬浮液在紫外光照射下建立了一个铁氧化物/草酸/长波紫外线(UVA)类光FENTON体系,以2-硫醇基苯骈噻唑(MBT)为目标污染物测试了该体系的催化活性.结果表明,该体系能有效降解MBT,不同铁氧化物组成的体系光化学活性依次为IO-320>IO-250>IO-420>IO-520>-ΓFEOOH.铁氧化物剂量和草酸的初始浓度显著影响体系的光化学活性,不同铁氧化物最佳剂量不同;草酸能显著促进MBT光化学降解,在各体系中其最佳浓度均为1.0 MMOL/L.反应过程中FE2+和FE3+的浓度及溶液PH值的变化均与铁氧化物的种类和草酸的初始浓度有关.Lepidocrocite was prepared by hydrothermal process and then underwent a phase transformation by sintering at 250, 320, 420, and 520℃. The obtained iron oxides were named as IO-250, IO-320, IO-420, and IO-520, respectively. The X-ray diffraction analyses indicated that IO-250 and IO-320 were a mixture of γ-Fe2O3 and α-Fe2O3 phases, and IO-420 and IO-520 existed in a pure a-Fe2O3 phase. The N2 adsorption results revealed that the total surface area decreased with the increase of sintering temperature. To investigate the photodegradation of organic pollutants in the iron oxides/oxalic acid system, the photo-Fentondike system was set up by mixing up the iron oxide powder and oxalic acid under ultraviolet A （UVA） irradiation. 2-Mercaptobenzothiazole （MBT） was selected as a model odorous substrate. The results indicated that MBT could be efficiently degraded in this system, and the photodegradation of MBT was strongly affected by the dosage of iron oxides and the initial concentration of oxalic acid. The catalytic activity was in the order IO-320 〉 IO-250 〉 IO-420 〉 IO-520 〉 γ-FeOOH. Oxalic acid could obviously promote the photodegradation of MBT, and its optimum initial concentration for all the iron oxides was 1.0 mmol/L. During the photochemical reaction process, Fe^2＋ and Fe^3＋ concentration and the pH value of the system depended on the kind of iron oxides and the initial oxalic acid concentration.

关 键 词：铁氧化物 类光Fenton体系 草酸 2-硫醇基苯骈噻唑 光降解 

分 类 号：O643.32[理学—物理化学]