【作者】 陈建新；

【导师】 朱利中；

【作者基本信息】 浙江大学 ， 环境科学， 2007， 博士

【摘要】 多相光助-芬顿技术是目前最具应用潜力的高级氧化技术之一。开发新型多相催化剂、拓宽pH适用范围、提高催化降解效率、降低成本是多相光助-芬顿技术工程化应用必须解决的关键问题。选择合适的载体以合成高效、稳定、廉价的多相催化剂是该技术的核心。膨润土比表面积大、吸附能力强、价格低廉，是理想的催化剂载体。本文制备了不同形态铁（聚合羟基铁离子、α-Fe₂O₃、α-FeOOH）柱撑的膨润土，比较研究了其在紫外光下催化过氧化氢降解偶氮染料橙Ⅱ的性能，重点探讨了聚合羟基铁柱撑膨润土催化降解橙Ⅱ的过程、机理及调控机制，取得了一些有价值的研究结果： 1．合成了新型聚合羟基铁柱撑膨润土UV-Fenton催化剂。该催化剂制备简单、催化活性和催化稳定性高，且在较宽的pH值范围（3.0～9.0）均具有较高的催化活性。在紫外光和过氧化氢存在下，橙Ⅱ溶液初始pH值高达9.0时，催化反应60min时染料可完全脱色，其矿化率高达82％。 2．基本探明了聚合羟基铁柱撑膨润土的UV-Fenton催化机理。发现多相光助-芬顿反应是催化过程的引发反应，均相光助-芬顿反应是整个催化过程的核心反应，柱撑膨润土是均相催化体系中铁离子的源和汇。橙Ⅱ降解过程中产生的草酸等中间产物能促进铁离子的溶出；当染料完全矿化后，溶液中的铁离子能重新被催化剂所吸附，催化剂得以循环使用，避免了催化活性组分损失和二次污染问题。 3．发现在聚合羟基铁柱撑膨润土催化的UV-Fenton体系中，加入适量草酸能促进铁离子溶出，显著提高橙Ⅱ脱色和矿化速率、降低反应能耗。例如，在初始pH值为3.0的催化体系中，加入浓度为0.1、0.2和0.4 mmol／L的草酸，橙Ⅱ的降解速率分别提高30％、46％和63％，体系90％矿化所需时间从60 min分别缩短至40、35和30 min。更多还原

【Abstract】 Heterogeneous photo-Fenton process is one of the most promising technologies for organic wastewater treatment. At present, a key problem of this technology development and its industrial application is to develope ideal catalyst, extend the range of pH values for Fenton-type oxidation, increase the catalytic activity of heterogeneous catalyst and lower the cost of treatment. And selection of catalyst supports is the most important during the preparation of novel heterogeneous catalyst. Bentonite is one of ideal catalyst supports because of its large surface area, high adsorption capacity and low cost. In this dissertation, the catalytic activities of Fe-pillared bentonite （pillared with hydroxyl-Fe-polycation, α-Fe₂O₃ and α-FeOOH） in UV-Fenton system were investigated in an aim to increase the discolouration and mineralization efficiency of Orange II （a model compound of azo-dye）. And the catalytic process, mechanism as well as regulation of hydroxyl-Fe-pillared bentonite were studied in detail. The main original conclusions of the work are drawn as following parts.1. A novel UV-Fenton catalyst, hydroxyl-Fe-pillared bentonite, was developed. This catalyst exhibited a high catalytic activity and good long-term stability in multiple runs in the discolouration and mineralization of Orange II. Furthermore, the catalyst could exhibite high catalytic activity in a wide range of pH values （3.0 ～ 9.0）. For example, almost 100% color removal and 82% TOC removal of 0.2 mM Orange II could be obtained within 60 min even if the initial pH of solution was as high as 9.0.2. A possible catalytic mechanism of hydroxyl-Fe-pillared bentonite was proposed. It was found that the homogeneous UV-Fenton process was the dominant reaction in the degradation of Orange II. The catalyst acted as not only heterogeneous catalyst for heterogeneous UV-Fenton process but also source and sink of iron ions更多还原