【作者】 吉励；

【导师】 雷乐成；

【作者基本信息】 浙江大学 ， 环境工程， 2009， 博士

【摘要】 吸附-催化臭氧氧化技术是水处理高级氧化技术的重要分支，该体系由吸附、臭氧氧化和催化氧化组成。本文分别采用活性炭和膨润土作为吸附剂，以硝基酚污染物和低浓度微污染源水为处理对象，对该体系的工艺参数、反应机理、吸附剂改性、有机污染物降解途径以及反应动力学模型等方面进行了系统的研究。采用活性炭吸附-催化臭氧氧化处理硝基酚模拟污染物。考察了该体系的处理效果，反应各因素对体系的影响，并发现pH是影响体系的重要参数。系统的考察了pH值对吸附、臭氧氧化和活性炭吸附-催化臭氧氧化的影响，并进行了三者的性能对比，证实了臭氧、活性炭在污染物去除中的协同效应，协同因子由pH4．0时的0．8增加到pH 10．0时的1．3。研究发现，活性炭吸附-催化臭氧氧化体系在酸性条件下以吸附-氧化再生反应过程为主，反应主要围绕着活性炭表面发生；而在碱性条件下主要为催化氧化反应过程，污染物的氧化反应主要在液相中进行。建立了吸附、氧化、再生的反应动力学模型，该模型较好的预测了污染物在体系中的降解过程，为工业化应用提供了理论指导。采用高压脉冲液电等离子体对活性炭进行表面改性研究。液电等离子体改性过程扩展了活性炭的孔结构，并改变了活性炭表面官能团的分布。在无气体氛围下进行的改性过程更能显著增加活性炭表面的酚羟基浓度，从而提升活性炭对水中硝基酚的吸附能力，吸附容量由原炭的254．9 mg/g增加到304．0 mg/g。改性后的活性炭强化了吸附-催化氧化体系中的吸附作用，有效的提升了污染物的处理效率。针对微污染源水中天然有机物和芳香化合物共存的特点，开发了新型的膨润土吸附-催化臭氧氧化体系。该体系一方面充分利用膨润土对天然有机物的吸附作用，减少了其对自由基的捕获；另一方面在体系中产生了大量的活性物质HO·自由基，促进了芳香化合物的降解。膨润土吸附-催化臭氧氧化体系克服了其他高级氧化技术处理微污染源水的缺点，实现了水中天然有机物和芳香有机化合物的同时高效去除。更多还原

【Abstract】 Adsorption-catalytic ozonation process is a novel alternative to Advanced Oxidation Technologies （AOTs）. It is composed of adsorption, ozonation and catalytic oxidation. In our work, Activated Carbon （AC） and Bentonite are selected as adsorbents in this process to degrade nitrophenol wastewater and slightly-polluted potable water. This paper investigates operation parameters; reaction mechanism; carbon modification and reaction kinetic model.Firstly, the process is utilized in degrading p-nitrophenol （PNP） wastewater by using AC as adsorbent. Treating efficiency and effect of operation parameters are investigated. PH is found to be the key parameter. Based on the optimized condition, comparison among adsorption, ozonation and adsorption-catalytic ozonation process is comprehensively investigated, and synergistic effects between ozone and AC are found, and the synergistic factor is increased from 0.8 at pH 4.0 to 1.3 at pH 10.0. The reaction mechanism of the adsorption-catalytic ozonation process is clarified. At acidic conditions, adsorption predominated in organics removal. The pollutants are congregated from aqueous to AC surface, and AC experiences an oxidation regeneration process. The reactions mainly take place on AC surface. At basic conditions, catalytic oxidation contributed primarily, and the reactions take place in aqueous phase. A corresponding adsorption-oxidation-regeneration kinetic model for the process is established. The model can acceptably simulate and predict the way of containment removal for further industrial applications.To improve adsorbility of AC and removal of organics in the adsorption-catalytic ozonation process, modification of AC by pulsed high-voltage electrohydraulic discharge non-thermal plasma is investigated. The modification process extends AC’s pore structure and redistributes its surface functional groups. Specially, the modification process in absence of gas introduces phenolic groups on AC surface, resulting in a considerable increase of the adsorbility of nitrophenol. The maximum adsorption capacity is increased from 254.9 mg/g to 304.0 mg/g. The modified AC enhances the adsorption effect in the adsorption-catalytic ozonation process, resulting in a promoted nitrophenol removal.Bentonite adsorption-catalytic ozonation process is investigated as a method of concurrent remove natural organic matters （NOM） and synthetic organic compounds （SOCs） from slightly-polluted potable water. Bentonite adsorbs or enmeshes NOM, which lowers its HO·scavenger effect. On the other hand, Fe³⁺ addition in this process promotes HO·generation, resulting in an enhancement in SOCs removal. The Bentonite adsorption-catalytic ozonation process remedies the drawbacks of AOTs in slightly-polluted water treatment, and realizes concurrent removal of NOM and aromatic containment.更多还原