【作者】 关春雨；

【导师】 马军；

【作者基本信息】 哈尔滨工业大学 ， 市政工程， 2009， 博士

【摘要】 当前饮用水水源的有机污染较为严重,有机污染物本身不仅具有极高的毒害作用,而且在加氯消毒后可能生成卤代消毒副产物（DBPs）,同时有机物的存在还会降低饮用水的生物稳定性,导致微生物在管网中的二次繁殖,因此减少饮用水中的有机污染物含量具有重要意义。常规水处理工艺对于有机污染物的去除效率较低,寻求经济、高效的处理技术势在必行。臭氧催化氧化技术在充分发挥臭氧氧化去除有机物优势的基础上,引发生成氧化性极高的羟基自由基（·OH）,从而可以有效去除水中难降解微量有机污染物、减少臭氧氧化副产物含量,是一种极具应用前景的饮用水处理方法。实验室研究表明,蜂窝陶瓷及活性炭催化臭氧氧化技术对水中微量有机物的去除具有较为明显的优势,但是催化氧化与活性炭联用工艺特性有待深入研究,因此通过中试考察了蜂窝陶瓷催化臭氧氧化及活性炭催化臭氧氧化与活性炭过滤联用工艺运行特征。试验条件下蜂窝陶瓷催化反应器的气液传质能力稍低于臭氧反应器,但当气水比大于0.15时气液传质能力将超过臭氧反应器。气量为0.1 m³/h时臭氧反应器与蜂窝陶瓷催化氧化反应器的气含率（εg）分别为0.19%和0.15%,说明催化氧化反应器内的气泡尺寸较大,不利于气液传质;液相脉冲加入试验中臭氧反应器与蜂窝陶瓷催化反应器的Pe准数分别为3.14和5.25,说明催化氧化反应器内液相平推流成分较高,有利于气液传质。气水比增加对催化氧化反应器的气液传质效率影响更大。蜂窝陶瓷催化氧化对有机物的去除能力高于臭氧氧化,序批试验中催化氧化对TOC及CHCl₃FP最高去除率均比臭氧氧化高约2倍。连续流试验中催化氧化对UV₂₅₄的去除效果在低臭氧投量时较为明显,臭氧投量为1 mg/L时催化氧化对UV₂₅₄去除率比臭氧氧化高16.7%,这是蜂窝陶瓷催化反应器平推流比例较高,使得液相臭氧浓度迅速上升结果。此外,蜂窝陶瓷催化氧化对BrO₃^-有较好的控制作用,臭氧投量为1 mg/L时催化氧化出水BrO₃^-含量比臭氧氧化低38.8%。活性炭催化剂能够促进臭氧的分解。连续运行时活性炭催化二级氧化工艺比臭氧二级氧化工艺对液相臭氧的消耗率平均高71.2%。对活性炭催化二级氧化工艺的臭氧消耗量与有机物含量间关系分析证明,活性炭在臭氧分解过程中可与臭氧直接反应或起自由基引发剂作用,在水中有机物含量较低时其臭氧分解促进作用尤为明显。当臭氧投量为1 mg/L时,催化二级氧化对MIB去除率比臭氧二级氧化高约1倍。当水中臭氧浓度为1.5 mg/L左右时,催化二级氧化使BrO₃^-浓度降低了0.04 mg/L。催化氧化与活性炭过滤组合工艺的净水效率较高。进水臭氧浓度0⁰.1 mg/L、进水UV₂₅₄为0.020⁰.030 1/cm时催化与臭氧后续活性炭对UV₂₅₄平均去除率分别为30%和21%,活性炭过滤对UV₂₅₄及DOC的去除率在进水水质及液相臭氧浓度适中时最大,液相臭氧相对浓度（O₃/DOC）约为0.3时DOC去除率达到最高值。催化氧化后续活性炭进水中有机物含量及臭氧浓度均较低,有利于活性炭保持吸附容量和表面性质。此外,催化剂流失的金属氧化物可被活性炭吸附,这也有助于促进臭氧在活性炭表面分解。更多还原

【Abstract】 Drinking water sources are now suffering ever severe organic pollution, and the presence of organics in water is not only harmful to human being by itself, but also responsible for the formation of disinfection by products （DBPs） after chlorination, and the organics may also decrease water biostability, leading to the propagation of microorganism in drinking water distribution system, so the organics in water is supposed to be removed as much as possible. The traditional water treatment processes is less capable on the removal of organics, which calling for more economic and efficient water treatment processes. Based on the advantage of ozone oxidation, catalytic ozonation may initiate the formation of hydroxyl radicals （·OH）, whose oxidation potential is much higher than ozone. Therefore, refractory micropollutants may be effectively degraded and the ozonation byproducts may be restrained by catalytic ozonation, which shows a promising application on drinking water treatment.Ceramic honeycomb catalytic ozonation （CH catazone） and activated carbon catalytic ozonation （carbozone） were proved to be efficient on the removal of certain micropollutants in bench experiments, while the operation character of carbozone-GAC processes remains to be explored, so in this study, the operating characteristics of CH catazone, carbozone and their following granular activated carbon （GAC） filtration were investigated by pilot experiments.Under the study condition, the gas-liquid mass transfer efficiency of CH contactor was slightly lower than that of ozone contactor unless gas-liquid ratio was larger than 0.15. At a flow rate of 0.1 m³/h, the gas holdup （εg） of ozone and CH contactor was 0.19% and 0.15% respectively, thus the bubble size was relatively larger in CH contactor, which was adverse on gas-liquid mass transfer. Calculated by liquid pulse tracer input test, the Pe number of ozone and CH contactor was 3.14 and 5.25 respectively, thus the portion of plug flow was relatively larger in CH contactor, which was positive on gas-liquid mass transfer. The increase of gas flow rate may promote gas-liquid mass transfer more obviously in CH contactor.The oxidation degradation efficiency of CH catazone was higher than ozonation, and the highest TOC and CHCl₃FP removal rate of CH catazone was 2 times higher than that of ozonation in batch experiment. The advantage of CH catazone on UV₂₅₄ removal was more pronounced at lower ozone dose in continuous flow experiment, and at an ozone dose of 1 mg/L, the UV₂₅₄ removal rate of CH catazone was 16.7% higher than that of ozonation, which was the result of the larger portion of plug flow and faster increase of dissolved ozone concentration in CH contactor. The BrO₃^- was better controlled by CH catazone, and the BrO₃^- concentration was 38.8% lower in CH catazone effluent comparing with that of ozonation at an ozone dose of 1 mg/L.Activated carbon catalyst may promote ozone decomposition. The dissolved ozone consumption ratio of 2nd carbozone process was 71.2% higher than that of ozonation process in long-term continuous flow experiment. Analysis on the relationship between ozone consumption and organic content in 2nd carbozone process proved the ozone decomposition and radical initiation effects of activated carbon, and those effects were more obvious at lower organic concentration. The MIB removal rate of 2nd carbozone was 1 times higher than that of ozonation at an ozone dose of 1 mg/L. BrO₃^- concentration decreased 0.04 mg/L in 2nd carbozone and process, when dissolved ozone concentration was about 1.5 mg/L.The water purification performance of catazone-GAC filtration process was better than its counterpart. The UV₂₅₄ removal rate of catazone subsequent GAC and ozonation subsequent GAC was 30% and 21% respectively, at an dissolved ozone concentration of 0¹.0 mg/L and influent UV₂₅₄ of 0.020⁰.030 1/cm. The UV₂₅₄ and DOC decreasing effect of GAC filtration was most obvious when both influent organic content and dissolved ozone concentration were in their moderate levels, and the highest DOC removal efficiency of GAC filtration appeared at a specific dissolved ozone dose （O₃/DOC） of 0.3. Organic and ozone concentration were both lower in the influent of GAC following catazone, which was helpful to the maintenance of adsorption capacity and the delay of surface oxidation. Moreover, metal oxides eluted from catalyst may be adsorbed by GAC, contributing to the decomposition of ozone on GAC surface.更多还原