O3/BAC工艺应用于城市污水深度处理

为使再生水适合不同用途,对经过混凝沉淀和砂滤处理的再生水进行了臭氧-生物活性炭的深度处理.在臭氧消耗量和反应时间分别为5 mg/L和10 min,BAC空床停留时间(EBCT)为10 min的条件下,臭氧-生物活性炭工艺对CODMn、DOC、UV254和色度平均去除率为32.4%、29.2%、48.6%和80.1%,出水CODMn、DOC、UV254和色度的平均值分别为3.3 mg/L、4.0mg/L、0.05 cm-1和2.0倍;臭氧生物活性炭工艺出水SDI《4,从而满足了反渗透系统的进水要求.     

污水厂二级处理出水的臭氧氧化特性及其动力学

研究了城市污水厂二级处理出水的臭氧氧化特性及其动力学规律。结果表明，臭氧氧化可以显著提高二级处理出水的可生化性，当臭氧投量为10mg／L、接触时间为2min时，可使其BDOC和TOC／UV254值分别提高约1倍；当接触时间为4min时，臭氧氧化对COD、TOC的去除率分别达到25．7％和16．5％，使UV254和色度分别降低了62．31％和79．25％，同时分子质量〈1ku的有机物所占比例由原来的52．9％升高到72．6％。当接触时间从2min延长到30min时，对NH3-N的去除率由1．3％增加到22．5％。拟合结果表明，在（0～1．6）、（1．6～16）和（16～30）min的时段内，臭氧氧化反应均为一级反应，但反应速率逐渐降低。     

预氧化与催化臭氧化深度处理工艺的生产运行效果

通过生产运行分析了生物预氧化、梯级催化臭氧化-生物活性炭滤池深度处理组合工艺在生产应用中的综合净化效果,分别评价了各处理单元的净化效能。生产运行结果表明,生物预氧化对氨氮的平均去除率为62％,但处理效果受温度变化的影响;生物预氧化对CODMn的去除作用有限,对锰的平均去除率为58％;高密度沉淀池对浊度、色度、铁、锰具有良好的去除作用,对CODMn的去除率为28％;臭氧总投量相同时,与催化臭氧化一次性投加相比,预氧化与催化臭氧化分别投加更有利于减少溴酸盐的生成;半挥发性微量有机污染物主要在催化臭氧化阶段去除,去除率为44％。     

臭氧—生物活性炭工艺去除饮用水中AOC的研究

AOC是衡量饮用水生物稳定性的重要指标.研究发现,不同的臭氧投加量下砂滤出水的AOC变化不显著,考虑氧化作用和消毒效果,将最佳的臭氧投量确定为1～2 mg/L.生物活性炭(BAC)滤池改善了臭氧氧化后出水的生物稳定性,对TAOC的去除率稳定在28%～65%,而对AOC-P17的去除效果优于AOC-NOX的,因而表现出一定的选择性.较长的空床接触时间(EBCT)并不能保证对AOC的良好去除,但有利于TOC的去除,同时水温的降低一定程度上影响了BAC对AOC的去除效果.     

负载型FeOOH催化臭氧氧化对THMFP的控制效果

采用连续流试验,研究了负载型羟基氧化铁(FeOOH)催化臭氧氧化和单独臭氧氧化控制三卤甲烷生成势(THMFP)的效果.结果表明,负载型羟基氧化铁催化臭氧氧化出水中的THMFP比单独臭氧氧化的低22%.这主要和催化氧化对TOC的去除率较高以及羟基自由基破坏卤代活性位的能力较强有关.在不同的臭氧投量、溴离子浓度及接触氧化的停留时间下,负载型FeOOH催化氧化都表现出了更好的控制THMFP的效果.随着臭氧投量的增加,催化臭氧氧化出水中的THMFP先升高后降低,但都比单独臭氧氧化出水的THMFP要低.溴离子浓度较高时THMs以溴代产物为主,催化氧化控制THMFP的优势相对更明显.延长接触氧化反应的停留时间可使催化臭氧氧化出水的THMFP进一步降低.     

蜂窝陶瓷催化臭氧氧化处理饮用水中试

在北京市某净水厂进行了臭氧催化氧化处理滤后水的中试，对各种操作条件下蜂窝陶瓷催化臭氧氧化／颗粒活性炭过滤工艺的净水效果进行了考察。结果表明，与臭氧单独氧化相比，臭氧催化氧化反应器中有较高的溶解性臭氧浓度，对天然有机物（NOM）及总有机物（TOC）的去除效果较好，三氯甲烷生成潜能（CHCl3FP）较低。臭氧催化氧化的后续活性炭滤柱上的生物量较多，出水TOC、UV254及CHCl3FP值也均低于臭氧单独氧化的后续活性炭滤柱出水。     

Effect of soil organic matter (SOM) and soil texture on the fatality of indigenous microorganisms in intergrated ozonation and biodegradation

In situ ozonation has been proposed as a method to remediate soils contaminated with organic pollutants. Soil column experiments were performed on eight different soils in order to investigate the effects of soil properties, such as soil organic matter (SOM) and soil texture on the survival and regrowth of indigenous microorganisms after in situ ozonation. Indigenous microorganisms were found to be very sensitive to ozone in the soil column experiments. The microbial fatality revealed a linear relationship with the SOM content in the range of 1.72–2.42% of SOM content, whereas water content was poorly correlated. Four weeks of incubation of ozone-treated soil samples allowed for the regrowth of indigenous microorganisms with inverse relation to ozonation time. The regrowth was also significantly influenced by the SOM content in the same soil texture. Oxidation and removal rate of hexadecane was affected by particle size distribution. Especially, sand exhibited the highest oxidation rate of hexadecane, which resulted from having the lowest SOM content, water content, and surface area with respect to the other samples. The soil samples ozonated for 90–180 min were determined to exhibit the lowest concentration of hexadecane, with the exception of sand, after 4 weeks of incubation. This study provided insight into the influence of SOM and soil texture on indigenous microbial potential to degrade hexadecane in integrated ozonation and biodegradation.     

A Study on the Action of Ozone on Multiwall Carbon Nanotubes

The functionalization of the surface of multiwall nanotubes (MWNTs) is the first step for the synthesis of more complex supramolecular structures and for their application by attaching molecules, macromolecules and biologically active molecules. Here we show in detail a couple of methods for introducing oxygenated surface groups on MWNTs by room temperature ozonization.

The reaction kinetics between MWNTs and O₃ has been studied in static conditions inside an IR gas cell. The pseudofirst order rate constant has been determined and compared with those of other carbon materials. MWNTs appear as the most reactive carbon materials with ozone, producing CO₂ and even CO in certain special conditions when treated with a stream of ozonized oxygen. The ozonization reaction is strongly exothermic and conforms to the Elovich equation, an equation normally employed for the gas-solid oxidation kinetics and the chemisorption of gases over solid surfaces. The ozonized MWNTs have been characterized qualitatively by FT-IR spectroscopy and different types of ketonic groups have been detected although the most common has been found the carboxyl moiety. The quantitative analysis of ozonized MWNTs has been made by thermogravimetric analysis under N₂ flow.     

Simultaneous depolymerization and decolorization of chitosan by ozone treatment

ABSTRACT:  Currently, depolymerization and decolorization of chitosan are achieved by chemical or enzymatic methods, which are time consuming and expensive. Ozone has been shown to be able to degrade macromolecules and remove pigments due to its high oxidation potential. In this study, the effects of ozone treatment on depolymerization and decolorization of chitosan were investigated. Crawfish chitosan was ozonated in water and acetic acid solution for 0, 5, 10, 15, and 20 min at room temperature with 12 wt% gas. In this study, the effects of ozone treatment on depolymerization and decolorization of chitosan were investigated by measuring the molecular weight, viscosity, and color of chitosan. The color of ozone-treated chitosan was analyzed using a Minolta spectrophotometer. The degree of deacetylation was determined by a colloid titration method. Molecular weight of ozone-treated chitosan in acetic acid solution decreased appreciably as the ozone treatment duration increased. Ozonation for 20 min reduced the molecular weight of the chitosan by 92% (104 kDa) compared to the untreated chitosan (1333 kDa) with a decrease in viscosity of the chitosan solution. Ozonation for 5 min markedly increased the whiteness of chitosan with a molecular weight of 432 kDa; however, further ozonation resulted in development of yellowness. In the case of the ozonation in water, there were no significant differences in the molecular weight and color between ozone-treated chitosans. This study showed that ozone can be used to modify molecular weight and remove pigments of chitosan without chemical use in a shorter time and with less cost.     

基于微滤膜和撞击流的臭氧氧化废液反应器的优化设计

优化设计了基于微滤膜和撞击流技术的臭氧氧化废液的反应器,提高了臭氧氧化废液的利用率.利用微滤膜管的孔径和压力特点,优化了反应器内部互为撞击的两相物质的运动轨迹.在撞击前使两相物质变成微米级颗粒,实现臭氧与废液的全方位充分接触,从而提高氧化效果和臭氧的利用率,降低了废液的处理成本.实验表明,在短时间内降解率可达95％.