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.     

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.     

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。     

Fe2+/UV催化臭氧法降解腈纶废水

 研究了Fe²⁺/UV催化臭氧对腈纶废水的降解特性,分析了[Fe²⁺]/[O₃]质量浓度比、气相臭氧质量浓度和光强各因素对Fe²⁺/UV催化臭氧降解性能的影响规律,讨论了Fe²⁺/UV催化臭氧工艺光催化反应动力学特征,并利用红外光谱分析法表征了废水中有机物基团的变化。结果表明,当[Fe²⁺]/[O₃]质量浓度比为3.2~3.8、气相臭氧质量浓度为20～30mg/L和光量子流密度为8.62×10-12 Einstein时,催化效果较好。Fe²⁺/UV催化臭氧工艺降解腈纶废水符合类一级动力学反应,初始COD值在320~400 mg/L范围内,一级反应速率常数为0.01518~0.01762 min-1。温度对动力学影响具有双重性,温度为25~30℃反应最快。经Fe²⁺/UV催化臭氧降解后,腈纶废水中有机基团被有效降解。     

臭氧在饮用水处理中的应用

阐述臭氧在水处理中的氧化消毒机理,其强氧化性能破坏了有机物的分子结构,将一部分有机物彻底分解,同时将大分子有机物生成小分子有机物,改变了有机物性质,提高了其可生化性。介绍臭氧在水处理中的应用,如预氧化对微污染水中有机物、无机物、藻类及颗粒物的去除,以及对饮用水消毒杀菌。     

改性蜂窝陶瓷催化臭氧氧化净水效能中试研究

通过中试考察了改性蜂窝陶瓷催化臭氧氧化(催化氧化)—活性炭过滤的净水效果,并与臭氧—活性炭工艺进行比较。试验条件下蜂窝陶瓷催化剂在静态和动态条件下均不会促进气体向水中的传质;静态条件下催化氧化对水中有机物的去除效率比臭氧单独氧化高;动态试验中,催化氧化对UV254的去除率高于臭氧氧化,但对TOC的去除没有优势,与臭氧氧化相比催化氧化有利于后续活性炭对有机物的去除。GC/MS测定表明,催化氧化及其后续活性炭出水中半挥发性有机物种类分别比臭氧单独氧化少9%和32%。经Ames试验发现,两种氧化及其后续活性炭处理后水的致突变活性均有微小增加。     

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%。     

Treatment of textile waste effluents by ozonation and chemical coagulation

Ozonation experiments in a multiple reactor system were conducted to investigate the efficiency of this process in reducing the color and chemical oxygen demand of the textile waste effluents. It has been observed that decolorization of those waste effluents can be achieved in less than 10 min in all tested cases. In conjunction with chemical coagulation, the chemical oxygen demand of those waste effluents can be consistently reduced by up to 70% or more. Ozonation is capable of decomposing the highly structured dye molecules into smaller ones which can be easily biodegraded in an activated sludge process. Hence combination of ozonation, chemical coagulation and the activated sludge processes can provide a very effective means for dealing with this particular type of industrial waste effluent.     

Using catalytic ozonation and biofiltration to decrease the formation of disinfection by-products

The effect of catalytic ozonation in a fluidized bed reactor (FBR) on the formation of individual disinfection by-products (DBPs) was investigated. A biofiltration column was used to evaluate the removal efficiency of biotreatment on DBP precursors. Dissolved organic carbon (DOC), simulated distribution system trihalomethanes (SDS THMs), and six simulated distribution system haloacetic acids (SDS HAA6) were monitored. The source water was polluted by domestic and agricultural effluents. Catalytic ozonation removed the concentration of DOC by 8.2-51.4% depending on the dosage of the catalyst. The decreases of SDS THMs and SDS HAA6 were 41.3-51.2% and 31.7-48.3%, respectively, under the same operating conditions. Biotreatment greatly improved the removal efficiency of DOC and decreased the formation of DBPs. Up to 81.7%, 76.1%, and 81.3% of DOC, SDS THMs precursors, and SDS HAA6 precursors were removed after the catalytic ozonation followed by biofiltration, respectively. The treatment processes also influenced the proportions of individual DBP species. The proportion of bromine-containing species from the SDS THMs and SDS HAA6 increased in water samples after being treated by biofiltration alone, ozonation alone, catalytic ozonation, and catalytic ozonation followed by biofiltration.     

Absolute Configuration of β- and α-Asymmetric Carbons within β-O-4-Structures in Hardwood Lignin

In this study, we investigated the proportion of erythro- and threo-forms of β-O-4-ether structures and their enantiomeric compositions in hardwood lignin by applying the ozonation method to birch wood meal. Optical activity was not substantially observed in either the erythronic or threonic acids obtained as the ozonation products of β-O-4-structures in birch wood meal. The proportions of the four stereoisomeric forms {(αS,βR)-erythro, (αR,βR)-threo, (αS,βS)-threo, and (αR,βS)-erythro forms} were estimated to be 37-38%, 13-14%, 12-13%, and 36-37% based on the yields of erythronic and threonic acids, and on their optical activities. The proportions suggest that the entire components of β-O-4-ether structures in birch wood lignin have R- and S-configurations at the β-carbon in approximately the same quantities {(βR)-β-O-4-structure: (βS)-β-O-4-structure = 50–52:48–50}; i.e., that the β-ether structures are essentially racemic. This estimation implies that, during lignin biosynthesis, an equal number of enantiomeric forms of β-O-4-bonded quinone methides were formed by radical coupling reactions.