Co/AC催化剂的制备及CWPO处理腈纶废水研究

以活性炭为载体，负载活性组分金属Co，制备了Co/AC催化剂，采用催化过氧化氢氧化技术（CWPO）处理腈纶废水，考察其催化氧化性能。实验结果表明：将预处理后的20～40目粒状活性炭浸渍于质量浓度为7％Co(NO3)2溶液中，浸渍9 h后，经自然晾干，在500℃的条件下焙烧4 h得到的Co/AC催化剂催化效果最好。     

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.     

催化臭氧氧化联合BAC工艺深度处理石化废水

针对石化废水难降解的问题，采用活性炭作为臭氧氧化单元的催化剂，并串联生物活性炭(BAC)单元，从水质变化、有机物分子质量分布和有机物结构等角度解析催化臭氧氧化对石化废水中难降解有机物的降解特性，以及对后续BAC单元出水水质的影响机理。结果表明，活性炭催化对臭氧氧化去除COD和UV₂₅₄均有一定的促进作用，且对后续BAC单元去除COD和UV₂₅₄的促进效果更明显，其中，对UV₂₅₄的去除效果影响更大，当臭氧投加量为15和20 mg/L时，催化臭氧氧化对UV₂₅₄的去除率比臭氧氧化分别提升9.4%和11.5%，后续BAC单元对UV₂₅₄的去除率比无催化条件时分别提升17.0%和15.4%；催化条件对进水有机物分子质量分布的改变在O₃投加量为15 mg/L时更明显，相比臭氧氧化，催化臭氧氧化对进水中不可吹扫有机碳(NPOC)的去除率提升5.4%，出水中分子质量<1 ku的NPOC比例增加6%；进水经催化臭氧氧化后，有机物结构显著改变，酚类、链烷烃类及不饱和...     

多相催化臭氧氧化法处理甲萘酚废水

以活性炭为载体、钾为助催化剂,采用浸渍法制备了Cu-K/AC催化剂,并考察了该催化剂催化臭氧氧化处理甲萘酚废水的效能.结果表明,当甲萘酚废水的COD为3 000 mg/L、含油量为120 mg/L时,在室温、pH=3、反应时间为120 min、催化剂投量为100 g/L、臭氧流量为5.2mg/min的条件下,催化臭氧氧化对COD及油类物质的去除率分别达到了93%和98%;臭氧氧化和催化臭氧氧化对COD的降解过程均符合表观一级反应动力学方程.     

钴改性硅矿石/臭氧催化氧化环丙沙星的性能

采用浸渍法制备Co_3O_4/硅矿石复合催化剂(CoSO),并对制备条件进行了优化。通过EDS、XRD、BET等方法对催化剂进行表征,同时比较了单独臭氧氧化、硅矿石吸附、CoSO吸附、SO/臭氧催化氧化和CoSO/臭氧催化氧化体系对环丙沙星(CIP)的降解能力。结果表明,Co_3O_4可成功负载于天然硅矿石表面,当浸渍液(硝酸钴)浓度为0. 5 mol/L、焙烧时间为5 h、焙烧温度为500℃时,制备的CoSO复合催化剂活性最高。采用CoSO/臭氧催化氧化CIP,30 min后对CIP的去除率为91. 5%,比单独臭氧氧化及SO/臭氧催化氧化分别提高了49%和25%。另外,单独臭氧氧化、SO/臭氧催化氧化和CoSO/臭氧催化氧化体系对CIP的降解过程符合拟一级反应动力学,并且CoSO/臭氧催化氧化体系对CIP的降解动力学常数为0. 082 min~(-1),分别为单独臭氧氧化和SO/臭氧催化氧化的4. 8和2. 4倍。     

ZnO/O3工艺降解水中微量有机物的研究

以实验室制备的粉末氧化锌(ZnO)为催化剂,考察了ZnO/O3工艺去除水中有机物的效能.采用总有机碳(TOC)指标反映水中有机污染物的含量.结果表明:臭氧投量为1 mg/L、ZnO投量为300 mg/L时,反应60 min后ZnO-O3工艺对TOC的去除率为46%,比单独臭氧化提高了1倍;反应温度明显影响该工艺对有机物的降解效果,在水温为5,10,20和25 ℃时,TOC的去除率分别为17.5%,31.5%,45.9%和51.3%.臭氧浓度和催化剂投量的增加,可以提高TOC的氧化降解效率.     

Ru/Al2O3催化臭氧氧化降解邻苯二甲酸二甲酯活性研究

系统地考察了Ru/Al2O3催化剂对邻苯二甲酸二甲酯(DMP)溶液臭氧氧化过程的影响.结果表明Ru/Al2O3可以显著提高臭氧氧化的效果,反应120 min后对TOC的去除率可以由单独臭氧氧化的23.9%提高到71.6%.在试验考察的范围内,Ru的最佳负载量为0.1%;BET和XRD分析表明焙烧温度在600℃、催化剂粒径为0.5～1.0 mm时催化剂载体主要以γ-Al2O3形式存在,得到的催化剂具有较大的表面积、较多的表面活性位点,此时催化臭氧氧化的活性最高.通过单独臭氧氧化,单独臭氧氧化后再进行催化剂吸附,催化臭氧氧化的对比试验证明了Al2O3催化剂对体系TOC的去除主要是基于催化作用.     

多金属氧化物催化臭氧氧化处理苯酚废水的研究

自制3种多金属氧化物负载催化剂,即MnO-CuO-FeO/活性炭、MnO-CuO-FeO/Al_2O_3、MnO-CuO-CeO/Al_2O_3,用于催化臭氧氧化处理苯酚废水,对其影响因素进行了研究,并与单独臭氧氧化工艺进行对比。结果表明,在pH值为9. 53、臭氧投加量为14. 8 mg/L、催化剂投加量为7. 5 g/L的条件下,MnO-CuO-FeO/活性炭催化剂催化臭氧氧化工艺对苯酚的去除效果最佳,去除率高达94. 8%,COD去除率为53. 4%,连续使用6次后,苯酚去除率仍可达到81. 6%。通过加入羟基自由基抑制剂叔丁醇的试验可知,羟基自由基对苯酚的降解起主要作用。     

负载型FeOOH催化臭氧氧化对HAAsFP的控制效果

考察了在连续流体系中,滤后水经负载型羟基氧化铁(FeOOH)催化臭氧氧化后5种卤乙酸的生成势(HAAsFP)。结果发现,经负载型FeOOH催化臭氧氧化后,滤后水的HAAsFP比单独臭氧氧化后的降低了33.1%,对TOC较高的去除率及.OH对卤代活性位较高的破坏能力,可能是连续流体系中催化臭氧氧化进一步控制HAAsFP的主要原因。同时还考察了Br-浓度、O3投量及停留时间对连续流体系中催化臭氧氧化控制滤后水中HAAsFP的影响。结果表明,在不同的反应条件下,FeOOH催化臭氧氧化都表现出明显控制HAAsFP的优势。Br-浓度的增加提高了溴代HAAs的比例,当[Br-]=1 mg/L时,FeOOH催化臭氧氧化降低滤后水中HAAsFP的优势相对更明显。增大臭氧投量和延长接触氧化的停留时间都能使FeOOH催化臭氧氧化滤后水中的HAAsFP值进一步降低。     

臭氧多相催化氧化技术在水厂深度处理中的应用

通过生产性对比试验考察了臭氧催化氧化技术用于给水深度处理时对有机物的去除效能.结果表明,相对于单纯的臭氧氧化,臭氧催化氧化明显地提高了对TOC及微量有机物的去除率,并使水中的剩余臭氧浓度降低了0.2 mg/L,有效地抑制了溴酸盐的生成.该技术可明显降低后续处理工艺的污染物负荷,并使有机物在活性炭上的吸附性能提高了近一倍,与生物活性炭联用后,对有机物的综合去除能力提高了14%～24%.臭氧催化氧化及其联用技术在兼顾有机物去除与臭氧化副产物控制方面具有明显的优势.     

Mineralization of some natural refractory organic compounds by biodegradation and ozonation

The objective of this study was to explore the extent of mineralization, reduction in color and reduction of COD of gallic acid, tannin and lignin by ozonation and a combination of aerobic biodegradation and ozonation. Ozonation of pure aliquots (phase I experiments) resulted in the decline in TOC, COD, COD/TOC ratio, UV absorbance at 280 nm and color of the three model compounds investigated, with COD removals of greater than 80% and high removals (>90%) of UV absorbance at 280 nm and color observed in all cases at an ozone dose of 6 mg ozone/mg initial TOC or higher. Aerobic biodegradation of pure gallic acid, tannin and lignin aliquots resulted in COD decline of approximately 36-38%. Subsequent ozonation (phase II experiments) resulted in further decline in TOC, COD, COD/TOC ratio, and increase in UV absorbance at 280 nm and color removals. COD and TOC removals comparable to phase I experiments were obtained with 30-40% lower ozone absorption in phase II experiments. The biodegradation step was quite effective in removing specific UV absorbance at 280 nm, with up to 75% removal observed. Subsequent ozonation increased overall specific UV absorbance at 280 nm to greater than 90%.     

Ozone and photocatalytic processes to remove the antibiotic sulfamethoxazole from water

In this study, water containing the pharmaceutical compound sulfamethoxazole (SMT) was subjected to the various treatments of different oxidation processes involving ozonation, and photolysis and catalysis under different experimental conditions. Removal rates of SMT and total organic carbon (TOC), from experiments of simple UVA radiation, ozonation (O(3)), catalytic ozonation (O(3)/TiO(2)), ozone photolysis (O(3)/UVA), photocatalytic oxidation (O(2)/TiO(2)/UVA) and photocatalytic ozonation (O(3)/UVA/TiO(2)), have been compared. Photocatalytic ozonation leads to the highest SMT removal rate (pH 7 in buffered systems, complete removal is achieved in less than 5min) and total organic carbon (in unbuffered systems, with initial pH=4, 93% TOC removal is reached). Also, lowest ozone consumption per TOC removed and toxicity was achieved with the O(3)/UVA/TiO(2) process. Direct ozone and free radical reactions were found to be the principal mechanisms for SMT and TOC removal, respectively. In photocatalytic ozonation, with buffered (pH 7) aqueous solutions phosphates (buffering salts) and accumulation of bicarbonate scavengers inhibit the reactions completely on the TiO(2) surface. As a consequence, TOC removal diminishes. In all cases, hydrogen peroxide plays a key role in TOC mineralization. According to the results obtained in this work the use of photocatalytic ozonation is recommended to achieve a high mineralization degree of water containing SMT type compounds.     

Mineralisation of coloured aqueous solutions by ozonation in the presence of activated carbon

The degradation of organic matter in coloured solutions of different classes of dyes by ozonation in the presence of activated carbon is investigated. The kinetics of the decolourisation and mineralisation of three different dyes solutions (CI Acid Blue 113, CI Reactive Red 241 and CI Basic Red 14) were studied in a laboratory scale reactor by three different processes: adsorption on activated carbon, oxidation with ozone and ozonation in the presence of activated carbon. The mineralisation of the solutions was followed by measuring the total organic carbon (TOC). Under the experimental conditions used in this work, activated carbon was not capable of completely removing the colour of the solutions in reasonable time. On the other hand, ozonation quickly decolourised all the solutions, but satisfactory removal of TOC was never achieved by this process. The combination of activated carbon with ozone enhanced the decolourisation of the solutions and especially the mineralisation of the organic matter. Activated carbon acts both as an adsorbent and as a catalyst in the reaction of ozonation. The surface chemistry of the activated carbon is an important parameter; it was observed that basic samples improve TOC removal. The main conclusions of this work were validated by treating a real textile effluent collected after the conventional biological treatment.     

Characterization of ozone decomposition in a soil slurry: kinetics and mechanism.

A series of soil slurry experiments were performed in a carefully conceived reactor set-up to investigate the characteristics of the catalytic decomposition of ozone on a sand and iron surface. Real time on-line monitoring of ozone in the reaction module was possible using flow injection analysis coupled with a computer-controlled UV detector and data acquisition system. The effects of the soil media and size, ozone dosage, pH and p-CBA as a probe compound were examined at the given experimental conditions. Two apparent phases existed, and ozone instantaneously decomposed within one second in the first phase. These were defined as the instantaneous ozone demand (ID) phase, and the relatively slow decay stage. The interactions of ozone with the soil organic matter (SOM) and metal oxides were attributed mostly to the instantaneous decomposition of ozone. From the probe (p-CBA) experiments, 60-68% of total p-CBA removal occurred during the ID phase. The generation of hydroxyl radicals (OH.) was demonstrated and was closely related with metal oxides as well as SOM. Metal oxides in soil surface were considered to have relatively faster reaction rate with ozone and provide more favorable reactive sites to generate higher amount of OH. than SOM. Even at one-tenth concentration of the sands, a goethite-induced catalytic reaction outfitted the removal rate ofp-CBA among all the soils tested. More than 40% of total p-CBA removal occurred on the soil surface. It was inferred that the radical reaction with the probe compound seemed to take place not only on the soil surface but also in the solid-liquid interface. Ozone decomposition and the reaction between OH. and p-CBA appeared to be independent of any change in pH.     

Study of catalyzed ozonation for advanced treatment of pulp and paper mill effluents

Ozonation and catalytic ozonation (TOCCATA process) were used as tertiary treatments of wastewaters from three different pulp and paper mills. Laboratory batch experiments were conducted to assess the efficiency of each oxidation system for removal of organic matter. The investigations measured ozone consumption rate, variations in chemical oxygen demand (COD), total organic carbon (TOC), suspended solids (SS) and molecular weight distribution with contact time. For conventional ozonation, ozone consumption rate was dependent on the nature of the effluent. Organic matter elimination occurred both by oxidation and precipitation. Precipitation played a major role on TOC removal varying with the effluent, and was responsible for production of high final SS concentrations. However, the effluent type did not affect the ozone consumption rate for TOCCATA-catalyzed reactions. Using TOCCATA, it was shown that organic matter was removed through steady conversion of organic carbon to carbon dioxide. Finally the two oxidation systems were compared with respect to their impact on molecular weight distribution. A total removal of the two initial fractions of compounds (high and low molecular weights) was observed with two effluents. With the third effluent, only the initial fraction of low molecular weight compounds was removed by the two oxidizing systems. The results showed that ozonation and TOCCATA-catalyzed ozonation could achieve removals of COD of 36-76%. Depending on the effluent type, the amount of ozone consumed per gram of COD removed was lower for conventional or for catalytic ozonation.     

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。     

亚硝酸盐氮对臭氧氧化有机物的影响研究

在臭氧氧化处理微污染原水的工艺中，臭氧对有机物的去除效果与水中还原性无机物的含量有关。通过试验考察了水中NO2^--N对臭氧氧化有机物的影响。结果表明，水中较高浓度的NO2^--N可消耗臭氧投加量的40％左右，并降低了臭氧对THMs前体物的去除率，也影响其提高水中可生物降解有机物浓度的能力；碱度的增加可增强NO2^--N对臭氧的竞争利用，降低臭氧对TOC和UV254的去除率。