臭氧-生物活性炭与单独活性炭工艺处理效果比较

为有效去除水中有机物,明确是否应在活性炭前投加臭氧,比较了臭氧-生物活性炭（O3-BAC）和单独活性炭（GAC）过滤对CODMn、UV254和TOC的去除效果以及两套系统对提高水质生物稳定性的作用.研究发现,O3-BAC对CODMn、UV254和TOC的平均去除率比GAC分别高10.3%、11.1%、7.1%,对AOC的去除率＞80%,出水AOC浓度为25.9～46.4μg乙酸碳/L,属生物稳定性水质;单独GAC柱对AOC的去除率在40%左右,出水AOC浓度为85.8～117.6μg乙酸碳/L,有时不能满足水质生物稳定性的要求.可见在活性炭前投加臭氧,可以强化活性炭对有机物的去除作用,延长活性炭的使用周期,增强活性炭滤池的生物降解能力.     

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.     

微污染北江源水的深度处理工艺优选

采用预氧化＋常规处理＋深度处理工艺对微污染北江源水进行了中试研究，考察了在预臭氧、预氯化和无预处理方式下，GAC和O3-BAC深度处理工艺的除污效果。结果表明：采用预臭氧氧化方式可大大改善常规处理工艺对CODMn、UV254的去除效果；在预臭氧氧化方式下，O3-BAC和GAC深度处理工艺均能在长时间内保持对有机物的高效去除，且前者的去除效果及其活性炭的使用周期均优于后者；活性炭吸附对氨氮无明显去除效果，而生物降解能较好地去除氨氮；预臭氧氧化能有效去除原水中的THMFP，但生成的CHCl3不能通过生物降解被去除，只能被活性炭所吸附，在活性炭吸附饱和后出水CHCl3浓度比进水的高；从长远角度考虑，对于北江源水，预臭氧＋常规处理＋O3-BAC是一种较优的组合工艺，它能够有效去除饮用水中的有毒、有害物质，并保障饮用水的安全性。     

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。     

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...     

微纳米气泡曝气提升臭氧/生物活性炭工艺的处理效能

将微纳米气泡曝气技术与臭氧/生物活性炭工艺结合,探讨了该组合工艺与传统臭氧/生物活性炭工艺在处理效能方面的差异。依托小试活性炭柱装置,分别采用微纳米气泡曝气技术和普通曝气技术进行32 d的连续流试验。结果表明,在臭氧氧化阶段微纳米气泡臭氧氧化对UV_(254)的去除率为60%,而大气泡臭氧氧化对UV_(254)的去除率为29%。在生物活性炭(BAC)处理阶段,与大气泡曝气培养的活性炭柱相比,微纳米气泡曝气培养的活性炭柱对TOC的去除效果更好。微纳米气泡曝气的活性炭柱出水消毒副产物生成势低于大气泡曝气的活性炭柱,两种不同曝气方式的活性炭柱出水消毒副产物相对含量与出水COD_(Mn)的相对值有密切关系,而进水则无此关系。微纳米气泡曝气的活性炭柱中微生物群落的物种丰富度和均匀度均高于大气泡曝气的活性炭柱,即微纳米气泡曝气方式影响了活性炭柱中微生物的群落结构。     

内循环流化床—臭氧催化氧化处理石化废水二级出水

采用内循环流化床-臭氧催化氧化工艺深度处理石化废水二级出水，通过单因素实验确定了该工艺的最佳运行条件，并在该条件下对臭氧催化氧化流化床与固定床工艺进行了效果对比。结果表明，流化床工艺能够更高效地降解石化废水中的有机物，在催化剂投加量为40 g/L、臭氧投加量为75 mg/（L·h）、反应时间为1 h的条件下，流化床工艺的TOC去除率为46.47%，臭氧利用率为68%，固定床工艺的TOC去除率为21.73%，臭氧利用率为39.8%；达到相同TOC去除效果时，流化床工艺所需催化剂投加量仅为固定床工艺的1/10。流化床催化剂1 h内可以吸附石化废水中30.23%的TOC，相同投量的固定床催化剂对TOC的吸附效果不明显。重复实验结果表明，臭氧催化氧化是流化床工艺去除污染物的主要途径。三维荧光光谱和UV254分析显示，相同条件下流化床工艺将臭氧转化为活性自由基的能力强于固定床工艺。内循环流化床-臭氧催化氧化工艺可大量减少催化剂使用量，提高臭氧利用率，降低废水处理成本，且效果稳定。     

粉末活性炭和臭氧在水处理中的试验研究

通过对臭氧在水中的反应途径和其对嗅味物质的氧化去除规律的分析,采用单独投加臭氧预氧化和臭氧与活性炭池联用处理工艺的试验,主要考察臭氧投加量、氧化时间对出水嗅阈值的影响。试验结果表明,随着臭氧投加量的增加,出水嗅味减少;延长臭氧氧化时间,除臭效果变好;随着臭氧投量的增加,氧化时间对除臭效果的影响下降。臭氧与粉末活性炭联用对嗅味的处理效果明显优于单独使用臭氧、单独使用粉末活性炭对嗅味的处理效果。     

串联微絮凝过滤工艺预处理低浊度海水研究

以三氯化铁和聚合氯化铝（PAC）作为絮凝剂，采用石英砂、沸石、锰砂和颗粒活性炭滤柱进行了单独及串联微絮凝过滤预处理低浊度海水的试验研究。结果表明，单独微絮凝过滤对浊度有较好的去除效果，其中锰砂的相对较差；颗粒活性炭滤柱对有机物的去除率较高，其余3种滤柱只能去除小部分的有机物；4种滤柱单独过滤的除盐能力均很弱。而串联过滤工艺明显提高了对有机物的去除率和除盐能力，几乎全部的浊度和绝大部分的有机物均能被有效去除。当采用三氯化铁作絮凝剂时，石英砂滤柱与颗粒活性炭滤柱串联的除盐效果最显著；而采用PAC作絮凝剂时，锰砂滤柱与颗粒活性炭滤柱串联的除盐能力最佳。     

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.     

MnOx/GAC多相催化臭氧氧化降解有机物机理探讨

通过考察羟基自由基抑制剂——叔丁醇对MnOx／GAC多相催化臭氧氧化过程的影响，探讨了其对有机物的降解是否遵循羟基自由基反应机理。试验结果表明，叔丁醇的存在并未降低MnOx／GAC多相催化臭氧氧化对贿基苯的降解效率，由此可推断羟基自由基并非是MnOx／GAC多相催化臭氧氧化反应中的主导活性氧化物种。此外，MnOx／GAC多相催化臭氧氧化降解硝基苯的效果也未受重碳酸盐的影响。因此，MnOx／GAC多相催化臭氧氧化工艺可能比遵循羟基自由基反应机理的其他高级氧化法具有更广泛的适用性。     

Effect of pH on MnOx/GAC catalyzed ozonation for degradation of nitrobenzene

The effect of pH on MnO(x)/GAC heterogeneous catalytic ozonation was investigated. Nitrobenzene was used as a model refractory organic pollutant. It was found that in MnO(x)/GAC catalytic ozonation, the degradation efficiency of nitrobenzene was higher under low pH conditions (pH 2.74-3.52) than that under high pH conditions (pH 6.72-9.61). This result was different from the case of ozonation alone, in which higher pH had positive effect on the degradation of nitrobenzene due to the formation of hydroxyl radical. In the presence of MnO(x)/GAC catalyst, ozone decomposition was accelerated, and higher pH condition favored ozone decomposition. It was assumed that hydroxyl radicals might not be the dominating active species in the catalytic oxidation, for the presence of t-butanol did not have any influence on MnO(x)/GAC heterogeneous catalytic ozonation. Adsorption of organic micropollutants on MnO(x)/GAC catalyst was an important step and would have direct influence on the effectiveness of catalytic oxidation. It was assumed that the organic pollutants might be further decomposed on the surface of catalyst.     

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.     

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.     

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.     

Ozonation kinetics of cork-processing water in a bubble column reactor

The oxidative degradation of organic pollutants present in cork-processing water at natural pH (6.45) was studied in a bubble column ozonation reactor. A steady reduction in both chemical oxygen demand (COD) and total organic carbon (TOC) was observed under the action of ozone alone and the feasibility of deep mineralisation (organic matter removal more than 90% in 120 min under the following experimental conditions: liquid volume 9L; superficial gas velocity 6.8x10(-3) m s(-1); ozone partial pressure 1.31 kPa; initial COD 328 mg L(-1); initial TOC 127 mg L(-1)) was demonstrated. The monitoring of pH, redox potential (ORP) and the mean oxidation number of carbon (MOC) was correlated with the oxidation and mineralisation of the organic species in the water. The ozonation of cork-processing water in the bubble column was analysed in terms of a mole balance coupled with ozonation kinetics modelled by the two-film theory of mass transfer and chemical reaction. Under the experimental conditions used, and in contrast with the literature, it was determined that the reaction follows a fast kinetic regime at the beginning of the oxidation process, shifting to the moderate and the slow kinetic regimes at later stages of the oxidation reaction. The dynamic change of the rate coefficient estimated by the model was correlated to changes in the water composition.     

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.     

Adsorption of natural organic matter oxidized with ClO2 on granular activated carbon

The paper describes the influence of the oxidation of natural organic matter (NOM) molecules with chlorine dioxide (ClO2) on granulated activated carbon (GAC) adsorption. In order to determinate the influence of ClO2 dosage on the NOM adsorption on GAC two parallel pilot scale experiments were performed. The raw water was treated respectively with 0.2 and 0.4 mg ClO2 L(-1) followed by the adsorption on GAC filters. Experiments were total organic carbon (TOC) measurements and size exclusion chromatography (SEC) controlled. The molecular weight distribution of NOM in the filtration bed outlet demonstrates that the low molecular weight molecules are less retained than the higher molecular weight components of NOM. It is shown that low molecular weight NOM causes less ClO2 demand. The oxidation of NOM molecules and very high capacity of GAC filter bed for NOM components can be used to control high ClO2 demand.     

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。