固载型TiO2光催化反应器对富营养水体杀藻作用研究

以泡沫镍作为载体,利用电沉积技术将纳米TiO2负载在泡沫镍上,制成固载型TiO2光催化反应器.研究表明,经过光催化反应器处理的富营养水体,30 h内叶绿素a由96.2 mg/m3降至2.2 mg/m3,下降率达97.6%,而未负载纳米TiO2普通泡沫镍材料,在同样光强的紫外灯照射下,叶绿素a下降率为74.3%,表明紫外光照射虽然也具有一定的杀藻功能,但是光催化反应才是藻类被杀灭的主要原因.利用9.54 m3景观喷水池进行杀藻中试,光催化反应器也同样表现出优异的杀藻性能,12 d内叶绿素a由18.7 mg/m3降至1.9 mg/m3,下降率达到89.8%,水体由浓绿变为清澈见底,这表明光催化反应器具有很强的杀藻能力,通过有效杀灭富营养水体中藻类、控制藻类基数,对应急处理城市景观水、湖泊等富营养水体和突发性藻华,提高生物-生态法处理效率,改善城市水环境具有十分重要的意义.     

微米级负载型 TiO2催化剂在光催化-膜分离反应器中的应用简

基于光催化-膜分离三相流化床反应器的结构特点及膜分离特性，以微米级MCM-41分子筛为载体，采用原位生成法制备微米级负载型TiO₂催化剂。针对微米级负载型TiO₂催化剂在光催化-膜分离反应器中的分布特性、悬浮特性、分离特性及膜污染特性进行研究。结果表明，曝气量一定的情况下，微米级负载型TiO₂催化剂在光催化-膜分离反应器中具有良好的悬浮特性，且优于纳米TiO₂。随着催化剂投加量的增加，悬浮浓度也随之增加。光催化反应器底部曝气0.3 m³/h、催化剂投加量为1 g/L时为宜。膜分离器中催化剂悬浮浓度明显低于光催化反应器；该微米级催化剂与纳米TiO₂相比具有不粘附、不堵塞膜孔等优良特性，能够有效降低膜污染，延长分离膜使用寿命。膜底曝气为0.1 m³/h时，反应器连续运行5 h（未加反冲洗）后，微米级负载型TiO₂催化剂和纳米TiO₂对膜组件的污染程度分别为膜通量衰减率4.3%和37.4%。反应器连续运行72 h，膜组件依然具有很好的分离特性。     

蜘蛛兰去除不同程度富营养水体中氮磷及抑藻效应简

研究了蜘蛛兰在不同程度富营养化水体中对氮、磷的去除和对藻类的抑制效应。结果表明，蜘蛛兰在3种不同程度富营养化水体中均能正常生长，且对富营养水体中的氮、磷和叶绿素a浓度均表现出良好的净化去除效果。在45 d的实验中，3种不同程度富营养水体的TN、NO₃^--N、NH₄⁺-N和TP浓度分别由初始的3.69~25.65、2.79~21.14、0.75~3.57和0.14~1.23mg/L降至1.25~18.99、1.08~16.03、0.18~1.39和0.06~0.77mg/L，在3种不同程度富营养水体中植物的平均生物量累积增长率分别为40.98% 、64.41% 和95.08%。实验各处理组富营养化水体中的叶绿素a浓度及荧光参数短期内都显著下降，而各对照组中则较稳定或略有下降。蜘蛛兰不仅可以净化富营养水体中营养元素，且对水体中藻类的生长有明显的抑制作用，其在水体生态修复工程中具有良好的应用前景。     

NO2对颗粒污泥甲烷化动力学特性的影响

采用间歇试验方法，以乙酸和乙酸盐混合物为基质，对取自EGSB反应器具有厌氧甲烷化反硝化与厌氧氨氧化活性的颗粒污泥的甲烷化动力学以及NO₂影响进行研究。无NO₂时，最大比基质降解速率为0.158 mg COD/mg VSS·h，半饱和常数为464 mg COD/L，甲烷的产率系数为0.254 mL CH₄/mg COD。添加微量NO₂对甲烷化有抑制作用，抑制程度随着微量NO₂浓度的增高而增大，在NO₂浓度为30.36 mg/m³、50.6 mg/m³、101.2 mg/m³、202.4 mg/m³和303.6 mg/m³条件下，甲烷化抑制程度分别为7.40％、11.87％、27.56％、39.75％和43.24％，外推得NO₂的甲烷化半抑制浓度IC₅₀值为383.8 mg/m³。NO₂气氛下甲烷化动力学可用反竞争性抑制动力学进行描述，最大比基质降解速率为0.148 mg COD/mg VSS·h，半饱和常数为396 mg COD/L，NO₂抑制系数为250 mg/m³。     

等离子体协同光催化去除模拟烟气中SO2的实验研究

近年来,低温等离子体技术以及纳米TiO₂光催化技术在烟气脱硫中的应用越来越引起人们的关注。利用填充床反应器将这2种技术有机地结合起来，进行了大量脱硫实验研究。研究结果表明，等离子体协同光催化去除烟气中的SO₂与单独采用等离子体技术相比，其SO₂的去除率可提高5%～20%。同时，探讨了等离子体协同TiO₂光催化剂的脱硫机理，分别研究了外加电压、气体流量和SO₂初始浓度等因素对脱硫效率的影响。实验结果表明，当SO₂初始浓度为800 mg/m³，输入电压为17.5 kV，气体流量为0.2 m³/h时，SO₂脱除率可以达到77.6%。     

TiO2/GeO2复合膜光催化氧化降解农药废水的研究

提出了一种新的TiO₂/GeO₂复合膜圆形光催化氧化反应器，研究了该反应器对经物化处理后的农药废水进行降解的过程。研究表明，光催化氧化的最佳条件是锌片镀TiO₂/GeO₂复合膜、pH=6.7、过氧化氢（H₂O₂）浓度为400 mg/L。并对其他氧化剂对该过程的影响进行了探讨。有机废水通过该反应器处理后，其COD值降为57mg/L。能使有机污染物全部降解为小分子无机物，废水达到国家一级排放标准。     

La2O3/ZnO/TiO2光催化降解活性艳红K-2BP的研究

采用溶胶-凝胶法制备了La₂O₃/ZnO/TiO₂复合光催化剂,以紫外灯为光源,活性艳红K-2BP为模型降解物,研究了La₂O₃/ZnO/TiO₂的光催化性能。结果表明：当锌和镧的掺杂量w(ZnO)=20%, w(La₂O₃)=0.5%, 煅烧温度为500℃时,La₂O₃/ZnO/TiO₂复合光催化剂的光催化活性最高；当催化剂投加量4 g/L,通气量800 mL/min,初始pH值3.12时,La₂O₃/ZnO/TiO₂对活性艳红K-2BP的降解效果最好。实验证明,La₂O₃/ZnO/TiO₂对活性艳红K-2BP的降解遵从Langmuir-Hinshelwood动力学模型,测得其反应速率常数k＝11.5 mg/(L·min)；吸附常数K＝2.88×10^-2 L/mg。     

银钛共负载型光催化材料降解甲基橙废水简

以膨胀珍珠岩为载体，采用溶胶凝胶法对其进行负载，制备出不同类型的光催化材料（TiO₂-EP、Ag⁺-TiO₂-EP），并在模拟日光条件下，研究其对甲基橙溶液的降解效果。结果表明，浸渍3次且担载0.04% Ag⁺的负载型TiO₂光催化活性最高，在光催化剂用量为0.3 g，20 mL初始浓度为10 mg/L甲基橙溶液光照4 h后降解率可达81.6%，且甲基橙的光催化降解服从一级动力学方程。回收3次后仍有较强的活性，其2 h降解率为24.8%。     

锰掺杂WO3-TiO2复合光催化剂的制备及其性能研究

溶胶-凝胶和浸渍相结合的方法制备锰掺杂WO₃-TiO₂复合光催化剂，RXD表征，考察WO₃和Mn²⁺掺入量、焙烧温度、焙烧时间及催化剂用量对光催化降解甲基橙的影响。结果表明，500℃焙烧2h，掺杂量n_{（Mn²⁺）}∶n_（WO3）∶n_（TiO2）＝0.8∶1∶100时，光催化活性最高，光催化降解甲基橙溶液，120min后，降解率达90%, 比单纯 TiO₂的光催化活性提高81%。     

水体中常见无机阴离子对TiO2薄膜光催化降解甲醛的影响

选择了5种水体中常见的阴离子(Cl^-，SO^2-₄，HPO^2-₄/HPO^2-₄，HCO^-₃/CO^2-₃和NO^-₃)，分别考查了其对TiO₂薄膜光催化降解模拟甲醛废水的反应速率的影响；从上述离子的光吸收，对·OH的捕获及其生成的相应的无机自由基的氧化作用以及与甲醛的竞争吸附3个方面讨论了上述离子影响TiO₂薄膜光催化降解模拟甲醛废水的反应速率的原因。结果表明，HCO^-₃/CO^2-₃对TiO₂薄膜光催化降解甲醛具有抑制作用，Cl^-和SO^2-₄的影响不大，H₂PO^-₄/HPO^2-₄和NO^-₃具有促进作用。造成上述结果的主要原因是HCO^-₃/CO^2-₃具有很强的·OH捕获作用；Cl^-，SO^2-₄对·OH捕获作用以及竞争吸附都较弱；H₂PO^-₄/HPO^2-₄在TiO₂表面具有较强的吸附能力，释放出的H⁺起到了酸催化剂的作用；NO^-₃在紫外光的照射下可以产生·OH，此外NO^-₃作为电子受体而降低了TiO₂表面光生电子和空穴的复合几率。     

Performance of photocatalytic reactors using immobilized TiO2 film for the degradation of phenol and methylene blue dye present in water stream

TiO2 thin film photocatalyst was successfully synthesized and immobilized on glass reactor tube using sol-gel method. The synthesized TiO2 coating was transparent, which enabled the penetration of ultra-violet (UV) light to the catalyst surface. Two photocatalytic reactors with different operating modes were tested: (a) tubular photocatalytic reactor with re-circulation mode and (b) batch photocatalytic reactor. A new proposed TiO2 synthesized film formulation of 1 titanium isopropoxide: 8 isopropanol: 3 acetyl acetone: 1.1 H2O: 0.05 acetic acid (in molar ratio) gave excellent photocatalytic activity for degradation of phenol and methylene blue dye present in the water. The half-life time, t1/2 of photocatalytic degradation of phenol was 56 min at the initial phenol concentration of 1000 microM in the batch reactor. In the tubular photocatalytic reactor, 5 re-circulation passes with residence time of 2.2 min (single pass) degraded 50% of 40-microM methylene blue dye. Initial phenol concentration, presence of hydrogen peroxide, presence of air bubbling and stirring speed as the process variables were studied in the batch reactor. Initial methylene blue concentration, pH value, light intensity and reaction temperature were studied as the process variables in the tubular reactor. The synthesized TiO2 thin film was characterized using SEM, XRD and EDX analysis. A comparative performance between the synthesized TiO2 thin film and commercial TiO2 particles (99% anatase) was evaluated under the same experimental conditions. The TiO2 film was equally active as the TiO2 powder catalyst.     

TiO2/β-SiC foam-structured photoreactor for continuous wastewater treatment

Introduction

This study of photocatalytic degradation of wastewater was carried out in alveolar cell ??-SiC foam-structured photocatalytic reactors working in a recirculation mode. The immobilization of TiO2 on ??-SiC foams was efficiently obtained through a sol?Cgel technique in acidic conditions.

Discussion

In order to optimize degradation yields obtained by the foam-structured prototype reactor for the photocatalytic water treatment, the operating conditions of the photoreactor have been investigated and the efficiency of the process was evaluated by measuring the photocatalytic degradation of Diuron (3-(3,4-dichlorophenyl)-1,1-dimethyl-urea)) under UV irradiation. Kinetic studies were carried out by investigating the influence of different parameters controlling the reaction (TiO2 loading and ??-SiC foam cell size). The ageing of TiO2/??-SiC foam photocatalytic materials and the mineralization (TOC, Cl?, NO3? and NH4+) of Diuron were investigated.     

光催化处理二甲苯废气的影响因素研究

使用自制光催化反应器,以多孔型载体分别负载纳米TiO2和普通TiO2,以256～265 nm紫外光为光源,探讨了TiO2光催化处理二甲苯废气的影响因素及处理性能.结果发现,在以纳米型TiO2作为催化剂、在紫外光强为1000 W且布光均匀、风量为1000 m3/h、进口浓度350 mg/m3、通入臭氧的工况条件下运行,整个系统对二甲苯的去除率平均在90%以上.     

蜘蛛兰去除不同程度富营养水体中氮磷及抑藻效应

研究了蜘蛛兰在不同程度富营养化水体中对氮、磷的去除和对藻类的抑制效应。结果表明，蜘蛛兰在3种不同程度富营养化水体中均能正常生长，且对富营养水体中的氮、磷和叶绿素a浓度均表现出良好的净化去除效果。在45d的实验中，3种不同程度富营养水体的TN、N03-N、NH4-N和TP浓度分别由初始的3．69～25．65、2．79～21．14、0．75～3．57和0．14—1．23mg／L降至1．25～18．99、1．08～16．03、0．18～1．39和0．06～0．77mg／L，在3种不同程度富营养水体中植物的平均生物量累积增长率分别为40．98％、64．41％和95．08％。实验各处理组富营养化水体中的叶绿素a浓度及荧光参数短期内都显著下降，而各对照组中则较稳定或略有下降。蜘蛛兰不仅可以净化富营养水体中营养元素，且对水体中藻类的生长有明显的抑制作用，其在水体生态修复工程中具有良好的应用前景。     

TiO2光催化降解水中土霉素的动力学研究

环境中抗生素的出现及其引起的危害正受到越来越多的关注。以高压汞灯为光源，选用较为广泛的抗生素土霉素（OTC）为处理对象。考察了初始质量浓度、反应过程中光照、催化剂投加量、溶液起始pH、溶液中DOM和NO^-₃对光催化降解的影响，研究了其光降解动力学。结果表明，TiO₂光催化氧化法能够有效去除水中半微量的OTC，OTC的光降解过程符合一级反应动力学模型；UV/TiO₂联用工艺对TOC也有很好的去除效果，反应90 min，TOC去除率可达74%；OTC的初始浓度从30 mg/L增大到90 mg/L，反应速率从0.0619 min^-1降低到0.0130 min^-1；随着光催化剂投加量的增大，光降解速率常数先增大后减小；增加溶液的pH值，速率常数逐渐减小；溶液中的DOM和NO^-₃也可以影响光降解效率。     

Kinetics and mechanism of TNT degradation in TiO2 photocatalysis

The photocatalytic degradation of TNT in a circular photocatalytic reactor, using a UV lamp as a light source and TiO(2) as a photocatalyst, was investigated. The effects of various parameters such as the initial TNT concentration, and the initial pH on the TNT degradation rate of TiO(2) photocatalysis were examined. In the presence of both UV light illumination and TiO(2) catalyst, TNT was more effectively degraded than with either UV or TiO(2) alone. The reaction rate was found to obey pseudo first-order kinetics represented by the Langmuir-Hinshelwood model. In the mineralization study, TNT (30 mg/l) photocatalytic degradation resulted in an approximately 80% TOC decrease after 150 min, and 10% of acetate and 57% of formate were produced as the organic intermediates, and were further degraded. NO(-)(3) NO(-)(2), and NH(+)(4) were detected as the nitrogen byproducts from photocatalysis and photolysis, and more than 50% of the total nitrogen was converted mainly to NO(-)(3)in the photocatalysis. However, NO(-)(3) did not adsorbed on the TiO(2) surface. TNT showed higher photocatalytic degradation efficiency at neutral and basic pH.     

Bactericidal effect of TiO2 photocatalyst on selected food-borne pathogenic bacteria

Titanium dioxide (TiO(2)) photocatalysts have attracted great attention as a material for photocatalytic sterilization in the food and environmental industry. This research aimed to design a new photobioreactor and its application to sterilize selected food borne pathogenic bacteria, Salmonella choleraesuis subsp., Vibrio parahaemolyticus, and Listeria monocytogenes. The photocatalytic reaction was carried out with various TiO(2) concentrations and Ultraviolet (UV) illumination time. A feasible synergistic effect was found that the bactericidal effect of TiO(2) on all bacterial suspension after UV light irradiation was much higher than that of without TiO(2). As the concentration of TiO(2) increased to 1.0 mg/ml, bactericidal effect increased. However, the bactericidal effect was rapidly abbreviated at TiO(2) concentration higher than 1.25 mg/ml to all selected bacteria. UV illumination time affected drastically the viability of all bacteria with different death rate. Similar trends were obtained from S. choleraesuis subsp. and V. parahaemolyticus that their complete killing was achieved after 3 h of illumination. However, L. monocytogenes was more resistant and its death ratio was about 87% at that time.     

Mechanistic analysis on the influence of humidity on photocatalytic decomposition of gas-phase chlorobenzene

The influence of humidity on the decomposition of gas phase chlorobenzene (CB) was studied in a batch photocatalytic reactor using TiO(2) (anatase). Increasing relative humidity (>7% at 25 degrees C and 1atm) resulted in an increasingly detrimental effect on the adsorption and photocatalytic decomposition rate of CB. Mechanistic analysis indicates that the relative hydrophilic/hydrophobic nature of a given chemical should dictate adsorption onto or penetration through water to the TiO(2) surface. It is suggested that multiple layers of water molecules are formed at the TiO(2) interface with air, even at low relative humidities. The multiple-layered film of water retards/prevents CB from reaching the reactive TiO(2) surface or contacting radical species in the boundary layer.     

固定化催化剂TiO2膜光催化降解三氯乙醛的研究

研究了负载于玻璃上的固定化催化剂TiO2膜光催化降解水中三氯乙醛的效果,探讨了TiO2膜光催化降解三氯乙醛的机理,考察了溶液pH值和三氯乙醛初始浓度埘TiO2膜光催化降解三氯乙醛的影响,并研究了固定化催化剂TiO2膜光催化降解三氯乙醛的动力学.结果表明,固定化催化剂TiO2膜光催化降解水中三氯乙醛的效果良好,当三氯乙醛初始浓度为2.25 mg/L时,在紫外光照时间3 h下,三氯乙醛的降解率高达100%.在相司紫外光照时间下,三氯乙醛的光催化降解率随着三氯乙醛初始浓度的增大而下降.在溶液pH=6.5时,三氯乙醛的降解效率最高.固定化催化剂TiO2膜光催化降解三氯乙醛的反应遵循一级反应动力学,反应速率常数随三氯乙醛初始浓度的增大而减小.