活性炭纤维负载TiO2光催化降解甲醛的影响因素

利用自制光催化气体反应器体系,以活性炭纤维负载TiO2作催化剂,在紫外光照射下模拟降解室内污染气体甲醛,测试了活性炭纤维负载TiO2催化剂的催化活性,探讨了紫外光光强、催化剂的酸度、反应器内湿度及反应时间等控制反应的主要因素对甲醛降解率的影响。结果表明,活性炭纤维与TiO2的协同作用大大提高了对甲醛的降解效果;紫外光强增倍对甲醛降解率有一定提高,但提高幅度仅为11.71%;活性炭纤维用pH=5的TiO2溶胶浸泡做催化剂对甲醛的降解效果最好,60 min内降解率达到68.37%;反应器内的湿度为81%甲醛降解率最高,反应60 min后达82.2%;随着反应时间的延长,甲醛降解率的上升幅度不断减小,最高只能达到94.59%。     

活性炭纤维负载TiO_2光催化降解甲醛的影响因素

利用自制光催化气体反应器体系,以活性炭纤维负载TiO2作催化剂,在紫外光照射下模拟降解室内污染气体甲醛,测试了活性炭纤维负载TiO2催化剂的催化活性,探讨了紫外光光强、催化剂的酸度、反应器内湿度及反应时间等控制反应的主要因素对甲醛降解率的影响.结果表明,活性炭纤维与TiO2的协同作用大大提高了对甲醛的降解效果;紫外光强增倍对甲醛降解率有一定提高,但提高幅度仅为11.71%;活性炭纤维用pH=5的TiO2溶胶浸泡做催化剂对甲醛的降解效果最好,60 min内降解率达到68.37%;反应器内的湿度为81%甲醛降解率最高,反应60 min后达82.2%;随着反应时间的延长,甲醛降解率的上升幅度不断减小,最高只能达到94.59%.     

TiO2/AC复合催化剂的制备及其对六氯苯的光催化降解性能研究

以颗粒活性炭（AC）和钛酸丁酯为原料，采用微波辐射法制备TiO₂/AC复合光催化剂，并对制备的催化剂进行了表征；采用该催化剂对六氯苯进行光催化降解，确定了六氯苯降解的最佳工艺条件，并就几种外加试剂对TiO₂/AC光催化降解六氯苯的强化作用进行了探讨。结果表明，制备的催化剂中TiO₂均匀分布在活性炭表面、呈单一的锐钛矿晶型，晶粒生长完善。该催化剂催化降解六氯苯的最佳工艺条件为：pH值为5、TiO₂负载量为18.2%、TiO₂/AC投加量为0.4 g/L、反应时间为60 min。在此条件下，六氯苯降解效率达90.3%。添加适量的H₂O₂、AgNO₃、K₂S₂O₈、KIO₄和KMnO₄均能提高TiO₂/活性炭对六氯苯的光催化降解效率。5种外加试剂的适宜添加量分别为0.3%、1.0、1.0、0.1和0.1 mmol/L，对TiO₂/AC光催化效率的强化作用大小顺序为：H₂O₂＞AgNO₃＞K₂S₂O₈＞KMnO₄＞KIO₄。     

TiO2膜降解水中污染物的稳定性考察与再生方法研究

针对实际水处理中对催化剂性能的要求，以光催化降解苯酚溶液作为探针反应，考察了玻璃纤维网上负载的TiO₂膜催化剂长期使用条件下的稳定性，研究了催化剂在自来水中使用失活后的再生方法。结果表明，经过50次使用之后，膜催化剂120 min反应对苯酚的降解率从100%下降至83%，总体上看，所制催化剂还是具有相当好的稳定性；在反应器中用蒸馏水浸泡配合光催化反应对TiO₂膜催化剂进行原位再生是一种可行的再生途径。     

负载V2O5-WO3/TiO2掺炭纤维脱除烟气中Hg0

通过固定床实验系统研究烟气脱除零价汞的实验，首先研究了滤袋常用的聚苯硫醚（polyphenylene sulfide，PPS）以及活性炭纤维（activated carbon fiber，ACF）在不同温度、不同气体组分下负载V₂O₅-WO₃/TiO₂催化剂，对模拟燃煤烟气中零价汞（Hg⁰）的脱除效果。然后对比研究了活性炭纤维协同滤袋常用纤维负载催化剂后，对模拟燃煤烟气中Hg⁰的脱除性能。结果表明，在汞蒸气入口浓度为50 μg/m³，纯N₂气氛下，当温度为25℃时，两者脱除率均能达到99%，当温度为200℃，负载催化剂的活性炭纤维脱除率在30%左右，PPS纤维仅为10%左右。在200℃情况下，模拟烟气的组分为N₂+O₂时，2种纤维的Hg⁰脱除率提高了10%~20%，当在混合气体中添加0.01‰后，负载催化剂的PPS纤维Hg⁰脱除率能达到80%，活性炭纤维Hg⁰脱除率能达到98%。当温度为200℃，模拟烟气的组分为N₂+O₂+HCl时，不同性能掺炭纤维负载催化剂后Hg⁰脱除率在69%~95%范围之间变化，其中PPS掺炭纤维对Hg⁰脱除效率最高达到95%，因此，负载V₂O₅-WO₃/TiO₂催化剂的PPS掺炭纤维能在高温烟气中保持较高的Hg⁰脱除率。     

镧负载改性TiO2太阳光催化降解微囊藻毒素的研究

考察了镧负载改性TiO₂催化剂在太阳光下降解微囊藻毒素LR (MCLR)的效果及其影响因素。结果表明，镧负载改性的TiO₂可显著增加MCLR在TiO₂表面的吸附量，同时提高MCLR在太阳光下的降解率。随着镧负载量的增加，太阳光下MCLR降解率可从65%提高到95%，pH降低可促进MCLR的降解。改性TiO₂对藻毒素的降解存在最佳投加量，实验结果表明，在pH=6，MCLR初始浓度为2 mg/L，0.001-La-TiO₂的最佳投量为0.5 g/L，在3 600 μW/cm²太阳光下照射30 min，降解率可达97%。     

掺硫改性TiO2对活性艳红X-3B的光催化降解性能研究

以硫脲为硫的源物质，以钛酸四丁酯为TiO₂的前驱体，采用溶胶-凝胶法制备了掺硫改性TiO₂光催化剂。以活性艳红X-3B为目标污染物，研究了该催化剂的光催化降解性能，对硫掺杂量、催化剂焙烧温度、溶液pH值以及催化剂添加量等影响因素进行了研究，并采用XRD分析手法对光催化剂进行表征。结果表明，经掺硫改性后的TiO₂的催化活性有了很大提高，且硫的掺杂有一个最佳值，即Ti∶S的摩尔比为1∶1。经掺硫改性的TiO₂在可见光区具备一定的催化活性， 180 min内对活性艳红X-3B的去除率可达35.1%,且在紫外光区的催化活性优于纯TiO₂。     

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。     

H4SiW12O40/TiO2/beads光催化降解亚甲基蓝的研究

以钛酸四丁酯为原料，空心微珠为载体，采用溶胶凝胶法制备TiO₂/beads光催化剂载体，然后浸渍法制备出H₄SiW₁₂O₄₀/TiO₂/beads表面负载修饰型复合光催化剂，并运用SEM、XRD、FT-IR和DRS对催化剂进行表征和分析。研究了H₄SiW₁₂O₄₀/TiO₂/beads对亚甲基蓝降解的光催化活性，考察了光强度、pH值、曝气量、底物浓度和催化剂用量等对催化效率的影响。实验结果表明，在中性条件下，H₄SiW₁₂O₄₀/TiO₂/beads催化剂的投加量为0.25 g/L，浓度为7.5 mg/L的亚甲基蓝溶液在250 W的紫外灯和600 W的可见光灯下光照60 min降解率分别可达到94.5%和55%。     

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%。     

纳米TiO2/活性炭复合光催化剂的制备及其对甲醛气体降解

研究了纳米TiO2/活性炭复合光催化剂对空气中典型污染气体甲醛的光催化降解特性。采用扫描电镜(SEM)表征复合催化剂的表面特征。结果显示,经改性后的纳米TiO2在复合催化剂表面分布均匀,呈球状。对甲醛气体的降解实验显示TiO2负载量为1%时对甲醛的去除效果最好,6 h去除率为61.7%。结果显示复合催化剂把甲醛气体分解成CO2,可以直接排空,无二次污染。     

泡沫镍负载改性TiO_2降解甲醛

为了消除甲醛气体对人类的危害,对甲醛气体的光催化降解行为进行了研究。采用沉淀-胶溶法制得了具可见光活性的纳米TiO2溶胶,然后将其负载于经过预处理的泡沫镍板上,置于自置的光催化反应器中,考察了在可见光照射下对密闭空间里面一定浓度的甲醛气体的降解情况。采用乙酰丙酮分光光度法,在最佳的检测条件下检测气相中甲醛气体经不同光照时间后的浓度。研究发现,负载了氮掺杂改性的TiO2的泡沫镍板在可见光照射下能够有效降解气相中的甲醛,反应240 min后对甲醛气体的降解率为93%;而同样条件下反应器中只有处理过的泡沫镍板时,甲醛气体浓度基本保持不变。     

Coupling of titania with multiwall carbon nanotubes for decomposition of gas-phase pollutants under simulated indoor conditions

This study synthesized multiwall carbon nanotube (MWNT)–titania (TiO₂) composites and examined their characteristics and photocatalytic performance for the cleaning of gas-phase benzene, toluene, ethyl benzene, and o-xylene (BTEX) under simulated indoor conditions. Optical and spectral surveys of the as-synthesized composite confirmed that the TiO₂ nanoparticles were bound intimately to the MWNT networks. The photocatalytic performance was evaluated using an annular-type reactor inner-coated with MWNT–TiO₂ or Degussa P25 TiO₂. The composite revealed gas removal ability superior to that of stand-alone TiO₂. This composite was also less affected by humidity during toluene decomposition compared to the previous result obtained from a stand-alone TiO₂. Unlike another previous result obtained from the TiO₂, the performance of the composite was not affected by changes in input concentration (IC) within a simulated indoor air quality range (0.1–1.0 ppm) but it decreased significantly when the IC was increased to 5 and 10 ppm. As the flow rate was decreased from 4.0 to 1.0 L min^?1, the average efficiency for the target compounds increased to 95% or ～100%. The MWNT–TiO₂ composite could be applied effectively to the decomposition for BTEX under certain simulated indoor conditions.

Implications: Unlike water applications, there are few reports of gas-phase applications of multiwall carbon nanotubes (MWCNT)–TiO₂ composites. This study found that MWCNT–TiO₂ composites showed performance in the removal of toxic gaseous aromatic superior to that of stand-alone TiO₂. In addition, the pollutant degradation efficiency of the composite was less affected by humidity than for a stand-alone TiO₂ unit within a simulated indoor relative humidity range. Moreover, unlike the TiO₂ unit, the composite's performance was not affected by variations in the input concentrations within the simulated indoor air quality (IAQ) range. In addition, the decomposition efficiencies increased to 100% with decreasing flow rate.     

Photocatalytic Degradation of the Herbicide Erioglaucine in the Presence of Nanosized Titanium Dioxide: Comparison and Modeling of Reaction Kinetics

The present work mainly deals with photocatalytic degradation of a herbicide, erioglaucine, in water in the presence of TiO₂ nanoparticles (Degussa P-25) under ultraviolet (UV) light illumination (30 W). The degradation rate of erioglaucine was not so high when the photolysis was carried out in the absence of TiO₂ and it was negligible in the absence of UV light. We have studied the influence of the basic photocatalytic parameters such as pH of the solution, amount of TiO₂, irradiation time and initial concentration of erioglaucine on the photodegradation efficiency of erioglaucine. A kinetic model is applied for the photocatalytic oxidation by the UV/TiO₂ system. Experimental results indicated that the photocatalytic degradation process could be explained in terms of the Langmuir–Hinshelwood kinetic model. The values of the adsorption equilibrium constant, K, and the second order kinetic rate constant, k, were 0.116 ppm^{? 1} and 0.984 ppm min^{? 1}, respectively. In this work, we also compared the reactivity between the commercial TiO₂ Degussa P-25 and a rutile TiO₂. The photocatalytic activities of both photocatalysts were tested using the herbicide solution. We have noticed that photodegradation efficiency was different between both of them. The higher photoactivity of Degussa P-25 compared to that of rutile TiO₂ for the photodegradation of erioglaucine may be due to higher hydroxyl content, higher surface area, nano-size and crystallinity of the Degussa P-25. Our results also showed that the UV/TiO₂ process with Degussa P-25 as photocatalyst was appropriate as the effective treatment method for removal of erioglaucine from a real wastewater. The electrical energy consumption per order of magnitude for photocatalytic degradation of erioglaucine was lower with Degussa P-25 than in the presence of rutile TiO₂.     

臭氧/紫外联合降解甲醛的试验研究

在臭氧单独作用、紫外光单独作用和UV/O₃ 3种条件下分别对甲醛进行降解试验，研究表明,臭氧和紫外在降解甲醛的试验中存在明显的协同促进作用。单独臭氧对甲醛降解效果并不显著。紫外单独作用时，对甲醛几乎没有降解作用。在UV/O₃条件下，甲醛的降解率大大提高，特别是在高浓度臭氧条件下，降解率高达63％。臭氧浓度增大，降解率增大；紫外光强度增大，降解效果提高；气体流量增大，降解率下降；湿度增大，降解率提高。对甲醛降解试验进行动力学研究，结果表明，光照强度和臭氧浓度增大，一级反应速率增大，提高臭氧浓度要比加强紫外强度更能促进甲醛的降解。     

Carbofuran removal in continuous-photocatalytic reactor: Reactor optimization,rate-constant determination and carbofuran degradation pathway analysis

Carbofuran (CBF) removal in a continuous-flow photocatalytic reactor with granular activated carbon supported titanium dioxide (GAC-TiO₂) catalyst was investigated. The effects of feed flow rate, TiO₂ concentration and addition of supplementary oxidants on CBF removal were investigated. The central composite design (CCD) was used to design the experiments and to estimate the effects of feed flow rate and TiO₂ concentration on CBF removal. The outcome of CCD experiments demonstrated that reactor performance was influenced mainly by feed flow rate compared to TiO₂ concentration. A second-order polynomial model developed based on CCD experiments fitted the experimental data with good correlation (R² ～ 0.964). The addition of 1 mL min^?1 hydrogen peroxide has shown complete CBF degradation and 76% chemical oxygen demand removal under the following operating conditions of CBF ～50 mg L^?1, TiO₂ ～5 mg L^?1 and feed flow rate ～82.5 mL min^?1. Rate constant of the photodegradation process was also calculated by applying the kinetic data in pseudo-first-order kinetics. Four major degradation intermediates of CBF were identified using GC-MS analysis. As a whole, the reactor system and GAC-TiO₂ catalyst used could be constructive in cost-effective CBF removal with no impact to receiving environment through getaway of photocatalyst.