介孔TiO2的制备及光催化降解黑液的影响因素

以钛酸四丁酯(TBOT)为前驱体,三嵌段共聚物(P123)为模板剂,溶胶-凝胶法合成了孔径分布均匀的介孔TiO_2,用小角X射线衍射(SAXRD)、X射线粉末衍射(XRD)、透射电子显微镜(TEM)等分析手段对产物结构和光学性能进行了表征。考察了光照时间、催化剂的用量、初始pH、通氧方式等对降解制浆黑液的影响因素。结果表明:介孔TiO2具有较高的催化活性,在催化剂用量为1.5g·L~(-1)、初始pH=6、连续通氧条件下降解效果最佳,光照反应12h后,黑液CODCr和色度去除率分别可达89.7%和92.6%。     

Co2+-TiO2纳米粒子光催化降解黑液的影响因素

用溶胶-凝胶法制备了Co^2＋掺杂TiO2纳米粒子，利用紫外一可见光谱（UV—Vig）和透射电子显微镜（TEM）对样品进行表征，考察了光催化体系中光照时间、催化剂用量、初始pH值、通氧方式等对降解制浆黑液的影响因素。结果表明，Co^2＋掺杂能提高TiO2的光催化活性，在催化剂用量为1．5g／l初始pH=12、连续通氧条件下降解效果最佳，光照反应8h后，黑液中CODCr及色度去除率分别达到70％和86．0％。     

Ni掺杂介孔TiO2的制备及其光催化降解造纸废水

采用溶胶-凝胶法合成了不同Ni掺杂量的介孔TiO2材料,用X射线衍射(XRD)、透射电子显微镜(TEM)、红外(FT-IR)和N2吸附脱附等分析技术对产物结构和组成进行了表征.结果表明,介孔骨架TiO2主要以锐钛矿存在,介孔孔径由未掺杂时的8.8 nm增加到掺杂2%后的10.6 nm,BET比表面积由未掺杂时的159 m2/g降至136 m2/g.在紫外光照射、初始pH值4、连续通氧、催化剂用量1.5 g/L的反应条件下,使用不同Ni掺杂量的TiO2作为催化剂光催化降解造纸废水.实验表明,当Ni掺杂量为2%时,造纸废水的光催化降解效果最佳.以Ni掺杂量为2%的TiO2为催化剂,光催化降解造纸废水,废水的色度和CODCr去除率分别为100%和83.4%.     

CEH漂白废水的TiO2光催化降解

以P25型TiO2为光催化剂,在悬浮态流化床催化反应器中对CEH三段漂白废水进行r光催化降解研究.以CODcr为评价指标,考察了催化剂用量、体系pH值、光催化降解时间及通氧方式等对降解CEH废水的影响因素.结果表明,TiO2投加量、光催化降解时间、体系pH值以及通氧对CODcr的去除影响显著.当TiO2用量为1.0g/L、初始pH值4.0、连续通气条件下降解效果最佳,光催化降解4h后,CEH漂白废水中CODcr去除率可84.8%.     

TiO2/H2O2光催化处理OCC造纸废水的探讨

以中压汞灯作光源、TiO2为催化剂,进行光催化降解OCC造纸废水的试验研究。考察了TiO2用量、H2O2用量、光照时间、pH值四个因素对降解效果的影响。试验表明：TiO2用量2.5g/L、H2O2用量（以体积分数计）为0.3%,CaO调节废水初始pH值为8的条件下,于25℃汞灯光照4h后,CODCr的去除率和脱色率分别...     

光催化对CEH漂白废水的处理研究

以国际通用的商品P25型TiO2为光催化剂,采用自行设计的光催化反应器对传统的CEH三段漂白废水进行光催化降解研究。以CODCr为评价指标,考察了催化剂用量、体系pH、光催化降解时间及通氧方式等对降解CEH废水的影响因素。结果表明：TiO2投加量、光催化降解时间、体系pH以及通氧对CODCr的去除影响显著。当TiO2用量为1．0g/L、初始pH=4．0、连续通气条件下降解效果最佳,光催化降解4h后,CEH漂白废水中CODCr去除率可达84．8％,出水水质达到国家二级排放标准。     

纳米TiO2光催化降解造纸废水中对羟基苯丙酸木素的研究

采用溶胶-凝胶法自制超细TiO2光催化剂,在圆柱型光催化反应器中,以UV-Alight（功率11W,波长253.7nm）作为光源,对含有木素类模型物-对羟基苯丙酸（HL）的有机废水进行光催化降解实验。研究了HL溶液初始浓度、催化剂用量、溶液PH值以及曝气量对HL模型物降解的影响。实验表明：经过暗反应60min后,溶液中的对羟基苯丙酸在TiO2催化剂表面可以达到吸附、解吸平衡;在降解过程中,降解率随溶液初始浓度增加而下降、随曝气量增加而提高,并且溶液的pH和催化剂用量存在一个最佳的操作条件。     

镧掺杂TiO2光催化降解酸性红B的研究

采用溶胶-凝胶法制备了La^3＋／TiO2光催化剂，在模拟太阳光照射下，考察了该催化剂对酸性红B的光催化降解效果。结果表明：掺杂量ω（La^3＋）1％、催化剂用量1g／L、通气量100 mL／min、体系pH值是7时，50mg/L的酸性红B经3 h光催化降解，其降解率可达92．9％：与纯TiO2相比，La^3＋／]TiO2光催化剂显示出良好的太阳光催化活性：     

掺Fe^3＋纳米TiO2的制备及在造纸废水处理中的应用

采用溶胶-凝胶法对纳米TiO2进行Fe3 掺杂改性处理,通过紫外-可见吸收光谱及XRD分析(X射线衍射分析),发现掺0.5? 的纳米TiO2在600℃下煅烧4 h后成为锐钛型和金红石型共存的混合晶体,具有较高的光催化活性;以其为催化剂采用光催化法处理造纸废水,在pH值为5.0、催化剂用量1 g/L、H2O2用量0.5%(体积分数)、300 W高压汞灯照射5 h的条件下得到较为理想的处理效果,CODcr去除率可达85%以上.同时讨论了煅烧温度和掺杂量对TiO2光催化活性的影响.     

介孔TiO2对饮料中4 种色素在太阳光下的光催化降解

以日落黄为模板,四异丙醇钛为原料合成介孔二氧化钛（MTiO2/SY）,在太阳光下对含有日落黄、柠檬黄、苋菜红、胭脂红等4 种色素的饮料进行光催化实验,通过进行X射线衍射（X-ray diffraction technique,XRD）、N2等温吸附-解吸和紫外-可见漫反射光谱表征。结果表明,MTiO2/SY具有介孔孔道结构,较大的比表面积和可见光区吸收,在太阳光下对饮料中日落黄、柠檬黄、苋菜红、胭脂红有较强的光催化降解活性,太阳光下光催化活性明显高于P25。光催化降解后的饮料可以进行自然排放,但不宜食用。     

悬浮纳米TiO2自然光助催化降解偶氮染料酸性大红GR

以自然光为光源,悬浮纳米TiO2为光降解催化剂,研究了溶液pH值、酸性大红GR初始质量浓度、TiO2质量浓度、H2O2的质量浓度及光照时间对偶氮染料酸性大红GR降解的影响.结果表明悬浮纳米TiO2自然光光助催化降解酸性大红GR的适宜条件为:溶液pH值6.5,酸性大红GR初始质量浓度40 mg/L,TiO2质量浓度1.2 g/L,H2O2质量浓度5 g/L,光照时间为120 min.在此条件下,酸性大红GR降解率达75%以上,且降解反应符合一级反应动力学,其动力学常数为0.011 min-1.     

Enhancement of activity and sulfur resistance of CeO2 supported on TiO2-SiO2 for the selective catalytic reduction of NO by NH3

A series of novel metal-oxide-supported CeO(2) catalysts were prepared via the wet impregnation method, and their NH(3)-SCR activities were investigated. The Ce/TiO(2)-SiO(2) catalyst with a Ti/Si mass ratio of 3/1 exhibited superior NH(3)-SCR activity and high N(2) selectivity in the temperature range of 250-450 °C. The characterization results revealed that the activity enhancement was correlated with the properties of the support material. Cerium was highly dispersed on the TiO(2)-SiO(2) binary metal oxide support, and the interaction of Ti and Si resulted in greater conversion of Ce(4+) to Ce(3+) on the surface of the catalyst compared to that on the single metal oxide supports. As a result of in the increased number of acid sites on Ce/TiO(2)-SiO(2) that resulted from the addition of SiO(2), the NH(3) adsorption capacity was significantly improved. All of these factors played significant roles in the high SCR activity. More importantly, Ce/TiO(2)-SiO(2) exhibited strong resistance to SO(2) and H(2)O poisoning. After the addition of SiO(2), the number of Lewis-acid sites was not decreased, but the number of Br?nsted-acid sites on the TiO(2)-SiO(2) carrier was increased. The introduction of SiO(2) further weakened the alkalinity over the surface of the Ce/TiO(2)-SiO(2) catalyst, which resulted in sulfate not easily accumulating on the surface of the Ce/TiO(2)-SiO(2) catalyst in comparison with Ce/TiO(2).     

Development of an E-H2O2/TiO2 photoelectrocatalytic oxidation system for water and wastewater treatment

In this study, an innovative E-H2O2/TiO2 (E-H2O2 = electrogenerated hydrogen peroxide) photoelectrocatalytic (PEC) oxidation system was successfully developed for water and wastewater treatment. A TiO2/Ti mesh electrode was applied in this photoreactor as the anode to conduct PEC oxidation, and a reticulated vitreous carbon (RVC) electrode was used as the cathode to electrogenerate hydrogen peroxide simultaneously. The TiO2/Ti mesh electrode was prepared with a modified anodic oxidation process in a quadrielectrolyte (H2SO4-H3PO4-H2O2-HF) solution. The crystal structure, surface morphology, and film thickness of the TiO2/Ti mesh electrode were characterized by X-ray diffraction and scanning electron microscopy. The analytical results showed that a honeycomb-type anatase film with a thickness of 5 microm was formed. Photocatalytic oxidation (PC) and PEC oxidation of 2,4,6-trichlorophenol (TCP) in an aqueous solution were performed under various experimental conditions. Experimental results showed that the TiO2/Ti electrode, anodized in the H2SO4-H3PO4-H2O2-HF solution, had higher photocatalytic activity than the TiO2/Ti electrode anodized in the H2SO4 solution. It was found that the maximum applied potential would be around 2.5 V, corresponding to an optimum applied current density of 50 microA cm(-2) under UV-A illumination. The experiments confirmed that the E-H2O2 on the RVC electrode can significantly enhance the PEC oxidation of TCP in aqueous solution. The rate of TCP degradation in such an E-H2O2-assisted TiO2 PEC reaction was 5.0 times that of the TiO2 PC reaction and 2.3 times that of the TiO2 PEC reaction. The variation of pH during the E-H2O2-assisted TiO2 PEC reaction, affected by individual reactions, was also investigated. It was found that pH was well maintained during the TCP degradation in such an E-H2O2/TiO2 reaction system. This is beneficial to TCP degradation in an aqueous solution.     

多元复合纳米光催化剂的制备及可见光下降解染料废水

以钛酸四丁酯为Ti源,通过溶胶-凝胶法制备TiO₂、CdS/TiO₂、BiPO₄/TiO₂、CdS/BiPO₄/TiO₂(BCT),对制备的材料进行UV-Vis、XRD、SEM、TG-DTG表征,并在可见光下对玫瑰红B模拟染料废水进行光催化,考察pH、煅烧温度、催化剂用量对降解效果的影响,对4种材料的光催化效果进行对比。结果表明,CdS/TiO₂、BiPO₄/TiO₂、BCT对可见光有较好的响应能力;在玫瑰红B初始质量浓度15 mg/L,催化剂用量1 mg/L,pH 7时,BCT光催化降解率达98.6%,效果相对最佳。研究4种催化剂材料在可见光下降解玫瑰红B的动力学,BCT常数为0.024 min_-1,循环使用5次后仍具有较好的光降解性能。     

Photocatalytic oxidation and decomposition of acetic acid on titanium silicalite

Transient reaction of adsorbed monolayers of acetic acid was used to characterize the photocatalytic properties of titanium silicalite zeolites (TS-1). The TS-1 zeolites having Si/Ti ratios of 5, 12.5, and 50 are effective catalysts at room temperature for both photocatalytic oxidation (PCO) and decomposition (PCD) of acetic acid. The rates of PCO are higher than the rates of PCD for each catalyst. Acetic acid oxidized photocatalytically in 0.2% O2 to form gas-phase CO2 and CH4 and adsorbed H2O on the TS-1 catalysts, whereas no CH4 formed on Degussa P25 TiO2. Isotope labeling showed that, on both TiO2 and TS-1 catalysts, the alpha-carbon formed CO2 whereas the beta-carbon formed CH4 and CO2. The rates of oxidation of the two carbons have different dependencies on UV intensity. The catalysts with higher Si/Ti ratios adsorbed significantly more acetic acid, and the PCO rates per gram of titanium are highest on the TS-1 catalyst with the lowest Ti content, apparently because a larger fraction of the Ti atoms are surface atoms on this catalyst. During PCD in an inert atmosphere, CO2, CH4, and C2H6 formed on TiO2 and on the catalyst with a Si/Ti ratio of 5, but C2H6 was not detected on the other catalysts. The CO2/CH4 selectivity during PCD increased with increasing Si/Ti ratio. The first step in PCO and PCD on TS-1 catalysts appears to be similar and involves formation of a CH3 radical.     

TiO2/SiO2的制备与光催化降解甲基橙

为了探讨Ti02晶粒形貌对光催化过程的作用规律,研究吸附法和浸渍法制备的TiO2光催化剂降解甲基橙的过程,并考察制备反应条件对催化剂形貌和活性的影响.通过剖析反应的基本过程后得出,扩散过程与表面反应过程耦合,催化剂活性与甲基橙浓度的相对高低决定反应过程的控制步骤,从而对表观级数产生影响.在催化剂活性的考评中发现,低Ti含量以及小粒径情况下影响光催化的关键因素是晶型,其次为含量、粒径.吸附法制备的光催化剂Ti含量高,粒径小,可控性好,具有比浸渍法制备的材料更好的催化性能.随着水量的增加,吸附相反应技术的优势越来越显著.     

厌氧微生物的分离及对黑液降解过程的分析

从制浆黑液贮存塘的底泥中分离出厌氧微生物,将其用来处理浓度10%的制浆黑液,研究表明,黑液与菌液体积比为2∶1是厌氧降解反应的最佳反应条件之一。同时测定了厌氧生物降解过程中黑液pH值、总糖含量、糖醛酸含量、化学需氧量（COD）、酸溶木质素含量、酸不溶木质素（Klason木质素）含量随时间变化的趋势,初步研究了制浆黑液厌氧降解的过程。研究结果表明,在厌氧生物降解过程中pH值、总糖含量、糖醛酸含量、COD、酸不溶木质素含量在黑液中都呈下降趋势,而酸溶木质素含量在该过程中不断上升。