多元多相光催化氧化反应器及其对水中2，4—二硝基苯酚有机污染物降解的研究

利用多元多相光催化氧化反应器，可更换不同氧化剂、光源、金属氧化物半导体催化膜、电子捕获器，进行化学氧化、光氧化、光化学氧化、光催化氧化和光化学催化氧化等5种类型多种组合试验，处理水中难降解有机物效果明显。设备具有持久性、灵活性、捕电性、简易性，适用于科研、工程试验中，亦可作教学设备。     

光反应器中UV/Fenton光降解湖水中微囊藻毒素的研究

在光催化反应器中,采用UV/Fenton光催化氧化技术,对湖水中微囊藻毒素的光催化降解过程中各影响因子分析表明:微囊藻毒素光催化氧化降解率受光照强度、氧化剂种类及浓度、溶液pH和不同光催化体系等多因素的影响.光促催化氧化体系对MC-LR藻毒素降解具有显著的作用,在紫外光与氧化剂的协同作用下,紫外光照强度越高,越易于促进MC-LR藻毒素快速降解,降解率可到达80%以上.     

光催化-臭氧氧化降解H酸的研究

采用光催化-臭氧氧化技术(催化膜/UV/O3)降解H酸.研究结果表明,光催化与臭氧氧化相结合具有明显的协同作用.实验进一步讨论了臭氧投加量、废水初始pH值和H酸初始浓度对光催化-臭氧氧化降解H酸的影响.降解后的H酸,萘环结构被破坏,可生化性提高.     

高浓度难降解有机废水的催化氧化技术及其进展

根据催化剂的激活因子不同 ,本文将催化氧化法分为湿式催化氧化法 (WCO)、光催化氧化法 (PCO)和电催化氧化法 (ECO)三种 ,并阐述了各自的反应机理及应用研究状况 ,提出了今后需要加强的研究方向     

光催化-臭氧氧化降解H酸的研究

采用光催化一臭氧氧化技术（催化膜／UV／O3）降解H酸。研究结果表明，光催化与臭氧氧化相结合具有明显的协同作用。实验进一步讨论了臭氧投加量、废水初始pH值和H酸初始浓度对光催化一臭氧氧化降解H酸的影响。降解后的H酸，萘环结构被破坏，可生化性提高。     

水中有机污染物超声强化氧化技术研究进展

超声波技术在化学、环境、制药以及生物等领域有着广阔的应用前景。在降解水中难降解有机污染物方面 ,超声强化氧化技术有一定优势 ,降解效果显著 ,符合绿色环保技术的要求。超声强化氧化技术主要可分为超声空化技术、超声强化化学 (催化 )氧化技术、超声强化电化学 (催化 )氧化技术、超声强化光化学 (催化 )氧化技术、超声 生物降解等几大类 ,本文对各类技术的优缺点进行了评述。     

催化氧化法处理有机废水催化剂的选择应用

催化氧化法是处理难降解有机废水的一项重要的新技术。在对化学氧化法的不断改进中，逐步发展出湿式催化氧化法、光催化氧化法、均相催化氧化法和多相催化氧化法。不同的氧化方法所用的催化剂不相同，有机化合物的种类和结构不同，催化剂与氧化剂之间存在匹配问题，因此对催化剂要进行筛选评价。     

高浓度难降解有机废水的催化氧化技术及其进展

根据催化剂的激活因子不同，本文将催化氧化法分为湿式催化氧化法（WCO）、光催化氧化法（PCO）和电催化氧化法（ECO）三种，并阐述了各自的反应机理及应用研究状况，提出了今后需要加强的研究方向。     

光催化氧化处理有机废水

介绍了光催化氧化法的原理,对光催化氧化法处理有机废水的可行性进行了试验,探讨了ＣＯＤ随反应时间的变化规律及催化剂用量,温度、浓度的影响。试验表明,光催化氧化可降解象洗涤剂这样难降解的有机物,反应１２０ｍｉｎＣＯＤ去除率可达５０％以上。     

TiO2光催化氧化脱除模拟烟气中的NOx

采用P25纳米TiO2为催化剂,对NOx浓度360 mg/m3的模拟烟气进行了光催化氧化实验研究,以期为此种方法在电厂烟气脱硝方面的应用提供依据.经SEM、XRD等表征手段,探讨了催化剂晶型尺寸对光催化的作用.实验考察了光催化反应过程规律以及负载量、光照度、NO初始浓度、O2含量、相对湿度和停留时间对光催化氧化效率的影响.结果表明,光催化反应是瞬态到稳态的过程,其催化效率与上述影响因子有密切关系.实验最优条件下NOx的脱除率为46％,但只需适当提高氧化效能,便能达到理想的效果.     

Simultaneous photocatalytic reduction of Cr(VI) and oxidation of phenol over monoclinic BiVO4 under visible light irradiation

BiVO4 powder with monoclinic structure was prepared and used as a visible-light catalyst simultaneously for the photooxidation of phenol and the photoreduction of Cr(VI). The photocatalytic efficiency was found to be rather low for either single phenol solution or single Cr(VI) solution. However, the photocatalytic reduction of Cr(VI) and photocatalytic oxidation of phenol proceed more rapidly for the coexistence system of phenol and Cr(VI) than for the single process, showing synergetic effect between the oxidation and reduction reactions. For the simultaneous photocatalytic reduction-oxidation process, the first-order kinetic constant of phenol degradation was 0.0314 min-1, being about six times higher than that for the photocatalytic process of single phenol. This result reveals the feasibility of using Cr(VI) as the electron scavenger of mBiVO4-mediated photocatalytic process of phenol degradation, and gives us an enlightenment to employ other semiconductor with a better visible light response but with a more positive band edge to efficiently degrade organic pollutants. This is the first report for simultaneous photocatalytic reduction of Cr(VI) and removal of phenol under visible light irradiation using photocatalyst mBiVO4.     

Photochemical and photocatalytic degradation of gaseous toluene using short-wavelength UV irradiation with TiO2 catalyst: comparison of three UV sources

The feasibility of the use of short-wavelength UV (254+185 nm) irradiation and TiO2 catalyst for photodegradation of gaseous toluene was evaluated. It was clear that the use of TiO2 under 254+185 nm light irradiation significantly enhanced the photodegradation of toluene relative to UV alone, owed to the combined effect of photochemical oxidation in the gas phase and photocatalytic oxidation on TiO2. The photodegradation with 254+185 nm light irradiation was compared with other UV wavelengths (365 nm (black light blue lamp) and 254 nm (germicidal UV lamp)). The highest conversion and mineralization were obtained with the 254+185 nm light. Moreover, high conversions were achieved even at high initial concentrations of toluene. Catalyst deactivation was also prevented with the 254+185 nm light. Regeneration experiments with the deactivated catalyst under different conditions revealed that reactive oxygen species played an important role in preventing catalyst deactivation by decomposing effectively the less reactive carbon deposits on the TiO2 catalyst. Simultaneous elimination of photogenerated excess ozone and residual organic compounds was accomplished by using a MnO2 ozone-decomposition catalyst to form reactive species for destruction of the organic compounds.     

Photoassisted bleaching of dyes utilizing TiO2 and visible light

Titanium dioxide was shown to be generally effective as a catalyst for photobleaching many structural classes of organic dyes in aqueous solution, using visible light. However, results from study of 15 dyes indicate that photobleaching rates differ significantly from families of dyes with different functionalities, and are dependent on the light source and crystalline form of TiO2 used. Sorption characteristic on the TiO2 surface and the aqueous solubility of the dyes also play an important role in the photobleaching rate. Kinetic analysis indicates that the dye photobleaching rates can usually be approximated as pseudo-first-order kinetics. In addition to the generally proposed photocatalytic oxidation mechanism for TiO2 reactions, we observed evidence for two kinds of electron transfer mechanisms that are "photosensitized reduction" and "photosensitized oxidation". Natural sunlight was effectively used to photobleach some of the dyes.     

Photocatalytic oxidation of gas-phase elemental mercury by nanotitanosilicate fibers

Photocatalytic fibers were generated from the continuous evaporation of titanium tetraisopropoxide with tetraethyl orthosilicate through a flame burner. The morphology, the crystal form, and the components of the nanotitanosilicate fibers were analyzed by Raman spectroscopy, Field emission-scanning electron microscope, X-ray diffraction, and Brunauer-Emmett-Teller surface area analysis. The nanotitanosilicates prepared by three different carrier gases (air, N(2), and Ar) were tested for their photocatalytic ability to remove/oxidize gas-phase elemental mercury. Under UV black light, the Hg(0) capture efficiencies were 78%, 86%, and 85% for air, N(2), and Ar, respectively. For air, the value was close to 90%, even under household fluorescent light. The Hg(0) capture efficiency by nanotitanosilcate was measured under fluorescent light, UV black light, and sunlight.     

Photocatalytic oxidation of xenobiotics in water with immobilized TiO2 on agitator

A novel photocatalytic oxidation reactor, using Degussa P-25 TiO2 as a stationary phase with a thickness of 1.5-2.0 um on the blades of agitator, was developed to study the photocatalytic oxidation of xenobiotics. Particularly in this device, separation of photocatalyst from the purified water after oxidation reaction was not necessary, and no other aeration equipment was required to supply oxygen. To examine the efficiency of this device, photocatalytic degradation of xenobiotic organics such as carbofuran was studied as an example. Results indicated that carbofuran could be degraded completely with mineralization efficiency of 20% after 6 hours of oxidation under the imposed conditions. The mineralization rate of carbofuran was found to follow the pseudo-first order reaction kinetics. Moreover, the rate constant of mineralization was found to be proportional to TiO2 film area and the square root of UV light intensity. These results implied the mineralization efficiency of carbofuran could be improved through increasing TiO2 film area and UV light intensity. Accordingly, this novel device showed potential application for degrading xenobiotics in water.     

Feasibility study of photoelectrochemical degradation of methylene blue with three-dimensional electrode-photocatalytic reactor

The photoelectrochemical degradation of methylene blue in aqueous solution was investigated with three-dimensional electrode-photocatalytic reactor. It was found that the methylene blue could be degraded more efficiently by photoelectrochemical process than by photocatalytic oxidation or electrochemical oxidation alone. The decolorization efficiency and COD reduction were 95% and 87% for a photoelectrochemical process, respectively, while they were only 78% and 68% for a single electrochemical process and 89% and 71% for a single photochemical process. The TOC reduction of the former also reached as high as about 81% within a reaction time of 30.0 min. And these degradation reactions conformed to pseudo-first-order kinetics.     

Photocatalytic oxidation of methyl orange in a three-phase fluidized bed reactor

The photocatalytic oxidation of methyl orange under weak illumination conditions was carried out in two different types of fluidized bed reactors. TiO2 powder was employed as the photocatalysts and a 15 W low pressure mercury lamp was used as the light source and the reactor volume was 2.5 l. The parametric study of photocatalytic oxidation of methyl orange in two different types of fluidized beds was investigated; effect of catalyst loadings, pH, air flow rate, initial concentration and oxygen concentration on the oxidation reaction rate. The experimental results were analyzed in conjunction with the characteristics of fluidized bed and the reactor geometry effect on the reaction rate was analyzed.     

紫外光助臭氧化处理活性艳红K-2BP废水研究

以 30 0W高压汞灯为光源 ,研究了紫外光联合臭氧化、单纯臭氧氧化及单纯紫外光照处理 4 0 0mg/L的活性艳红K 2BP废水的可行性。结果表明 :光催化臭氧化可加速有机物的矿化。在同样时间条件下 ,三者氧化能力由大至小为 :UV/O3 >单独O3 >单独UV。运用TOC、紫外 可见光谱 (UV Vis)、毛细管电泳 (CE)等分析技术初步探讨了紫外光催化臭氧化活性艳红K 2BP溶液的降解效果及降解机理。     

Photocatalytic oxidation of xenobiotics in water with immobilized TIO2 on agitator

Abstract

A novel photocatalytic oxidation reactor, using Degussa P‐25 T_iO₂ as a stationary phase with a thickness of 1.5–2.0 um on the blades of agitator, was developed to study the photocatalytic oxidation of xenobiotics. Particularly in this device, separation of photocatalyst from the purified water after oxidation reaction was not necessary, and no other aeration equipment was required to supply oxygen. To examine the efficiency of this device, photocatalytic degradation of xenobiotic organics such as carbofuran was studied as an example. Results indicated that carbofuran could be degraded completely with mineralization efficiency of 20 % after 6 hours of oxidation under the imposed conditions. The mineralization rate of carbofuran was found to follow the pseudo‐first order reaction kinetics. Moreover, the rate constant of mineralization was found to be proportional to T_iO₂ film area and the square root of UV light intensity. These results implied the mineralization efficiency of carbofuran could be improved through increasing T_iO₂ film area and UV light intensity. Accordingly, this novel device showed potential application for degrading xenobiotics in water.     

Bacterial response to photocatalytic degradation of 6-chlorovanillin

The oxidation of a 186 ppm 6-chlorovanillin solution was performed using impregnated TiO2 glass rings in a 1 l photochemical reactor. Fifty per cent degradation was obtained after 60 min with recirculation of the solution. Then, oxidised samples were submitted under aerobic conditions to bacterial degradation in the Pseudomonas paucimobilis (S37) and Burkholderia cepacia (PZK). Both selected aerobic bacteria degrade more efficiently the photocatalysed samples, being PZK strain better than S37. A first-order kinetic was observed in both systems photocatalytic and bacterial degradation.