有机污染物半导体多相光催化氧化机理及动力学研究进展

本文系统总结了有机污染物半导体多相光催化氧化机理及动力学研究进展现状，阐述了几种特定有机污染物的光催化氧化机理，并对有关机理方面进一步研究的必要性和方向进行了探讨。     

光催化反应器在污水处理中的研究现状与发展趋势

根据光催化反应的光源不同，将多相光催化反应器分为聚光式反应器和非聚光式反应器。本文主要介绍了国内外近年来有关污水处理中的光催化反应器研制与应用的进展情况，同时展望其发展趋势。论述了适用于工业化光催化反应器的特点及今后的发展方向。     

二氧化钛光催化氧化研究进展

光催化氧化是日益引起重视的污染治理的新技术。对国内外有关水中污染物的光催化氧化过程的研究结果进行了总结,讨论了该过程所涉及的反应机理,催化剂备及提高催化活性的方法,并提出了光催化氧化法今后的研究方向。     

光催化反应器在污水处理中的研究现状与发展趋势

根据光催化反应的光源不同 ,将多相光催化反应器分为聚光式反应器和非聚光式反应器。本文主要介绍了国内外近年来有关污水处理中的光催化反应器研制与应用的进展情况 ,同时展望其发展趋势。论述了适用于工业化光催化反应器的特点及今后的发展方向     

光催化反应器的研究进展

介绍了国内外近年来有关多相光催化反应中光催化反应器设计与研究的进展情况，按催化剂在反应中存在的形式分类论述了各种反应器的结构原理和主要特点，以及光反应器设计中存在的问题和今后的研究方向。     

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。     

光催化反应器的研究进展

介绍了国内外近年来有关多相光催化反应中光催化反应器设计与研究的进展情况,按催化剂在反应中存在的形式分类论述了各种反应器的结构原理和主要特点,以及光反应器设计中存在的问题和今后的研究方向。     

水中有机污染物的光催化氧化

本文系统综述了十余年来光催化氧化法去除水中有机污染物的基础研究成果，讨论了光催化氧化法的机理、影响光催化氧化反应速率的因素及提高光催化反应效率的途径，旨在为该方法的应用开发研究提供有益的帮助。     

TiO2纳米粒子气-固复相光催化氧化VOCs作用的研究进展

本文总结了90年代以来TiO2纳米粒子气-固复相光催化氧化气相有机污染物的影响因素、反应机理和动力学,阐述了几种特定有机污染物的光催化氧化过程,并对应用前景作出展望.     

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     

无机离子对光催化水处理过程影响的研究进展

无机离子在自然水体和生产废水中广泛存在。在不同的反应体系,无机离子对光催化反应的影响不同。深入了解无机离子对光催化水处理过程的影响有助于研究光催化反应的机制,增强金属离子与有机污染物光催化反应的协同作用,提高光催化反应的效率。     

Graphene-based photocatalytic nanocomposites used to treat pharmaceutical and personal care product wastewater: A review

Photocatalytic technology has been widely studied by researchers in the field of environmental purification. This technology can not only completely convert organic pollutants into small molecules of CO₂ and H₂O through redox reactions but also remove metal ions and other inorganic substances from water. This article reviews the research progress of graphene-based photocatalytic nanocomposites in the treatment of wastewater. First, we elucidate the basic principles of photocatalysis, the types of graphene-based nanocomposites, and the role of graphene in photocatalysis (e.g., graphene can accelerate the separation of photon-hole pairs and increase the intensity and range of light absorption). Second, the preparation, characterization, and application of composites in wastewater are introduced. We also discuss the kinetic model of the photocatalytic degradation of pollutants. Finally, the enhancement mechanism of graphene in terms of photocatalysis is not completely clear, and graphene-based photocatalysts with high catalytic efficiency, low cost, and large-scale production have not yet appeared, so there is an urgent need for more extensive and in-depth research.

     

环境中有机污染物的半导体光催化降解研究进展

应用半导体二氧化钛光催化剂促进氧化降解环境中常见有机污染物是一种有效的清洁处理技术,对光催化活性的半导体的必要性质,影响光催化效率的内在因素以及反应器,反应条件等方面的因素进行了讨论。     

TiO2光催化剂在污水处理中的应用

在污水处理方面TiO2光催化剂以其独特的氧化活性、光学性能和无机化能力引起了人们极大的关注.对TiO2光催化原理、农药、染料和环境荷尔蒙等有机污染物的分解,提高催化效率的方法以及其实用技术等方面,分别作了综合评述.     

Effect of ZnFe2O4 doping on the photocatalytic activity of TiO2

The photocatalytic oxidation of the organic pollutants with the TiO2 as photocatalyst has been widely studied in the world, and many achievements have been got. The degradation of pollutants is highly related with the photocatalytic activity of TiO2. It is demonstrated that doping ions or oxides to TiO2 is one way to enhance the photocatalytic activity of TiO2. In this paper, the ZnFe2O4-doped TiO2 nanoparticles were prepared from butyl titanate by a sol-gel method and characterized by means of X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results showed that when TiO2 was doped with ZnFe2O4, its particle size will decrease and its crystal structure will partly transform from anatase to rutile. The photocatalytic activity of the elaborated powders was studied following the degradation of Rhodamine B. The results showed that doping ZnFe2O4 to TiO2 will enhance the photocatalytic activity of TiO2 and that ZnFe2O4-doped TiO2 in the coexistence of anatase and rutile has higher efficiency for the degradation of Rhodamine B than that in the anatase phase alone. Also the different role of O2 in the direct photolysis and photocatalysis of Rhodamine B was discussed.     

Removal and degradation of aromatic compounds from a highly polluted site by coupling soil washing with photocatalysis

The possible application of two environmental remediation technologies - soil washing and photocatalysis - to remove and decompose various aromatic pollutants present in excavated soils of a contaminated industrial site has been investigated. Aqueous solutions containing the non-ionic surfactant Brij 35 were used to extract the contaminants from the soil samples. The photocatalytic treatment of the obtained washing wastes, performed in the presence of TiO(2) suspensions irradiated with simulated sunlight, showed a slow abatement of the toxic compounds due to the relevant concentrations of organics in the waste. A neat improvement of the process performances, obtained by operating in the presence of added potassium peroxydisulfate, suggests a feasible treatment route.     

Photocatalytic ozonation of pesticides in a fixed bed flow through UVA-LED photoreactor

In this study, a fixed bed flow through UVA-LED photoreactor was used to compare the efficiency of ozone, photocatalysis and photocatalysis-ozone degradation, and mineralization of two pure pesticides, 2,4-dichlorophenoxyacetic acid (2,4-D) and 2-methyl-4-chlorophenoxyacetic acid (MCPA), and a commercial one, Killex®. For the degradation of the parent compounds, ozone-based processes were more effective. While for mineralization, photocatalytic processes were more effective. Photocatalytic ozonation was the most efficient process for both the degradation and mineralization of the parent compounds. The degradation rates and mineralization by photocatalytic ozonation were higher than the summation of the corresponding rates by ozonation and photocatalysis, indicating a symbiotic relationship.Overall, the photocatalytic ozonation process with the fixed bed TiO₂ reduces the time needed for the degradation and mineralization of the pesticides, reduces the costs of powder catalyst separation and overcomes the reduced efficiency of immobilized catalysts, which makes the process quite attractive for practical applications.     

NORMACAT project: normalized closed chamber tests for evaluation of photocatalytic VOC treatment in indoor air and formaldehyde determination

Background, aim

The aims of the NORMACAT project are: to develop tools and unbiased standardized methods to measure the performance and to validate the safety of new materials and systems integrating photocatalysis, to develop new photocatalytic media with higher efficiency and to give recommendations aimed at improving the tested materials and systems.

Method

To achieve this objective, it was necessary to design standardized test benches and protocols to assess photocatalytic efficiency of materials or systems used in the treatment of volatile organic compounds (VOCs) and odour under conditions close to applications. The tests are based on the validation of robust analytical methods at the parts per billion by volume level that not only follow the disappearance of the initial VOCs but also identify the secondary species and calculate the mineralization rates.

Results

The first results of inter-laboratory closed chamber tests, according to XP B44-013 AFNOR standard, are described. The photocatalytic degradation of mixtures of several defined pollutants under controlled conditions (temperature, relative humidity, initial concentration) was carried out in two independent laboratories with the same photocatalytic device and with various analytical procedures. Comparison of the degradation rate and of the mineralization efficiency allowed the determination of the clean air delivery rate in both cases. Formaldehyde was the only by-product detected during photocatalytic test under standardized experimental conditions. The concentration of transient formaldehyde varied according to the initial VOC concentration. Moreover the photocatalytic reaction rate of formaldehyde in mixture with other pollutants was analysed. It was concluded that formaldehyde concentration did not increase with time.

Conclusion??perspective

This type of experiment should allow the comparison of the performances of different photoreactors and of photocatalytic media under controlled and reproducible conditions against mixtures of pollutants including formaldehyde.     

Are photocatalytic processes effective for removal of airborne viruses from indoor air? A narrative review

A wide variety of methods have been applied in indoor air to reduce the microbial load and reduce the transmission rate of acute respiratory diseases to personnel in healthcare sittings. In recent months, with the occurrence of COVID-19 pandemic, the role of portable ventilation systems in reducing the load of virus in indoor air has received much attention. The present study delineates a comprehensive up-to-date overview of the available photocatalysis technologies that have been applied for inactivating and removing airborne viruses. The detection methods for identifying viral particles in air and the main mechanisms involving in virus inactivation during photocatalysis are described and discussed. The photocatalytic processes could effectively decrease the load of viruses in indoor air. However, a constant viral model may not be generalizable to other airborne viruses. In photocatalytic processes, temperature and humidity play a distinct role in the inactivation of viruses through changing photocatalytic rate. The main mechanisms for inactivation of airborne viruses in the photocatalytic processes included chemical oxidation by the reactive oxygen species (ROS), the toxicity of metal ions released from metal-containing photocatalysts, and morphological damage of viruses.

     

TiO2光催化技术处理饮用水微污染及杀灭微生物的研究

光催化处理饮用水微量污染物以及在饮用水消毒和杀菌方面的研究是近年来研究的热点.本文论述了 TiO2光催化处理饮用水中的微量卤代物、腐殖质、微生物代谢产物,以及杀灭细菌、真菌和病毒等微生物的研究进展.探讨了光催化杀灭微生物的作用机制,最后对该研究领域的发展方向提出建议和展望.