光催化净化空气研究进展

光催化氧化技术是一种新兴的气相污染物净化技术。综述了二氧化钛光催化氧化技术处理气相污染物的氧化机理,分析了气相光催化氧化反应器设计及该技术在降解空气中有毒有害气体、病毒、细菌和微生物等许多领域的应用现状和前景。     

光催化氧化技术处理废水中抗生素的研究进展

本文综述了光催化氧化技术处理废水中抗生素污染物的研究现状,主要介绍了半导体光催化剂、光催化复合膜及一些与光催化氧化技术相关的联合技术在废水抗生素污染物处理领域的应用进展,同时详细地介绍了各种方法对抗生素污染物的处理效果及其优缺点。最后,展望了光催化氧化技术在废水中抗生素污染物处理领域未来的研究重点和发展趋势。     

纳米氧化锌在水处理方面的研究

本文介绍了纳米ZnO光催化氧化的机理,阐述了ZnO光催化氧化技术在降解水中有机污染物、无机污染物及饮用水净化处理中的研究进展,并对ZnO光催化氧化技术的研究前景进行了展望。     

光催化氧化法降解有机污染物影响因素及其效率提高途径

分析了催化剂类型、污染物性质、反应条件等因素对光催化氧化法降解有机污染物的影响,从催化剂改性、高效光催化氧化反应器及光催化与其他技术联用等方面探讨了提高光催化氧化效率的途径,展望了光催化氧化法发展前景及其工业化应用时需解决的关键问题。     

半导体二氧化钛光催化氧化的研究进展

介绍了二氧化钛光催化氧化的基本原理,分析了光催化氧化的影响因素。阐述了光催化剂的固定方法及降解有机污染物的现状及发展方向,并提出了光催化氧化技术未来的发展趋势。     

光催化氧化技术在污染物处理方面的应用

本文阐述了光催化氧化反应的反应机理及其在工业废水和气相污染物处理中的应用,简要地分析了光催化氧化反应速率的影响因素和今后光催化氧化技术的发展方向.     

光催化技术在环境治理方面的研究概述

光催化技术能够氧化降解有机污染物,主要应用于水分解、二氧化碳还原和有机污染物降解,而且具有操作简单、成本低等优点。分析了光催化技术的基本原理,介绍了光催化技术在降解废水、净化空气、制氢、治理污染等方面的应用。     

超声波辅助光催化氧化技术在废水处理中的研究进展

超声波辅助光催化氧化技术,可以克服传统光催化技术的缺点,从而提高降解有机废水的效率。综述了超声波辅助光催化技术的机理和处理有机污染物的研究现状,详细介绍了影响降解有机污染物效率的因素,展望了超声波辅助光催化技术在废水处理中的发展前景。     

新型环保功能涂料制备技术

该涂料是具有抗菌、抗霉、自洁、净化空气等功能的水性绿色环保乳胶漆。 该技术利用涂料中添加的纳米二氧化钛的光催化特性,氧化分解杀灭各种有毒有害微生物、细菌、病毒、霉菌等;降解有机污染物;去除甲醛、氮氧化物、一氧化碳、二氧化硫、各种有毒有害有机气体、臭味、异味等大气污染气体。     

光催化氧化技术在VOCs废气治理过程中存在的难点及对策

光催化氧化技术在VOCs废气治理领域有较为广泛的应用。光催化氧化技术在VOCs废气治理过程中的效率和稳定性受污染物吸附性能、光催化氧化接触时间、湿度、催化剂活性、光子利用效率、催化剂附着稳定性等诸多因素影响。总结了光催化氧化技术在VOCs废气治理过程中存在的难点问题,并多角度探讨了解决以上问题的相关对策。     

光催化协同臭氧深度处理高浓度制药废水

采用光催化协同臭氧技术处理高浓度制药废水,研究了光催化/臭氧法处理的主要影响参数。结果表明光催化法和臭氧法之间存在明显的协同作用。随着催化剂添加量的提高,废水COD的去除率逐渐提高,增加臭氧的流量有利于提高COD去除率;溶液初始pH值则对降解的影响较小。     

光催化协同TiO2动态膜去除水中腐植酸及膜污染特性

针对物理扰动模式控制动态膜污染使涂膜层脱落方面的局限性,提出光催化氧化技术协同动态膜降低膜污染,对比了陶瓷微滤膜、动态膜、光催化协同动态膜处理含腐植酸废水及含腐植酸/TiO₂混合废水过程中的膜通量、污染物去除率及膜污染阻力分布的变化趋势。结果表明:光催化协同作用可有效提高动态膜过滤腐植酸溶液过程中的膜通量、总有机碳(TOC)及UV₂₅₄的去除率,并同时降低可逆污染阻力及不可逆污染阻力,其中可逆污染阻力明显大于其他部分阻力,可逆污染是造成膜通量衰减的主要原因。光催化预处理时间越长,稳态膜通量、TOC及UV₂₅₄去除率增幅越显著,控制膜污染越有效。光催化预处理2h和8h再动态膜过滤时TOC去除率分别可达到80%和90%以上,UV₂₅₄去除率都可达95%以上。     

Photocatalytic Degradation of 4,4′-Isopropylidenebis(2,6-dibromophenol) on Magnetite Catalysts vs. Ozonolysis Method: Process Efficiency and Toxicity Assessment of Disinfection By-Products

Flame retardants have attracted growing environmental concern. Recently, an increasing number of studies have been conducted worldwide to investigate flame-retardant sources, environmental distribution, living organisms’ exposure, and toxicity. The presented studies include the degradation of 4,4′-isopropylidenebis(2,6-dibromophenol) (TBBPA) by ozonolysis and photocatalysis. In the photocatalytic process, nano- and micro-magnetite (n-Fe₃O₄ and μ-Fe₃O₄) are used as a catalyst. Monitoring of TBBPA decay in the photocatalysis and ozonolysis showed photocatalysis to be more effective. Significant removal of TBBPA was achieved within 10 min in photocatalysis (ca. 90%), while for ozonation, a comparable effect was observed within 70 min. To determine the best method of TBBPA degradation concentration on COD and TOC, the removals were examined. The highest oxidation state was obtained for photocatalysis on μ-Fe₃O₄, whereas for n-Fe₃O₄ and ozonolysis, the COD/TOC ratio was lower. Acute toxicity results show noticeable differences in the toxicity of TBBPA and its degradation products to Artemia franciscana and Thamnocephalus platyurus. The EC₅₀ values indicate that TBBPA degradation products were toxic to harmful, whereas the TBPPA and post-reaction mixtures were toxic to the invertebrate species tested. The best efficiency in the removal and degradation of TBBPA was in the photocatalysis process on μ-Fe₃O₄ (reaction system 1). The examined crustaceans can be used as a sensitive test for acute toxicity evaluation.     

Advanced oxidation of catechol: A comparison among photocatalysis, Fenton and photo-Fenton processes

The aim of this work was to compare the behaviour of Fenton, photo-Fenton and photocatalysis processes to treat catechol solutions which are pollutants occurring in wastewaters from many industries. The effect of different process parameters, such as initial catechol concentration, H₂O₂/FeSO₄ ratio in Fenton and photo-Fenton oxidation, TiO₂ loadings in photocatalysis and irradiation times has been studied.Fenton and photo-Fenton (H₂O₂/FeSO₄ = 600/500 (w/w) and 30 min reaction time) processes allowed us to achieve a high efficiency in the mineralization of catechol (COD removals up to 83% and 96% respectively), and removal of aromaticity (UV₂₈₀) (up to 93% and 98% respectively), for an initial catechol concentration of 110 mg/l. On the opposite, photocatalysis was not effective in the removal of higher catechol concentrations (110 and 200 mg/l), whereas a significant removal of aromaticity versus time was observed for 50 mg/l. Gas chromatography-mass spectrometry analysis, performed under selected treatment conditions, showed that total removal of catechol can occur after Fenton (2000/500 w/w; 30 min), photo-Fenton (600/500 w/w; 30 min), and photocatalysis (3 g TiO₂/l; 240 min) treatments.     

Influence of water vapour on plasma/photocatalytic oxidation efficiency of acetylene

Non-thermal plasma as well as photocatalysis is intensively investigated for volatile organic compounds (VOCs) oxidation. Their association exhibits high performances for air pollutant removal and mineralization. Nevertheless, numerous experimental investigations are performed under dry conditions, or on very short range of water vapour amounts. This article aims at determining the influence of water vapour on the oxidation efficiency of (i) photocatalysis, (ii) non-thermal plasma, and (iii) their association. The amount of water vapour investigated in dry conditions ranges from 0 ppm to 23,000 ppm. Acetylene has been selected as a model pollutant. The presence of water vapour in the gas stream induces a strong decrease in the photocatalytic oxidation of acetylene. The mineralization process is modified. The efficiency of acetylene removal by non-thermal plasma decreases regularly with the water vapour amount. Nevertheless, the presence of water vapour improves significantly the selectivity of carbon dioxide. The same tendency is reported for plasma/photocatalysis association. Those results are interpreted in terms of oxidative species modification due to the presence of water. Moreover, the investigation of water vapour contribution into oxidative processes improves the understanding of plasma/photocatalytic association mechanisms.     

Effect of pre‐treatments based on UV photocatalysis and photo‐oxidation on toluene biofiltration performance

BACKGROUND: The integration of UV photocatalysis and biofiltration seems to be a promising combination of technologies for the removal of hydrophobic and poorly biodegradable air pollutants. The influence of pre‐treatments based on UV_{254 nm} photocatalysis and photo‐oxidation on the biofiltration of toluene as a target compound was evaluated in a controlled long‐term experimental study using different system configurations: a standalone biofilter, a combined UV photocatalytic reactor‐biofilter, and a combined UV photo‐oxidation reactor (without catalyst)‐biofilter. RESULTS: Under the operational conditions used (residence time of 2.7 s and toluene concentrations 600–1200 mg C m^?3), relatively low removal efficiencies (6–3%) were reached in the photocatalytic reactor and no degradation of toluene was found when the photo‐oxidation reactor was operated without catalyst. A noticeable improvement in the performance of the biofilter combined with a photocatalytic reactor was observed, and the elimination capacity of the biological process increased by more than 12 g C h^?1 m^?3 at the inlet loads studied of 50–100 g C h^?1 m^?3. No positive effect on toluene removal was observed for the combination of UV photoreactor and biofilter. CONCLUSIONS: Biofilter pre‐treatment based on UV_{254 nm} photocatalysis showed promising results for the removal of hydrophobic and recalcitrant air pollutants, providing synergistic improvement in the removal of toluene. Copyright © 2011 Society of Chemical Industry     

TiO2光催化处理含甲基橙微污染水的动力学研究

通过溶胶-凝胶和浸渍相结合的方法制备出负载型纳米TiO2光催化剂,在光催化氧化反应器中对含有甲基橙的微污染水进行了光催化氧化研究.确定影响甲基橙光催化氧化的主要影响因素为TiO2光催化剂投加量、氧化剂投加量.结果表明,光催化氧化要比无催化剂的光氧化效果好,甲基橙的降解过程符合一级反应动力学模型;最佳的催化剂投加质量浓度为0.40 g/L;增加H2O2的投加量有助于甲基橙的去除.     

Comparison of granular activated carbon bio-sorption and advanced oxidation processes in the treatment of leachate effluent

Landfill leachate is a toxic effluent of a decomposing landfill that is produced when rainwater percolates through the landfill leaching out contaminants and pollutants. Untreated leachate is a potential source for the contamination of soil, surface and ground water. In this study, the treatment processes such as granular activated carbon (GAC) adsorption/bio-sorption (batch), and advanced oxidation processes (AOP) viz. photocatalysis and Fenton’s process were evaluated and compared by using synthetic landfill leachate (SLL) as a contaminant. TiO₂ was used as a catalyst in photocatalysis, and Fenton’s reagent (H₂O₂/Fe⁺²) was used in Fenton’s process. The degradation of SLL effluent by the three above-mentioned processes was characterized by the % TOC removal. The % TOC removed by photocatalysis, Fenton oxidation and bio-sorption (which includes adsorption and biodegradation) was 30, 60 and 85%, respectively. The bio-sorption increased with the increasing GAC dose. The optimum dose of Fenton’s reagent in advanced oxidation was 15 and 400 milli moles of Fe⁺² and H₂O₂, respectively. The Fenton’s process showed faster degradation kinetics compared to biodegradation and photocatalysis.     

TiO2光催化氧化气相甲醛暾研究进展

室内多种建筑材料释放出的甲醛，对人类的生存危害极大。因此，用TiO2光催化剂降解气相甲醛成为一个研究热点。文章回顾了近年来用TiO2光催化剂降解气相甲醛取得的成果。     

g-C3N4/MIL-125(Ti)磁性复合材料制备及其去除罗丹明B

为解决能源短缺和环境污染等问题,探究半导体光催化材料去除有机污染物,以MIL-125(Ti)为光催化剂载体,g-C₃N₄为有机半导体,Fe₃O₄@SiO₂为磁性载体,通过溶剂热法合成了一系列不同质量配比的可见光响应型MIL-125(Ti)复合材料。通过傅里叶变换红外光谱仪、X射线衍射仪、场发射扫描电子显微镜、热重分析仪等对复合材料的样品组成、结构、形貌及光学性能等进行表征分析。进一步通过正交试验评价该复合材料去除罗丹明B的性能。研究结果表明,最适宜去除罗丹明B的操作工艺条件为：光催化时间为4.0h,g-C₃N₄与MIL-125(Ti)的质量配比为1∶20,催化剂投加量为0.01g,罗丹明B溶液的浓度为10.0mg/L。在该条件下罗丹明B的去除率可达到96.57%。经过4次循环实验后,去除率仍能达到86.52%。g-C₃N₄/MIL-125(Ti)磁性复合材料的制备工艺和去除有机染料机理可为相关研究提供借鉴。