Photocatalytic oxidation (PCO) air purification technology is reviewed based on the decades of research conducted by the United Technologies Research Center (UTRC) and their external colleagues. UTRC conducted basic research on the reaction rates of various volatile organic compounds (VOCs). The knowledge gained allowed validation of 1D and 3D prototype reactor models that guided further purifi...

The synthesis of ZnO nanoparticles has attracted considerable interest because of their unique properties and potential applications in a variety of solid state devices, catalytic media etc. By using water-in-oil (w/o) microemulsions, nanodroplets of water were used as chemical reactor to synthesize nanoparticles of zinc oxide. Addition of reducing agent ((NH4)2CO3) and zinc salt (Zn(NO3)2) fol...

This study presents results of the photocatalytic inactivation of two groups of microorganisms: spores of the anaerobic bacterium Clostridium perfringens and coliphage. A cylindrical reactor impregnated with titanium dioxide and irradiated with ultraviolet light (15 W) was used. Parameters such as color, turbidity, hydraulic detention time (HDT) and initial concentration of microorganisms were ...

In the present work the degradation of nitrogen oxides (NOx) by concrete paving stones containing TiO2 to be applied in road construction is studied. A kinetic model is proposed to describe the photocatalytic reaction of nitric oxide (NO) in a standard flow laminar photoreactor irradiated with UV lamps. In addition the influence of several parameters that can affect the performance of these sto...

This study explores the synergy between photocatalytic oxidation and membrane filtration using a membrane. Titanium dioxide coated alumina membranes were fabricated tested in customized Photocatalytic Membrane Reactor (PMR) module. The discoloration of methylene blue (MB), 3.2 mg·L−1 an aqueous solution, was evaluated dead-end mode. A simple 1D analytic transport surface reaction model used bas...

A novel visible light-driven photocatalyst film, MoS₂/Ag/TiO₂, was synthesized on a glass-fiber membrane. The composite catalyst film had a multi-layer structure with Ag as nanoconjunctions between the MoS₂ and TiO₂ layers. The catalyst film performed well for both photocatalytic hydrogen production and organic degradation in a two-chamber photo-reactor under either solar or visible light. Hydr...

Photocatalytic oxidation of the sulfur-containing compounds, trimethylene sulfide (C3H6S), propylene sulfide (C3H6S), thiophene (C4H4S), and methyl disulfide (C2H6S2), was carried out using an annular plug flow reactor with TiO2 in a supported form. Formation of products and byproducts was monitored in real time using a mass spectrometry online system. Mineralization of the sulfur-containing co...

In this study the aqueous styrene photocatalytic degradation reaction was evaluated using TiO 2 P-25 (Degussa) as catalyst. The experiments were accomplished in a batch reactor, with temperature control and catalyst in suspension. The radiation source was a 28 W UV lamp. Determinations of styrene concentrations were done by gas chromatography with a flame ionization detector (FID). Preliminary ...

The lack of access to clean water remains a severe issue all over the world. Coupling photocatalysis with the membrane separation process, which is known as a photocatalytic membrane reactor (PMR), is promising for water treatment. PMR has developed rapidly during the last few years, and this paper presents an overview of the progress in the configuration and operational parameters of PMRs. Two...

In this study, photocatalysis was used to improve the dewaterability and settleability of waste activated sludge (WAS) by a solar photocatalytic reactor with transparent Ag/TiO2 film as photocatalyst. Specific resistance of filtration (SRF) and sludge volume index (SVI) were used to evaluate WAS dewaterability and settleability, respectively, and the mechanism of photocatalysis was interpreted ...