Search results for "Photocatalytic"

Photocatalytic inactivation of Legionella Pneumophila and aerobic bacteria consortium in water over TiO2/SiO2 fibres in a continuous reactor

2005

A continuous photoreactor, working in a total recycle mode and irradiated by a low-pressure Hg lamp, has been used to study the bactericidal effect of a photocatalyst, formed by TiO2 embedded in SiO2 fibres, on Legionella pneumophila and a consortium of common gram-negative aerobic bacteria: (Escherichia coli, Klebsiella sp., Pseudomona sp. and Proteus sp.) in water. The kinetic modeling of the inactivation process, carried out with the measured values of viable bacteria concentration at the outlet of photoreactor, evidenced that for each pass inside the photoreactor the ratio between the outlet and inlet cell concentrations was of order of 0.01 for the inactivation of L. pneumophila. For t…

Heterogeneous photocatalysis: a promising advanced oxidation process

2018

This chapter reports the fundamentals of heterogeneous PC. In particular, different kinetic models and the influence of some parameters (such as pH, temperature, light intensity) on the rate of PC are described, and the effects of some photocatalyst modifications are discussed. Methods for photoreactor modeling are analyzed and the coupling of PC with other AOPs using H2O2, O3, and peroxydisulfate are discussed.

PMRs Utilizing Non–Pressure-Driven Membrane Techniques

2018

In the present chapter it is shown how photocatalytic membrane reactors utilizing membrane processes, which are not pressure driven, can exploit various mechanisms to obtain a substantial improvement of the process. The fundamentals of this particular type of membrane reactors are reviewed including the effects of the most important parameters and the methods and rules of coupling photocatalysis and membrane separation. The survey of the studies on photocatalytic membrane reactors (PMRs) utilizing pervaporation, dialysis, membrane contactors and membrane distillation offers the opportunity of discussing the advantages with respect to PMRs adopting pressure driven membrane processes. Indeed,…

Photocatalytic membrane reactors: fundamentals, membrane materials and operational issues

2013

Abstract: This chapter reports the properties of semiconductor materials used in heterogeneous photocatalysis together with a comparison of heterogeneous photocatalytic systems and a brief description of the types of membranes that can be used. Some aspects of membrane operations, such as fouling, separation of a photocatalyst and effectiveness of photodegradation on permeate quality are discussed.

Guidelines for the Assessment and the Validation of the Rate Law of Slurry Photocatalytic Reactions

2017

The assessment of the rate law of slurry photocatalytic reactions appears to be a hard task, mainly because in this type of reactions the average rate of reaction, which is experimentally observed in a real reactor, could be very different from the “true” (intrinsic) rate of reaction, which cannot be measured directly. In the present work, it is shown how a proper mathematical model allows the utilization of the differential and/or the integral methods of kinetic analysis. The mathematical model must take into account not only the momentum and the mass balances, but also the radiative transfer equation. However, the discrimination among different proposed kinetic laws remains difficult sinc…

Polymer leaf of expanded material coated with titanium dioxide exhibiting photocatalytic activity, container and package for foodstuffs obtained from…

2010

Photocatalytic membrane reactors: configurations, performance and applications in water treatment and chemical production

2013

Abstract: The configurations and performance of photocatalytic membrane reactors (PMRs) assembled with membranes (also photocatalytic type) and/or suspended photocatalyst are described. Examples of the application of PMRs in water/wastewater treatment as well as in photocatalytic synthesis are shown. An outline of the modeling of PMRs is presented with a brief economic analysis; future trends in PMRs are also discussed.

Enhancing Selectivity of Photocatalytic Synthesis of p-Anisaldehyde in Water under Solar Irradiation by N- Doped TiO2

2014

Photocatalytic ozonation:Maximization of the reaction rate and control of undesired by-products

2014

In theso-calledphotocatalyticozonation(PO)synergisticeffectsbetweenphotocatalysisandozonation enhance therateofoxidationoforganiccompounds,thereforethisintegratedprocessisverypromising for useinwatertreatment.Inthepresentwork,itisdemonstratedthattheimprovementthatcanbe obtained bytheintegratedprocessincomparisonwiththeuncoupledprocessesdependsontherelative weight between photocatalysis and ozonation. In this respect, it has been found that a relatively low rate of photocatalysis (0.3 times the rate of ozonation)issufficienttogetthehighestsynergyandtomaximize the performancesintheoxidationofformate,theadoptedmodelorganiccompound.Thebenefitsof the couplingofphotocatalysistoozonationarenotlimi…

A facile way to synthesize noble metal free TiO2 based catalysts for glycerol photoreforming

2023

In this work anaerobic heterogeneous photocatalytic solar/UV light reforming of glycerol in aqueous media was performed with Pt-photodeposition and noble metal free modified TiO2 photocatalysts prepared through ball milling, a very simple and cheap coupled catalyst preparation method. Different amounts of Cu2O or 3% CuO were loaded on TiO2 using ball milling and during each run glycerol conversion, hydrogen and CO2 formed in the gas phase and 1,3-dihydroxyacetone (DHA) and glyceraldehyde (GA) in the liquid phase were determined. The results were compared with the aim to verify the effectiveness of Cu2O in replacing Pt. Using noble metal free photocatalysts, 33% glycerol conversion, 10.3% an…