Search results for "Advanced oxidation process"
showing 10 items of 13 documents
Visible light photocatalytic activity of macro-mesoporous TiO2-CeO2inverse opals
2018
Macro-mesoporous TiO2 inverse opal materials were synthesized and they were tested as photocatalysts under visible light irradiation. The influence of cerium oxide addition towards the Rhodamine B (RhB) photodegradation activity was evaluated. Structural, textural, spectral and surface properties of the TiO2-CeO2 inverse opal nanocomposites were studied by XRD, XPS, SEM, TEM, N2 adsorption-desorption, Diffuse Reflectance UV–vis and Photoluminescence spectroscopies. Compared to commercial TiO2 anatase, the macro-mesoporous TiO2 inverse opal exhibited six times higher kinetic rate constant in the RhB degradation under visible light irradiation. The good photocatalytic activity was related to …
Combination of ozonation and photocatalysis for purification of aqueous effluents containing formic acid as probe pollutant and bromide ion
2014
The treatment by advanced oxidation processes (AOPs) of waters contaminated by organic pollutants and containing also innocuous bromide ions may generate bromate ions as a co-product. In the present work heterogeneous photocatalysis and ozonation have individually been applied and in combination (integrated process) to degrade the organic compounds in water containing also bromide anions. The results show that: i) the sole photocatalysis does not produce bromate ions and in the case of its presence, it is able to reduce bromate to innocuous bromide ions; ii) the integration of photocatalysis and ozonation synergistically enhances the oxidation capabilities; and iii) in the integrated proces…
Electrochemical treatment of aqueous solutions of catechol by various electrochemical advanced oxidation processes: Effect of the process and of oper…
2017
Abstract Catechol, one of the most abundant compounds in olive mills wastewaters, which is generated in the Fenton degradation of various aromatic compounds, is a toxic, possible carcinogen, persistent pollutant and it is not readily biodegradable. Hence, its degradation requires the utilization of advanced oxidation processes (AOPs). Here, the electrochemical treatment of aqueous solutions of catechol was investigated. The utilization of various electrochemical processes, such as electro-Fenton (EF), direct anodic oxidation (AO), indirect oxidation by electro-generated active chlorine and coupled processes was investigated. Furthermore, the effect of various operating conditions (including…
A survey of photocatalytic materials for environmental remediation
2012
Abstract Heterogeneous photocatalysis is an advanced oxidation process which has been the subject of a huge amount of studies related to air cleaning and water purification. All these processes have been carried out mainly by using TiO 2 -based materials as the photocatalysts and ca. 75% of the articles published in the last 3 years is related to them. This review illustrates the efforts in the search of alternative photocatalysts that are not based on TiO 2 , with some exceptions concerning particularly innovative modifications as nanoassembled TiO 2 or TiO 2 composites with active carbon, graphite and fullerene. Papers reporting preparation, characterization and testing of binary, ternary…
Water Depollution by Advanced Oxidation Technologies
2020
This chapter deals with water treatments by advanced oxidation processes (AOPs) based on chemical and photochemical reactions. The most used processes are described, and for each of them, the main reaction mechanisms, principles, advantages, drawbacks, performances and formation of by-products, coupled with technologies and their applications to waters and wastewater depollution, have been analysed, supporting the main results of studies published in the pertinent literature.
Combination of advanced oxidation processes and active carbons adsorption for the treatment of simulated saline wastewater
2016
Abstract In the present work, an integrated process combining three different technologies, i.e. heterogeneous photocatalysis, homogeneous ozonation and adsorption on granular activated carbon (GAC) was used for the treatment of a synthetic solution simulating saline wastewater. The synergistic effects between the different methods enhance the oxidation rate of the organic compounds in the integrated process, so that its use may result sustainable. It has been found that a relatively low oxidation rate is sufficient to obtain the highest synergy between the three technologies and to maximize the performances. In particular, coupling ozonation and photocatalysis resulted in 20% enhancement i…
Photocatalytic membrane reactors for water treatment
2015
Abstract Heterogeneous photocatalysis is an advanced oxidation process largely studied in the field of environment recovery by the total degradation of organic and inorganic pollutants and for synthesis. In this chapter, the basic principles of photocatalysis are discussed with the advantages related to its coupling with a membrane separation in photocatalytic membrane reactors (PMRs). The types of membranes most widely used and their criteria of selection are briefly discussed. PMRs’ classification based on their configuration and on the type of membrane operation is also discussed, evidencing as their appropriate choice is a key step in view of large-scale implementation. Finally, some ca…
Electrochemical Abatement of Organic Pollutants in Water by Electro- Fenton with Natural Heterogeneous Catalysts Under Pressure
2020
In recent decades, electrochemical advanced oxidation processes (EAOPs) have proved as alternative technologies to conventional processes. Indeed, EAOPs can often allow to treat wastewater containing toxic and POPs. Among them, electro-Fenton (EF) is considered particularly promising for the treatment of recalcitrant organics, since it presents various advantages, including high abatements for many organic pollutants, simplicity of equipment and operations, relatively low cost and low consumption of chemicals. Recently, the utilization of some natural heterogeneous catalysts was proposed in order to avoid some disadvantages of the conventional EF process. In this frame, in this work EF proc…
Process for the production of bromine
2016
A process for the preparation of molecular bromine, by means of advanced oxidation processes or their combination is disclosed
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.