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Stefanos Giannakis

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Publications associées (67)

Iron oxide-mediated semiconductor photocatalysis vs. heterogeneous photo-Fenton treatment of viruses in wastewater. Impact of the oxide particle size

Michaël Bensimon, César Pulgarin, Sami Rtimi, Masoud Talebi Amiri, Stefanos Giannakis, Siting Liu, Anna Carratala Ripolles

The photo-Fenton process is recognized as a promising technique towards microorganism disinfection in wastewater, but its efficiency is hampered at near-neutral pH operating values. In this work, we overcome these obstacles by using the heterogeneous photo ...

Elsevier2017

Effect of reactor material and its reuse on photo-Fenton process efficiency at near-neutral pH: Alterations in E-coli inactivation and resorcinol degradation kinetics in water

Stefanos Giannakis, Angelica Varon Lopez

The effect of reactor material (borosilicate and polyethylene terephthalate-PET) and its reuse on the microbiological and chemical decontamination of water by the photo-Fenton reaction at near-neutral pH was assessed. Escherichia coli was used as an indica ...

Elsevier2017

Iohexol degradation in wastewater and urine by UV-based Advanced Oxidation Processes (AOPs): Process modeling and by-products identification

Hubert Girault, César Pulgarin, Simon Schindelholz, Natalia Gasilova, Stefanos Giannakis, Miquel Pastor Gelabert, Milica Jovic

In this work, an Iodinated Contrast Medium (ICM), Iohexol, was subjected to treatment by 3 Advanced Oxidation Processes (AOPs) (UV, UV/H2O2, UV/H2O2/Fe2+). Water, wastewater and urine were spiked with Iohexol, in order to investigate the treatment efficien ...

Elsevier2017

Modeling and treatment optimization of pharmaceutically active compounds by the photo-Fenton process: The case of the antidepressant Venlafaxine

César Pulgarin, Idriss Hendaoui, Sami Rtimi, Stefanos Giannakis

In this study, the anti-depressant Venlafaxine, a new emerging contaminant of interest for the Swiss legislation, was subjected to systematic degradation. In order to develop an efficient framework for the treatment of emerging contaminants at industrial s ...

Elsevier Sci Ltd2017

FeOx magnetization enhancing E-coli inactivation by orders of magnitude on Ag-TiO2 nanotubes under sunlight

Juan Kiwi, César Pulgarin, Arnaud Magrez, Ivica Zivkovic, Sami Rtimi, Stefanos Giannakis, Marco Mangayayam

Drastic bacterial enhancement was observed when the Ag(3%)-TiO2 nanotubes were modified with FeOx (3%) magnetic oxide. On bare TiO2- nanotubes a reduction of 0.21og(10)CFU was observed within one hour under simulated low intensity solar light. Under simila ...

Elsevier2017

Effect of Fe(II)/Fe(III) species, pH, irradiance and bacterial presence on viral inactivation in wastewater by the photo-Fenton process: Kinetic modeling and mechanistic interpretation

Michaël Bensimon, César Pulgarin, Sami Rtimi, Stefanos Giannakis, Siting Liu, Anna Carratala Ripolles

Advanced Oxidation Processes and in particular photo-Fenton, represent promising strategies of pathogen inactivation in wastewater effluents. Nevertheless, its full potential is not yet unlocked, as the efficacy of photo-Fenton against viruses has not been ...

Elsevier2017

New evidence for disinfection, self-cleaning and pollutant degradation mediated by GF-TiO2-Cu mats under solar/visible light in mild oxidative conditions

Michaël Bensimon, Juan Kiwi, César Pulgarin, Laura Victoria Suárez Murillo, Stefanos Giannakis

This study presents the performance of GF-mats loaded with TiO2 and Cu under solar/visible light leading to bacterial inactivation and pollutant degradation at both solid-air and solid-liquid interfaces. The GF-mats show effective water disinfection, self- ...

Elsevier2017

A green solar photo-Fenton process for the elimination of bacteria and micropollutants in municipal wastewater treatment using mineral iron and natural organic acids

Michaël Bensimon, Luiz Felippe De Alencastro, Dominique Grandjean, César Pulgarin, Sami Rtimi, Stefanos Giannakis, Paola Villegas Guzman

In this investigation, a new, green photo-Fenton process for wastewater treatment is proposed, involving the use of a natural iron source and natural additives, deriving from wastes, acting as iron chelators. The use of mineral iron as precursor in the pho ...

Elsevier Science Bv2017

Remarkable enhancement of bacterial inactivation in wastewater through promotion of solar photo-Fenton at near-neutral pH by natural organic acids

César Pulgarin, Stefanos Giannakis, Paola Villegas Guzman

In this work, the near-neutral photo-Fenton process, as a means of wastewater disinfection, was enhanced by the addition of Organic Acids (OAs), namely citric, ascorbic, tartaric and caffeic acid. The addition of OAs exhibited significant bacterial inactiv ...

Elsevier2017

Solar photo-Fenton and UV/H2O2 processes against the antidepressant Venlafaxine in urban wastewaters and human urine. Intermediates formation and biodegradability assessment

Luiz Felippe De Alencastro, Hubert Girault, Dominique Grandjean, César Pulgarin, Idriss Hendaoui, Stefanos Giannakis, Milica Jovic

In this work, the use of Advanced Oxidation Processes (AOPs) against the degradation of an emerging contaminant has been subjected under systematic investigation. The optimization of treatment of the anti- depressant drug Venlafaxine (VFA) was performed, u ...

Elsevier Science Sa2017

Light-Assisted Advanced Oxidation Processes for the Elimination of Chemical and Microbiological Pollution of Wastewaters in Developed and Developing Countries

César Pulgarin, Sami Rtimi, Stefanos Giannakis

In this work, the issue of hospital and urban wastewater treatment is studied in two different contexts, in Switzerland and in developing countries (Ivory Coast and Colombia). For this purpose, the treatment of municipal wastewater effluents is studied, si ...

Molecular Diversity Preservation International2017

Comparative effect of growth media on the monitoring of E. coli inactivation and regrowth after solar and photo-Fenton treatment

César Pulgarin, Rosa Mosteo, Stefanos Giannakis

This study intends to assess the cultivability of photo-treated Escherichia coil K-12 on media With different selectivity (PCA, LBA, T-7, T-7 + TTC, VRBA and MAC) and to establish optimal conditions for bacterial recuperation. For these purposes, immediate ...

Elsevier2017

Phototransformation of Acesulfame K in surface waters: Comparison of two techniques for the measurement of the second-order rate constants of indirect photodegradation, and modelling of photoreaction kinetics

Stefanos Giannakis

By use of photochemical modelling we show that acesulfame K (ACE) can undergo photodegradation in surface waters, mainly by reaction with (OH)-O-center dot and possibly (CDOM)-C-3* (the triplet states of chromophoric dissolved organic matter). With the pos ...

Elsevier2017

Micropollutant degradation, bacterial inactivation and regrowth risk in wastewater effluents: Influence of the secondary (pre)treatment on the efficiency of Advanced Oxidation Processes

Luiz Felippe De Alencastro, Dominique Grandjean, César Pulgarin, Anoys Magnet, Stefanos Giannakis

In this work, disinfection by 5 Advanced Oxidation Processes was preceded by 3 different secondary treatment systems present in the wastewater treatment plant of Vidy, Lausanne (Switzerland). 5 AOPs after two biological treatment methods (conventional acti ...

Elsevier2016

Solar disinfection is an augmentable, in situ-generated photo-Fenton reaction-Part 1: A review of the mechanisms and the fundamental aspects of the process

César Pulgarin, Stefanos Giannakis

The present manuscript is a conceptual review concerning the photo-Fenton reaction at near-neutral pH, used for bacterial inactivation. In this first Part, an overview of the mechanisms involved, as well as the fundamental concepts governing the near-neutr ...

Elsevier Science Bv2016

Supported TiO2 films deposited at different energies: Implications of the surface compactness on the catalytic kinetics

Michaël Bensimon, Juan Kiwi, César Pulgarin, Rosendo Sanjines, Sami Rtimi, Stefanos Giannakis

Insight is provided in this study for the effect of the TiO2film densification/compactness on polyethy-lene (PE-TiO2) by sputtering TiO2at two very different energy levels. Uniform, adhesive low energy filmswere prepared by direct current magnetron sputter ...

Elsevier2016

Solar disinfection is an augmentable, in situ-generated photo-Fenton reaction Part 2: A review of the applications for drinking water and wastewater disinfection

César Pulgarin, Stefanos Giannakis

This is the second part of a comprehensive review article about photo-Fenton reaction at near-neutral pH used for water and wastewater disinfection. In this part, a critical revision of the fundamental physical, chemical and biological parameters affecting ...

Elsevier2016

Castles fall from inside: Evidence for dominant internal photo-catalytic mechanisms during treatment of Saccharomyces cerevisiae by photo-Fenton at near-neutral pH

César Pulgarin, Cristina del Socorro Lonfat, Sami Rtimi, Stefanos Giannakis

In this work, the antimicrobial effects of the photo-Fenton process on yeast cells were tested (Saccharomyces cerevisiae), an essential eukaryotic unicellular model of living cells. Near-neutral pH was used in all studies, while iron sulfate and iron citra ...

Elsevier2016

Insight on the photocatalytic bacterial inactivation by co-sputtered TiO2-Cu in aerobic and anaerobic conditions

Michaël Bensimon, Juan Kiwi, César Pulgarin, Rosendo Sanjines, Sami Rtimi, Stefanos Giannakis

Co-sputtered TiO2-Cu polyester (TiO2-Cu-PES) under actinic light induced bacterial reduction of E. coli in the presence of O2 (air) and under anaerobic conditions. The bacterial inactivation/oxidation proceeds in the absence of O2 (air) probably due to the ...

Elsevier2016

Environmental considerations on solar disinfection of wastewater and the subsequent bacterial (re)growth

César Pulgarin, Stefanos Giannakis

In this work, solar disinfection of wastewater was studied, focusing on the effect of selected environmental variables, namely light intensity, continuous/intermittent light delivery, and post-irradiation storage as well as dilution in lake water. These va ...

Royal Society of Chemistry2015

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