Publications by Julian Andrés Rengifo Herrera

Why five decades of massive research on heterogeneous photocatalysis, especially on TiO2, has not yet driven to water disinfection and detoxification applications? Critical review of drawbacks and challenges

César Pulgarin, Julian Andrés Rengifo Herrera

For fifty years, heterogeneous photocatalysis has been considered as having potential to remove organic and microbiological pollutants from water under either artificial UV light or sunlight irradiation. However, after tens of thousands of published resear ...

Elsevier Science Sa2023

Low-frequency ultrasound induces oxygen vacancies formation and visible light absorption in TiO2 P-25 nanoparticles

César Pulgarin, Andrzej Sienkiewicz, Julian Andrés Rengifo Herrera

Low-frequency ultrasound (LFUS) irradiation induces morphological, optical and surface changes in the commercial nano-TiO2-based photocatalyst, Evonik-Degussa P-25. Low-temperature electron spin resonance (ESR) measurements performed on this material provi ...

2012

Solar disinfection of wild Salmonella sp. in natural water with a 18 L CPC photoreactor: Detrimental effect of non-sterile storage of treated water

César Pulgarin, Frédéric Sciacca, Julian Andrés Rengifo Herrera

For the first time solar disinfection of liters of water containing wild Salmonella sp. and total coliforms was carried out in a compound parabolic collector (CPC) photoreactor at temperatures of almost 50 degrees C. Using surface water with high turbidity ...

2011

Synthesis, Characterization, and Photocatalytic Activities of Nanoparticulate N, S-Codoped TiO2 Having Different Surface-to-Volume Ratios

László Forró, Juan Kiwi, Jacques-Edouard Moser, César Pulgarin, Andrzej Sienkiewicz, Julian Andrés Rengifo Herrera, Katarzyna Pierzchala

An efficient, visible light active, N, S-codoped TiO2-based photocatalyst was prepared by reacting thiourea with nanoparticulate anatase TiO2. Commercial anatase powders were manually ground with thiourea and annealed at 400 degrees C in two crucibles with ...

American Chemical Society2010

Dramatic enhancement of solar disinfection (SODIS) of wild Salmonella sp in PET bottles by H2O2 addition on natural water of Burkina Faso containing dissolved iron

César Pulgarin, Frédéric Sciacca, Julian Andrés Rengifo Herrera

Disinfection of surface water containing dissolved iron (0.3 mg L-1) at natural neutral pH (similar to 7.5) was carried out via solar disinfection (SODIS) treatment in PET bottles with H2O2 (10 mg L-1). Wild coliforms and Salmonella sp. were monitored for ...

Elsevier2010

TiO2 PHOTOCATALYTIC INACTIVATION UNDER SIMULATED SOLAR LIGHT OF BACTERIAL CONSORTIA IN DOMESTIC WASTEWATERS PREVIOUSLY TREATED BY UASB, DUCKWEED AND FACULTATIVE PONDS

César Pulgarin, Julian Andrés Rengifo Herrera

In this work, TiO2 photocatalysis was used to disinfect domestic wastewaters previously treated by different biological treatment systems: Upward-flow Anaerobic Sludge Blanket (UASB), facultative pond, and duckweed pond. The microorganisms monitored were E ...

Sociedade Brasileira de Quimica / Sociedade Brasileira de Química2010

The effect of Fe2+, Fe3+, H2O2 and the photo-Fenton reagent at near neutral pH on the solar disinfection (SODIS) at low temperatures of water containing Escherichia coli K12

César Pulgarin, Julian Andrés Rengifo Herrera

The effect of Fe2+, Fe3+, H2O2 and the photo-Fenton system (Fe2+or3+/H2O2/hv) on solar water disinfection (SODIS) at low temperature and at near neutral pH are discussed in detail. We focus on Escherichia coil K12 suspended in either MilliQ water, water co ...

2010

Photocatalytic activity of N, S co-doped and N-doped commercial anatase TiO2 powders towards phenol oxidation and E. coli inactivation under simulated solar light irradiation

César Pulgarin, Julian Andrés Rengifo Herrera

Nitrogen and sulfur co-doped and N-doped TiO2 anatase TKP 102 (Tayca) were prepared by manual grinding with thiourea and urea, respectively, and annealing at 400 degrees C. Both materials showed visible-light absorption as measured by Diffuse Reflectance S ...

2010

N, S co-doped and N-doped Degussa P-25 powders with visible light response prepared by mechanical mixing of thiourea and urea. Reactivity towards Escherichia coli inactivation and phenol oxidation

Juan Kiwi, César Pulgarin, Julian Andrés Rengifo Herrera

2009

Correlations for photocatalytic activity and spectral features of the absorption band edge of TiO2 modified by thiourea

César Pulgarin, Julian Andrés Rengifo Herrera

Doping of nanocrystalline TiO2 powders with sizes ranging from 9.5 nm up to 19.1 nnn was carried out with thiourea (TU) to introduce the C, N and S-species into the TiO2. The crystal size was determined by X-ray diffraction. Doped-TiO2 particles were color ...

2009

Abatement of organics and Escherichia coli by N, S co-doped TiO2 under UV and visible light. Implications of the formation of singlet oxygen (1O2) under visible light

László Forró, Juan Kiwi, César Pulgarin, Andrzej Sienkiewicz, Julian Andrés Rengifo Herrera

2009

Preparation, characterization and photocatalytic activity of commercial TiO2 powders co-doped by N and S

Julian Andrés Rengifo Herrera

Heterogeneous photocatalysis over TiO2 using the sunlight seems to be a promising technology for waste-water treatment and drinking water production. However, the overall efficiency of TiO2 under natural sunlight is limited to the UV-driven activity (λ < 4 ...

EPFL2009

Escherichia coli inactivation by N, S co-doped commercial TiO2 powders under UV and visible light

Juan Kiwi, César Pulgarin, Nikola Castillo, Julian Andrés Rengifo Herrera

2008

Effect of suspended TiO2 physicochemical characteristics on benzene derivatives photocatalytic degradation

César Pulgarin, Damien Gumy, Julian Andrés Rengifo Herrera

2008

Elargissement du spectre d'absorption vers le visible de poudres commerciales de TiO2 par dopage par N, S, C. Préparation, caractérisation et activité photocatalytique antibactérienne

Juan Kiwi, César Pulgarin, Nikola Castillo, Julian Andrés Rengifo Herrera

2007

A Comparison of Solar Photocatalytic Inactivation of Waterborne E. Coli Using Tris(2,2’-bipyridine)ruthenium(II), Rose Bengal and TiO2

César Pulgarin, Julian Andrés Rengifo Herrera

Background. The development of alternative processes to eliminate pathogenic agents in water is a matter of growing interest. Current drinking water disinfection procedures, such as chlorination and ozonation, can generate disinfection by-products with car ...

2007