Julio C Morales | Universidad Nacional Autónoma de México (original) (raw)

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Papers by Julio C Morales

Research paper thumbnail of Uso De Colectores Solares Para La Remoción Fotocatalítica De Disruptores Endócrinos Presentes en Agua Contaminada

Research paper thumbnail of Remocion biologica simultanea de fosforo y nitrogeno de agua residual en un reactor de lecho movil

Research paper thumbnail of Synthesis and Characterization of TiO2 Nanoparticles: Applications in Research on the Interaction of Colloidal TiO2 with Human Serum Albumin by Fluorescence Spectroscopy

Analytical Sciences, 2012

Titanium dioxide (TiO2) nanoparticles (NPs) are widely used as an important kind of biomaterials ... more Titanium dioxide (TiO2) nanoparticles (NPs) are widely used as an important kind of biomaterials due to their large surface area, enhanced chemical reactivity and easy penetration into cells. Nano TiO2 with pure anatase phase was successfully prepared by solvothermal method. Its particle size was about 21 nm, while the larger specific surface area of TiO2 was 77.43 m 2 /g. The interaction of colloidal TiO2 with human serum albumin was studied by using absorption spectra and fluorescence spectra. The apparent binding constants (K) were 345.780 × 10 5 , 4.376 × 10 5 , 0.035 × 10 5 at 298, 303 and 308 K, respectively. In addition, the number of binding sites (n) was gradually decreased with the increase of temperature, which indicated that the quenching mechanism of albumin by colloidal TiO2 was static fluorescence quenching process. Based on fluorescence resonance energy transfer, the energy transfer efficiency (E) and critical transfer distance (r0) between donor (human serum albumin, HSA) and acceptor (colloidal TiO2) were calculated to be 0.862 and 6.244 nm, which suggested that non-radiative energy transfer occurred between TiO2 and HSA. Furthermore, the conformational changes of HSA were shown by synchronous fluorescence.

Research paper thumbnail of Photocatalytic oxidation of aqueous naproxen with a horizontally placed solar CPC slurry reactor

DESALINATION AND WATER TREATMENT, 2017

Research paper thumbnail of Thick TiO2 Sol – gel Films for Water Detoxification: Synthesis, Characterization and Use for Photocatalytic Oxidation

Journal of Advanced Oxidation Technologies, 2013

Thick TiO 2 films, prepared using the sol-gel method on soda lime glasses, were used for the phot... more Thick TiO 2 films, prepared using the sol-gel method on soda lime glasses, were used for the photocatalytic oxidation of methylene blue. Several sintering temperatures and times were tested. The maximum discoloration efficiency was obtained with films sintered by 2 hours at 575 and 605°C. Films were characterized by Raman Spectroscopy (Raman), X-Ray Diffraction Spectroscopy (XRD), Scanning Electron Microscopy (SEM) and UV-Visible Spectrophotometry (UV-Vis). Additionally, the effect of number of layers was analyzed, and polyethylene glycol was added to the organic precursor to determine whether this addition has a beneficial effect on the catalyst activity. It was determined that the crystalline phase predominance of TiO 2 is directly related to the photocatalytic oxidation performance. Activ TM (Pilkington) glasses were also studied for comparison with the performance of the thick films.

Research paper thumbnail of Solar Photocatalytic Oxidation of Triclosan with TiO2 Immobilized on Volcanic Porous Stones on a CPC Pilot Scale Reactor

Research paper thumbnail of Solar Photocatalytic Oxidation of Hydroxy Phenols in a CPC Reactor with Thick TiO2 Films

Energy Procedia, 2014

Solar Photocatalysis is an advanced oxidation process that is involved on water detoxification as... more Solar Photocatalysis is an advanced oxidation process that is involved on water detoxification as a very promising technology. This process has been used for polishing industrial and municipal wastewaters, mainly with titanium dioxide (TiO 2) as a catalyst. Most of the reactors use TiO 2 as a powder and need a pump in order to have the water moving through the system. A novel photocatalytic reactor, based on Compound Parabolic Collectors (CPC), was developed. The reactor has TiO 2 fixed as a thick film in the CPC tubes and water flows inside by density differences exclusively. This reactor is designed to avoid catalyst separation and water pumping, steps that are energydemanding and expensive. The films were prepared by conventional solgel method on 13 mm diameter Pyrex tubes. The films were firmly bounded to tubes and used for several test with good efficiencies. Films had a mix of anatase and rutile crystalline phases and its particles are nanoscopic. A CPC reactor with 20 tubes connected to the tank by its upper side only was developed and used. Resorcinol was effectively removed from water, either with or without persulfate as electron acceptor, at laboratory bench (one CPC tube experiments) and at pilot scale (20 tubes in the reactor). Main reaction sub-products (trihydroxy benzenes) were also oxidized in reasonable solar irradiation times.

Research paper thumbnail of Solar photocatalytic oxidation of Triclosan with TiO 2 immobilized on volcanic porous stones on a CPC pilot scale reactor

Triclosan (TCS) has been used as an antimicrobial agent for more than 30 years and is present in ... more Triclosan (TCS) has been used as an antimicrobial agent for more than 30 years and is present in effluents from wastewater treatment plants, in receiving rivers, in tap water and even in groundwater. This compound is resistant to conventional water treatment processes and has been classified as endocrine disruptor and emerging concern pollutant by several organizations. For this reason it is essential to find an efficient process that allows its degradation to non-toxic substances. In this study, TiO 2 was immobilized by forming thick TiO 2 films on volcanic meso-porous stones, creating a photocatalyst that fills a Pyrex® CPC reactor (packed bed reactor type CPC). This reactor is used to remove aqueous Triclosan from water. Films structure and composition is determined experimentally. Efficiency of the organic molecule removal is being related with initial conditions. Films present a very high mechanical stability, excellent adhesion on stones and photocatalytic activity. Reactor, packed with covered stones, presents a reasonable pressure drop. One of the main goals is to have the reactor in operation without any solid – liquid separation step (which is quite expensive energy – demanding) and to employ locally available and inexpensive packing material for the reactor, reaching high cleaning of polluted water.

Research paper thumbnail of Uso De Colectores Solares Para La Remoción Fotocatalítica De Disruptores Endócrinos Presentes en Agua Contaminada

Research paper thumbnail of Remocion biologica simultanea de fosforo y nitrogeno de agua residual en un reactor de lecho movil

Research paper thumbnail of Synthesis and Characterization of TiO2 Nanoparticles: Applications in Research on the Interaction of Colloidal TiO2 with Human Serum Albumin by Fluorescence Spectroscopy

Analytical Sciences, 2012

Titanium dioxide (TiO2) nanoparticles (NPs) are widely used as an important kind of biomaterials ... more Titanium dioxide (TiO2) nanoparticles (NPs) are widely used as an important kind of biomaterials due to their large surface area, enhanced chemical reactivity and easy penetration into cells. Nano TiO2 with pure anatase phase was successfully prepared by solvothermal method. Its particle size was about 21 nm, while the larger specific surface area of TiO2 was 77.43 m 2 /g. The interaction of colloidal TiO2 with human serum albumin was studied by using absorption spectra and fluorescence spectra. The apparent binding constants (K) were 345.780 × 10 5 , 4.376 × 10 5 , 0.035 × 10 5 at 298, 303 and 308 K, respectively. In addition, the number of binding sites (n) was gradually decreased with the increase of temperature, which indicated that the quenching mechanism of albumin by colloidal TiO2 was static fluorescence quenching process. Based on fluorescence resonance energy transfer, the energy transfer efficiency (E) and critical transfer distance (r0) between donor (human serum albumin, HSA) and acceptor (colloidal TiO2) were calculated to be 0.862 and 6.244 nm, which suggested that non-radiative energy transfer occurred between TiO2 and HSA. Furthermore, the conformational changes of HSA were shown by synchronous fluorescence.

Research paper thumbnail of Photocatalytic oxidation of aqueous naproxen with a horizontally placed solar CPC slurry reactor

DESALINATION AND WATER TREATMENT, 2017

Research paper thumbnail of Thick TiO2 Sol – gel Films for Water Detoxification: Synthesis, Characterization and Use for Photocatalytic Oxidation

Journal of Advanced Oxidation Technologies, 2013

Thick TiO 2 films, prepared using the sol-gel method on soda lime glasses, were used for the phot... more Thick TiO 2 films, prepared using the sol-gel method on soda lime glasses, were used for the photocatalytic oxidation of methylene blue. Several sintering temperatures and times were tested. The maximum discoloration efficiency was obtained with films sintered by 2 hours at 575 and 605°C. Films were characterized by Raman Spectroscopy (Raman), X-Ray Diffraction Spectroscopy (XRD), Scanning Electron Microscopy (SEM) and UV-Visible Spectrophotometry (UV-Vis). Additionally, the effect of number of layers was analyzed, and polyethylene glycol was added to the organic precursor to determine whether this addition has a beneficial effect on the catalyst activity. It was determined that the crystalline phase predominance of TiO 2 is directly related to the photocatalytic oxidation performance. Activ TM (Pilkington) glasses were also studied for comparison with the performance of the thick films.

Research paper thumbnail of Solar Photocatalytic Oxidation of Triclosan with TiO2 Immobilized on Volcanic Porous Stones on a CPC Pilot Scale Reactor

Research paper thumbnail of Solar Photocatalytic Oxidation of Hydroxy Phenols in a CPC Reactor with Thick TiO2 Films

Energy Procedia, 2014

Solar Photocatalysis is an advanced oxidation process that is involved on water detoxification as... more Solar Photocatalysis is an advanced oxidation process that is involved on water detoxification as a very promising technology. This process has been used for polishing industrial and municipal wastewaters, mainly with titanium dioxide (TiO 2) as a catalyst. Most of the reactors use TiO 2 as a powder and need a pump in order to have the water moving through the system. A novel photocatalytic reactor, based on Compound Parabolic Collectors (CPC), was developed. The reactor has TiO 2 fixed as a thick film in the CPC tubes and water flows inside by density differences exclusively. This reactor is designed to avoid catalyst separation and water pumping, steps that are energydemanding and expensive. The films were prepared by conventional solgel method on 13 mm diameter Pyrex tubes. The films were firmly bounded to tubes and used for several test with good efficiencies. Films had a mix of anatase and rutile crystalline phases and its particles are nanoscopic. A CPC reactor with 20 tubes connected to the tank by its upper side only was developed and used. Resorcinol was effectively removed from water, either with or without persulfate as electron acceptor, at laboratory bench (one CPC tube experiments) and at pilot scale (20 tubes in the reactor). Main reaction sub-products (trihydroxy benzenes) were also oxidized in reasonable solar irradiation times.

Research paper thumbnail of Solar photocatalytic oxidation of Triclosan with TiO 2 immobilized on volcanic porous stones on a CPC pilot scale reactor

Triclosan (TCS) has been used as an antimicrobial agent for more than 30 years and is present in ... more Triclosan (TCS) has been used as an antimicrobial agent for more than 30 years and is present in effluents from wastewater treatment plants, in receiving rivers, in tap water and even in groundwater. This compound is resistant to conventional water treatment processes and has been classified as endocrine disruptor and emerging concern pollutant by several organizations. For this reason it is essential to find an efficient process that allows its degradation to non-toxic substances. In this study, TiO 2 was immobilized by forming thick TiO 2 films on volcanic meso-porous stones, creating a photocatalyst that fills a Pyrex® CPC reactor (packed bed reactor type CPC). This reactor is used to remove aqueous Triclosan from water. Films structure and composition is determined experimentally. Efficiency of the organic molecule removal is being related with initial conditions. Films present a very high mechanical stability, excellent adhesion on stones and photocatalytic activity. Reactor, packed with covered stones, presents a reasonable pressure drop. One of the main goals is to have the reactor in operation without any solid – liquid separation step (which is quite expensive energy – demanding) and to employ locally available and inexpensive packing material for the reactor, reaching high cleaning of polluted water.