Author: JOSE RENE RANGEL MENDEZ

Inmovilización de oxihidróxidos de lantano sobre carbón activado para incrementar su capacidad de remoción de fluoruros del agua

Anchorage of lanthanum oxyhydroxides on activated carbon to increase its fluoride removal from water

ESMERALDA VENCES ALVAREZ JOSE RENE RANGEL MENDEZ (2017)

"El flúor es beneficioso para la salud humana a una concentración de 0.7 mg L-1, pero se considera peligroso cuando es ingerido a concentraciones superiores a 1.5 mg L-1, el cual es el límite recomendado por la Organización Mundial de la Salud (OMS). La contaminación del agua por fluoruros es un problema que se encuentra presente a nivel mundial. Por lo tanto, se requiere invertir en el desarrollo de nuevos materiales y tecnología más eficientes para la remoción de contaminantes prioritarios. El objetivo de esta investigación fue anclar óxidos de lantano sobre un carbón activado granular (CAG) comercial para remover fluoruros presentes en el agua. El CAG modificado con lantano se caracterizó mediante FT-IR, XRD, SEM, distribución de pKa´s y punto de carga cero (PCC) con la finalidad de elucidar el posible mecanismo de anclaje del lantano sobre la superficie del carbón activado y el mecanismo de adsorción de fluoruros en el carbón modificado. realizaron experimentos de adsorción en batch para estudiar el efecto del pH, de la presencia de aniones co-existentes, y la capacidad máxima de adsorción en solución acuosa. Los resultados mostraron que la capacidad de adsorción del carbón modificado con lantano (CAG-La) aumentó 5 veces con respecto al CAG comercial a una concentración inicial de F- de 20 mg L-1, a pH 7 y 25 °C. La presencia de aniones co-existentes no tiene ningún efecto en la capacidad de adsorción del fluoruro a concentraciones menores de 30 mg L-1."

"Fluoride is beneficial to humans health at a concentration of 0.7 mg L-1, but it is considered dangerous when ingested at concentrations above 1.5 mg L-1, which is the limit concentration recommended by the World Health Organization (WHO). Water pollution by fluorides occurs in many places around the world. Therefore, more efficient materials and technology are required to overcome this environmental problem. The objective of this research was to anchor lanthanum oxides on a commercial granular activated carbon (GAC) to remove fluorides from water. The modified GAC was characterized by FT-IR, XRD, SEM, pKa’s distribution, and point of zero charge (PZC) in order to suggest how lanthanum anchors on the activated carbon surface and also to propose the fluoride adsorption mechanism on the modified carbon. Adsorption experiments were carried out in batch to study the effect of pH, presence of co-existing anions, and the maximum adsorption capacity in aqueous solution. These results showed that the adsorption capacity of the modified carbon (GAC-La) increased 5 times compared to the commercial GAC at an initial concentration of 20 mg L-1 of F- at pH 7 and 25° C. Finally, the presence of co-existing anions has no effect on the fluoride adsorption capacity at concentrations below 30 mg L-1."

Article

INGENIERÍA Y TECNOLOGÍA

Evaluación de minerales de hierro naturales como posibles colectores de arsénico y fluoruro

Evaluation of natural iron mineral as possible collectors of arsenic and fluoride

KARDIA JEANETTE RAMIREZ MUÑIZ JOSE RENE RANGEL MENDEZ (2017)

"En este trabajo se caracterizó y evaluó la remoción de arsénico y fluoruro sobre óxidos de hierro naturales de bajo y alto contenido de Fe, colectados de las principales minas de hierro en operación en México. De los seis materiales evaluados, dos interactúan eficientemente con arsénico y fluoruro. Las isotermas de adsorción de ambos aniones ajustan por el modelo de Langmuir, y las cinéticas de adsorción son lentas para ambos aniones. Se evalúo el efecto de la presencia de arsénico en la capacidad de adsorción de fluoruro, y viceversa. Además, se determinó el efecto del pH y de los aniones coexistentes en agua natural sobre la capacidad de adsorción de arsénico y fluoruro sobre los óxidos de hierro naturales."

"Natural iron oxides of low and high Fe content were characterized and evaluated to remove arsenic and fluoride from water. These iron oxides were collected from the main iron ore mines in operation in Mexico. Of the six materials evaluated, two eectively interacted with arsenic and fluoride. Adsorption isotherms of both anions adjusted to the Langmuir model, and adsorption kinetics for both anions were slow. The eect of the presence of arsenic in the fluoride adsorption capacity, and vice verse, was evaluated. Moreover, the eect of pH and the presence of coexisting anions in natural water were determined on the adsorption capacity of arsenic and fluoride on natural iron oxides."

Article

Óxidos de hierro naturales Arsénico Fluoruro Adsorción Cinética INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS INGENIERÍA Y TECNOLOGÍA QUÍMICAS INGENIERÍA Y TECNOLOGÍA QUÍMICAS

Tolerance to cadmium of agave lechuguilla (agavaceae) seeds and seedlings from sites contaminated with heavy metals

CARMEN ALEJANDRA MENDEZ HURTADO JOSE RENE RANGEL MENDEZ LAURA YAÑEZ ESPINOSA JOEL DAVID FLORES RIVAS (2013)

"We investigated if seeds of Agave lechuguilla from contaminated sites with heavy metals were more tolerant to Cd ions than seeds from noncontaminated sites. Seeds from a highly contaminated site (Villa de la Paz) and from a noncontaminated site (Villa de Zaragoza) were evaluated. We tested the effect of Cd concentrations on several ecophysiological, morphological, genetical, and anatomical responses. Seed viability, seed germination, seedling biomass, and radicle length were higher for the non-polluted site than for the contaminated one. The leaves of seedlings from the contaminated place had more cadmium and showed peaks attributed to chemical functional groups such as amines, amides, carboxyl, and alkenes that tended to disappear due to increasing the concentration of cadmium than those from Villa de Zaragoza. Malformed cells in the parenchyma surrounding the vascular bundles were found in seedlings grown with Cd from both sites. The leaves from the contaminated place showed a higher metallothioneins expression in seedlings from the control group than that of seedlings at different Cd concentrations. Most of our results fitted into the hypothesis that plants from metal-contaminated places do not tolerate more pollution, because of the accumulative effect that cadmium might have on them."

Article

INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS

Synthesis of reduced graphene oxide (rGO) films onto carbon steel by cathodic electrophoretic deposition: anticorrosive coating

JAVIER ALAN QUEZADA RENTERIA LUIS FELIPE CHAZARO RUIZ JOSE RENE RANGEL MENDEZ (2017)

"The use of graphene based materials as anticorrosive coatings for the protection of metals is still a controversial subject worthy of debate. The electrophoretic deposition (EPD) is one of the most used techniques to produce anticorrosive coatings onto metals, including graphene oxide (GO) and reduced graphene oxide (rGO) coatings. However, for the specific case of carbon steel's protection, EPD of GO has not achieved positive results. This work proposes a variation in the EPD process of GO, which consisted in changing the GO's charge to positive values by adsorbing Ca2+, allowing the electrophoretic deposition of GO onto the cathode (cEPD). The achieved film was characterized by scanning electron microscopy (SEM), Raman Spectroscopy, X-ray photoelectron spectroscopy (XPS) and evaluated electrochemically. The coating diminished by three times the corrosion of carbon steel: the corrosion current was reduced from 11.83 to 4.14 mA cm−2, the charge transfer resistance incremented from 84 to 406 Ω and a shift in the corrosion potential from −0.72 to −0.61 V was observed. An electrochemical reduction mechanism of GO involving hydrogenation/hydrogenolysis reactions is suggested as the main reason to achieved an effective coating by cEPD in comparison to the films produced by an anodic EPD."

Article

Graphene oxide Reduced graphene oxide Electrophoretic deposition Anticorrosive coating Carbon steel BIOLOGÍA Y QUÍMICA QUÍMICA

Immobilized redox mediators for the treatment of contaminated waters and gas emissions

Mediadores redox inmovilizados para tratamiento de aguas contaminadas y emisiones de gas

JOSE RENE RANGEL MENDEZ ALBERTO GARCIA ESPINOSA MARIA ANTONIETA MORENO REYNOSA ELIAS RAZO FLORES (2012)

"The present invention relates to a treatment process applicable to degrade or transform organic and inorganic pollutants, commonly found in industrial wastewaters, contaminated aquifers and gas emissions, in which reduction or oxidation reactions (e.g. redox reactions) are involved. The treatment concept comprises reactors in which catalysts, with redox mediating properties, have been immobilized on ion exchange resins in order to improve and accelerate the transformation of priority pollutants by chemical or biological means."

"La presente invención se relaciona con un proceso de tratamiento aplicable para degradar o transformar contaminantes orgánicos e inorgánicos, comúnmente encontrados en aguas residuales industriales, acuíferos contaminados y emisiones de gas, en el cual se involucran reacciones de reducción u oxidación (por ej. reacciones redox). El concepto de tratamiento comprende reactores en los cuales los catalizadores, con propiedades mediadas por redox, han sido inmovilizados en resinas de intercambio iónico para mejorar y acelerar la transformación de contaminantes prioritarios por medios químicos o biológicos."

Patent

C02F1/461 B01D53/8678 B01J47/016 C02F1/42 C02F3/2846 B01D2257/2064; B01D2257/40; B01D2257/70; B01D53/84 B01J31/08 C02F2001/422 C02F2101/006 C02F2101/308 C02F2101/322 C02F2101/36 C02F2101/38 C02F2209/02 C02F2209/06 C02F2209/40 INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS INGENIERÍA Y TECNOLOGÍA DEL MEDIO AMBIENTE TECNOLOGÍA DE AGUAS RESIDUALES

Studies of adsorption of heavy metals onto spent coffee ground: equilibrium, regeneration, and dynamic performance in a fixed-bed column

NANCY ELIZABETH DAVILA GUZMAN FELIPE DE JESUS CERINO CORDOVA MARGARITA LOREDO CANCINO JOSE RENE RANGEL MENDEZ (2016)

"Equilibrium and dynamic adsorption of heavy metals onto spent coffee ground (SCG) were studied. The equilibrium adsorption of Cd2+, Cu2+, and Pb2+ in a batch system was modeled by an ion-exchange model (IEM) based on an ion-exchange of heavy metals with calcium and protons bonded to active sites on SCG surface. The maximum amount of adsorbed metal ions obtained using the IEM was 0.12, 0.21, and 0.32 mol/g of Cd2+, Cu2+, and Pb2+, respectively. Regeneration of SCG was evaluated using citric acid, calcium chloride, and nitric acid. The observed trend of desorption efficiency through four adsorption-desorption cycles was HNO3 > CaCl2 > C6H8O7. The effect of process variables such as flow rate and bed height during the dynamic adsorption was evaluated. Moreover, the applicability of a mass transfer model based on external mass transfer resistance, axial dispersion, and ion-exchange isotherm was evaluated, and the results were in good agreement with the experimental data for the adsorption in SCG packed column. The sensitivity analysis of the model parameters showed that axial dispersion coefficient is the most significant parameter in the dynamic simulation. The results obtained showed the potential of SCG as a low-cost material for wastewater metal removal in continuous systems."

Article

INGENIERÍA Y TECNOLOGÍA

Facile synthesis and characterization of MnxZn1-xFe2O4/activated carbon composites for biomedical applications

Jorge Carlos Ríos Hurtado JOSE RENE RANGEL MENDEZ ELIA MARTHA MUZQUIZ RAMOS (2016)

"The synthesis of MnxZn1-xFe2O4 ferrites (x = 0.4, 0.5 and 0.6) by means of the co-precipitation method is reported. Furthermore, a composite of Mn0.4Zn0.6Fe2O4/activated carbon was prepared with the mechanosynthesis method. The magnetic, structural, morphological and chemical properties were analyzed by means of VSM, XRD, SEM, FTIR and Boehm's titration. The heating capacity was evaluated under a magnetic field using solid-state induction heating equipment, in addition a hemolysis test was performed using human red blood cells. With regard to the synthesis of manganese-zinc ferrite, the results indicated that Mn0.4Zn0.6Fe2O4 ferrite showed higher saturation magnetization (64.48 emu/g) than the other ferrite obtained, with superparamagnetic behavior. The Mn0.4Zn0.6Fe2O4/activated carbon composite was able to heat in concentrations of 10 mg/ml under a magnetic field (10.2 kAm-1 and frequency 200 kHz), increasing the temperature up to 42.5 °C. The hemolysis test indicated that the presence of activated carbon reduces the hemolytic behavior of the ferrite. Thanks to its heating capacity and non-hemolytic activity, theMn0.4Zn0.6Fe2O4/activated carbon composite is a potential candidate for use in biomedical applications."

Article

Mn-Zn ferrite Superparamagnetic Activated carbon Composite Hemolysis INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS CIENCIAS TECNOLÓGICAS

Simultaneous adsorption of Pb(Ii)-Cd(Ii), Pb(Ii)-phenol, and Cd(Ii)-phenol by activated carbon cloth in aqueous solution

JAVIER ANTONIO ARCIBAR OROZCO JOSE RENE RANGEL MENDEZ PAOLA ELIZABETH DIAZ FLORES (2015)

"The aim of the present work was to determine the effect of the simultaneous adsorption of lead(II)-cadmium(II), lead(II)-phenol, and cadmium(II)-phenol by activated carbon cloths (ACCs). Three commercial ACCs were characterized and tested for individual metal adsorption, and competitive adsorption experiments were carried out with the best ACC (AW1104). The specific surface areas of all ACCs were >1000 m2/g, yet only AW1104 presented a high content of acidic sites (1.0 meq/g). Competitive adsorption experiments indicate that cadmium uptake is strongly affected by the presence of lead. This can be attributed either to a more favorable hydroxyl complexation of Pb(II) (that adsorbs strongly),or to the smallest hydrated radius of the Pb(II) molecule (that more easily diffuses). On the contrary, lead uptake was not considerably decreased in the presence of an equimolar cadmium concentration, indicating that AW1104 is more selective for Pb(II) than for Cd(II). Also, the presence of phenol causes a decrease in the heavy metal adsorption capacity, especially for cadmium (40 %). The former might be due to adsorbed phenol, which creates steric hindrance for cations to adsorb on specific oxygenated groups on the ACC. On the other hand, when heavy metals adsorb on the ACC surface, they stabilize the repulsive forces on the surface of the ACC for phenol adsorption, resulting in an increase of the adsorption capacity."

Article

Adsorption Cadmium Lead Phenol Activated carbon cloth CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA

Electrodos de pasta de carbón modificados con partículas de hierro y su aplicación como sensores en la detección de As(V)

Iron-modified carbon paste electrodes and their application as sensors in As(V) detection

EDUARDO TORAL SANCHEZ JOSE RENE RANGEL MENDEZ LUIS FELIPE CHAZARO RUIZ (2017)

"La detección electroquímica de arsénico(V) fue evaluada en un electrodo de pasta de carbón modificado con partículas de hidro(óxidos) de hierro en medio electrolítico de NaNO3. El polvo de grafito modificado se preparó fácilmente utilizando el método “slurry”. El material resultante fue caracterizado mediante la determinación de su distribución de carga superficial y punto de carga cero, distribución de pKa’s de los grupos funcionales superficiales, área superficial y distribución de tamaño del poro mediante la ecuación de Brunauer- Emmett-Teller (BET) y la identificación de las formas cristalinas de los compuestos de hidro(óxidos) de hierro por difracción de rayos X. Adicionalmente, se encontró que el material modificado exhibió una buena capacidad de remoción de As(V), incluso en el medio electrolítico. Para la detección de As(V), se utilizó la técnica de voltamperometría de pulso diferencial, para la cual se aplicó un potencial de reducción/acumulación de -1.10 V(vs. Ag/AgCl/KCl (sat.) por 180 segundos a pH 2.5. La caracterización fisicoquímica de los materiales modificados y el análisis electroquímico, permitió proponer un mecanismo de reducción de As(V) sobre la superficie del electrodo. El límite de detección (LOD) de As(V) alcanzado fue de 19.40 μg/L, por lo cual este electrodo podría ser potencialmente aplicado como sensor en la detección de este contaminante en muestras de agua."

"The electrochemical detection of arsenic (V) [As(V)] was evaluated on a carbon paste electrode modified with iron hydro(oxide) particles in the presence of NaNO3 salt used as electrolytic media in the experiments. The modified graphite powder was easily prepared using the slurry method. The resulting material was examined by surface charge and pKa’s distribution, point of zero charge, Brunauer-Emmett-Teller (BET) surface area and pore size distribution, potentiometric titration and X-ray diffraction. Adsorption experiments with the modified materials exhibited good As(V) removal capacity even in the presence of electrolytic media. For the As(V) detection, differential pulse voltammetry technique was used by the application of reduction potential of -1.10 V for 180 s at pH 2.5. The detailed physicochemical characterization of modified materials and electrochemical analysis allowed to propose a reduction mechanism of As(V) on the electrode surface. Detection limit of 10 μg/L can be achieved for As(V), therefore this electrode could potentially be applied as a sensor for the detection of this pollutant in water samples."

Article

INGENIERÍA Y TECNOLOGÍA

Bioreactores empacados con fibras de carbón activado como mediadores redox en la biotransformación anaerobia de 4-Nitrofenol hacia 4-Aminofenol

Bioreactors packed with activated carbon fibers as redox mediators in the anaerobic biotransformation of 4-Nitrophenol to 4-Aminophenol

HECTOR JAVIER AMEZQUITA GARCIA JOSE RENE RANGEL MENDEZ FRANCISCO JAVIER CERVANTES CARRILLO ELIAS RAZO FLORES (2017)

"La función de los grupos funcionales superficiales sobre los carbones activados es de gran interés en procesos biológicos con actividad redox porque tales grupos pueden incrementar la eficiencia de biotransformación de compuestos tóxicos y con esto reducir los costos del tratamiento de aguas. En este estudio se usaron fibras de carbón activado (FCAs) como soportes biológicos y mediadores redox para la biotransformación contínua de 4-nitrofenol (4-NF) hacia 4-aminofenol (4-AF) en condiciones anaerobias. Diversas FCAs se prepararon a partir del material original (AW) incluyendo FCAs tratadas con ácido nítrico (AW-OX) y modificadas con antraquinina- 2,6-disulfonato (AW-AQDS). Éstas FCAs fueron caracterizadas por titulaciones potenciométricas (punto de carga cero ó PCC, Boehm), FT-IR, y adsorción de N2 a bajas temperaturas (método BET). Los reactores empacados con FCAs (AW, AW-OX y AW-AQDS) y con biomasa granular anaerobia fueron evaluados por su capacidad para reducir continuamente el 4-NF a 4-AF. Estos resultados se compararon con el reactor control que carecía de FCAs en su interior y sólo contenía biomasa anaerobia granular. Los resultados muestran que las FCAs con una alta concentración de grupos carbonilo AW-OX > AW-AQDS > AW (1.3 > 1.0 > 0.8 meq/g) mejoraron la biotransformación de 4-NF por 2.11 > 1.97 > 1.47 – veces, respectivamente, comparando con el reactor control."

"The role of functional groups on the surface of activated carbons is of great interest in biological redox processes because they could improve the rate of biotransformation of toxic compounds and reduce costs of water treatment. In this study, we used activated carbon fibers (ACFs) as biological supports and redox mediators for the continuous biotransformation of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). Different ACFs were prepared from the original material (AW), including HNO3-treated ACF (AW-OX), and redox-active anthraquinone-2,6- disulfonate anchored on ACF surface (AW-AQDS). These ACFs were characterized by potentiometric titrations (point of zero charge and Boehm), FT-IR, and N2-adsorption (BET method). The ACF-packed bed bioreactors (AW, AW-OX and AW-AQDS) with anoxic granular biomass were evaluated for their ability to reduce 4-NF to 4-AP under continuous conditions, and compared to a control bioreactor with only anoxic granular biomass. Our results show that ACFs with a higher concentration of carbonyl groups AW-OX > AW-AQDS > AW (1.3 > 1.0 > 0.8 meq/g) improved the biotransformation of 4-NF by 2.11 > 1.97 > 1.47 – fold, respectively, as compared to the control bioreactor."

Article

INGENIERÍA Y TECNOLOGÍA