Leonel Hernández-Mena
National Autonomous University of Mexico
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Featured researches published by Leonel Hernández-Mena.
Environmental Monitoring and Assessment | 2010
Leonel Hernández-Mena; Hugo Saldarriaga-Noreña; Patricia Carbajal-Romero; Ricardo Cosío-Ramírez; Benjamín Esquivel-Hernández
Atmospheric aerosol particles were collected from January to December 2007 at two sites in the City of Guadalajara. The first site (Centro) is located in the downtown, which is characterized by high vehicular traffic, and the second site (Miravalle) is in the southern part of the city, characterized by emissions from high industrial and vehicular activity. Sulfates, nitrates, and ammonium were the most abundant ions at both sites. Similar concentrations of sulfates, nitrates, and ammonium were observed throughout the year at Centro while only sulfates and nitrates were similar at Miravalle. From the balance of anions and cations at the two sites, Centro was determined to have acidic particles, while at Miravalle, the particles were alkaline. Based on the analysis of the ammonium/sulfate molar ratios, it was determined that in Centro, there was not enough ammonium to neutralize the sulfate, while at Miravalle, ammonium practically neutralized all sulfate.
Environmental Technology | 2013
Alberto López-López; María Guadalupe Albarrán-Rivas; Leonel Hernández-Mena; Elizabeth León-Becerril
The lack of available technologies that assembled both the technical and economical characteristics for domestic wastewater treatment is a major problem for rural communities. In response to this issue, a technical assessment of an up-flow anaerobic filter (UAF) was carried out in the laboratory to treat domestic wastewater. Tezontle, a volcanic rock, was used as the packing media and as the support for the biofilm. It was selected due to its abundance, low cost and high porosity. The UAF assessment was based on an experimental design of two variables, hydraulic retention time (HRT) and temperature, with three and four levels of operation, respectively. Each test at HRT of 12, 18 and 24 h was carried out at temperatures of 20, 25, 30 and 35°C. Methane production rates were 32.4, 110 and 191 mL of CH4/g of chemical oxygen demand removed for HRT of 12, 18 and 24 h, respectively, at a temperature of 35°C. In order to reach a high removal of organic matter (higher than 80%) the optimum operational conditions for the UAF were HRT=24 h and T=35°C. The temperature was the determining factor for achieving the greatest removal efficiencies in the UAF.
Bulletin of Environmental Contamination and Toxicology | 2011
Leonel Hernández-Mena; Mario Murillo-Tovar; Martín Ramírez-Muñíz; Edith Colunga-Urbina; Iliana de la Garza-Rodríguez; Hugo Saldarriaga-Noreña
In this study, the Enrichment Factors and elemental composition profiles of the PM2.5 were used to suggest the emission sources. The selected sites were Miravalle and Centro, and in both cases there were high values lead, Cadmium, Cobalt, Chromium, Cupper, Molybdenum, Nickel, Antimony, Selenium and Zinc for EF (>5), suggesting an anthropogenic origin. The remaining elements (Iron, Magnesium, Manganese, Strontium and Titanium) had Enrichment Factors <5, attributable to a geological origin, probably due to the suspension of particles from motor vehicles or wind. Comparing the elemental composition profiles of the two sites allowed establishing similarities with some reference profiles (SPECIATE database Version 4.2-EPA) from sources such as Paved Road Dust (PRD) and Industrial Soil (IS) and profiles of combustion sources such as Diesel Exhaust (DE). Through the estimation the Enrichment Factors and of the elemental composition profiles of two different sites in the city, it was possible to suggest not only the general type of emission source (geological or anthropogenic), but also more specific sources based on elemental composition of PM2.5.
Atmospheric Environment | 2006
Rafael Villalobos-Pietrini; Omar Amador-Muñoz; Stefan M. Waliszewski; Leonel Hernández-Mena; Zenaida Munive-Colín; Sandra Gómez-Arroyo; José Luis Bravo-Cabrera; Alejandro Frías-Villegas
Mutation Research-genetic Toxicology and Environmental Mutagenesis | 2007
Rafael Villalobos-Pietrini; Leonel Hernández-Mena; Omar Amador-Muñoz; Zenaida Munive-Colín; José Luis Bravo-Cabrera; Sandra Gómez-Arroyo; Alejandro Frías-Villegas; Stefan M. Waliszewski; José Ramírez-Pulido; Rocío Ortiz-Muñiz
Atmospheric Research | 2013
Omar Amador-Muñoz; S. Bazán-Torija; S.A. Villa-Ferreira; Rafael Villalobos-Pietrini; José Luis Bravo-Cabrera; Zenaida Munive-Colín; Leonel Hernández-Mena; Hugo Saldarriaga-Noreña; Mario Murillo-Tovar
Atmospheric Environment | 2010
Omar Amador-Muñoz; Rafael Villalobos-Pietrini; Ma. Cristina Agapito-Nadales; Zenaida Munive-Colín; Leonel Hernández-Mena; Magdalena Sánchez-Sandoval; Sandra Gómez-Arroyo; José Luis Bravo-Cabrera; Judith Guzmán-Rincón
Journal of Environmental Monitoring | 2009
Hugo Saldarriaga-Noreña; Leonel Hernández-Mena; Martín Ramírez-Muñíz; Patricia Carbajal-Romero; Ricardo Cosío-Ramírez; Benjamín Esquivel-Hernández
American Journal of Analytical Chemistry | 2011
Ramiro Vallejo-Rodríguez; Alberto López-López; Hugo Saldarriaga-Noreña; Mario Murillo-Tovar; Leonel Hernández-Mena
Atmosphere | 2015
Hugo Saldarriaga-Noreña; Rebecca López-Márquez; Mario Murillo-Tovar; Leonel Hernández-Mena; Efrén Ospina-Noreña; Enrique Sánchez-Salinas; Stefan M. Waliszewski; Silvia Montiel-Palma