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Hernandez A.J.,University of Alcala | Pastor J.,CCMA | Ball A.S.,Flinders University
Journal of Environmental Management | Year: 2012

Landfills are often the final recipient of a range of environmentally important contaminants such as hydrocarbons, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). In this study the influence of these contaminants on microbial activity and diversity was assessed in a municipal solid waste (MSW) landfill placed in Torrejón de Ardoz (Madrid, Spain).Soil samples were collected from four selected areas (T2, T2B, T8 and T9) in which the amount of total hydrocarbons, PAHs and PCBs were measured. Soil biomass, substrate induced respiration (SIR) and physiological profiles of soil samples were also determined and used as indicators of total microbial activity.Highest concentration of total hydrocarbons was detected in T2 and T9 samples, with both PCBs and benzopyrene being detected in T9 sample. Results corresponding to microbial estimation (viable bacteria and fungi, and SIR) and microbiological enzyme activities showed that highest values corresponded to areas with the lowest concentration of hydrocarbons (T2B and T8). It is noticeable that in such areas was detected the lowest concentration of the pollutants PAHs and PCBs. A negative significant correlation between soil hydrocarbons concentration and SIR, total bacteria and fungi counts and most of the enzyme activities determined was established. DGGE analysis was also carried out to determine the microbial communities' structure in the soil samples, establishing different profiles of Bacteria and Archaea communities in each analysed area. Through the statistical analysis a significant negative correlation was only found for Bacteria domain when Shannon index and hydrocarbon concentration were correlated. In addition, a bacterial 16S rRNA gene based clone library was prepared from each soil. From the clones analysed in the samples, the majority corresponded to Proteobacteria, followed by Acidobacteria and Actinobacteria. It is important to remark that the most polluted sample (T9) showed the lowest microbial diversity only formed by six phyla being Proteobacteria and Acidobacteria the most representative. © 2010 Elsevier Ltd.

Hernandez A.J.,University of Alcala | Bartolome C.,University of Alcala | Perez-Leblic M.I.,University of Alcala | Rodriguez J.,University of Alcala | And 2 more authors.
Journal of Environmental Management | Year: 2012

Assessing the environmental impact of a soil-topped landfill requires an accurate ecotoxicological diagnosis. This paper describes various diagnostic protocols for this purpose and their application to a real case: the urban solid waste (USW) municipal landfill of Getafe (Madrid, Spain). After their initial sealing with soil from the surroundings about 20 years ago, most USW landfills in the autonomous community of Madrid have continued to receive waste. This has hindered precise assessment of their impact on their environment and affected ecosystems. The procedure proposed here overcomes this problem by assessing the situation in edaphic, aquatic and ecological terms.The present study focused on the most influential soil variables (viz. salinity due largely to the presence of anions, and heavy metals and organic compounds). These variables were also determined in surface waters of the wetland most strongly affected by leachates running down landfill slopes. Determinations included the characterization of plant communities and microbial biodiversity.The study was supplemented with a bioassay under controlled conditions in pots containing soil contaminated with variable concentrations of Zn (as ZnCl 2) intended to assess ecochemical actions in a population of Bromus rubens, which grows profusely in the landfill. © 2010 Elsevier Ltd.

Gutierrez-Gines M.J.,University of Alcala | Pastor J.,CCMA | Hernandez A.J.,University of Alcala
Fresenius Environmental Bulletin | Year: 2010

Heavy metals in the soils of old mining areas, besides affecting the productivity of their ecosystems, could also affect animal and human health. To test this hypothesis, we assessed the bioavailability of heavy metals to forage crops used as human food sources or components of fodder. The sites examined were the surrounding soils of two abandoned mines in Central Spain polluted with Al, Fe, Mn, and more than one of the heavy metals Zn, Pb, Cd, Cu, Cr or Ni, and As. All elements were determined by plasma emission spectroscopy with the exception of As, which was quantified by XRF. Levels of Zn, Pb, Cd, Cu and Fe were high in roots as well as in the above-ground parts of the plants, and high As levels were also found in roots. The accumulation of heavy metals by this plant was assessed in terms of its possible use for phytoremediation but also in view of its possible detrimental impacts on humans as well as wild and domestic animals. Strategies for education in areas faced with this problem are also proposed. People living in rural areas will need to be taught ecological concepts but we will also have to alert political leaders and administrators to the problem to encourage them to invest in dealing with polluted soils. In this context, it is essential to understand both the elements and processes affecting ecosystems and the perception and opinions held by the rural population of the problem of soil pollution. © by PSP.

Alexis S.,University of Alcala | Garcia-Montero L.G.,Technical University of Madrid | Hernandez A.J.,University of Alcala | Garcia-Abril A.,Technical University of Madrid | Pastor J.,CCMA
Agroforestry Systems | Year: 2010

In the jaragua-bahoruco-enriquillo biosphere reserve, located on the southern border between the Dominican Republic and Haiti, there are depressed rural areas with soils with high content in Cadmium and other heavy metals which originate naturally in the geological substrate. Data from 80 soils and an inventory of 76 plantations (coffee and kidney bean were used) to design a GIS (geographic information systems) tool which integrated statistical multivariate methods, soil parameters including heavy metal content into models of land planning, agricultural development, forests and protection of the health of the area's inhabitants and the natural environment. This GIS tool is based on raster models of an open source, which use combination and reclassification operations based on the maps, geostatistical methods (Kriging), statistical analyses external to the GIS, and cartography of limiting and excluding particular factors for crops (including heavy metal soil content). The GIS tool developed discriminates extreme situations in sustainable agroforestry planning in contaminated rural areas of the Caribbean, Central America and other tropical regions. © 2009 Springer Science+Business Media B.V.

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