Fractionation of heavy metals and assessment of contamination of the sediments of Lake Titicaca

Chemical weathering is one of the major geochemical processes that control the mobilization of heavy metals. The present study provides the first report on heavy metal fractionation in sediments (8–156 m) of Lake Titicaca (3,820 m a.s.l.), which is shared by the Republic of Peru and the Plurinational State of Bolivia. Both contents of total Cu, Fe, Ni, Co, Mn, Cd, Pb, and Zn and also the fractionation of these heavy metals associated with four different fractions have been determined following the BCR scheme. The principal component analysis suggests that Co, Ni, and Cd can be attributed to natural sources related to the mineralized geological formations. Moreover, the sources of Cu, Fe, and Mn are effluents and wastes generated from mining activities, while Pb and Zn also suggest that their common source is associated to mining activities. According to the Risk Assessment Code, there is a moderate to high risk related to Zn, Pb, Cd, Mn, Co, and Ni mobilization and/or remobilization from the bottom sediment to the water column. Furthermore, the Geoaccumulation Index and the Enrichment Factor reveal that Zn, Pb, and Cd are enriched in the sediments. The results suggest that the effluents from various traditional mining waste sites in both countries are the main source of heavy metal contamination in the sediments of Lake Titicaca.     

Trisomy 2 due to a 3:1 segregation in an abortion studied by QF-PCR and CGH

Balanced reciprocal translocation is one of the known causes of recurrent spontaneous abortions. Cytogenetic studies of unbalanced miscarriages are difficult due to the growth failure of early loss and usually macerated abortions. We present a molecular study of an abortion in which the father carries a balanced reciprocal translocation t(2;17)(q32.1;q24.3) using QF-PCR and CGH techniques. DNA analysis showed the presence of a trisomy 2 due to a 3:1 interchange segregation. Recombinant events could also be investigated by comparing DNA samples from the family. We propose QF-PCR in addition to CGH as an efficient diagnostic method to improve our knowledge of unbalanced offspring in balanced translocation carriers. Copyright © 2005 John Wiley & Sons, Ltd.     

Economic viability and optimization of solar microgrids with hybrid storage in a non-interconnected zone in Colombia

Environment, Development and Sustainability - A developing country that does not have adequate energy solutions in non-interconnected zones (ZNIs) undoubtedly experiences adverse effects in terms...     

Levels of polychlorinated biphenyls and organochlorine pesticides in serum samples of Egyptian Vulture (Neophron percnopterus) from Spain

Concentrations of 23 polychlorinated biphenyls (PCBs), p,p'-DDT and two of its metabolites, p,p'-DDE and p,p'-TDE have been measured in serum samples of up to 1 ml of Egyptian Vulture (Neophron percnopterus) gathered from five populations in Spain. SigmaPCB concentrations were found to be in the range 3.2-97 ng/ml, while those of SigmaDDTs ranged from 0.93 to 38 ng/ml. p,p'-DDT/p,p'-DDE ratios higher than one were only found in the Segovia population, which could be an indication of recent use of p,p'-DDT in the area. In all cases, PCB profiles were dominated by congeners 52, 132 + 105, 138, 153 and 180. However, some differences among the five populations studied became evident when their profiles were compared with those of technical PCB mixtures by principal components analysis. The DDT and PCB levels detected in the serums analysed were lower than those previously reported for similar avian species and those reported to have deleterious effects on survival or reproduction of birds.     

The effect of dissolved glyphosate upon the sorption of copper by three selected soils

The effect of the pesticide glyphosate (GPS) on adsorption processes of copper onto three soils of different characteristics has been studied. Cu adsorption decreases in general with increasing GPS concentration in solution, due principally to the lower equilibrium pHs, although this is not the only variable affecting copper adsorption. For the same pH values, Cu adsorption is higher in two of the three soils in the presence of GPS, but for the third soil, Cu adsorption is higher in the absence of GPS. This behavior is explained by the possibility of GPS adsorption on these soils and by the formation of Cu-GPS complexes in solution. The soils showing a higher Cu adsorption in the presence of GPS than in its absence for the same pH are able to adsorb this pesticide. In these soils, copper can be adsorbed directly on the soil surfaces, and also through the formation of bonds with GPS previously adsorbed. The third soil was not able to adsorb GPS. Consequently, all the pesticide remained in solution, forming strong Cu complexes with low tendency to be adsorbed on this soil. For this reason, the concentration of free Cu in solution is drastically reduced, and the adsorption of copper on this soil is lower.     

Heavy metals in coastal sediments in Guipuzcoa (Spain)∗

Surficial sediment samples were wet digested (HNO₃‐HCI‐HF) and analysed by atomic absorption spectroscopy. The background values in the area, and the Pollution Index Load in the sampling points were calculated. Metal inputs of continental origin are specially important in Deva, Oria and Urola river mouths.     

Characterization of fulvic acids during olive mill waste composting (Elemental,Thermal and fluorescence analyses)

Elemental analysis, fluorescence spectroscopy and differential scanning calorimetry (DSC) were applied to the study of fulvic acids isolated from different stages during olive mill waste composting. The fulvic extracted acids are characterized by a high nitrogen content and O/C ratio values that may result from the high degree of humification and the synthesis of more condensed humic complexes. This was confirmed by fluorescence spectroscopy in the synchronous-scan mode by the decrease of shoulder intensities at intermediate wavelengths indicating the increase of polycondensation and conjugation of unsaturated structures and the greater uniformity of fluorophores. Fluorescence spectra in the emission, excitation and synchronous modes became simpler with compost maturation. This was confirmed by DSC results which proved the high degree of polycondensation of aromatic nuclei of fulvic acid molecules during olive mill waste composting.     

Influence of climate on grape production and wine quality in the Rías Baixas, north-western Spain

Climate exerts an important role on grape production and wine quality. For one of the main areas protected under the denomination of origin Rías Baixas, in Galicia, Spain, we explore the relationships among grape production, wine quality, rainfall and temperature for the period 1987–2005. The influence of climatic variability was analysed in terms of the relationship between the productivity of the grapevines and the main meteorological teleconnection patterns affecting the North Atlantic region. We also investigate the daily variation in atmospheric circulation through the study of the influence of weather types derived using an automated daily classification. We consider three bioclimatic indices for viticultural zoning, Winkler and Huglin, and the hydrothermic index of Branas, Bernon and Levadoux. While significant trends were identified in the Winkler and Huglin indices, there were no significant trends in the Branas, Bernon and Levadoux index, for the period 1958–2005. For the coming decades, using the scenario A1B evaluated by the regional climate models used in the ENSEMBLES project, the positive trends of Winkler and Huglin indices continue, while Branas, Bernon and Levadoux implies a negative trend. In all cases, these trends induce significant changes in the viticulture of the region.     

Scaled-up and economic assessment approach of the split-phase glycolysis process for the recycling of flexible polyurethane foam wastes

The economic viability of the split-phase glycolysis process for the recycling of any kind of flexible polyurethane foam waste employing crude glycerol as cleavage agent has been demonstrated. First, experiments at pilot plant scale were carried out to check that the process can be extrapolated to larger scales. With the goal of scaling-up the process from laboratory scale to pilot plant, geometric similarity criteria were applied together with dynamic similarity for laminar flow in agitated tank reactors. Hence, a pilot plant installation was designed with geometrically similar equipment to those used for lab scale, obtaining analogous results in terms of recovered polyol properties. Then, the basic design of a split-phase glycolysis industrial plant with a capacity for treating 270 Tm per year of flexible PU foams scraps was proposed. Finally, the economic feasibility of such recycling process was confirmed because of the obtention of a Net Present Value (NPV) of 1,464,555€, with an Internal Rate of Return (IRR) of 27.99%, and a payback time between 4 and 5 years.