MASS TRANSFER CORRELATION FOR THE REMOVAL OF COPPER IONS FROM WASTEWATER

One of the biggest problems with ore processing in extractive metallurgical industries is the high toxicity of the heavy metals waste content (e.g., copper, lead, nickel and chrome). This work investigates the copper (II) íons removal from aqueous solutions in concentrations up to 1000 ppm. Therefore, a fluidized bed electrolytic reactor was used with flow-by configuration considered as a hopeful method due to the large specific surface area and the high mass transfer rate. The performance of the electrochemical reactor was investigated by using different porosities. Dimensionless Sherwood and Reynolds numbers were correlated to characterize the mass transport properties of the reactor, and they were fitted to the equation Sh = a.Reb.Sc1/3

PARAMETRIC ANALYSES OF AN ABSORPTION REFRIGERATION SYSTEM WITH WATER AND LITHIUM BROMIDE IN STEADY STATE POWERED BY SOLAR ENERGY

The demand of energy utilization is increasing expressively as fast as the development of countries. Besides being available everywhere and virtual inexhaustible, renewable energy is undoubtedly necessary to avoid depleting the planet’s natural resources and global warming. Even considering the primordially environmental importance, the result of no emissions by renewable energy grant attractive also for political and economics statement.  It should be noted the sun is the most abundant primary energy source in the planet and essential for eco-friendly process like photosynthesis, wind action, water cycle as well direct uses as electric and thermal generations. Consequently, nowadays several methodologies have been applied in order to transfer energy between the cycle and its surroundings optimizing for instance the coefficient of performance and heat exchangers. An absorption system is widely applied in these cases due to supply a unique solution for a range of technological problems from solar cooling to steam-driven refrigeration. Alternatively, this article main objective is modulating an absorption refrigeration system (ARS) which uses water-lithium bromide as a working fluid. Therefore, using the software Engineering Equation Solver (EES) is possible to obtain a thermodynamic single effect code that allows elaborating parametric analyses. In other words, performed and verified the influence of some input parameters over other output parameters. First, it was necessary to consider the cycle operating as reversible and steady state. Furthermore, it is assumed that no chemical reactions occur between water and lithium bromide. Thus, in the meantime apply the heat exchangers and a Solar Collector to receive the thermal energy and provide to the refrigeration cycle. Similarly, water from external sources was used to change heat with the fluid water-lithium bromide. Satisfactory results were founded and it enable to calculate and evaluate all system heat transfers rates and coefficient of performance. Almost all of input parameters introduced brought adequate values over output parameters, but the most convenient were: mass balance of water-lithium bromide solution and temperature of cold water from outside source. Clearly, results always can be found but in conclusion this article can be used to verify parameters sensitivity, optimized absorption refrigeration solutions and supply knowledge for future applications

GEMAS: Indium in agricultural and grazing land soil of Europe - Its source and geochemical distribution patterns

Indium is a very rare element, which is usually not reported in geochemical data sets. It is classified as a critical metal, with important applications in the electronics industry, especially in the production of solar panels and liquid-crystal displays (LCDs).Over 4000 samples of agricultural and grazing land soil have been collected for the "Geochemical Mapping of Agricultural and Grazing Land Soil of Europe" (GEMAS) project, carried out by the EuroGeoSurveys Geochemistry Expert Group. Indium concentrations in soil have been analysed using aqua regia extraction followed by ICP-MS. Median values of In for both land use types are nearly identical, 0.0176. mg/kg for agricultural soil and 0.0177. mg/kg for grazing land soil.The spatial distribution patterns of In in European soil are mainly controlled by geology and the presence of Zn and Sn mineralisation. The preference of In to accumulate in the fine-grained fraction of soil with high clay content dominates the major anomaly patterns on the geochemical maps. In the Mediterranean region, secondary In enrichment is visible in karst areas. A notable feature of the In spatial distribution is the large difference between northern and southern Europe, with median values of 0.012 and 0.021. mg. In/kg, respectively, suggesting that, in addition to lithology, weathering and climate are important factors influencing In soil enrichment over time. \ua9 2015 Elsevier B.V

Geochemical fingerprinting and source discrimination of agricultural soils at continental scale

2108 agricultural soil samples (Ap-horizon, 0-20cm) were collected in Europe (33 countries, area 5.6 million km2) as part of the recently completed GEMAS (GEochemical Mapping of Agricultural and grazing land Soil) soil mapping project. GEMAS soil data have been used to provide a general view of element origin and mobility with a main focus on source parent material (and source rocks) at the continental scale, either by reference to average crustal abundances or to normalized patterns of element mobility during weathering processes. The survey area covers a large territory with diverse types of soil parent materials, with distinct geological history and a wide range of climate zones, and landscapes.To normalize the chemical composition of European agricultural soil, mean values and standard deviation of the selected elements have been compared to model compositions of the upper continental crust (UCC) and mean European river suspended sediment. Some elements are enriched relative to the UCC (Al, P, Pb, Zr,) whereas others, such as Mg, Na and Sr are depleted. The concept of the UCC extended normalization pattern has been applied to selected elements. The mean values of Rb, K, Y, Ti, Al, Si, Zr, Ce and Fe are very similar to the values from the UCC model, even when standard deviations indicate slight enrichment or depletion. Zirconium has the best fit to the UCC model using both mean value and standard deviation. Lead and Cr are enriched in European soil when compared to the UCC model, but their standard deviation values span a large, particularly towards very low values, which can be interpreted as a lithological effect.GEMAS soil data have been normalized to Al and Na, taking into account the main lithologies of the UCC, in order to discriminate provenance sources. Additionally, sodium normalization highlights variations related to the soluble and insoluble behavior of some elements (e.g., K, Rb versus Ti, Al, Si, V, Y, Zr, Ba, and La, respectively), their reactivity (e.g, Fe, Mn, Zn) and association with carbonates (e.g., Ca and Sr). Maps of Europe showing the spatial distribution of normalized compositions and element ratios reveal difficulties with the use of classical element ratios because of the large lithological differences in compositions of soil parent material. The ratio maps and color composite images extracted from the GEMAS data can help to discriminate the main lithologies in Europe at the regional scale but need to be used with caution due to the complexity of superimposed processes responsible for the soil chemical composition

Mobile Metal Ion® analysis of European agricultural soils: bioavailability, weathering, geogenic patterns and anthropogenic anomalies

Two thousand one hundred and eight agricultural soils (0–20 cm depth) collected at a density of one sample per 2500 km2 under the auspices of the Geochemical Mapping of Agricultural Soils (GEMAS) project over most of the European continent have been analysed using the Mobile Metal Ion (MMI®) partial extraction technique with ICP-MS finish. For a number of elements, notably Ce, Ni, and Ca, coherent geogenic patterns have been observed which relate to underlying lithology. For Fe and Al, coherent patterns are also observed but the effects of weathering are evident, and provide a mechanism to explain the acidity of soils in high rainfall areas. Individual anomalies, many related to anthropogenic activity (mining, metallurgy, agriculture) have been observed for Ag, Au, Cu, Pb, Cd and Zn. Comparison of the results with aqua regia digestion and the equivalent National Geochemistry Survey of Australia (NGSA) provides insights into weathering processes and the concept of bioavailability

GEMAS: Prediction of solid-solution partitioning coefficients (Kd) for cationic metals in soils using mid-infrared diffuse reflectance spectroscopy

Partial least squares regression (PLSR) models, using mid-infrared (MIR) diffuse reflectance Fourier-transformed (DRIFT) spectra,wereusedtopredictdistributioncoefficient(Kd)valuesforselectedaddedsolublemetalcations(Agþ,Co 2þ,Cu 2þ,Mn 2þ,Ni 2þ, Pb2þ, Sn 4þ, and Zn2þ) in 4813 soils of the Geochemical Mapping of Agricultural Soils (GEMAS) program. For the development of the PLSR models, approximately 500 representative soils were selected based on the spectra, and Kd values were determined using a singlepointsolublemetal orradioactiveisotopespike.Theoptimummodels, usingacombinationofMIR–DRIFTspectra andsoilpH,resulted ingoodpredictionsforlogKdþ1forCo,Mn,Ni,Pb,andZn(R20.83)butpoorpredictionsforAg,Cu,andSn(R2<0.50).Thesemodels wereappliedtothepredictionoflogKdþ1valuesintheremaining4313unknownsoils.ThePLSRmodelsprovidearapidandinexpensive tool to assess the mobility and potential availability of selected metallic cations in European soils. Further model development and validationwillbeneededtoenablethepredictionoflogKdþ1valuesinsoilsworldwidewithdifferentsoiltypesandpropertiesnotcovered in the existing mode