Brazilian coal mining residues and sulphide oxidation by Fenton's reaction: An accelerated weathering procedure to evaluate possible environmental impact

AbstractFenton's reaction is proposed as an accelerated weathering test for sulphides associated with Brazilian Coal Mining Residues (CMR), that are exposed to oxygen and water during the mining of coal. TEM and SEM/EDX were used to evaluate the nature, occurrence and distribution of minerals in remaining coals and other lithological units, before and after applying the test. Oxidation of CMRs was examined by analyzing soluble sulphur (sulphate) and dissolved metals by ICP-MS or ICP OES. As dissolved sulphate increases, dissolved Zn, Cd, Cu and Co concentrations increase, leading to undetectable amounts in the remaining solid phases; dissolved Ni and Mn also increase with the mobilized sulphur, but the remainder in the solids is the most important fraction; Fe and Pb are not mobilized due to precipitation as jarosite or hematite in the case of Fe or as sulphate in the case of Pb. Agreement between the observed results and the predictions by geochemical modelling is discussed

Overview of the techniques used for the study of non-terrestrial bodies: Proposition of novel non-destructive methodology

Meteorites and impact glasses have been largely analysed using different techniques, but most studies have been focused on their geologicalemineralogical characterization and isotopic ratios, mainly of a destructive nature. However, much more information can be gained by applying novel non-destructive analytical procedures and techniques that have been scarcely used to analyse these materials. This overview presents some new methodologies to study these materials and compares these new approaches with the commonly used ones. Techniques such as X-Ray Fluorescence (XRF) and Laser Induced Breakdown Spectroscopy (LIBS), for elemental characterization, the hyphenated Raman spectroscopy- SEM/EDS and the combination of them, allow extracting simultaneous information from elemental, molecular and structural data of the studied sample; furthermore, the spectroscopic image capabilities of such techniques allow a better understanding of the mineralogical distribution. © 2017 Elsevier B.V. All rights reserved.Ministerio de Economía, Industria y Competitividad (project ESP2014-56138-C3-2-R

Multianalytical approaches to the characterisation of minerals associated with coals and the diagnosis of their potential risk by using combined instrumental microspectroscopic techniques and thermodynamic speciation

AbstractA routine multianalytical methodology based on the combination of Optical Microscopy (OM) with instrumental microscopic techniques like Electron Microscope (HR-TEM and SEM) coupled to Energy Dispersive X-Ray Spectroscopy (EDS), Confocal Microscopy (CM) and Micro-Raman Spectroscopy (MRS) provides a powerful approach for the research of the mineralogical composition. Coals from different origins (five continents) and different mineralogical composition were selected for analysis. The analytical approach makes use of OM to select the different mineral phases associated to coal samples with subsequent use of the instrumental microscopic techniques on selected targets. The SEM/EDS, HR-TEM/EDS, and MRS analysis showed no significant differences in the chemical composition of the main minerals found associated to coal, such as oxides, sulphides, sulphates, silicates, carbonates, and others. The instrumental techniques provide fast, non-destructive and highly-selective analysis of both the whole coal and particle surfaces. Moreover, thermodynamic speciation through chemical modelling simulations gives the required information to confirm the stability of secondary minerals detected in the samples and helps to diagnose the potential environmental risks associated with weathering

A rapid routine methodology based on chemometrics to evaluate the toxicity of commercial infant milks due to hazardous elements

The toxicity and the health risk assessment associated to the presence of some hazardous elements (HEs) in dried (infant formula and powdered) milks due to manufacturing and packaging process, raw materials used, environmental conditions, etc. need to be determined. With this aim, a new methodology based on the combination of health risk quotients and nonsupervised (as cluster analysis (CA) and principal component analysis (PCA)) chemometric techniques is proposed in this study. The methodology was exemplifed using the concentration of 27 elements, some of them HEs, measured in 12 powdered milk samples produced for children and adults in Brazil and Colombia. The concentration values were obtained by inductively coupled plasma-mass spectrometry (ICP-MS) after acid microwave digestion. Elemental concentrations vary depending upon the type of milk (initiation, growing-up, follow-on milks and adult milks). However, hazard quotients (HQ) and carcinogenic risk (CR) values showed no risk associated to the presence of HEs on milks. The methodology designed made possible to conclude that adults’ milks are more characteristic of elements naturally present in milk. Children milks present major presence of trace and minor elements. Between infant milks, sample H, designed for babies between 12 and 36 months, was identifed as of poor quality. Moreover, it was possible to deduce that while the fortifcation process applied to children powdered milks is a probable metal and metalloid source, together with the manufacturing, the skimming process is not a contamination source for milks.Springer New Yor

Metals and metalloids in high-altitude Pyrenean lakes: sources and distribution in pre-industrial and modern sediments

High-altitude Pyrenean lakes are ecosystems far from local pollution sources, and thus they are particularly sensitive to the atmospheric deposition of metals and metalloids. This study aims to quantify the effect of human activity in 18 lakes located in both side of the France–Spain frontier. Sediment cores were collected in summer 2013, sampled at a 1cm resolution and the concentration of 24 elements was measured by ICP-MS. Statistic and chemometric analysis of the results highlights the influence of the geographical position and lithogenic features of each lake basin on trapping pollutants. More than the 80% of the lakes showed values of enrichment factor (EF) above 2 for at least one of the elements investigated in at least one core interval, which corroborates the existence of historical anthropogenic inputs of elements in the studied area. The results demonstrate the natural origin of As and Ti in Pyrenees, together with the significant anthropogenic inputs of Cd, Pb, Sb and Sn from ancient times. The data set points mining activities as the main historical source of pollution and illustrate the large impact of the industrial revolution. The regional variability could reflect also differential long-range transport, followed by dry or wet deposition