Mapping Co-Cr-Cu and Fe Occurrence in a Legacy Mining Waste Using Geochemistry and Satellite Imagery Analyses

Abandoned mining wastes are both an environmental challenge and a possible secondary raw material source. The characterization and monitoring of these sites are often expensive and cumbersome because of the need of repeated field surveys. Remote sensing data are a cost-effective alternative that helps in producing multiscale maps of mining wastes. These maps can be used to investigate and monitor the spatial patterns of different elements within the mining wastes. In this work, Sentinel-2 images are combined with the geochemical samples in order to map the distribution of iron, copper, chromium, and cobalt. The target area was the Vigonzano mining wastes in Northern Apennines (Italy) where there are a small number of geochemical analyses but a large amount of satellite image data. We used the multivariate geostatistical estimation method (Co-Kriging) that exploit the meaningful spatial correlation between the elements of interest and band ratios (obtained from Sentinel-2 images). The concentration maps highlighted subareas for Cu and Cr with an estimated grade of about 0.3% and 0.2%, respectively. In addition, the critical element Co showed an enrichment in the south-east part of the mining wastes, in a similar pattern as Cr. Instead, the obtained maps show Ce, La, Rb, and Nb depletion compared to the surrounding agricultural areas. The concentration maps were intended as a prefeasibility study to determine enriched areas for further detailed investigation

Mn- and Fe-carbonate rich layers in Meso-Cenozoic shales as proxies of environmental conditions: A case study from the southern Apennine, Italy

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Geoquímica sedimentaria y tasas de acumulación en la plataforma nororiental del golfo de Cádiz (SO de la península Ibérica)

Geochemistry, total organic carbon and total nitrogen of three sediment cores collected in the Gulf of Cádiz and the Guadalquivir prodelta areas in Spain were investigated. The C/N ratio, mostly around 10, seems to indicate a predominantly marine origin for the sedimentary organic matter. Major and minor elements (Si, Ti, Al, Fe, Mg, Ca, K, Na, P, S) and trace elements (Mn, Sc, V, Cr, Ni, Cu, Zn, Rb, Sr, Y, Zr, Ba, Ce, Pb, Hg) showed significant differences in bulk chemical composition between the two areas. Despite the effects of bioturbation, vertical changes in downcore profiles of heavy metals occur only in the cores of the Cádiz area, although the concentrations keep to low levels. The relatively high concentrations of Zr and Y, elements commonly associated with the heavy minerals fraction, at the top of cores from the Cádiz area are attributed to an enrichment of heavy minerals related to selective transport that concentrates this fraction. 137Cs and 210Pb activities in one of the two sediment cores collected in the Gulf of Cádiz were also measured. The distribution of excess 210Pb was used to determine the modern (last 100 yr) mass accumulation rate and the depth of sediment mixing on the continental shelf of the gulf. Estimated sediment accumulation rate was 0.1 g cm-2 yr-1. The uppermost 4 cm had uniform excess 210Pb activity profiles above a region of steadily decreasing 210Pb activity, and this phenomenon was attributed to sediment mixing (bioturbation). 137Cs activity was lower than 3 Bq kg-1 and the profile does not show evidence of fallout peaks.Se ha estudiado la geoquímica, el carbono orgánico total y el nitrógeno total de tres testigos de sedimento tomados en el área del Golfo de Cádiz así como en el área del prodelta del río Guadalquivir (España). El cociente C/N, con un valor alrededor de 10, parece indicar un origen predominantemente marino para la materia orgánica sedimentaria. Elementos mayoritarios y minoritarios (Si, Ti, Al, Fe, Mg, Ca, K, Na, P, S) y oligoelementos (Mn, Sc, V, Cr, Ni, Cu, Zn, Rb, Sr, Y, Zr, Ba, Ce, Pb, Hg) muestran diferencias significativas en el grueso de la composición química entre las dos áreas. A pesar de los efectos de la bioturbación, sólo aparecen cambios verticales en los perfiles de metales traza de los testigos del área de Cádiz, si bien las concentraciones se mantuvieron en niveles bajos. Las concentraciones relativamente altas de Zr y Y, elementos generalmente asociados a fracciones de minerales pesados, en la parte superior de los testigos del área de Cádiz se atribuyen a un enriquecimiento de minerales pesados relacionado con el transporte selectivo que ayuda a concentrar esta fracción. También se han medido las actividades de 137Cs y 210Pb en uno de los dos testigos de sedimento tomados en el Golfo de Cádiz. Se ha empleado la distribución de exceso de 210Pb para determinar la tasa reciente de acumulación de masa (para los últimos 100 años), así como la profundidad de mezcla de sedimentos en la plataforma continental del golfo. La tasa de acumulación de sedimentos estimada fue de 0.1 g -2 yr-1. Los 4 cm superiores mostraron unos perfiles de exceso de actividad de 210Pb uniformes, por encima de una región de firme actividad decreciente en actividad de 210Pb y este fenómeno se atribuyó a mezcla del sedimento (bioturbación). La actividad de 137Cs fue inferior a 3 Bq kg-1 sin presentar los perfiles evidencias de picos debidos a lluvia radiactiva

Natural Versus Anthropic Influence on North Adriatic Coast Detected by Geochemical Analyses

This study focused on the geochemical and sedimentological characterization of recent sediments from two marine sites (S1 and E1) located in the North Adriatic Sea, between the Po River prodelta and the Rimini coast. Major and trace metal concentrations reflect the drainage area of the Po River and its tributaries, considered one of the most polluted areas in Europe. Sediment geochemistry of the two investigated sites denote distinct catchment areas. High values of Cr, Ni, Pb and Zn detected in sediments collected in the Po River prodelta (S1 site) suggest the Po River supply, while lower levels of these elements characterize sediments collected in front of the Rimini coast (E1 site), an indication of Northern Apennines provenance. Historical trends of Pb and Zn reconstructed from the sedimentary record around the E1 site document several changes that can be correlated with the industrialization subsequent to World War II, the implementation of the environmental policy in 1976 and the effects of the Comacchio dumping at the end of 1980. At the S1 site, the down core distributions of trace elements indicate a reduction of contaminants due to the introduction of the Italian Law 319/76 and the implementation of anti-pollution policies on automotive Pb (unleaded fuels) in the second half of the 1980s

Deriving Natural Background Levels of Arsenic at the Meso-Scale Using Site-Specific Datasets: An Unorthodox Method

Arsenic is found in groundwater above regulatory limits in many countries and its origin is often from natural sources, making the definition of Natural Background Levels (NBLs) crucial. NBL is commonly assessed based on either dedicated small-scale monitoring campaigns or large-scale national/regional groundwater monitoring networks that may not grab local-scale heterogeneities. An alternative method is represented by site-specific monitoring networks in contaminated/polluted sites under remediation. As a main drawback, groundwater quality at these sites is affected by human activities. This paper explores the potential for groundwater data from an assemblage of site-specific datasets of contaminated/polluted sites to define NBLs of arsenic (As) at the meso-scale (order of 1000 km2). Common procedures for the assessment of human influence cannot be applied to this type of dataset due to limited data homogeneity. Thus, an \u201cunorthodox\u201d method is applied involving the definition of a consistent working dataset followed by a statistical identification and critical analysis of the outliers. The study was conducted in a highly anthropized area (Ferrara, N Italy), where As concentrations often exceed national threshold limits in a shallow aquifer. The results show that site-specific datasets, if properly pre-treated, are an effective alternative for the derivation of NBLs when regional monitoring networks fail to catch local-scale variability

Critical evaluation of an intercalibration project focused on the definition of new multi-element soil reference materials (AMS-MO1 and AMS-ML1)

Soils are complex matrices and their geochemical investigation necessarily needs reliable Certified Reference Materials (CRMs), i.e. standards, to support analytical precision and accuracy. In particular, the definition of soil multi-element CRMs is particularly complex and involves an inter-laboratory program that employs numerous analytical techniques. In this study, we present the results of the inter-calibration experiment focused on the certification of two new soil standards named AMS-ML1 and AMS-MO1. The two soils developed on sandstone and serpentinite parent materials, respectively. The experiment involved numerous laboratories and focused on the evaluation of soil physicochemical parameters and geochemical analyses of major and trace elements by X-ray fluorescence (XRF) and Inductive Coupled Plasma techniques (ICP-OES and ICP-MS). The data was statistically elaborated. Three levels of repeatability and accuracy in function of the different analytical methods and instrumentation equipment was observed. The statistical evaluation of the results obtained by ICP-OES on Aqua Regia extracts (i.e., Lilliefors test for normally, Grubbs test for outliers, Cochran test for outliers in variances and ANOVA) allowed to computed some certified values for the two proposed soil standards. This preliminary study will represent the first step of a more thorough intercalibration ring-test involving a higher number of laboratories, in order to propose the investigated matrices as CRMs

A non‑lethal method to assess element content in the endangered Pinna nobilis

The fan shell Pinna nobilis is the largest bivalve endemic to the Mediterranean and is actually a strongly endangered species. Due to the biological, ecological, and historical relevance of this species, the research of a non-lethal method to relate the element content in organism’s tissues and environment can provide information potentially useful to evaluate environmental pollution and organism physiological status. In this study, a screening on element concentration in the animal growing environment (seawater and sediments) and in four soft tissues (hepatopancreas, gills, mantle, and muscle), and two acellular tissues (calcite shell layer, and byssus) was performed. The comparison among these results was used to assess whether the no-lethal acellular tissue element concentration can be used to reveal the element presence in the environment and soft tissues. Elements, such as B, Ag, As, Mn, Mo, Pb, or Se, showed a possible relationship between their presence in the byssus and soft tissues. In the byssus Cr, Sb, Sn, and V have shown to be mostly related to the environment, more than the soft tissues, and might be used to draw a historical record of the exposure of the organism. The element concentration in the calcite shell layer did not relate with environmental element concentrations. Essential elements, like Cu, Fe, Ni, and Zn, were present in calcite shell layer and byssus and are likely related to their biological activity in the organism. The research also gave an overview on the presence of pollution and on the preferential intake route of the element. In summary, this study, performed on a limited number of specimens of this protected species, indicated that element concentration in the byssus can be applied as non-lethal method to monitor this endangered species and its interaction with the elements in the growing environment

POTENTIALLY TOXIC ELEMENTS ALONG SOIL PROFILES IN AN URBAN PARK, AN AGRICULTURAL FARM, AND THE SAN VITALE PINEWOOD (RAVENNA, ITALY) ELEMENTS POTENTIELLEMENT TOXIQUES LE LONG DES PROFILS DU SOL DANS UN PARC URBAIN, UNE EXPLOITATION AGRICOLE ET DANS LA PINE

Abstract Potentially toxic elements (PTEs) abundances in top soil and along the soil profiles from areas affected by different anthropogenic inputs were investigated.. The study area is located within the Ravenna Municipality, a complex territorial system highly affected by industrial (a large petrolchemical complex) agricultural activities. Three zones with distinct environmental features were identified: the San Vitale Pinewood affected by atmospheric deposition pollutans from the industrial complex (PW1, PW4, PW6 and PW8 soil profiles); a public garden within the Ravenna city center, mainly affected by traffic pollution (GP1 soil profile); the "Luigi Perdisa" farm located immediately northwards Ravenna was selected due to the use of fertilizers as well as atmospheric deposition (PER2 soil profile). The total concentration of PTEs (Ba, Cr, Cu, Cr, Ni, Pb, Zn) was determined by X ray fluorescence spectrometry (XRF), and the pseudo-total concentration with aqua regia digestion (AR) and ICP-OES quantification in order to evaluate the extractability of the elements. Results showed a significant increase of some PTEs (Cu, Pb, Zn) in the top soil compared to the pedological substrate. In the Ravenna urban park (GP1 station), Pb and Zn concentrations exceeded the threshold values established by current Italian laws for soils from "public, residential and private areas" (D. Lgs 152/2006). The correlation between top soil and the subsoil highlighted that some PTEs, such as Cu, Pb and Zn, are anthropogenic and they are mainly associated to the deposition of airborne pollutants, whereas other elements (Cr and Ni) are lithologenic. Key-words: heavy metals; enrichment factor; soil profiles; Pinewood San Vitale; ICP-OES;XRF Résumé Le but de cette étude est d'évaluer le taux de concentration d'éléments potentiellement toxiques (EPT) dans les horizons supérieurs et le long du profil de sols intéressés par les différents impacts anthropiques. Les études ont été conduites dans la zone qui englobe la commune de Ravenne, caractérisée par un système territorial complexe en raison de la présence d'un pôle pétrochimique mais aussi d'une agriculture très productive. Trois zones avec des impacts différents pour l'environnement ont été identifiées : la Pinède de San Vitale touchée par des dépôts atmosphériques dérivant de l'activité de l'industrie pétrolochimique (profils pédologiques PW1, PW4, PW6 et PW8) ; un jardin public qui se trouve dans le centre historique de la ville de Ravenne et qui subit une pollution due à la circulation automobile (profil pédagogique GP1). Pour finir, l'entreprise agricole "Luigi Perdisa" située immédiatement au nord-est de Ravenne a été choisie aussi bien à cause de la contamination possible par des produits chimiques utilisés en agriculture que pour les différents types de dépôts atmosphériques (profil pédologique PER2). Les études ont permis de déterminer les concentrations totales en spectrométrie de fluorescence aux rayons X (XRF) mais aussi pseudo-totales avec solubilisation dans l'eau régale (AR) de certains métaux lourds (Ba, Cr, Cu, Cr, Ni, Pb, Zn), à la suite de quoi a eu lieu la lecture en ICP-OES dans le but d'évaluer dans quelle mesure ces éléments peuvent être extraits. Les déterminations effectuées démontrent un enrichissement significatif de certains EPT (Cu, Pb, Zn) dans les horizons de surface par rapport au substrat pédologique. Riassunto Scopo di questo studio è la valutazione del grado di anomalia di elementi potenzialmente tossici (EPT) negli orizzonti superficiali e subsuperficiali di suoli soggetti a differenti iuput antropogenici. L'area di studio ha interessato il comune di Ravenna, caratterizzata da un sistema territoriale complesso per la presenza di un polo petrolchimico, ma anche soggetta ad un'attività agricola intensa ed altamente produttiva. Sono state identificate tre zone potenzialmente impattate da differenti attività antropiche: la Pineta di San Vitale interessata da deposizioni EQA -Environmental quality/Qualité de l'Environnement/Qualità ambientale, 2 (2009) 1-14 DOI: 10.6092/issn.2281-4485/3822 3 atmosferiche derivanti dall'attività dell'industria petrolchimica (profili pedologici PW1, PW4, PW6 e PW8); un giardino pubblico presente nel centro storico della città di Ravenna, interessato da inquinamento da traffico veicolare (profilo pedologico GP1); l'azienda agricola "Luigi Perdisa" collocata immediatamente a nord-est di Ravenna scelta sia per la possibile contaminazione da prodotti chimici usati in agricoltura sia per i diversi tipi di deposizioni atmosferiche (profilo pedologico PER2). Di alcuni metalli pesanti (Ba, Cr, Cu, Cr, Ni, Pb, Zn) sono state determinate sia le concentrazioni totali in spettrometria di fluorescenza a raggi X (XRF), sia quelle pseudo totali con solubilizzazione in aqua regia (AR) e successiva lettura in ICP-OES con lo scopo di valutare il livello di estraibilità di tali elementi. Le determinazioni effettuate mostrano un significativo arricchimento di alcuni EPT (Cu, Pb, Zn) negli orizzonti di suolo superficiale rispetto al substrato pedologico; nel parco urbano di Ravenna (GP1), le concentrazioni di Pb e Zn sono superiori ai limiti previsti dalla legislazione italiana (D. Lgs 152/2006) per le aree residenziali e di verde pubblico. La correlazione tra i valori di concentrazione di alcuni EPT, quali Cu, Pb e Zn, riscontrati negli orizzonti superficiali e di profondità evidenzia chiaramente la loro origine antropica per lo più dovuta a deposizioni di contaminanti presenti in atmosfera, mentre per altri elementi (Cr e Ni) la loro provenienza risulta litologenica. Parole chiave: EPT; fattore di arricchimento; profili del suolo; Pineta di San Vitale; ICP-OES; XRF