Characterization of a mine legacy site: an approach for environmental management and metals recovery.

The characterization of historical mine tailings provides important information for land-management decisions, in particular when considering potential reprocessing activities or the development of an environmental protection program. In addition, outcomes from such characterization may define the scope for a more detailed investigation. The present work describes the characterization of the waste material from the Cabeço do Pião tailings impoundment performed within the project ReMinE: Improve Resource Efficiency and Minimize Environmental Footprint. The purpose of the work was to investigate alternative mine waste management options such as the extraction of valuable resources from an environmental liability. The study involved the collection of 41 samples at different locations at two different depths, physical and chemical characterization of the wastes, natural leaching tests, and potential for acid generation. The results showed that, apart from the potential instability of the dyke (with an average slope of 35°), the drained solutions flowing by percolation contain very small particles with high arsenic contents that are being incorporated into the river sediments. In addition, these very fine-grained materials are available for the transport by the wind creating secondary sources of environmental contamination. This data is fundamental for economic and environmental assessment of the two main alternatives, reprocessing or removal.

Tailings microbial community profile and prediction of its functionality in basins of tungsten mine.

In a circular economy concept, where more than 300 million tons of mining and quarrying wastes are produced annually, those are valuable resources, supplying metals that are extracted today by other processes, if innovative methods and processes for efficient extraction of these elements are applied. This work aims to assess microbiological and chemical spatial distribution within two tailing basins from a tungsten mine, using a MiSeq approach targeting the 16S rRNA gene, to relate microbial composition and function with chemical variability, thus, providing information to enhance the efficiency of the exploitation of these secondary sources. The tailings sediments core microbiome comprised members of family Anaerolineacea and genera Acinetobacter, Bacillus, Cellulomonas, Pseudomonas, Streptococcus and Rothia, despite marked differences in tailings physicochemical properties. The higher contents of Al and K shaped the community of Basin 1, while As-S-Fe contents were correlated with the microbiome composition of Basin 2. The predicted metabolic functions of the microbiome were rich in genes related to metabolism pathways and environmental information processing pathways. An in-depth understanding of the tailings microbiome and its metabolic capabilities can provide a direction for the management of tailings disposal sites and maximize their potential as secondary resources.

Effect of plants in constructed wetlands for organic carbon and nutrient removal: a review of experimental factors contributing to higher impact and suggestions for future guidelines.

Constructed wetland is a proven technology for water pollution removal, but process mechanisms and their respective contribution are not fully understood. The present review details the effect of plants on removal efficiency of constructed wetlands by focusing on literature that includes experiments with unplanted controls for organic carbon and nutrient (N and P) removal. The contribution of plant direct uptake is also assessed. Although it was found that several studies, mostly at laboratory or pilot scales, showed no statistical differences between planted and unplanted controls, some factors were found that help maximize the effect of plants. This study intends to contribute to a better understanding of the significance of the effect of plants in a constructed wetland, as well as to suggest a set of experimental guidelines in this field.

Extensive review of shale gas environmental impacts from scientific literature (2010-2015).

Extensive reviews and meta-analyses are essential to summarize emerging developments in a specific field and offering information on the current trends in the scientific literature. Shale gas exploration and exploitation has been extensively debated in literature, but a comprehensive review of recent studies on the environmental impacts has yet to be carried out. Therefore, the goal of this article is to systematically examine scientific articles published between 2010 and 2015 and identify recent advances and existing data gaps. The examined articles were classified into six main categories (water resources, atmospheric emissions, land use, induced seismicity, occupational and public health and safety, and other impacts). These categories are analyzed separately to identify specific challenges, possibly existing consensus and data gaps yet remained in the literature.

Role of three different plants on simultaneous salt and nutrient reduction from saline synthetic wastewater in lab-scale constructed wetlands.

Constructed Wetlands (CWs) can be a valuable technology to treat high salinity wastewaters but it is not known their potential for removal of both nutrients and salt, and the type of plants to use. This study evaluated the effect of three plants on salt reduction and simultaneous nutrient removal in CWs microcosms with expanded clay and in hydroponic conditions. Initial values of the synthetic wastewater tested were EC=15dSm-1, SAR=151; NH4+-N=24mgL-1; PO43--P=30mgL-1 and NO3--N=34mgL-1. With expanded clay CW removal efficiency for NH4+-N was 21, 88 and 85%, while for NO3--N, it was 4, 56 and 68% for Spartina maritima, Juncus maritimus and Arundo donax, respectively. PO43--P was adsorbed completely in the expanded clay. However, in hydroponic system, removal efficiencies for NH4+-N were 53 and 50%, while PO43--P removal was 89 and -14% for Spartina maritima and Juncus maritimus, respectively. Nutrient removal in planted microcosms was statistically higher than unplanted controls for NH4+-N and PO43--P. However, salt removal was apparent in the hydroponic system only after 23days of HRT, despite clear salt excretion visible in both Spartina maritima and Juncus maritimus. This study demonstrates the potential of two halophytic plants for saline wastewater treatment. However, salt removal in such a scenario could not be well documented and might prove to be impractical in future work.

Phytoremediation of salt-affected soils: a review of processes, applicability, and the impact of climate change.

Soil salinization affects 1-10 billion ha worldwide, threatening the agricultural production needed to feed the ever increasing world population. Phytoremediation may be a cost-effective option for the remediation of these soils. This review analyzes the viability of using phytoremediation for salt-affected soils and explores the remedial mechanisms involved. In addition, it specifically addresses the debate over plant indirect (via soil cation exchange enhancement) or direct (via uptake) role in salt remediation. Analysis of experimental data for electrical conductivity (ECe) + sodium adsorption ratio (SAR) reduction and plant salt uptake showed a similar removal efficiency between salt phytoremediation and other treatment options, with the added potential for phytoextraction under non-leaching conditions. A focus is also given on recent studies that indicate potential pathways for increased salt phytoextraction, co-treatment with other contaminants, and phytoremediation applicability for salt flow control. Finally, this work also details the predicted effects of climate change on soil salinization and on treatment options. The synergetic effects of extreme climate events and salinization are a challenging obstacle for future phytoremediation applications, which will require additional and multi-disciplinary research efforts.

Occupational exposure during remediation works at a uranium tailings pile.

The aim of this study was to assess by different approaches the occupational exposure during the remediation of a tailings dam in an abandoned uranium mining site, with an area of about 13.3 ha and an estimated volume of 1.39 million m³. A hypothetical scenario was created in which the workers involved in the remediation activities were exposed to radiation through both internal and external pathways. It was intended to assess quantitatively the potential exposure of the workforce involved in the remediation works, focussing particularly on the inhalation of radon and on the gamma irradiation from the contaminated soil. Different methodologies were considered based on a deterministic and a probabilistic approach for dose assessment and risk assessment, respectively. The deterministic approach typically employs a highly "conservative" single value for each input parameter. The probabilistic approach employs sensitivity and uncertainty analysis of input parameters using probabilistic distributions of the sensitive parameters. The results indicate that annual effective dose limit for occupational exposure (worst scenario case created) may reach a significant fraction of occupational radiation protection limits. This is also stressed by the values obtained for the occupational risk estimated by Monte Carlo methodology using probabilistic distributions for the input parameters. The results also showed that the pathway with the highest dose does not necessarily correspond to the pathway with the highest risk. Nevertheless, it is well known that probabilistic analysis generally produces more realistic results.

Procedimento e complicações anestésicas no manejo de lavagem pulmonar total em paciente obeso com proteinose alveolar pulmonar: relato de caso / Anaesthetic, procedure and complications management of serial whole lung lavage in an obese patient with pulmonary alveolar proteinosis: case report / Procedimiento y complicaciones anestésicas en el manejo del lavado pulmonar total en paciente obeso con proteinosis alveolar pulmonar: relato de caso

JUSTIFICATIVA E OBJETIVOS: O primeiro caso de proteinose alveolar pulmonar (PAP) foi descrito por Rose em 1958, mas ainda é um distúrbio raro. PAP é caracterizada pela deposição de material lipoproteico secundário ao processamento anormal de surfactantes pelos macrófagos. Os pacientes podem ter dispneia progressiva e tosse, às vezes acompanhadas pelo agravamento da hipóxia, e seu curso pode variar de deterioração progressiva a melhora espontânea. Muitas terapias foram usadas, incluindo antibióticos, drenagem postural e ventilação com pressão positiva intermitente com acetilcisteína, heparina e soro fisiológico em aerossol. Atualmente, a base do tratamento é a lavagem pulmonar total (LPT). A LPT, embora seja geralmente bem-tolerada, pode estar associada a algumas complicações. RELATO DE CASO: Relatamos um caso de PAP grave durante o procedimento anestésico e as complicações no manejo da proteinose alveolar pulmonar em um paciente que havia sido submetido a múltiplas e alternadas lavagens de um dos pulmões ao longo de sete anos (os últimos três em nosso hospital), com melhora dos sintomas depois de cada tratamento.

BACKGROUND AND OBJECTIVES: The first case of Pulmonary Alveolar Proteinosis (PAP) was described by Rose in 1958, but it is still a rare disorder. PAP is characterized by deposition of lipoproteinaceous material secondary to abnormal processing of surfactant by macrophages. Patients may suffer from progressive dyspnea and cough that at times is accompanied by worsening hypoxia and its course can vary from progressive deterioration to spontaneous improvement. Many therapies have been used to treat PAP including antibiotics, postural drainage, and intermittent positive pressure breathing with aerosolized Acetylcysteine, heparin and saline. At present, the mainstay of treatment is whole lung lavage (WLL). Although generally well tolerated, WLL can be associated with some complications. CASE REPORT: We report a case of severe PAP through the anaesthetic, procedure and complications management of pulmonary alveolar proteinosis in one patient who has undergone multiple, alternating, single-lung lavages over the past seven years, the last three in our hospital, with improvements in her symptoms following each therapy.

JUSTIFICATIVA Y OBJETIVOS: El primer caso de proteinosis alveolar pulmonar (PAP) fue descrito por Rose en 1958, pero todavía continúa siendo un trastorno raro. La PAP se caracteriza por la deposición de material lipoproteico secundario al procesamiento anormal de surfactantes por los macrófagos. Los pacientes pueden tener disnea progresiva y tos, a veces seguidas de un agravamiento de la hipoxia, y su curso puede variar de deterioración progresiva a una mejoría espontánea. A lo largo de los años, muchas terapias han sido usadas para tratar la PAP, incluyendo antibióticos, drenaje postural y ventilación con presión positiva intermitente con acetilcisteína, heparina y suero fisiológico en aerosol. Hoy por hoy, la base del tratamiento es el lavado pulmonar total (LPT), descrito por primera vez por Ramirez-Rivera y col. Existen tres variantes de la enfermedad: congénita, secundaria y adquirida. Las recientes investigaciones sugieren que en la forma más común (PAP adquirida [idiopática]), la autoinmunidad contra el factor estimulador de las colonias de granulocitos y macrófagos (FEC-GM) pulmonares desempeña un importante papel. El factor recombinante que estimula las colonias de granulocitos y macrófagos parece beneficiarse con un subconjunto de pacientes adultos con PAP y puede representar una alternativa en el tratamiento de la enfermedad, pero la tasa de éxito todavía no es suficiente para substituir la LPT. La LPT, aunque sea generalmente bien tolerada, puede estar asociada con algunas complicaciones. RELATO DE CASO: Relatamos un caso de PAP grave durante el procedimiento anestésico y las complicaciones en el manejo de la proteinosis alveolar pulmonar en un paciente que había sido sometido a múltiples y alternados lavados de uno de los pulmones a lo largo de siete años (los últimos tres en nuestro hospital), con una mejoría de los síntomas después de cada tratamiento.

Anaesthetic, procedure and complications management of serial whole-lung lavage in an obese patient with pulmonary alveolar proteinosis: case report.

BACKGROUND AND OBJECTIVES: The first case of Pulmonary Alveolar Proteinosis (PAP) was described by Rose in 1958, but it is still a rare disorder. PAP is characterized by deposition of lipoproteinaceous material secondary to abnormal processing of surfactant by macrophages. Patients may suffer from progressive dyspnea and cough that at times is accompanied by worsening hypoxia and its course can vary from progressive deterioration to spontaneous improvement. Many therapies have been used to treat PAP including antibiotics, postural drainage, and intermittent positive pressure breathing with aerosolized Acetylcysteine, heparin and saline. At present, the mainstay of treatment is whole lung lavage (WLL). Although generally well tolerated, WLL can be associated with some complications. CASE REPORT: We report a case of severe PAP through the anaesthetic, procedure and complications management of pulmonary alveolar proteinosis in one patient who has undergone multiple, alternating, single-lung lavages over the past seven years, the last three in our hospital, with improvements in her symptoms following each therapy.

Insight into the phenomenology of the Cr(VI) reduction by metallic iron using an electron probe microanalyzer.

Research was performed to gain insight into the heterogeneous reaction of Cr(VI) reduction by zero-valent iron, which is frequently used in the treatment of contaminated groundwater using permeable reactive barriers. An electron probe microanalyzer was used to clarify in detail relevant aspects of the reaction with consequences for the conception of interpretative kinetic models. Spherical particles of iron with controlled grain sizes were used after being subjected to a previous washing with diluted acid in order to remove oxidation products. These spheres were immersed in solutions of Cr(VI) in nonagitated flasks using different operating procedures. The iron particles were photographed so that the time evolution of the grain size distribution could be established. A sample of the iron balls after the reaction and samples of the raw material and the precipitates of the reaction products were analyzed by backscattering electron images and elemental mapping produced by wavelength-dispersive spectroscopy. The analysis of the spatial distribution of the concentrations in iron, oxygen, and chromium indicates that there are three distinct mechanisms for the reaction with different limiting steps.

Heterogeneous kinetics of the reduction of chromium (VI) by elemental iron.

Zero valent iron (ZVI) has been extensively used as a reactive medium for the reduction of Cr(VI) to Cr(III) in reactive permeable barriers. The kinetic rate depends strongly on the superficial oxidation of the iron particles used and the preliminary washing of ZVI increases the rate. The reaction has been primarily modelled using a pseudo-first-order kinetics which is inappropriate for a heterogeneous reaction. We assumed a shrinking particle type model where the kinetic rate is proportional to the available iron surface area, to the initial volume of solution and to the chromium concentration raised to a power alpha which is the order of the chemical reaction occurring at surface. We assumed alpha=2/3 based on the likeness to the shrinking particle models with spherical symmetry. Kinetics studies were performed in order to evaluate the suitability of this approach. The influence of the following parameters was experimentally studied: initial available surface area, chromium concentration, temperature and pH. The assumed order for the reaction was confirmed. In addition, the rate constant was calculated from data obtained in different operating conditions. Digital pictures of iron balls were periodically taken and the image treatment allowed for establishing the time evolution of their size distribution.

An insight into soil bioremediation through respirometry.

Respirometric tests on a soil contaminated by crude oil were performed. Continuous measurements of oxygen and carbon dioxide concentrations and temperature in the soil atmosphere resulted in a large volume of data. Time series and system identification theories were used to analyze data as a biological signal, allowing us to detect some particularities related to daily cycles of the studied variables as well as its time relationships through autocorrelation and cross-correlation functions. Using system identification techniques, it was possible to build black box models, namely autoregressive moving average models which enable to predict oxygen concentration at the outlet in a good agreement with measured data.

National Donation Network: what reality for heart transplantation?

The National Organ Donation Network is the structure that provides donation logistics for all transplant programmes currently functioning in Portugal (including cadaver donation, organs and tissues). In this article the authors present the Network, analyze the potential for heart donation, discuss the criteria for heart donor assessment and viability and suggest the adoption of recipient urgency grading schemes and the implementation of allocation criteria. In the coming years a realistic prediction for the maximum capacity of effective heart donation of the national network is 70-80 heart transplants per year, matching the figure of 7-8 heart transplants per million population and meeting 70-80% of the estimated needs for heart transplantation at national level. When this level is reached, it can be presumed that further improvement will necessitate expanding the donor pool, with less restrictive criteria for heart donor acceptance.