Nanoparticles and interfaces with toxic elements in fluvial suspended sediment

Studies examining nanoparticles (NPs) and hazardous elements (HEs) contained in suspended sediments (SSs) are vital for watershed administration and ecological impact evaluation. The biochemical consequence of titanium-nanoparticles (Ti-NPs) from SSs in Colombia's Magdalena River was examined utilizing an innovative approach involving nanogeochemistry in this study. In general, the toxicity and the human health risk assessment associated with the presence of some Ti-NPs + HEs in SSs from riverine systems need to be determined with a robust analytical procedure. The mode of occurrence of Ti-NPs, total Ti and other elements contained within SSs of the Magdalena River were evaluated through advanced electron microscopy (field emission scanning electron microscope-FE-SEM and high resolution transmission electron microscope-HR-TEM) coupled with an energy dispersive X-ray microanalysis system (EDS); X-Ray Diffractions (XRD); and inductively coupled plasma-mass pectrometry (ICP-MS). This work showed that enormous quantities of Ti-NPs were present in the river studied and that they displayed diverse eochemical properties and posed various possible ecological dangers. Ti-NP contamination indices must be established for measuring the environmental magnitudes of NP contamination and determining contamination rank among rivers. Finally, SS contamination guidelines must be recommended on an international level. This study contributes to the scientific understanding of the relationship of HE and Ti-NP dynamics from SSs in riverine systems around the world

Técnicas utilizadas no armazenamento de informação

Apresenta princípios de funcionamento de algumas tecnologias presentes em nosso cotidiano. O texto aborda os seguintes tópicos: as pinturas rupestres e esculturas na pré-história; a escrita e o surgimento da imprensa; a câmara escura e o processo químico usado na fotografia, a lanterna mágica e o cinema; os autômatos musicais; o fonógrafo e o gramofone; o toca disco; o fonofilme; o alto-falante e os microfones eletrostáticos, de fita, dinâmico e os que utilizam variação de resistência elétrica; o telegrafone de Poulsen, as fitas e discos magnéticos; a técnica usada para transformar imagem em corrente elétrica nos equipamentos de vídeo e as técnicas de reprodução com tubo de imagem, LED ("Light Emitting Diode"), LCD ("Liquid Crystal Display") e plasma; o ábaco; os logaritmos e os bastões de Napier, os círculos de proporção e a régua de cálculo; a pascalina e o cilindro de Leibniz; a máquina analítica e os cartões perfurados; a formação da base da atual ciência da computação com George Boole; a origem da IBM, a importância do triodo e de Claude Shannon no surgimento do ENIAC ("Electronic Numerical Integrator and Computer"); John von Neurnann e Alan Turing; a tecnologia de "delay line memory"; a "core memory"; os transistores e o microprocessador no armazenamento de informação; o "photostore"; o disco rígido; os discos ópticos; a holografia

Release kinetics of multi-nutrients from volcanic rock mining by-products: evidences for their use as a soil remineralizer

Great quantities of stone by-products are stored alongside different exploiting mines in south Brazil, which are becoming an unsustainable environmental issue. Powder materials of andesite and dacite rocks were obtained from two mining companies of Southern Brazil. The particle size classification of the materials was determined by sieving. The X-ray diffraction (XRD) technique was used to identify the mineral phases of the by-products and X-ray fluorescence (XRF) was applied to determine their chemical compositions. The concentrations of calcium (Ca), potassium (K), magnesium (Mg), phosphorus (P) and silicon (Si) released by the by-products were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Dissolution rates of andesite and dacite rocks were measured in Milli-Q water, and in solutions of 0.1 mol L−1 citric acid, and Milli-Q water acidified with 0.5 mol L−1 acetic acid, as a function of reaction times at 24–96 h (short-term), and at 96–5760 h (long-term). The solutions were agitated continuously on a mechanical rotatory shaker at room temperature. The parabolic diffusion, simplified Elovich, and power function models were applied at both time slots of solid-solution reaction. The results indicated that the relationships of quantity of released multi-nutrients were well described by power equation: ln qt = ln a + b ln t. Dissolution rates were obtained based on the release of Ca, K, Mg, P and Si at a steady state under far from equilibrium conditions. Dissolution rates of both by-products were not affected, within the experimental uncertainty, by Milli-Q water. Although the by-products dissolution rates were unaffected by Milli-Q water, its rates are increased along the time. The dissolution of the by-products minerals was significantly affected by the pH of the solutions. The multi-elements release by both by-products in 0.1 mol L−1 citric acid solution was significantly larger than another solutions, indicating that exchangeable cations were readily available in citric acid solution. The results obtained from power function model in two reaction time intervals can contribute to estimate the multi-nutrients-supplying power of by-products to soil. The present study provides both to solving an environmental issue associated with Brazilian rock exploitation and to create an alternative for soil fertilization and a more sustainable agriculture

A tool for realistic study of nanoparticulate coal rejects

Pollution caused by hazardous and carcinogenic inorganic elements and organic compounds from coal may be more severe when coupled by other sources of pollution. In addition, the modes of occurrence of potential hazardous elements (PHEs) in coal cleaning rejects (CCRs) have been widely investigated using different methods, including statistical methods, which, however, in some cases resulted in misleading interpretations. In order to verify this potential problem and find an effective solution, we selected a data set, which contained comprehensive analyses of CCRs. The secondary products in sulphides-bearing coal mine rejects were studied in demand to determine their geochemical and ecological structures and to assess their position in the reduction of PHEs in the nature. A zone located in south Brazil, which is the major coal power plant in South America, can be given as an example of such a problem. In this work, a novel methodology for the analysis of PHEs in soils and sediments is proposed for this affected coal area. The analytical method combining X-Ray Diffraction (XRD) and advanced electron microscopies shows the importance of nanomineralogy in understanding different circumstances of coal contamination. Several ultrafine-nanoparticles (UNPs) were identified in the sampled soils and river sediments together with the PHEs. A decrease in PHEs was identified in association with UNPs. However, still further investigations are required with regard to the mobility of PHEs in water, atmosphere, soils, and sediments. The site studied around the coal power plant showed the highest sorption capacity possibly due to the high retention ability of components of soil and sediments such as carbon and clay. These observations of the coal-derived nanoparticles confirm their capability of regulating the mobility of hazardous elements, implying the need for restoring complex abandoned coal areas.

Implications of iron nanoparticles in spontaneous coal combustion and the effects on climatic variables

Atmosphere, water, and soil contamination with toxic compounds is a recurrent issue due to environmental disasters, coal burning, urbanization, and industrialization, allf of which have contributed to soil contamination over the decades. Consequently, understanding of the nanomineralogy and potential hazardous elements (PHEs) in coal area soil are always a vital topic since contaminated soil can affect the environment, agricultural safety, and human health. Colombian coal mining in the La Guajira zone has been usually been related with important health and ecological effects. Coalmine rejects from active and/or abandoned operations are causes of high intensities of potential hazardous elements (PHEs) and nanoparticles (NPs, minerals and/or amorphous compounds). Although these pollutants can be reduced by sorption to NPs, in this study was recognized an analytical procedure for understand distribution of PHEs and their relationship to iron NPs(Fe-NPs) was recognized. Non and poorrly crystalline Fe-NPs performances as the major PHEs association. This complex interaction is constant and efficient in resolving PHEs in proportions above monitoring quantities. The indefinite basis of PHEs in Colombian (La Guajira area) coalmine rejects sources results in years-long leaching of PHEs into rivers and drainages. The iron-clays and their great geomobility interfere the mitigating character that Fe hydr/oxides alone show through adsorption of PHEs and their control in spontaneous coal combustion (SCC) zones. This can have significant consequences to the probable availability of several pollutants (e.g. drinking water). The new results presented in this study add novel viewpoints into the description of Fe-NPs and its incidence in SCC areas. The methodology utilized in this work can be applied as a supplementary technique to evaluate the influence of coalmining actions on ecological and human health

Comparative carbon emission assessments of recycled and natural aggregate concrete: Environmental influence of cement content

This work examines the environmental and geochemical impact of recycled aggregate concrete production with properties representative for structural applications. The environmental influence of cement content, aggregate production, transportation, and waste landfilling is analysed by undertaking a life cycle assessment and considering a life cycle inventory largely specific for the region. To obtain a detailed insight into the optimum life cycle parameters, a sensitivity study is carried out in which supplementary cementitious materials, different values of natural-to-recycled aggregate content ratio and case-specific transportation distances were considered. The results show that carbon emissions were between 323 and 332 kgCO2e per cubic metre of cement only natural aggregate concrete. These values can be reduced by up to 17% by replacing 25% of the cement with fly ash. By contrast, carbon emissions can increase when natural coarse aggregates are replaced by recycled aggregates in proportions of 50% and 100%, and transportation is not included in analysis. However, the concrete with 50% recycled aggregate presented lower increase, only 0.3% and 3.4% for normal and high strength concrete, respectively. In some cases, the relative contribution of transportation to the total carbon emissions increased when cement was replaced by fly ash in proportions of 25%, and case-specific transportation distances were considered. In absolute values, the concrete mixes with 100% recycled aggregates and 25% fly ash had lower carbon emissions than concrete with cement and natural aggregates only. Higher environmental benefits can be obtained when the transportation distances of fly ash are relatively short (15–25 km) and the cement replacement by fly ash is equal or higher than 25%, considering that the mechanical properties are adequate for practical application. The observations from this paper show that recycled aggregate concrete with strength characteristics representative for structural members can have lower carbon emissions than conventional concrete, recommending them as an alternative to achieving global sustainability standards in construction

El desarrollo del turismo industrial en la región minera de Santa Catarina/Brasil para fomentar la recuperación medioambiental

Desde su descubrimiento el carbón genera diversos impactos en las regiones mineras del sur del estado de Santa Catarina (Brasil), hecho que justifica la importancia de estudios científicos que evalúen los efectos provocados por su exploración, para buscar alternativas que reduzcan los impactos medioambientales y aceleren los procesos de recuperación de las áreas afectadas. En este sentido, este trabajo pretende demostrar cómo el turismo puede desempeñar un papel importante en la recuperación medioambiental y en el desarrollo socioeconómico de la región analizada, fomentando así la mejora de la calidad de vida de la población local. Para ello, el estudio señaliza herramientas que se pueden llevar a cabo para que esta actividad prospere en los municipios de la cuenca carbonífera de Santa Catarina, como son la planificación territorial, la creación de productos turísticos y la puesta en valor del legado cultural y medioambiental.Since coal its discovery various impacts generated in mining regions the south of Santa Catarina state (Brazil), this fact justifies the importance of scientific studies to evaluate the effects caused by your exploration , for looking for alternatives that reduce environmental impacts and accelerate recovery processes in the affected areas. In this sense, this work want demonstrate how the tourism can be an important role in environmental restoration and economic development in the study region, to improving quality of life of local people. For this, the study signals tools like as territorial planning, development tourist products and post in value the cultural heritage and environment, to make possible that this activity to flourish in the municipalities of Santa Catarina coal basin

Nanomineralogy of mortars and ceramics from the Forum of Caesar and Nerva (Rome, Italy): the protagonist of black crusts produced on historic buildings

The recent focus of the impacts of atmospheric pollution on effective conservation methods for historic structures of great cultural heritage has been shown to be of critical importance for preservation. This work focuses on medieval Roman mortars and ceramics from the historic Forum of Caesar and Nerva, in Rome, Italy, and analyzes the urgency of repair of defects in rendered façades based on the inspection of surfaces where defects were detected, defining a methodology to predict the repair urgency of defects and building elements. X-ray spectroscopy (EDS), field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), and X-ray powder diffraction (XRD) analyses are well equipped to study mineralogy, ultra-fine particles, and nanoparticles (NPs, minerals and amorphous phases) that are present in medieval Roman ruins. Applied analysis of ruin-derived mortar and ceramics detected the presence of materials, primarily constituted of quartz, alumino-silicates, Fe-hydr/oxides, portions of amorphous phases, calcareous minerals, pyroxene, and carbonaceous materials. The Forum of Caesar and Nerva are two of the greatest remaining symbols of historic Roman construction. Many compounds recognized by XRD can be revealed by advanced microscopies and vice versa. The incidence of NPs containing potentially toxic elements (PTEs), and numerous carbonaceous complexes linked with building material alterations due to moisture and atmospheric contamination were also discovered. This study assesses the philosophies of preservation and culture, while considering the exhaust emitted by vehicular traffic in order to propose a justifiable and effective method to best conserve historic Roman structures located in high traffic areas

Atmospheric nanocompounds on lanzarote island: vehicular exhaust and igneous geologic formation interactions

Atmosphere contamination management is one of the most important features in pollution risk management. The worldwide rise in tourism increases apprehension about its probable destructive conservation influence on various aspects of global conservation. One of the principal dangers increased by tourism-based modes of travel are nanoparticles (NPs) containing potentially hazardous elements (PHEs) contamination. One example of this is island destination of Lanzarote, in Spain's Canary Islands in which we examined contamination of the local atmosphere, water and soil. Important NPs containing PHEs, (e.g. arsenic, chromium, lead, and mercury), were found in this locale. It is reasonable to assume that this pollution poses an increased environmental danger to the local biome(s). Modes of transport (i.e. by car, airplane, bus) were shown to be an important contributor to this localized contamination as demonstrated by particulate matter (PM) readings collected near the island's airport. If no measures are taken to reduce vehicle and aircraft traffic, the tendency is to increase environmental degradation will continue unabated. As this particular area of Lanzarote is also one of wine production, increased pollution has the potential for negative impacts on the region's economy

The impact of air pollution on the rate of degradation of the fortress of Florianópolis Island, Brazil

The study of the prevalence of agglomerated nanoparticles (ANPs) containing potentially hazardous elements (PHEs) in the atmosphere is an emerging field of research. As such, the development of effective analytical procedures for the documentation of ANPs in air dust is vital for the evaluation of human health consequences. X-ray powder diffraction (XRD), Raman spectroscopy (RS), Mossbauer spectroscopy (MS) and advanced microscopy (AM) analyses of levels of pollutant concentration have been completed for many years in buildings worldwide. The chemical and mineralogical features of the Fortress of Nossa Senhora da Conceição de Araçatuba in the Brazilian state of Santa Catarina were utilized to catalog the geologic makeup of the structure's raw materials. Analyses of diverse categories of historical building were developed and performed to show the incidence of normal and anthropogenic compounds with PHEs. These geochemical effects and the subsequent fate and transport of nanoparticulate and colloidal (1–1000 nm) compounds in the atmosphere have remained a focus of study for many years. However, the data published in the scientific literature is nowhere near adequate to generate an exhaustive standard of the performance, fate, and transport of natural and anthropogenic ANPs in the atmosphere. Studies to date do provide a preliminary argument for the human health risk calculations from historical buildings due to ANPs. Thus, the geochemical makeup of ANPs and their position in collected nanomineral–organic accumulations may offer some insight into their source. Our ability to detect such ANPs may decrease over time due to the tendency of historical buildings to accrete sludge over the years. The occurrence of PHEs in atmospheric ANPs has not formerly been recognized on the island environment examined in this study. However, it has been shown that it presents a clear and present danger to the preservation of historical monuments