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

The use of industrial heritage as a dynamic factor in the south of Santa Catarina - Brazil

Este trabalho almeja demonstrar a valia dos potenciais recursos existentes na região Encantos do Sul (Santa Catarina, Brasil) para a implementação do turismo industrial. Dado que a aplicação deste segmento turístico pode requalificar o uso de antigas estruturas físicas desativadas ou em desuso pelo corpo empresarial e governamental, conseguindo convergir os conhecimentos científicos, políticos, administrativos e empresariais produzidos em um determinado período, usando a herança tecnológica, material e imaterial existente de forma benéfica à comunidade. Ao mesmo tempo, tal atividade busca minimizar as problemáticas ambientais e sociais existentes em determinadas áreas após o término de concessões industriais ou sem uma identidade turística consolidada, através da implantação de novas perspectivas econômicas, acadêmicas ou de lazer. Para demonstrar tal fato, o presente estudo selecionou estruturas existentes no entorno do polígono tecnológico regional sul de Santa Catarina, os quais contemplam estudos técnico-ambientais avançados, bem como localidades restauradas que poderão ser convertidas em produtos turísticos culturais, a fim de que estes possam contribuir para o desenvolvimento socioeconômico cultural dos distritos envolvidos.This article aims to demonstrate the potential value of the existing resources in the region of Encantados do Sul (Santa Catarina, Brazil) for the implementation of industrial tourism. Since the employment of this touristic segment may reclassify the use of ancient inactive physical structures or not used anymore by industry or government, by getting convergence of scientific, politics, administrative or business knowledge produced in a given period and also by using the existing material and/or immaterial technological legacies in a beneficial way for the community. At the same time, this activity try to minimize some environmental and social problems existent in specific areas either due to the end of some industry concessions or with no consolidated touristic identity by implementing new economic, academic and/or leisure perspectives. To do so, this study has chosen some existing structures around technological polygon of Santa Catarina south region, which present some advanced technical and environmental evaluations as well as restored sites that may be converted into cultural tourism products, so that, they may contribute to the socioeconomic and cultural development in the involved districts

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

Analysis of the influence of thickness on fire reaction performance in polyisocyanurate core sandwich panels

Sandwich panels (also known as insulated panels) have been traditionally used for industrial buildings and warehouses, but nowadays are being increasingly a favorable choice in building construction, mainly in wall cladding and roofing systems. This paper presents the results of an experimental and statistical comparative analysis of Fire Reaction development in sandwich panels consisting of steel sheeting and Polyisocyanurate (PIR) foam core. All these PIR core sandwich panels with joints kept the same dimensions (1000 mm × 1500 mm) + (500 mm × 1500 mm), but different thicknesses (30, 50, 100 and 150 mm). Five Single Burning Item (SBI) tests were carried out on individual PIR sandwich panels with vertical joints and their results were compared between themselves. It was possible to observe through an analysis of variance that there is an influence of the sample thickness in the individual results of the SBI test parameters; however, this variability has no significant influence on the Fire Reaction performance of the samples. Overall, the importance of these alternative sandwich panels is the increase in performance in the constructive processes and the offered comfort through its thermal insulation characteristics

Atmospheric contaminations and bad conservation effects in Roman mosaics and mortars of Italica

The advanced microscopic (AM) analyses of mosaics and mortars from ancient construction have been studied for millennia in several Roman buildings in Europe. The geochemical characteristics of mosaics and mortars in Italica, Spain, were composed of amorphous and crystalline raw materials. Applied AM and X-ray diffraction (XRD) studies of different mosaics and mortars were carried out to observe the occurrence of natural and anthropogenic phases with organic and inorganic hazardous compounds. The results revealed a broad range of particles (micro-to nano-scale) including coarse (2.5–10 μm), fine (0.1–2.5 μm), and ultrafine ones (<0.1 μm), down to a few nanometers, as measured on electron microscope images. The particles occur typically in the form of aggregates, even in the ultrafine scale. Single, i.e., non-agglomerated particles are more common in the ultrafine fraction than at larger sizes. Geochemical studies of the samples showed that high proportions of aluminum, calcium, iron, potassium, silicon, and titanium yielded high standards of cementation manifestations. In addition, it was confirmed in this study that many of the mosaics blanketed by land remained unchanged; however, when the soil was removed, such mosaics began to undergo changes, mainly by weathering and atmospheric contamination. Several materials identified by XRD can also be detected using a highresolution transmission electron microscopy (H-TEM)/field emission scanning electron microscope (FE-SEM) and vice versa. The occurrence of minerals containing potential hazardous elements (PHEs) and several associated organic compounds due to the modification caused by moisture and pollution was also demonstrated. The results offered important information about the building materials that were used to meet the mechanical requirements of the buildings

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

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

Nanoparticles as vectors of other contaminants in estuarine suspended sediments: natural and real conditions

Studding the behaviour and danger of nanoparticles (NPs, minerals and amorphous phases) in the estuarine ecosystem is presently incomplete by the lack of measureable description of NPs in the ecological conditions, such as suspended-sediments (SS). In the last years, several works have revealed the toxic consequences of ultra-fine and nanoparticulate compounds on diverse systems, raising apprehensions over the nanocontaminants behaviour and destiny in the numerous ecological partitions. The general objective of the manuscript is to explain the geochemical conditions of the LES (Laguna estuarine system, southern Brazil) suspended sediments covering an area around the main South American coal plant, enhancing the creation of future public policies for environmental recovery projects. Subsequently the discharge of nanoparticles and toxic element (TE) in the ecosystem, NPs react with several constituents of the nature and suffers active alteration progressions. Contamination coming from engineering actions, wastewater, are something identifiable, however when these contaminations are accompanied by other contamination sources (e.g. mining and farming) the work gets defaulted. By combining material about the concentration of TE contaminants and NPs occurrences, this work offers novel visions into contaminant contact and the possible effects of such exposure on estuarine systems in Brazil. The results presented here will be useful for different areas of estuaries around the world