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Brazilian mining ventures aged 30 years or older were studied, revealing historical oversights in environmental planning that have caused substantial environmental liabilities during active mining and decommissioning. Electrical resistivity tomography surveys were conducted in a decommissioning uranium mine in southeast Brazil. The results provided valuable insights into local hydrogeological dynamics, revealing the flow of acid mine drainage in two distinct systems: the porous waste rock pile and the fractured underlying crystalline basement. Geo-electrical sections displayed conductive anomalies indicating hydraulic connectivity between the waste rock pile and the underlying fractured aquifer through crystalline basement fractures. This connection was substantiated by sub-vertical zones of low electrical resistivity interpreted as groundwater influx from the porous system to the fractured aquifer. Consequently, the waste rock pile acted as a localized recharge zone for the regional aquifer, facilitating chemical exchanges between the two systems. Furthermore, the study successfully differentiated less impacted saturated zones (resistivity ≈80 Ω·m) from those associated with acid mine drainage (< 40 Ω·m). Preliminary investigations identified a complex fracture network in the study area, comprising two main fault systems with preferential NE and NW orientations, nearly orthogonal to each other. This fracture network demonstrated continuity, playing a fundamental role in sustaining flow within the local and regional drainage network. [ABSTRACT FROM AUTHOR]

The mineland rehabilitation can be a challenge due to high soil density and low levels of organic matter and nutrients. This study assessed soil chemical attributes and leaf nutritional contents of two native species (Mimosa acutistipula var. ferrea and Vismia baccifera) grown in an iron waste pile under environmental rehabilitation in the Carajás Mineral Province, Eastern Amazon, Brazil. Soil samples were collected close to plant species in three different chronosequences of rehabilitation. Regardless of the rehabilitation stage, the soils have low levels of phosphorus, potassium, calcium, magnesium, and boron. A tendency of organic matter accumulation was observed at the advanced stage (5–8 years after the onset of rehabilitation process) and it was correlated with other soil nutrients. The leaf nutrient' contents of M. acutistipula and V. baccifera tend to be distinct from each other, which could indicate that the studied species have different nutritional requirements. The V. baccifera presented higher leaf concentrations of sulfur, copper, and zinc, while M. acutistipula stood out for presenting a higher leaf nitrogen content, which is possibly related to its nitrogen-fixing capacity. In general, an improvement of soil chemical attributes was achieved with the advance of the rehabilitation stages, showing the efficiency of the procedures performed to rehabilitate the studied areas. [ABSTRACT FROM AUTHOR]

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Various arthropods are active in composting process. One undesirable factor of this process is the growing population of flies among which the stable flies (Stomoxys calcitrans) are biting and blood sucking insects. The objective of this study was to investigate the frequency of producing this type of fly in the process of composting in laboratory. This research was a descriptive one in which waste was taken to laboratory. Then, the compostable components were integrated after separation and from the mentioned pile 9 basins were filled in 3 places with each basin containing 20 kilograms of waste. The fly larvae were sampled during the process of composting and samples underwent diagnosis after being taken to the laboratory. Thereafter, the results were compared through charts and tables. From among Diptera order, Muscidae family were the most frequent sample abundant larvae. As a whole, 2657 samples of stable fly larvae were detected and as the time of the process expanded, the number of samples gathered from basin was increased. The highest number of larvae was collected from underground basins. This study demonstrated that in composting process, a lot of arthropods are produced among which stable flies or Stomoxys calcitrans are considered as the most important species for being biting creatures that feed on human and animal blood. Therefore, the sites of producing compost must be established far away from human habitats. [ABSTRACT FROM AUTHOR]

During the working of thermal power plants, due to technological process of coal combustion, waste matter, which takes up large areas of land, degrades and pollutes the environment, is created. In the last years, a significant progress has been made in the world in researching new technologies that implement technogenic materials which have wide range of optimal economic use. An example for this is electrofilterash which is, as technogenic raw material, largly and more often used in building industry. This resulted in decreasing negative effects of ash which was deposited considerably on ash waste piles. The use of ash for different industry purposes decreases the costs, increases a company's profitand removes the negative effects on the environment and human health. [ABSTRACT FROM AUTHOR]

Phosphogypsum (PG) is a by-product of the phosphoric acid productionprocess that contains high concentrations of U-series radionuclides.PG piles formed during the last 30 years cover about 1,200 hectares and are located close to the town of Huelva (Spain) on a salt-marsh. The regional government of Andalusia restored the area beginning in 1990 by covering it with a 25-cm-thick layer of natural soil. With this restoration, the external gamma-dose rate in the zone has decreaseddrastically, approaching near environmental background values. This conclusion is based on results obtained through in-situ monitoring measurements and through a dosimetric model developed for that particular radiation source. As the model uses average parameters of the studied site, its output does not show a correlation point by point with the in-situ monitoring measurements. However, a good agreement is observed in average values over the covered piles. The model gives an average dose rate of 0.41 mGy y-1 and the in situ monitoring0.40 mGy y-1. Based on this model, it is possible to calculate the necessary thickness of soil to reduce the dosimetric contribution from a similar extension of PG until the desired level is reached. In our conditions, in a 25-cm-thick soil, about 0.19 mGy y-1 is the increase produced by the PG layer in relation to an infinitum soil layer. Consequently, no radiological concern exists in the restored zones with respect to the external gamma radiation. [ABSTRACT FROM AUTHOR]