Multivariate analysis applied to X-ray fluorescence to assess soil contamination pathways: case studies of mass magnetic susceptibility in soils near abandoned coal and W/Sn mines.

Determining the origin and pathways of contaminants in the natural environment is key to informing any mitigation process. The mass magnetic susceptibility of soils allows a rapid method to measure the concentration of magnetic minerals, derived from anthropogenic activities such as mining or industrial processes, i.e.

Assessment of ecotoxicological effects of Fojo coal mine waste elutriate in aquatic species (Douro Coalfield, North Portugal).

The exploitation of anthracite A in the Pejão mining complex (Douro Coalfield, North Portugal) resulted in the formation of several coal waste piles without proper environmental control. In 2017, a new pedological zonation emerged in the Fojo area, after the ignition and self-burning of some of the coal waste piles, namely: unburned coal waste (UW); burned coal waste, and a cover layer (BW and CL, respectively); uphill soil (US); mixed burned coal waste (MBW); downhill soil (DS). This study aimed to evaluate the toxic effects of 25 soil elutriates from different pedological materials.

Phytotoxicity of coal waste elutriates (Douro Coalfield, North Portugal) in Lactuca sativa.

One of the most important mining areas in the Douro Carboniferous Basin is the Pejão Coalfield. In the summer of 2017, a wildfire promoted the ignition and self-burning some of the coal waste piles in the area and caused important environmental changes, promoting a new heterogenic pedological zonation. This study aims to assess the ecotoxicological effects of 25 soil elutriates from these different soil types in seed germination and individual (emergence, growth, and morphologic alterations) and subindividual parameters in Lactuca sativa.

Wildfires effects on organic matter of soils from Caramulo Mountain (Portugal): environmental implications.

The investigation about wildfires has demonstrated that research should include studies on the overall assessment of the processes, thus promoting the public awareness about impacts. The aim of this study is to assess the changes on the carbon content of soils affected by wildfires in Caramulo Mountain (Portugal) to therefore identify the environmental impacts arisen from those changes. Soils from different parent rocks, affected and non-affected by wildfires, were collected.

Extensive FE-SEM/EDS, HR-TEM/EDS and ToF-SIMS studies of micron- to nano-particles in anthracite fly ash.

The generation of anthropogenic carbonaceous matter and mixed crystalline/amorphous mineral ultrafine/nano-particles in the 1 to 100 nm size range by worldwide coal power plants represents serious environmental problems due to their potential hazards. Coal fly ash (CFA) that resulted from anthracite combustion in a Portuguese thermal power plant was studied in this work. The physico-chemical characterization of ultrafine/nano-particles present in the CFA samples and their interaction with environment are the aim of this study.

Polycyclic aromatic hydrocarbons (PAHs) in burning and non-burning coal waste piles.

The coal waste material that results from Douro Coalfield exploitation was analyzed by gas chromatography with mass spectrometry (GC-MS) for the identification and quantification of the 16 polycyclic aromatic hydrocarbons (PAHs), defined as priority pollutants. It is expected that the organic fraction of the coal waste material contains PAHs from petrogenic origin, and also from pyrolytic origin in burning coal waste piles. The results demonstrate some similarity in the studied samples, being phenanthrene the most abundant PAH followed by fluoranthene and pyrene.

Identification of nanominerals and nanoparticles in burning coal waste piles from Portugal.

A range of carbon nanoparticles, agglomerates and mineral phases have been identified in burning coal waste pile materials from the Douro Coalfield of Portugal, as a basis for identifying their potential environmental and human health impacts. The fragile nature and fine particle size of these materials required novel characterization methods, including energy-dispersive X-ray spectrometry (EDS), field-emission scanning electron microscope (FE-SEM), and high-resolution transmission electron microscopy (HR-TEM) techniques. The chemical composition and possible correlations with morphology of the nanominerals and associated ultra-fine particles have been evaluated in the context of human health exposure, as well as in relation to management of such components in coal-fire environments.