Arsenic in Soils Affected by Mining: Microscopic Studies vs. Sequential Chemical Extraction.
Jessica Álvarez-QuintanaRodrigo ÁlvarezAlmudena OrdóñezPublished in: International journal of environmental research and public health (2020)
Soil samples from three inactive mines, corresponding to different Arsenic-bearing mineralization types, were collected and studied. The aim was to determine the influence of mine wastes mineralogy/geochemistry and texture in As mobility and to compare results from sequential chemical extraction and microscopic techniques (optical and electron) at a grain scale. Arsenic in soils is found mainly associated to the residual fraction, indicating that mechanical As dispersion is mainly responsible for As soil pollution. The use of objective microscopic techniques (i.e., Scanning Electron Microscopy-Energy Dispersive Spectroscopy -SEM-EDS-, High Resolution Transmission Electron Microscopy -HR-TEM) has pointed out that the selected sequential extraction method overestimates the role of Mn amorphous oxy-hydroxides and organic matter in As retention while underestimating the mechanism of As adsorption onto clay particle surfaces.
Keyphrases
- electron microscopy
- heavy metals
- high resolution
- organic matter
- health risk assessment
- risk assessment
- sewage sludge
- drinking water
- room temperature
- human health
- solid state
- computed tomography
- plant growth
- single molecule
- ionic liquid
- magnetic resonance
- magnetic resonance imaging
- biofilm formation
- climate change
- particulate matter
- pseudomonas aeruginosa
- contrast enhanced
- transition metal