Arsenic mobility in pyrite ashes was studied because of the possible effects on water systems. The batch extraction method was used to assess kinetics and extent of As release induced by contact of the material either with rainwater or groundwater. Self-established pH-Eh range of pyrite ashes/water mixtures brought both As(III) and As(V) to be present in the water phase, as neutral arsenite H3AsO3 and anionic arsenate HAsO42-, respectively. Tests in reagent water showed both rate and extent of arsenite release higher than arsenate; total As concentration ([As] = 12 µg/L) at equilibrium little exceeded its EU Maximum Concentration Level (MCL) for surface and groundwater ([As] = 10 µg/L). Tests in groundwater, instead, showed a much higher release rate and extent for arsenate than for arsenite and the chemistry of groundwater mainly influenced arsenate mobility; total As almost instantly exceeded its MCL and it was markedly higher ([As] = 31 µg/L) at equilibrium. Overall, the study has shown the environmental implications of As mobility in the pyrite ashes, also casting light on some limits of the environmental representativeness of leaching tests in reagent water.
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Sci Total Environ
May 2020
Departamento de Ingeniería Minera y Civil, Universidad Politécnica de Cartagena, 52, Paseo Alfonso XIII, 30203, Cartagena, Murcia, Spain.
The lack of environmental regulations before 1998 brought about significant ecological consequences in Europe. There are 4,000,000 ha potentially contaminated by waste, resulting from industrial activity. These sites present abnormal values of salinity, alkalinity, and organic and inorganic pollutants.
View Article and Find Full Text PDFFront Chem
March 2018
Department of Soil Science and Agricultural Chemistry, Engineering Polytechnic School, Universidade de Santiago de Compostela, Lugo, Spain.
The purpose of this work was to elucidate the repercussion of changing pH, incubation time and As(V) competition on fluoride (F) sorption on forest and vineyard soil samples, pyritic, and granitic materials, as well as on the by-products pine sawdust, oak wood ash, mussel shell ash, fine and coarse mussel shell, and slate processing waste fines. To reach this end, the methodological approach was based on batch-type experiments. The results indicate that, for most materials, F sorption was very high at the start, but was clearly diminished when the pH value increased.
View Article and Find Full Text PDFWaste Manag Res
June 2016
Mineral-Metal Recovery and Recycling Research Group, Suleyman Demirel University, Isparta, Turkey
The pyrite ashes formed as waste material during the calcination of concentrated pyrite ore used for producing sulphuric acid not only has a high iron content but also contains economically valuable metals. These wastes, which are currently landfilled or dumped into the sea, cause serious land and environmental pollution problems owing to the release of acids and toxic substances. In this study, physical (sulphation roasting) and hydrometallurgical methods were evaluated for their efficacy to recover non-iron metals with a high content in the pyrite ashes and to prevent pollution thereby.
View Article and Find Full Text PDFSci Total Environ
September 2016
Environmental Technology, Biotechnology and Geochemistry Group, C/Gonzalo Gutiérrez Quirós s/n, 33600 Mieres, Asturias, Spain.
Here we addressed the contamination of soils in an abandoned brownfield located in an industrial area. Detailed soil and waste characterisation guided by historical information about the site revealed pyrite ashes (a residue derived from the roasting of pyrite ores) as the main environmental risk. In fact, the disposal of pyrite ashes and the mixing of these ashes with soils have affected a large area of the site, thereby causing heavy metal(loid) pollution (As and Pb levels reaching several thousands of ppm).
View Article and Find Full Text PDFEnviron Monit Assess
January 2015
Environmental Management Division, CSIR Central Institute of Mining and Fuel Research, Digwadih Campus PO: FRI, Dhanbad, 828 108, India,
The presence of potentially toxic elements in lignite and coal is a matter of global concern during energy extraction from them. Accordingly, Barsingsar lignite from Rajasthan (India), a newly identified and currently exploited commercial source of energy, was evaluated for the presence of these elements and their fate during its combustion. Mobility of these elements in Barsingsar lignite and its ashes from a power plant (Bikaner-Nagaur region of Thar Desert, India) is presented in this paper.
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