Vol.:(0123456789) 1 3 Environmental Earth Sciences (2018) 77:217 https://doi.org/10.1007/s12665-018-7388-4 ORIGINAL ARTICLE Risk assessment of bottom ash from fuel oil power plant of Italy: mineralogical, chemical and leaching characterization M. Di Bella 1  · F. Italiano 1  · S. Magazù 2  · A. F. Mottese 3  · M. Interdonato 2  · F. Gentile 3  · G. Sabatino 4 Received: 2 August 2017 / Accepted: 26 February 2018 © Springer-Verlag GmbH Germany, part of Springer Nature 2018 Abstract The main aim of the present study is to contribute to the field of environmental research by providing new data on bot- tom ash samples derived from an oil power plant located in Southern Italy. To achieve this purpose, the mineralogical and chemical properties of representative bottom ash samples were investigated through the integrated employment of different analytical techniques, i.e., X-ray powder diffraction, scanning electron microscopy, X-ray fluorescence and atomic absorption spectrometry. The obtained experimental results show that quartz, alunogen, rhomboclase and potassium hydrogen silicate are the major crystalline phases of all the analyzed samples. Furthermore, the revealed main ash constituents are SiO 2 and SO 3 , with low contents of Fe 2 O 3 and Al 2 O 3 , and little amounts of CaO, Na 2 O, K 2 O, MgO, P 2 O 5 and TiO 2 . Among the trace elements, very high amounts of heavy metals, i.e., V, Cr, Ni, La, Pb and Mo, were detected. The comparison of the obtained heavy metal abundance data with those reported in the literature highlights significant differences. Leaching test evidenced V, Ni and Cr values that make these ashes a potential contamination source for groundwater quality and for soil, nearby the ash disposal landfills area. All the obtained findings show that these materials are highly harmful for the human health, with a greater extent for the heavy metal concentrations. Keywords Environmental research · Bottom ash · XRPD · SEM–EDX · WD-XRF · Heavy metals Introduction In the last years, the potential presence of toxic trace ele- ments in power plant combustion systems has received a growing interest by research and industry operators. This is mainly due to the circumstance that, in order to meet electric power requirements, world population has become critically dependent on fossil fuel as coal, natural gas and in a few cases fuel oil for producing electrical energy. However, fos- sil fuel combustion is also responsible for the huge produc- tion of pollutants, either as combustion residues or as solid wastes. Nitrogen oxides, sulfur dioxide, carbon dioxide, methane and volatile organic compounds, as well as particulates and heavy metals, are the main pollutants that potentially come out from the smoke stacks of the power plants (Alonso- Hernández et al. 2011). During combustion in the furnace of thermal power plants, some incombustible material is produced (Vassilev and Vassileva 2005) and, among the unburned products, besides slags, deposited residues in the bottom of the furnace called “bottom ashes” are present (Yuksel et al. 2007; Al-Degs et al. 2014). Usually, bottom ashes are at first removed from the furnace, then reduced by crushing them to a size of about 4 meshes (< 5 mm), sent out on a water train and finally disposed in landfills as hazard- ous waste. The disposal of such industrial waste materials is a critical task due to their potential impact on terrestrial ecosystems; this latter includes: the leaching of potentially toxic substances into soils and groundwater; reductions in * G. Sabatino gsabatino@unime.it 1 National Institute of Geophysics and Volcanology, Palermo Section, Via Ugo La Malfa, 153, 90146 Palermo, Italy 2 Department of Mathematics and Informatics, Physic and Earth Sciences, University of Messina, Viale Ferdinando Stagno d’Alcontres 31, S. Agata, 98166 Messina, Italy 3 Department of Biomedical and Dental Sciences and Morphofunctional Imaging Sastas Section, University of Messina, Viale Annunziata, 98168 Messina, Italy 4 Centro di Eccellenza Ricerca e Innovazione Strutture e Infrastrutture di Grandi Dimensioni (CERISI), University of Messina, Viale Ferdinando Stagno d’Alcontres 31, S. Agata, 98166 Messina, Italy