Superparamagnetic iron oxides nanoparticles from municipal solid waste incinerators

V Funari; L Mantovani; L Vigliotti; M Tribaudino; E Dinelli; R Braga

doi:10.1016/j.scitotenv.2017.11.289

Superparamagnetic iron oxides nanoparticles from municipal solid waste incinerators

Sci Total Environ. 2018 Apr 15:621:687-696. doi: 10.1016/j.scitotenv.2017.11.289. Epub 2017 Dec 1.

Authors

V Funari¹, L Mantovani², L Vigliotti³, M Tribaudino², E Dinelli⁴, R Braga⁴

Affiliations

¹ Instituto di Scienze Marine, Consiglio Nazionale delle Ricerche (ISMAR-CNR), Bologna, Italy; Dipartimento di Scienze Biologiche Geologiche e Ambientali (BiGeA), Università di Bologna, Bologna, Italy. Electronic address: geo.valerio.funari@gmail.com.
² Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Parma, Parma, Italy.
³ Instituto di Scienze Marine, Consiglio Nazionale delle Ricerche (ISMAR-CNR), Bologna, Italy.
⁴ Dipartimento di Scienze Biologiche Geologiche e Ambientali (BiGeA), Università di Bologna, Bologna, Italy.

PMID: 29197288
DOI: 10.1016/j.scitotenv.2017.11.289

Abstract

During their production, management, and landfilling, bottom (BA) and fly (FA) ashes from municipal solid waste incineration may liberate Fe-bearing, ultrafine particles and easily enter different environmental sinks of the biosphere. We aim to explore a collection of BA and FA samples from Italian incinerators to probe magnetic mineralogy and the fraction of harmful superparamagnetic (SP) nanoparticles (d<30nm). X-ray diffraction, electron microscopy observation, temperature- and frequency-dependent magnetometry, and Mossbauer analysis are performed. The integration of information from our rock magnetic and non-magnetic techniques leads us to conclude that the dominant magnetic carrier in our samples is magnetite and its intermediate/impure forms, while sulphides (i.e., monoclinic pyrrhotite) are important ancillary magnetic phases. The SP fraction fluxing from the BA and FA outputs of a single incinerator is detected and estimated in 10³tons/year. This work stresses the need to calibrate the current technologies towards a safer management of combustion ashes and certainly to inform the environmental impact assessment by using a combination of different methods.

Keywords: Anthropogenic pollution; Fly ash and bottom ash; Iron oxides; Magnetic susceptibility; Municipal solid waste incineration (MSWI); Superparamagnetic (SP) particles.