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Optimization Routes for the Bioleaching of MSWI Fly and Bottom Ashes Using Microorganisms Collected from a Natural System

Funari, V.; Gomes, H. I.; Cappelletti, M.; Fedi, S.; Dinelli, E.; Rogerson, M.; Mayes, W. M.; Rovere, M.


V. Funari

H. I. Gomes

M. Cappelletti

S. Fedi

E. Dinelli

M. Rogerson

M. Rovere


This paper presents a route for the treatment of MSWI fly (FA) and bottom ashes (BA) using microorganisms to critically assess whether bioleaching is within reach of effective industrial application. The leaching of metals from BA and FA was investigated in a controlled laboratory environment using a culture isolated from a natural system where the dominant strains are acidophilic bacteria, mainly Acidothiobacillus thiooxidans and Acidothiobacillus ferrooxidans. The community of microorganisms (mostly acidophilic, S- and Fe-oxidizing bacteria) was collected directly from overflows and ponds at the sediment–water interface of a natural system near a post-mining site. Pre-cultivation was done in 250mL flasks followed by the adaptation to the different substrates (both FA and BA). The effect of different material pre-treatment and elemental sulphur concentrations were evaluated for both BA and FA, at a starting pH of 4. The bioleaching of BA and FA substrates experienced good yields of metal extraction with an optimum duration of two weeks. The results showed that more than 90% Zn, Cu, and 10% Pb are removed from FA; while 100% Cu, 80% Zn and 20% Pb are removed from BA samples. Batch experiments with regenerating ion-exchange resins did not perform well for metal recovery, but could serve as a valuable decontamination step. The techniques used here with FA and BA can be used for urban mining purposes (e.g. ashes and other meal-rich anthropogenic wastes), but also low-grade ores in the mining industry, contributing to resource recovery or decontamination agendas.


Funari, V., Gomes, H. I., Cappelletti, M., Fedi, S., Dinelli, E., Rogerson, M., …Rovere, M. (2019). Optimization Routes for the Bioleaching of MSWI Fly and Bottom Ashes Using Microorganisms Collected from a Natural System. Waste and biomass valorization, 10(12), 3833-3842.

Journal Article Type Article
Acceptance Date May 9, 2019
Online Publication Date May 9, 2019
Publication Date Dec 1, 2019
Deposit Date Nov 4, 2021
Journal Waste and Biomass Valorization
Print ISSN 1877-2641
Electronic ISSN 1877-265X
Publisher Springer Verlag
Peer Reviewed Peer Reviewed
Volume 10
Issue 12
Pages 3833-3842
Keywords Municipal solid waste incineration (MSWI); MSWI bottom ash MSWI fly ash; Ion exchange resins; Resource recovery; Acidophilic bacteria
Public URL
Additional Information Received: 21 November 2018; Accepted: 29 April 2019; First Online: 9 May 2019