Author:
Ghezzi Lisa,Mugnaioli Enrico,Perchiazzi Natale,Duce Celia,Pelosi Chiara,Zamponi Erika,Pollastri Simone,Campanella Beatrice,Onor Massimo,Abdellatief Mahmoud,Franceschini Fabrizio,Petrini Riccardo
Abstract
AbstractPyrolysis in an inert atmosphere is a widely applied route to convert tannery wastes into reusable materials. In the present study, the Cr(III) conversion into the toxic hexavalent form in the pyrolyzed tannery waste referred to as KEU was investigated. Ageing experiments and leaching tests demonstrated that the Cr(III)–Cr(VI) inter-conversion occurs in the presence of air at ambient temperature, enhanced by wet environmental conditions. Microstructural analysis revealed that the Cr-primary mineral assemblage formed during pyrolysis (Cr-bearing srebrodolskite and Cr-magnetite spinel) destabilized upon spray water cooling in the last stage of the process. In the evolution from the higher to the lower temperature mineralogy, Cr is incorporated into newly formed CrOOH flakes which likely react in air forming extractable Cr(VI) species. This property transforms KEU from an inert waste to a hazardous material when exposed to ordinary ambient conditions.
Publisher
Springer Science and Business Media LLC
Reference53 articles.
1. Laurenti, R., Redwood, M., Puig, R. & Frostell, B. Measuring the environmental footprint of leather processing technologies. J. Ind. Ecol. 21, 1180–1187 (2016).
2. Dixit, S., Yadav, A., Dwivedi, P. D. & Das, M. Toxic hazards of leather industry and technologies to combat threat: A review. J. Clean. Prod. 87, 39–49 (2015).
3. Sivaram, N. M. & Barik, D. Toxic waste from leather industries. In Energy from Toxic Organic Waste for Heath and Power Generation (ed. Barik, D.) 55–67 (Woodhead Publishing, 2019).
4. Tasca, A. L. & Puccini, M. Leather tanning: Life cycle assessment of retanning, fatliquoring and dyeing. J. Clean. Prod. 226, 720–729 (2019).
5. Rosu, L., Varganici, C. D., Crudu, A. M., Rosu, D. & Bele, A. Ecofriendly wet–white leather vs conventional tanned wet–blue leather. A photochemical approach. J. Clean. Prod. 177, 708–720 (2018).