Incorporation of calcium in glasses: a key to understand the vitrification of sewage sludge

The quantity of sewage sludge generated daily by wastewater treatment plants represents a major environmental problem and a financial burden for plant operators. Valorization strategies focusing on reusing sewage sludge as a raw material are currently developed. Vitrification can help us reduce the...

Descripción completa

Detalles Bibliográficos
Autores: Tarragó Aymerich, Mariona, Royo, I., Martínez Manent, Salvador, Garcia Vallès, Maite, Neuville, D.R.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2021
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/176930
Acceso en línea:https://hdl.handle.net/2445/176930
Access Level:acceso abierto
Palabra clave:Basalt
Cristal·lització
Vidre
Crystallization
Glass
Descripción
Sumario:The quantity of sewage sludge generated daily by wastewater treatment plants represents a major environmental problem and a financial burden for plant operators. Valorization strategies focusing on reusing sewage sludge as a raw material are currently developed. Vitrification can help us reduce the volume of waste and binds the components in the structure of chemically stable glasses and glass‐ceramics. In this study, the vitrification of sewage sludge inside a basaltic rock has been simulated by producing glasses and a glass‐ceramic from basalt enriched in calcium that lie between the stability fields of pyroxene and melilite in the system CaO‐MgO‐SiO2‐Al2O3. CaO addition causes the oxidation of the melt at above the liquidus, increases the crystallization temperature, decreases the melting temperature and improves the microhardness of the glasses Glass‐ceramic processes improves the properties of the Ca‐doped basalt glass. The microhardness of the glass (8.2 GPa) and the glass‐ceramic (8.6 GPa) and leaching tests (in the ppb range) place both the glass and the glass‐ceramics at the high end of the mechanical properties and chemical resistance of ceramic tiles for the building industry.