Valorisation of Inorganic Fractions of Waste Generated by Hydrothermal Treatment of Sewage Sludge in Alkaline Cement

Hydrothermal processing technology provides an innovative and promising solution to achieve significant reductions in the volume of sewage sludge and the recovery of raw materials. In this work, we evaluated the possibility of using inorganic mineral residue (IMR) from hydrothermal sewage treatment...

ver descrição completa

Detalhes bibliográficos
Autores: Fernández-Jiménez, Ana, Maltseva, O., Palomo, Ángel, Marian, Narcisa Mihaela, Sturini, Michela, Riccardi, Maria P., Zema, Michele, Tarantino, Serena C.
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2025
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositório:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/396652
Acesso em linha:http://hdl.handle.net/10261/396652
Access Level:Acceso aberto
Palavra-chave:Geopolymer
Sewage sludge
Characterisation
Leaching
http://metadata.un.org/sdg/6
Ensure availability and sustainable management of water and sanitation for all
Descrição
Resumo:Hydrothermal processing technology provides an innovative and promising solution to achieve significant reductions in the volume of sewage sludge and the recovery of raw materials. In this work, we evaluated the possibility of using inorganic mineral residue (IMR) from hydrothermal sewage treatment in a geopolymer binder. Initially, the waste was characterised, and thermal treatment was carried out at 800 °C to eliminate the organic matter. Calcined clay (3 h at 800 °C) was used to manufacture the geopolymer. Calcined clay/residue mixtures at ratios of 100/0, 90/10, and 80/20 were prepared and activated using a 6 M NaOH solution. The pastes were cured for 20 h at 85 °C, their compressive strengths were evaluated, and the reaction products were characterised using XRD and microscopy. The results show low reactivity in the residue. However, it was observed that some of the phosphorus present in the residue could be incorporated into the products of alkaline activation. A leaching study was also carried out, in which all the toxic metals remained confined except for chromium.