Résumé:
Our study focuses on the characterization of the residual sludge from the Sidi Marouane de Mila wastewater treatment plant with a view to their recovery.
Qualitative analysis of seasonal and annual sludge by X-ray fluorescence
spectroscopy shows that the Sidi Merouane site is stable. XRD analyzes reveal that
the mineral matrix contained in the mud studied is mainly composed of quartz and
calcite, with the presence also of sillimanite and portlandite. Furthermore, the results
obtained by FTIR correlate with the main phases highlighted in the X-ray and XRF
diffraction analyses.The study of thermal behavior, in particular that of
dehydroxylation and decarbonation, leads to the formation of lime. The final
combination between the lime obtained and SiO2, Al2O3 and Fe2O3 gives the main
minerals of the clinker. Calcination of the sludge shows that the main components
which have been identified in the calcined sludge are Calcite; Quartz; Hatrurite and
Hedenbergite. Thus, the presence of minor components such as phlogopite; dolomite
and gehlenite.(Ca2Al2SiO7). The thermal decomposition of calcite begins around
550°C, and ends around 750°C. At temperatures above 800°C CaO, SiO2 and Al2O3
begin to react to form calcium and aluminum silicates.
