Valorization of wastewater sludge in cement CPJ45
S. Naamane1*, Z. Rais1, N.H. Mtarfi1, M. El Haji2, M. Taleb1
1 Laboratoire d’Ingénierie des Matériaux, de Modélisation et d’Environnement, Faculté des sciences Dhar El Mehraz,
B.P. 1796, 30000 Atlas Fès, Maroc
2 Laboratoire : Laboratoire Ressources Naturelles et Environnement, Faculté Polydisciplinaire de Taza
* Corresponding author. E-mail: firstname.lastname@example.org
Received: 17 April 2014; revised version accepted: 19 October 2014
The influence of sewage sludge on cement-based materials has been studied in this paper. The sewage sludge was used in its raw state, dried at 105 °C and calcined at 500 °C. Then, the CPJ45 cement was partially replaced by sewage sludge admixture in mortar at various percentages. The characterization of sewage sludge by inductivity coupled plasma-atomic emission spectrometer (ICP-AES), X-ray Diffraction (XRD), scanning electron microscopy (SEM), X-ray fluorescence, and the evaluation of its use in cement are presented in this study.
Results show that sewage sludge is composed of a significant amount of oxides and metals, plus an irregular morphology of its grains. The introduction of sewage sludge in cement decreases of mortar workability. The presence of absorbed water and organic matter in sewage sludge prolongs strongly the setting time and affects negatively the compressive strength of mortars. The best mechanical results are obtained for the substitution of 5 % of calcined sewage sludge at 28 days.
Keywords: Sewage sludge; Cement; Physico-chemical and mechanical characterization.