Evolution of the properties of a municipal sewage sludge during flocculation and centrifugation

Christophe Charlou (1) , A. Ndong Obame (1) , Martial Sauceau (1) , Patricia Arlabosse (1)

1 RAPSODEE - Centre de recherche d'Albi en génie des procédés des solides divisés, de l'énergie et de l'environnement

Regardless the valorization or disposal route, a municipal sewage sludge must undergo transformations to reach the final desired properties. The knowledge of the properties of a sludge during its treatment is thus of prime importance for a better control of the final properties. The present study concerns the characterization of two aerated sewage sludges, sampled in an urban wastewater treatment plant before and after anaerobic digestion, during two essential steps: flocculation and centrifugation. The influence on the properties of polymer concentration and dry solid content is more particularly investigated. Several physico-chemical properties are used to monitor the structure evolution of the sludges: particle size distribution (Mastersizer 2000, Malvern instrument), zeta potential (Zetamètre nano S, Malvern) and rheological properties (RS150 Rheostress, Haake). Finally, the same optimal flocculant concentration is identified with the three techniques for both sludges. Moreover, the rheological properties of the sludges during the centrifugation is measured by using oscillatory mode for solid concentrations from 8 to more than 25 % of dry matter.

Mots clés: rheology; zeta potential; particle size distribution; centrifugation; flocculation; sewage sludge

Domaines: Génie des procédés; Ingénierie de l'environnement

Christophe Charlou, A. Ndong Obame, Martial Sauceau, Patricia Arlabosse. Evolution of the properties of a municipal sewage sludge during flocculation and centrifugation. 4th European Conference on Sludge Management (ECSM 2014), May 2014, Izmir, Turkey. ⟨hal-01729029⟩