Dewaterability of Anaerobic Digested Sludge with Cations and Chitosan as Dual Conditioners
Anaerobic digested sludge dewatering is very important in sludge management and disposal. In this study, flocculation and dewatering behaviour of anaerobic digested sludge were investigated using metal cations (sodium, magnesium, calcium, ferric and aluminium salts) and chitosan as dual conditioners. The trivalent ferric and aluminium ions were found to be more effective than the monovalent and divalent cations in improving sludge dewaterability as measured by capillary suction time (CST). Post-addition of chitosan into the sludge pre-coagulated with metal cations further enhanced the sludge dewaterability. This study suggests that pre-destabilisation of sludge by coagulation with metal cations followed by chitosan addition as polymeric flocculant may improve the dewaterability of anaerobic digested sludge.
KeywordsTotal Dissolve Solid Extracellular Polymeric Substance Sludge Sample High Molecular Weight Polymer Anaerobic Digested Sludge
The authors would like to acknowledge Physics Department at Curtin Perth for the image analysis. Dominique Dodge-Wan proofreads this chapter.
- APHA (2005). Standard methods for the examination of water and wastewater. 21st edn. Washington, DC, American Public Health Association, American Water Works Association, and Water Environment Federation.Google Scholar
- CST Equipment Manual (1998). Essex: Triton Electronics Ltd.Google Scholar
- Rose, G. R. & ST. John, M. R. (2010). Encyclopedia of polymer science and technology. (2nd edn., Vol 7. pp. 211–233). Nalco Chemical Company.Google Scholar
- Sanin, F. D., Vatansever, A., Turtin, I., Kara, F. & Durmaz, B. (2006). Operational conditions of activated sludge: Influence on flocculation and dewaterability. Drying Technology 24(10), 1297–1306.Google Scholar
- Turovskiy, I. S. & Mathai, P. K. (2006). Wastewater sludge processing. New Jersey: Wiley.Google Scholar