Use of activated sludge biomass as an agent for advanced primary separation.
Conventional primary settling is a physical process of solid-liquid separation, normally presenting low removal efficiencies. Improvement of this separation process would result in energetic advantages: lower aeration requirements and higher biogas production form primary and secondary sludges. Secondary sludge has been proposed as a potential agent promoting an increase in primary separation efficiency. Few processes have been proposed, based on the cultivation of sludge under special conditions. However, one can speculate that regular sludge may have a similar effect. The aim of this research was to study that possibility. Sludges from different activated sludge reactors were tested. Results showed that COD removals were up to 55%, 2 times higher than that for simple settling. Under that condition, COD balances showed that aeration requirements would reduce 40%, and biogas production from primary and secondary sludges would increase 50%. It is inferred then that the application of activated sludge as an external agent represents an interesting alternative that have the potential to significantly improve energetic efficiency of sewage treatment plants.
Departamento de Depuración, Gerencia de Operaciones, Aguas Araucanía, Vicuña Mackenna, N°0202, Temuco, Chile; Master of Engineering Sciences with Specialization in Biotechnology, Universidad de La Frontera, Temuco, Chile. Electronic address: michael.araneda@aguasaraucania.cl.
Michael
M
Araneda
Department of Chemical Engineering, Universidad de La Frontera, Francisco Salazar, 01145, Temuco, Chile; Master of Engineering Sciences with Specialization in Biotechnology, Universidad de La Frontera, Temuco, Chile. Electronic address: javier.pavez@ufrontera.cl.
Javier
J
Pavez
Department of Chemical Engineering, Universidad de La Frontera, Francisco Salazar, 01145, Temuco, Chile. Electronic address: b.luza01@ufromail.cl.
Benjamín
B
Luza
Department of Chemical Engineering, Universidad de La Frontera, Francisco Salazar, 01145, Temuco, Chile; Scientific and Technological Bioresource Nucleus (BIOREN), Universidad de La Frontera, Francisco Salazar, 01145, Temuco, Chile. Electronic address: david.jeison@ufrontera.cl.
David
D
Jeison
D056804:Biofuels / Q000032:analysis; D057919:Biological Oxygen Demand Analysis; D018533:Biomass; D019149:Bioreactors; D012722:Sewage; D014865:Waste Disposal, Fluid / Q000379:methods*
D056804:Biofuels; D012722:Sewage
Activated sludge; Advanced primary separation; Bioflocculation; Biogas; Biosorption