title: Influence of an oxic settling anoxic system on biomass yield, protozoa and filamentous bacteria.
abstract: An oxic settling anoxic system coupled with an activated sludge process has been studied to reduce sewage sludge production. The reduction of sludge yield, excess sludge production and active biomass yield were 51.7%, 52.9% and 67.1%, respectively, compared with the control system. The oxic reactor of the oxic settling anoxic system, even with a lower active biomass concentration than the oxic reactor of control system, showed a higher metabolic activity in their active biomass. Diversity and crawling ciliates group have been shown as promising bioindicators of active biomass yield reduction. The identification of floc-forming bacteria in the control system suggested that oxic settling anoxic system will improve settling properties compared to a Conventional Activated Sludge process.
authors.affiliation: Departamento de Ingeniería Química y Ambiental, Escuela Politécnica Superior, Universidad de Sevilla, C/ Virgen de África 7, 41011 Sevilla, Spain. Electronic address: santirodper@gmail.com.
authors.forename: Santiago
authors.initials: S
authors.lastname: Rodriguez-Perez
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Gutierrez
authors.affiliation: Instituto de la Grasa, Consejo Superior de Investigaciones Científicas (C.S.I.C.), Ctra. de Utrera, km. 1, Campus Universitario Pablo de Olavide - Edificio 46, 41013 Sevilla, Spain.
authors.forename: Fernando G
authors.initials: FG
authors.lastname: Fermoso
authors.forename: Carmen
authors.initials: C
authors.lastname: Arnaiz
mesh_terms: D018533:Biomass; D010100:Oxygen / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D012722:Sewage / Q000382:microbiology / Q000469:parasitology; D014865:Waste Disposal, Fluid
chemical_list: D012722:Sewage; D010100:Oxygen
keywords: Excess sludge; Filamentous bacteria; Oxic settling anoxic system; Protozoa population; Sludge yield