title: Particulate organics degradation and sludge minimization in aerobic, complete SRT bioreactors.
abstract: The study evaluates the assumption that in activated sludge processes and under specific operating conditions, the considered unbiodegradable particulate organic fractions of influent (XU) organic solids and biomass decay residues (cell debris, XE) are degraded. The evaluation was performed by comparing sludge observed yield (Yobs) evolution in two full scale, complete solids retention time (SRT), aerobic bioreactors, to the predictions of two activated sludge models. The results showed that in steady state operating conditions of complete solids retention AS processes very low solids accumulation occur. In these conditions, solids accumulation is slightly affected by kinetic coefficients and significantly affected by XU and XE degradation rates. High endogenous residues degradation rate values of 0.05 d(-1) and 0.02 d(-1) were estimated for the two bioreactors, resulting in low solids accumulation, calculated at 1.6 tons and 3.59 tons per year respectively, of which 1.37 and 0.87 tons were non volatile suspended solids. Depending on WWTP operating conditions the endogenous residues degradation rate is the limiting factor of solids accumulation and consequently for particulate organics degradation.
authors.affiliation: Environmental Chemistry and Waste Water Treatment Lab., Environmental Engineering and Pollution Control Department, Technological Education Institute of Western Macedonia, Koila, Kozani, 50100, Greece. Electronic address: eAmanatidou@teiwm.gr.
authors.forename: Elisavet
authors.initials: E
authors.lastname: Amanatidou
authors.affiliation: Environmental Chemistry and Waste Water Treatment Lab., Environmental Engineering and Pollution Control Department, Technological Education Institute of Western Macedonia, Koila, Kozani, 50100, Greece.
authors.forename: Georgios
authors.initials: G
authors.lastname: Samiotis
authors.affiliation: Environmental Chemistry and Waste Water Treatment Lab., Environmental Engineering and Pollution Control Department, Technological Education Institute of Western Macedonia, Koila, Kozani, 50100, Greece.
authors.forename: Eleni
authors.initials: E
authors.lastname: Trikoilidou
authors.affiliation: Environmental Chemistry and Waste Water Treatment Lab., Environmental Engineering and Pollution Control Department, Technological Education Institute of Western Macedonia, Koila, Kozani, 50100, Greece.
authors.forename: Lazaros
authors.initials: L
authors.lastname: Tsikritzis
mesh_terms: D000003:Abattoirs; D001673:Biodegradation, Environmental; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors; D008962:Models, Theoretical; D052638:Particulate Matter / Q000032:analysis; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D052638:Particulate Matter; D012722:Sewage
keywords: Activated sludge models; Aerobic complete SRT bioreactors; Particulate organics degradation; Solids accumulation; Unbiodegredable organics