Size fractionation of COD in urban wastewater from a combined sewer system

Autor: D. Marani, V. Renzi, Roberto Ramadori, Camilla Maria Braguglia
Rok vydání: 2004
Předmět:
Zdroj: IWA Spec. Conf. on Nano and microparticles in water and wastewater treatment, Zurich, 2003
info:cnr-pdr/source/autori:MARANI D., RENZI V., RAMADORI R., BRAGUGLIA C./congresso_nome:IWA Spec. Conf. on Nano and microparticles in water and wastewater treatment/congresso_luogo:Zurich/congresso_data:2003/anno:2003/pagina_da:/pagina_a:/intervallo_pagine
Water science and technology 50 (2004): 79–86.
info:cnr-pdr/source/autori:MARANI D. (1); RENZI V. (2); RAMADORI R. (1); BRAGUGLIA C.M. (1)/titolo:Size fractionation of COD in urban wastewater from a combined sewer system/doi:/rivista:Water science and technology/anno:2004/pagina_da:79/pagina_a:86/intervallo_pagine:79–86/volume:50
ISSN: 1996-9732
0273-1223
DOI: 10.2166/wst.2004.0698
Popis: The objective of this work was to determine the partitioning of the pollutant load in urban wastewater in order to improve the conventional sewage treatment. In addition to settling tests, physical fractionation of COD in the degritted influent of Roma-Nord sewage treatment plant was performed via sequential filtration through sieves and membrane filters of the following pore size: 150-100-50-25-1-0.2 μm, and 100 kD (about 0.02 μm). Biodegradability studies were also performed on the different size fractions. Size fractionation showed that COD in Roma-Nord sewage is predominantly associated with settleable and supracolloidal (> 1 μm) particles, each size range including about 40% of total COD. Biodegradability tests indicated that the large fraction of COD associated with supracolloidal particles, which are not removed in the primary treatment, is characterised by slow degradability. This suggests that removal of these particles prior to biological treatment may greatly improve the overall treatment scheme. Preliminary pilot plant coagulation tests with lime at pH 9 showed that lime-enhanced primary treatment may increase COD removal efficiencies from typical 30-35% up to 65-70%, by inducing almost complete removal of the COD fraction associated with supracolloidal particles.
Databáze: OpenAIRE
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