Organic matter parameters in WWTP – a critical review and recommendations for application in activated sludge modelling

Abstract

This paper includes a comprehensive literature review of sludge composition data from wastewater treatment plants. 722 data sets from 249 sources were used to establish typical ratios between COD and solids-based parameters and to verify rule-of-thumb values, respectively. Confirmation of these typical ratios can also be accomplished by using biochemical composition data. It is shown that a correlation between data from proteins, lipids and carbohydrates analysis can be related to COD/VSS ratios. Finally, using the findings from the literature review, the organic and inorganic conversion factors of COD fractions in activated sludge models are adjusted to solids-based parameters. It was shown that with the adjustments of the factors and a partition of the particulate inert fraction into a fraction assigned to the influent and a fraction assigned to the endogenous products, a better agreement with the ratios of COD/VSS in the individual sludge streams can be established. HIGHLIGHTS Currently the largest collection of literature-based sludge data on municipal wastewater treatment plants.; Recommendations for adjustment of specific VS contents in model fractions of activated sludge models and further model improvements.; Linking biochemical data with typical wastewater parameters.;

Keywords

• activated sludge modelling
• chemical composition
• cod characterization
• organic solids
• routine data
• sludge composition
• wwtp