Title

Mathematical Modeling Of The High Rate Activated Sludge System: Optimizing The Cod:N Ratio In The Process Effluent

Keywords

Carbon removal; COD:N ratio; Denitritation; Flocculation; High-rate activated sludge; Mathematical modeling; Nitritation; Nitrite shunt; Oxidation; Storage

Abstract

This paper discusses the application of a high rate activated sludge (HRAS) model to describe the effects of varying specific operating parameters including SRT, DO, influent COD and temperature on the effluent COD:N ratio. This model will include process mechanisms for flocculation of particulate and colloidal substrate, hydrolysis, production of extracellular polymeric substances (EPS) and intracellular storage products. The COD:N ratio would be suitable for a downstream nitritation/denitritation process implementing nitrite shunt. In the downstream process the goal is to eliminate nitrite oxidizing bacteria (NOB) from the reactor while selecting for ammonia oxidizing bacteria (AOB). Based a data set collected from an A/B pilot scale process, a COD:N ratio of 7:1 was used to support the B-stage nitritation/denitritation process. The HRAS model was able to predict that a suitable COD:N ratio could be maintained at an SRT at or below 0.25 days. This was confirmed when the model results were compared to the A/B pilot data which showed a consistent COD:N ratio suitable to support the B-Stage nitritation/denitritation process at an SRT of approximately 0.2 d.

Publication Date

10-1-2014

Publication Title

87th Annual Water Environment Federation Technical Exhibition and Conference, WEFTEC 2014

Volume

3

Number of Pages

913-926

Document Type

Article; Proceedings Paper

Personal Identifier

scopus

DOI Link

https://doi.org/10.2175/193864714815941009

Socpus ID

85055638820 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/85055638820

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