Temperature as an alternative tracer for the determination of the mixing characteristics in wastewater treatment plants

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Abstract

The hydraulic characteristics, i.e. the residence time distributions, of wastewater treatment plant reactors are usually determined using conventional tracers. This paper aims to present an alternative approach based on wastewater temperature. The step in temperature change, e.g. from stormwater events with cold rainwater, is used as a tracer signal. The method was verified using lab- and pilot-scale tests that showed very good agreement of the time series estimated both with conventional and temperature tracer methods. Results from lab-scale tests exhibit a zone with a minor water exchange of about 10% of the volume of all reactors, while the respective zone in the pilot-scale tests was estimated at about 30% of the total volume. The short-circuit flow was more than 50% of the inflow resulting from gaps between the walls inside the reactor cascade. An application example shows the importance of reliable residence time distribution underlying activated sludge modelling and the uncertainty associated with neglecting the determination of appropriate flow-through characteristics.

Details

OriginalspracheEnglisch
Seiten (von - bis)1765-1776
Seitenumfang12
FachzeitschriftWater research
Jahrgang44
Ausgabenummer6
PublikationsstatusVeröffentlicht - März 2010
Peer-Review-StatusJa

Externe IDs

PubMed 20036410
WOS 000275962200009
ORCID /0000-0001-9033-1847/work/139669801

Schlagworte

Schlagwörter

  • Activated sludge modelling, Compartment model approach, Dead zone, Flow-through characteristics, Residence time distribution, Short-circuiting, Temperature, Tracer