Model sewage treatment plant

OECD 303 A , Regulation (EC) No 440/2008, C.10, DIN EN ISO 11733, DIN 38412-26

Principle

Determination of biodegradability in a model sewage treatment plant via DOC/COD-measurement and substance specific analysis. Experiments with laboratory-scale sewage treatment plants are performed to simulate the complex behaviour of substances or wastewater in biological treatment plants.

Abstract

Two laboratory treatment plants are inoculated by an activated sludge taken from a municipal treatment plant, and receive synthetic wastewater in a flow-through mode. One laboratory treatment plant will receive the test substance (= test system), and one plant operates without test substance (= control system). The DOC value of the composite samples is determined daily in the effluent of both treatment plants. From the difference of the DOC obtained in the outflow, the different degradation and elimination extents are calculated in relation to the carbon content of the test substance.

The mean value of the outliner-free elimination extents within the plateau phase (for a period of at least 21 days) is defined as the test result.

Test substance properties

The method is used for substance which are soluble in water, not toxic and which have a low volatility.

Optional kann die Nitrifikation der Anlagen mittels Stickstoffanalytik bestimmt werden, um versuchs- oder prüfsubstanzbedingte Störeinflüsse in der Versuchsdurchführung zu erkennen.

Das Verfahren kann mit Ökotoxizitäts-Tests gekoppelt werden, um die aquatische Toxizität der Prüfsubstanzreste bzw. Abbauprodukte im Ablauf zu bestimmen. Dieses Verfahren wird beispielsweise für Sickerwässer aus Mülldeponien empfohlen (Anhang 51 AbwV).