Related to deliverables No:
D.2.3.1, D.2.3.2, D.2.3.7, D.2.3.14, D.2.3.17
Version 20 Nov. 09
Tool title and potential use
Water-Sediment Screening Tool (WSST)
Screening tool to determine biodegradation rates and kinetics of organic chemicals in
water-sediment systems.
Novelty and background
Background:
Currently available models for the prediction of the environmental fate of chemicals
were developed mainly for organic compounds with simple molecular structures.
Furthermore, most of the underlying experimental data were generated in qualitative
form (e.g. ready vs. not ready biodegradable) and available data sets are typically
related to water-only systems and not to sediments, where sorption, ageing,
sequestration and cross coupling may affect bioavailability, transformation and
degradation. Hence, there is need for reliable, quantitative biodegradation data for
more complex environmental matrices.
A water-sediment screening tool (WSST) was developed based on the OECD
Guideline 301C (MITI) to generate biodegradation data. The developed WSST is the
first water-sediment test system on screening test level.
Decription of tool and current state
The WSST and experimental procedures were tested and validated using aniline
(CAS No. 62-53-3) as training substances. The experiences and the data gained from
the experiments with the developed water-sediment test system are reproducible and
within the expected range. Thus, the WSST is ready for use for the generation of
biodegradation data and kinetics, which can be used for hazard assessment, risk
assessment and persistency assessment within the context of the new European
Community Regulation on chemicals and their safe use (REACH). Due to the
integration of the sediment compartment, the environmental fate of organic
compounds can be investigated under screening test conditions in consideration of
effects like sorption, ageing and sequestration.
A series of biodegradation experiments were performed for organic chemicals of
various chemical classes using the WSST and the MITI test system. The evaluation
of the results and the corresponding conclusions are in preparation.
References
1. Junker T, Paatzsch C, Knacker T, (submitted) A water-sediment screening
tool for measuring biodegradation of organic chemicals Sci Total Environ
2. Junker T, Knacker T, (2009). Report on experimental biodegradation kinetics
for selected chemicals and mixtures in water and sediment. (NoMiracle
Deliverable D.2.3.17)
3. Junker T, Knacker T, (2008). Report on investigation of important
confounding factors and comparison of results with literature data.
(NoMiracle Deliverable D.2.3.14)
4. Junker T, Kötting N, Knacker T, (2007) Report on experimental
biodegradation kinetics for selected test compounds in water and sediment
and identification of confounding factors. (NoMiracle Deliverable D.2.3.7)
5. Junker T, Elste C, Knacker T, Meller M, (2006). Report on Experimental
biodegradation kinetics for some model compounds in water and sediment.
(NoMiracle Deliverable D.2.3.2)
Responsible scientists:
Thomas Junker, ECT Oekotoxikologie GmbH, D-65439 Flörsheim, Germany, thjunker@ect.de