Title: Biodegradation of organic pollutants in river sediment under various biogeochemical conditions

Primary Researcher: Jasperien de Weert
Email address: jasperien.deweert@deltares.nl
Submitted on: August 16, 2005

Start date: 01 June 2004
End date: 01 June 2009

Introduction:

Two processes are very important in the environment in relation to organic pollutants: biodegradation and bioavailability.
Biodegradation of organic pollutants depends on several biogeochemical conditions like aerobic-anaerobic conditions, temperature, redox potential and present electron donors. These conditions can changes, for example because of flooding of a floodplain (aerobic-anaerobic) or the change in composition of the river water. These changes will also influence the biodegradation of organic pollutants in floodplains.
Biodegradation can only take place if a compound is available. A hydrophobic organic pollutants like nonylphenol adsorbs well to soil organic matter. Adsorbed organic pollutants might not be available for micro organisms to degrade it. Adsorption plays an important role in the bioavailability of hydrophobic organic pollutants.
Environmental conditions and the bioavailability of the pollutants influence biodegradation. Knowledge of the role of these parameters on biodegradation gives more insight in the self regulating capacity of river systems in relation to pollutants and the risk of these pollutants for the river system. To get more insight in the influence of pollutants on the functioning of river systems and the potential risk, it is necessary to investigate these environmental conditions and bioavailability in relation to biodegradation.

Aim:

The aim of this research is to improve the knowledge about biodegradation of organic pollutants in different river systems under various conditions, and to investigate the bioavailability in relation to biodegradation.

Research:

Biodegradation of MtBE, VC, 1,2-DCA, nonylphenol and atrazine is studied in the laboratory using batch experiments. Sediment material and river water from the three river basins (Ebro, Elbe and Danube) is used. The experiments are performed under various redoxconditions and temperature conditions.
Bioavailability experiments will be performed with sediment polluted with nonylphenol. This will be investigated with Solid Phase Extraction (SPE) with Tenax.

External funding

Yes