The objective is to investigate the influence of defined chemical structural elements on the anaerobic biodegradation behaviour of xenobiotics and to establish general guidelines for predicting anaerobic biodegradability on the basis of the structure of chemical compounds.
For tests of the anaerobic biodegradability of xenobiotics an ECETOC task force has designed a tentative screening method. Using this flexible methodology the project will determine the influence of structural elements of anionic, nonionic and cationic surfactants on their biodegradation under anaerobic environmental conditions.
The following chemical structures will be examined : sulfonate substituents; propylene glycololigomers; ethylene glycol polymers; alkylphenol structures; quaternary ammonium structures (surfactant related structures); alkylene glycol structures; structures containing ether linkages; molecules containing carbon nitrogen carbon bonds; aldehydes; ketones; thiols; and cyclic, aliphatic and heterocyclic compounds. From this screening it is intended to establish structure and biodegradability relationships which can be generalized for a wide spectrum of chemical structural elements.
Due to the particular relevance of anaerobic degradability for insoluble or poorly soluble compounds an optimization of the methodology of introducing those compounds into the test system will be performed.
In addition, it will be tested whether the ECETOC screening test could be applicable also for the nonmethanogenic biodegradation (ie under denitrifying and desulfurizing conditions).
Finally, the project intends to investigate the predictive value of the screening test results by applying carbon-14 labelled test compounds in a model test simulating the sludge digester of a sewage treatment plant.
Funding SchemeCSC - Cost-sharing contracts
L63 3JW Bebington Wirral - Merseyside