Co-Authors:
1) Dominic Armbruster, TZW: DVGW-Technologiezentrum Wasser, Karlsruhe
2) Anja Coors, ECT Oekotoxikologie GmbH, Flörsheim
3) Philipp Egeler, ECT Oekotoxikologie GmbH, Flörsheim
4) Oliver Happel, TZW: DVGW-Technologiezentrum Wasser, Karlsruhe
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Detergents and cleaning agents contain, among other things, organic ingredients that are difficult to biodegrade, and whose environmental behaviour is not yet fully understood. These substances also include phosphonic acids that strongly adsorb to sediment and suspended solids, such as 1-hydroxyethane-1,1-diphosphonic acid (HEDP) and 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTC). Although in very small quantities, these substances enter surface waters via a steady inflow through the effluents of sewage treatment plants and thus come into contact with the sediments or suspended particles in the water. However, organisms living in, in close contact with, or on sediments or sediment components have not yet been studied to assess the ecotoxicological potential of HEDP and PBTC.
A research project has been set up to study the effects of HEDP or PBTC adsorbed to sediments on macrozoobenthic organisms. First results from ecotoxicological tests investigating the dermal and/or oral route of exposure using Lumbriculus variegatus (according to OECD TG 225) as well as testing the effects of phosphonates on the reproduction and development of Chironomus riparius (according to OECD TG 233) in reconstituted sediment-water systems are presented, and preliminary ecotoxicological parameters are derived. The effect profiles obtained for the phosphonates studied on sediment-dwelling organisms are intended to enable a more realistic risk assessment of both substances.