In search for the ecological and toxicological relevance of sediment re-mobilisation and transport during flood events

Abstract

In response to increasing concerns about the potential toxicological impacts of (extreme) flood events, scientists from several disciplines have joined to form the interdisciplinary research project named FLOODSEARCH. FLOODSEARCH is one of the recent Pathfinder Projects supported by the German Excellence Initiative via the Exploratory Research Space at RWTH Aachen (ERS). FLOODSEARCH aims to combine methodologies of hydraulic engineering and ecotoxicology in a new interdisciplinary approach to assess the risks associated with the remobilisation of particulate bound contaminants often observed after severe flood events. Impacts of extreme flood events and aspects of re-mobilisation of sedimentbound toxic compounds will be characterised and evaluated in controlled experiments fusing flood simulation technologies with biological effects assessment. The overall goal is to establish a novel and more realistic approach towards flood event testing that can be applied to a number of different questions and species. Specifically, model aquatic species such as rainbow trout (Onchorhynchus mykiss) will be exposed to particle-bound contaminants in flood-like conditions in a specifically designed annular flume that

Effect-directed analysis (EDA) in aquatic ecotoxicology: state of the art and future challenges

“…Especially sediments represent important long-term sinks for many toxicants (Apitz 2008;Brils et al 2007;Bunge et al 2007;Chen and White 2004;Forstner and Salomons 2008;Karlsson et al 2008;Kase et al 2008;Keiter et al 2006), which can become bioavailable through flood events or benthic or bottomdwelling organisms (Babek et al 2008;Gerbersdorf et al 2007;Hilscherova et al 2007;Schulze et al 2007;Wolz et al 2009). Consequently, there has been an increasing awareness of the relevance of particle-bound contaminants in the environment, an aspect that has not been considered satisfactorily in classic EDA approaches.…”

Modeling desorption kinetics of a persistent organic pollutant from field aged sediment using a bi-disperse particle size distribution

“…These results stretch the importance to combine traditionally separated disciplines utilized in water research as proposed in Wolz et al (2009). The combination of hydrodynamic and ecotoxicological technologies will provide a fundament to unravel the true environmental impact of contaminated sediments and the effect of short-"pulse" exposure, which is characteristic for flood events.…”

“…Most of the research is focussed on the transport of particulates themselves (e.g., (Rovira and Ibanez 2007). Only recently, the role of sediments as secondary source of pollution is recognized (Wolz et al 2009) Mass transfer of organic compounds like Persistent Organic Pollutants (POPs) from sediment particles to the surrounding aqueous phase, and vice versa, is affecting fate and transport of these chemicals in the aqueous environment. Mass transfer and mass transfer limitation of organic contaminants in polluted sediments and soil has been a key research issue for the last decades, and hundreds of articles have been published in this area of research (Reichenberg and Mayer 2006).…”

The Yangtze-Hydro Project: a Chinese–German environmental program

“…They will work on the process understanding of biological transformation, bioaccumulation and ecotoxicological evaluation of pollutants (Wolz et al 2009). & Technische Universität München (TUM) has developed a monitoring tool for evaluating the bioaccumulation of non-polar organic compounds.…”