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BIOCHEM-ORCHESTRA: A tool for evaluating chemical speciation and ecotoxicological impacts of heavy metals on river flood plain systems

Vink, J.P.M., Meeussen, J.C.L.
Environmental pollution 2007 v.148 no.3 pp. 833-841
rivers, floodplains, sediment contamination, heavy metals, chemical speciation, ecotoxicology, environmental impact, risk assessment, decision support systems, bioaccumulation, bioavailability, soil water content, redox potential, chemical constituents of plants, invertebrates, mathematical models, uptake mechanisms, case studies, soil properties, Netherlands
The chemical speciation model BIOCHEM was extended with ecotoxicological transfer functions for uptake of metals (As, Cd, Cu, Ni, Pb, and Zn) by plants and soil invertebrates. It was coupled to the object-oriented framework ORCHESTRA to achieve a flexible and dynamic decision support system (DSS) to analyse natural or anthropogenic changes that occur in river systems. The DSS uses the chemical characteristics of soils and sediments as input, and calculates speciation and subsequent uptake by biota at various scenarios. Biotic transfer functions were field-validated, and actual hydrological conditions were derived from long-term monitoring data. The DSS was tested for several scenarios that occur in the Meuse catchment areas, such as flooding and sedimentation of riverine sediments on flood plains. Risks are expressed in terms of changes in chemical mobility, and uptake by flood plain key species (flora and fauna). A diagnostic risk-assessment tool for heavy metals, based on biotic and abiotic interactions, compares risks under different environmental scenarios.