Ecotoxicological risk assessment linked to infilling quarries with treated dredged seaport sediments

Abstract

The dredged sediments of polluted seaports now raise complex management problems since it is no longer possible to discharge them into the sea. This results in the need to manage them on land, raising other types of technical, economic and environmental problems. Regarding the technical and economic dimensions, traditional waste treatment methods have proved to be poorly adapted, due to very high costs and low absorbable volumes. In this context, filling quarries in coastal areas with treated sediments could represent an interesting alternative for these materials. Nevertheless, for the environmental dimension, it is necessary to demonstrate that this possibility is harmless to inland ecosystems. Consequently, a specific ecotoxicological risk assessment methodology has been formulated and tested on three sediments taken from seaboards of France, in view to providing an operational and usable tool for the prior validation of any operation to fill quarries with treated seaport sediments. This method incorporates the formulation of a global conceptual model of the scenario studied and the definition of protocols for each of its steps: the characterisation of exposures (based on a simulation of sediment deposit), the characterisation of effects (via the study of sediments ecotoxicity), and the final ecotoxicological risk assessment performed as a calculation of a risk quotient. It includes the implementation in parallel of two types of complementary approach: the "substances" approach derived from the European methodology for assessing new substances placed on the market, and the "matrix" approach which is similar to methods developed in France to assess ecological risks in other domains (waste management, polluted site management, …). The application of this dual approach to the three sediments tested led to conclude with reliability that the project to deposit sediments "1" and "2" presented a low risk for the peripheral aquatic ecosystems while sediment "3" presented a high risk.

Use of digestate from a decentralized on-farm biogas plant as fertilizer in soils: An ecotoxicological study for future indicators in risk and life cycle assessment

“…Nevertheless, it is possible to use the results obtained from the matrix-based approach combined with the substance-based approach in order to improve the evaluation of the digestate impact (Perrodin et al, 2012 It is worth mentioning that digestate from only animal manure or from waste has a different composition (Tambone et al, 2015;Fuchs et al, 2008;Alburquerque et al, 2012 (Anonymous, 2001). …”

Functional properties of soils formed from biochemical ripening of dredged sediments—subsidence mitigation in delta areas

“…Several studies regarding the use of dredged sediments characterised only part of the parameters described above, leading to a risk of non-optimal performance of ripened sediments in its beneficial use (Giulio Bernstein et al 2002;Torres et al 2009;Zentar et al 2009;Malasavage et al 2012;Perrodin et al 2012;Dang et al 2013). The objective of this study is to characterise the functional properties of five types of dredged sediments before and after dewatering and biochemical ripening in order to assess their suitability to mitigate land subsidence in agricultural-delta areas.…”

Heavy metal concentrations in the sediment profiles of the anthropogenically transformed plociduga reservoir

“…Evaluations of pollutant concentrations in bottom deposits should also account for their effect on the functioning of water ecosystems. Various assessment methods have been proposed [21,22]. In line with a popularly applied method, the pollutants' threshold and probable effects on aquatic environments are evaluated with the involvement of TEL (Threshold Effects Level) and PEL (Probable Effects Level) indicators [23].…”