Abstract

The processes by which lead is released from corroded cables and dredged material are complex, but have to be taken into consideration when assessing the potential risk of dredging and removal activities. In this research, the effect of various physical factors on the release and dispersion of lead from corroded sub-marine cables and bottom sediments was studied. Among these factors are the hydrological and physical properties of the water body (e.g. flow rates, resuspension and settling), situation and position of cables (e.g. on the surface or at different depths), physico-chemical characteristics (e.g. adsorption, desorption and diffusion rate), transport of toxicant (e.g. advective and dispersive mixing) and dredging activities (e.g. mechanical and hydraulic). In order to show the effect of different factors, a conceptual model called the Model for Fate of Corroded Lead ( MFCL ) was developed. The objective was to predict lead concentration in the water column in dissolved and particulate forms. The MFCL model is a powerful tool for predicting the changes in risk resulting from the implementation of various remedial actions, including the "no action" alternative.