Particle mediated transport of contaminants. A risk assessment of the new Bedford Harbor Superfund Site

A three-dimensional particle transport model was developed to assess the particle mediated transport of pollutants within the New Bedford Harbor Superfund Site. A mixed setting column was used to obtain vertical setting rates for cohesive particles under varying salinities, shear rates, particles concentrations, and particle types. The particles used in this column were obtained from three different locations within the New Bedford Superfund Site. A vertical transport model, which included flocculation, was developed and calibrated with this laboratory data. Results show that particles will floc, thus increasing the settling velocity and settling within the harbor. The hydrodynamics of the harbor were determined by extending this model in the horizontal direction to incorporate three dimensions. This involved a finite segment approach for solution which requires the input of advection and dispersion coefficients and segment dimensions, in each of the three dimensions. The model was verified using typical literature values for these coefficients. Calibration of the model used current velocities, tidal currents, river inflows, and wind stress from field observations. All efforts were combined to predict the transport of particles resuspended by proposed dredging operations to remediate the underwater New Bedford Harbor Superfund Site.

Particle mediated transport of contaminants. A risk assessment of the new Bedford Harbor Superfund Site Academic Article