Long-Term Effects of Dredging Operations Program. Development of a Modified Elutriate Test for Estimating the Quality of Effluent from Confined Dredged Material Disposal Areas

摘要

The quality of effluent discharged from confined dredged material disposal areas is an environmental concern when the sediments to be dredged are contaminated. This report describes the development of a modified elutriate test procedure for prediction of the quality of effluent from confined dredged material disposal areas. The test was developed to simulate the physicochemical conditions in confined disposal areas which would affect the release of contaminants. The test development included experiments comparing suspended solids and particle grain-size distributions for test vessel selection. Factorial experiments were then conducted to select appropriate test factors for simulating the oxidizing conditions and retention times present in confined disposal areas. Limited field evaluations of effluent water quality were compared with the laboratory data. The test was found to adequately predict the dissolved concentration of contaminants and the fractions of contaminants associated with the suspended solids in the effluent.