The concept of contaminated sediment treatment producing a useful product has emerged in recent years, motivated by the cost of sediment disposal and by recognition of sediment as a resource rather than a waste. Contaminated sediment presents unique challenges for treatment, however, due to the character and complexity of the matrix, and the logistics and economics involved in coupling the process with a dredging operation. The objectives of this document are to capture the technical status of several promising treatment technologies of this type, to describe the process efficiency in terms of mass balance, to understand pre-treatment and posttreatment processing requirements, and to estimate full scale implementation costs at a scale compatible with a dredging operation. Overall, the document overlays a consistent and transparent structure on the comparative evaluation with the objective of providing an equivalent basis for comparison between these and other candidate treatment processes, such that it has utility of remediation to project managers and others engaged in technology selection efforts. Relying on publicly available demonstration reports, the following technologies were evaluated in depth: JCI/Upcycle rotary kiln thermal treatment/light-weight aggregate (LWA); Cement-Lock ® technology/cement; Minergy ® glass furnace technology/glass aggregate; and BioGenesis SM sediment washing process/manufactured soil. DISCLAIMER: The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. All product names and trademarks cited are the property of their respective owners. The findings of this report are not to be construed as an official Department of the Army position unless so designated by other authorized documents.

The sediment-to-air fluxes of two polycyclic aromatic hydrocarbons (phenanthrene and pyrene) and a heterocyclic aromatic hydrocarbon (dibenzofuran) from a laboratorycontaminated sediment and those of three polycyclic aromatic hydrocarbons (naphthalene, phenanthrene, and pyrene) from three field sediments were investigated in experimental microcosms. The flux was dependent on the sediment moisture content, air-filled porosity, and the relative humidity of the air flowing over the sediment surface. The mathematical model predictions of flux from the laboratoryspiked sediment agreed with observed values. The fluxes of compounds with higher hydrophobicity were more air-side resistance controlled. Conspicuous differences were observed between the fluxes from the laboratoryspiked and two of the three field sediments. Two field sediments showed dramatic increases in mass-transfer resistances with increasing exposure time and had significant fractions of oil and grease. The proposed mathematical model was inadequate for predicting the flux from the latter field sediments. Sediment reworking enhanced the fluxes from the field sediments due to exposure of fresh solids to the air. Variations in flux from the lab-spiked sediment as a result of change in air relative humidity were due to differences in retardation of chemicals on a dry or wet surface sediment. High moisture in the air over the dry sediment increased the competition for sorption sites between water and contaminant and increased the contaminant flux.

No abstract

No abstract

No abstract

No abstract

No abstract

A pilot-scale field simulation was conducted to estimate the air emissions from contaminated dredged material stored in a confined disposal facility (CDF). Contaminated dredged material with a variety of organic chemicals, obtained from Indiana Harbor Canal, was used in the study. It was placed in an outdoor CDF simulator (i.e., a lysimeter of dimensions 4 ft x 4 ft x 2 ft). A portable, dynamic flux chamber was used to periodically measure emissions of various polynuclear aromatic hydrocarbons (PAHs). A weather station was set up to monitor and record the meteorological conditions during the experiment. The fluxes of several PAHs were monitored over time for 6 1/2 months. Initial 6-hr average fluxes varied from 2 to 20 ng/cm2/hr for six different PAHs. The flux values declined rapidly for all compounds soon after placement of the dredged material in the CDE Chemical concentrations derived from flux values were generally of low magnitude compared with ambient standards. Data obtained from the experiment were compared against those predicted using models for air emissions. Model simulations showed that initially the flux was largely from exposed pore water from saturated (wet) sediment, whereas the long-term flux was controlled by diffusion through the pore air of the unsaturated sediment. Model predictions generally overestimated the measured emissions. A rainfall event was simulated, and the dredged material was reworked to simulate that typical of a CDF operation. Increased flux was observed upon reworking the dredged material.