Air Emission Flux from Contaminated Dredged Materials Stored in a Pilot-Scale Confined Disposal Facility

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.

Effect of transition from slip to free molecular flow on gas transport in porous media

“…1,2 Gas transport models are applied in catalysis and adsorption problems, 3 remediation for removal of volatile organic compounds ͑VOCs͒ and nonaqueous phase liquids ͑NAPLs͒, 4,5 prediction of gas transport into surrounding from the disposal of hazardous waste sites, 6 transport throughout membranes, 7,8 and gas transport through microelectromechanical systems ͑MEMSs͒, 9 among others. 1,2 Gas transport models are applied in catalysis and adsorption problems, 3 remediation for removal of volatile organic compounds ͑VOCs͒ and nonaqueous phase liquids ͑NAPLs͒, 4,5 prediction of gas transport into surrounding from the disposal of hazardous waste sites, 6 transport throughout membranes, 7,8 and gas transport through microelectromechanical systems ͑MEMSs͒, 9 among others.…”

Use of Activated Carbon to Control Volatilization of Organic Contaminants from the Indiana Harbor Confined Disposal Facility

“…Thus, volatilization of PAHs in exposed sediment tests is expected. Fluxes were not measured in the 1987 study, but PAH flux from exposed Indiana Harbor sediment has been measured in other studies (Ravikrishna et al 1998(Ravikrishna et al , 2001) using sediment that was much less contaminated than that collected for this study. Valsaraj et al (1997) measured phenanthrene and pyrene fluxes from exposed Rouge River sediment that was much less contaminated than the sediment collected for this study.…”

Vapor-Phase Transport of Explosives from Buried Sources in Soils

“…Low signatures were observed for explosives under all environmental conditions. Diffusion models, developed previously to predict polyaromatic hydrocarbon release from exposed dredged sediment, 13,14 were applied to simulate the explosives flux data satisfactorily with one fit parameter-soil to air partition constant.…”