Grantee Research Project Results

Final Report: Modeling Air Emissions of Organic Compounds from Contaminated Sediments and Dredged Materials title change in last year to "Long-term Release of Pollutants from Contaminated Sediment Dredged Material"

EPA Grant Number: R825513C017
Subproject: this is subproject number 017 , established and managed by the Center Director under grant R825513
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: HSRC (2001) - South and Southwest HSRC
Center Director: Reible, Danny D.
Title: Modeling Air Emissions of Organic Compounds from Contaminated Sediments and Dredged Materials title change in last year to "Long-term Release of Pollutants from Contaminated Sediment Dredged Material"
Investigators: Valsaraj, Kalliat T. , Price, C. B. , Reible, Danny D. , Meyers, T. E. , Thibodeaux, Louis J. , Brannon, J. M. , Gulliver, John S.
Institution: Louisiana State University - Baton Rouge
EPA Project Officer: Hahn, Intaek
Project Period: January 1, 1994 through January 1, 1998
Project Amount: Refer to main center abstract for funding details.
RFA: Hazardous Substance Research Centers - HSRC (1989) RFA Text |  Recipients Lists
Research Category: Hazardous Substance Research Centers , Land and Waste Management

Objective:

The main focus of this research is to obtain experimental data on the emission of volatile organic chemicals and metals from contaminated sediments in order to test and validate existing theoretical models. The three major objectives are:

1) To develop and test theoretical models that account for the various parameters that effect air emissions from contaminated dredged material;
2) To measure the toxic chemical flux to air from contaminated mud flats sediment and dredged material using an emission flux chamber;
3) To study the effects of cyclic wet-dry sediment conditions, cyclic flat and cracked surface conditions, cyclic temperature and cyclic humidity on toxic air emissions.

Summary/Accomplishments (Outputs/Outcomes):

The core experiments in this work were conducted in an experimental microcosm, or flux chamber. The chamber was constructed of 1 in anodized aluminum blocks, 30 cm long by 9 cm wide to which a sediment chamber measuring 10 cm long, 3 cm wide and 2 cm deep is attached. An air gap of about 0.2 cm is used to pass air of varying relative humidities. The contaminants that may vaporize into this moving air phase arecollected on an adsorbent trap in the effluent. Inoculated or field-contaminated sediment may be placed in the flux chamber and the potential for volatilization of contaminants measured. The observed vaporization rates were compared to models of the process.

The experiments were able to reproduce a wide range of conditions that may apply in the field, from air-side to sediment-side mass transfer resistance controlled, to moisture content controlled volatilization.

To illustrate, the air emissions of two polycyclic aromatic hydrocarbons (pyrene and phenanthrene) and one heterocyclic compound (dibenzofuran) from an aged contaminated sediment (Rouge River, Mi) were studied. The sediment was initially saturated with water. The magnitude of the flux varied as dibenofuran>phenanthrene>pyrene consistent with the magnitude of the vapor pressures and Henry's Law constants of these compounds. At a low air flow rate (10 ml/min) the flux was low and air-phase resistance controlled. At a larger air flow rate (100 ml/min), the flux was initially high and then declined, consistent with sediment-side mass transfer resistances. The flux declined very rapidly if dry air were passed over the sediment, consistent with the drying of the surface sediment layers and the increased adsorption and retardation of hydrophobic organics on dry mineral surfaces. Subsequent exposure of the dry surface sediments to moist air caused an immediate increase in contaminant flux.

A variety of mathematical models were developed corresponding to different initial and boundary conditions and experimental scenarios. The models were based upon local equilibrium between the air, sediment and water phases. The models were capable of accurately describing the experimental results using measured chemical and sediment properties and empirical measurements of transition between strongly sorbing "dry" sediment states and weakly sorbing " moist" sediment states. Further studies of sorption phenomena confirmed the qualitative behavior observed in the sediments.
The work has led to follow-up studies supported by the US Army Corps of Engineers to make practical estimates of evaporation rates from exposed sediment and dredged material. This has included work on a field demonstration scale flux chamber.

Summary of Results:

Demonstrated capabilities of a flux chamber approach to measuring evaporation from sediments and dredged material

Demonstrated that, under some conditions, evaporation can either be sediment or air-side controlled.

Showed that very dry sediments, as might occur during midday on the surface of exposed sediments or dredged material, may sorb vapors strongly, dramatically reducing contaminant flux.

Showed that the addition of moisture, for example in the form of a morning dew, can dramatically increase the vaporization flux for short times.

Showed that the presence of oil and grease can slow evaporation of contaminants from sediments due to the partitioning of contaminants into that phase.

Journal Articles on this Report : 11 Displayed | Download in RIS Format

Publications Views

Other subproject views:	All 23 publications	13 publications in selected types	All 11 journal articles
Other center views:	All 392 publications	154 publications in selected types	All 106 journal articles

Publications

Type	Citation	Sub Project	Document Sources
Journal Article	deSeze G, Valsaraj KT, Reible DD, Thibodeaux LJ. Sediment-air equilibrium partitioning of semi-volatile hydrophobic organic compounds Part 2. Saturated vapor pressures, and the effects of sediment moisture content and temperature on the partitioning of polyaromatic hydrocarbons. Science of the Total Environment 2000;253(1-3):27-44.	R825513C017 (Final)	not available
Journal Article	de Seze G, Valsaraj KT, Reible DD, Thibodeaux LJ. Sediment-air equilibrium partitioning of semi-volatile hydrophobic organic compounds. Part 1. Method development and water vapor sorption isotherm. Science of the Total Environment 2000;253(1-3):15-26	R825513C017 (Final)	not available
Journal Article	Ravikrishna R, Valsaraj KT, Yost S, Price CB, Brannon JM. Air emissions from exposed sediments and contaminated dredged materials. 2. Diffusion from laboratory-spiked and aged field sediments. Journal of Hazardous Materials 1998;60(1):89-104.	R825513C017 (Final)	not available
Journal Article	Ravikrishna R, Choy BC, Valsaraj KT, Reible DD, Thibodeaux LJ, Price CB, Brannon JM. The efficiency of capping to control air emissions from exposed contaminated sediments and dredged material. Environmental Engineering Science 2000;17(2):97-106.	R825513C017 (Final)	not available
Journal Article	Ravikrishna R, Valsaraj KT, Thibodeaux LJ, Reible DD, Price CB, Brannon JM, Myers TE, Yost S. Air emission flux from contaminated dredged materials stored in a pilot-scale confined disposal facility. Journal of the Air & Waste Management Association 2001;51(3):361-373.	R825513C017 (Final)	not available
Journal Article	Valsaraj KT, Thibodeaux LJ, Reible DD. A quasi-steady state pollutant flux methodology for determining sediment quality criteria. Environmental Toxicology and Chemistry 1997;16(3):391-396.	R825513C010 (Final) R825513C017 (Final)	not available
Journal Article	Valsaraj KT, Choy B, Ravikrishna R, Thibodeaux LJ, Reible DD, Price CB, Brannon JM, Myers TE. Air emissions from exposed sediments and contaminated dredged material. 1. Experimental data in laboratory microcosms and mathematical modelling. Journal of Hazardous Materials 1997;54(1-2):65-87.	R825513C017 (Final)	not available
Journal Article	Valsaraj KT, Ravikrishna R, Orlius J, Thibodeaux LJ, Reible DD, Smith JS, Gulliver JS. Sediment-to-Air mass transfer of semi-volatile contaminants due to sediment resuspension in water. Advances in Environmental Research 1997;1(2):145-156.	R825513C017 (Final)	not available
Journal Article	Valsaraj KT, Ravikrishna R, Choy B, Reible DD, Thibodeaux LJ, Price CB, Yost S, Brannon JM, Myers TE. Air emissions from exposed contaminated sediments and dredged material. Environmental Science & Technology 1999;33(1):142-149.	R825513C017 (Final)	Full-text: ACS Full Text Exit Other: ACS PDF Exit
Journal Article	Valsaraj KT, Thibodeaux LJ. On the linear driving force model for sorption kinetics of organic compounds on suspended sediment particles. Environmental Toxicology and Chemistry 1999;18(8):1679-1685.	R825513C017 (Final)	not available
Journal Article	Valsaraj KT, Thibodeaux LJ, Reible DD. Modeling air emissions from contaminated sediment dredged materials. ASTM Special Technical Publication 1995;1293:227-238.	R825513C017 (Final)	not available

Supplemental Keywords:

volatile organic compounds, contaminant flux, and volatilization., RFA, Scientific Discipline, Air, Waste, Ecosystem Protection/Environmental Exposure & Risk, Chemical Engineering, air toxics, Contaminated Sediments, Environmental Chemistry, Monitoring/Modeling, Analytical Chemistry, Hazardous Waste, Ecology and Ecosystems, Environmental Engineering, Hazardous, vaporization, environmental technology, sediment treatment, hazardous waste management, hazardous waste treatment, risk assessment, volatile air toxics, contaminated sediment, air qialty model, air pollution, chemical contaminants, contaminated soil, airborne metals, Volatile Organic Compounds (VOCs)

Progress and Final Reports:

Original Abstract

1994

1995

1996

Main Center Abstract and Reports:

R825513    HSRC (2001) - South and Southwest HSRC

Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R825513C001 Sediment Resuspension and Contaminant Transport in an Estuary.
R825513C002 Contaminant Transport Across Cohesive Sediment Interfaces.
R825513C003 Mobilization and Fate of Inorganic Contaminant due to Resuspension of Cohesive Sediment.
R825513C004 Source Identification, Transformation, and Transport Processes of N-, O- and S- Containing Organic Chemicals in Wetland and Upland Sediments.
R825513C005 Mobility and Transport of Radium from Sediment and Waste Pits.
R825513C006 Anaerobic Biodegradation of 2,4,6-Trinitrotoluene and Other Nitroaromatic Compounds by Clostridium Acetobutylicum.
R825513C007 Investigation on the Fate and Biotransformation of Hexachlorobutadiene and Chlorobenzenes in a Sediment-Water Estuarine System
R825513C008 An Investigation of Chemical Transport from Contaminated Sediments through Porous Containment Structures
R825513C009 Evaluation of Placement and Effectiveness of Sediment Caps
R825513C010 Coupled Biological and Physicochemical Bed-Sediment Processes
R825513C011 Pollutant Fluxes to Aquatic Systems via Coupled Biological and Physicochemical Bed-Sediment Processes
R825513C012 Controls on Metals Partitioning in Contaminated Sediments
R825513C013 Phytoremediation of TNT Contaminated Soil and Groundwaters
R825513C014 Sediment-Based Remediation of Hazardous Substances at a Contaminated Military Base
R825513C015 Effect of Natural Dynamic Changes on Pollutant-Sediment Interaction
R825513C016 Desorption of Nonpolar Organic Pollutants from Historically Contaminated Sediments and Dredged Materials
R825513C017 Modeling Air Emissions of Organic Compounds from Contaminated Sediments and Dredged Materials title change in last year to "Long-term Release of Pollutants from Contaminated Sediment Dredged Material"
R825513C018 Development of an Integrated Optic Interferometer for In-Situ Monitoring of Volatile Hydrocarbons
R825513C019 Bioremediation of Contaminated Sediments and Dredged Material
R825513C020 Bioremediation of Sediments Contaminated with Polyaromatic Hydrocarbons
R825513C021 Role of Particles in Mobilizing Hazardous Chemicals in Urban Runoff
R825513C022 Particle Transport and Deposit Morphology at the Sediment/Water Interface
R825513C023 Uptake of Metal Ions from Aqueous Solutions by Sediments
R825513C024 Bioavailability of Desorption Resistant Hydrocarbons in Sediment-Water Systems.
R825513C025 Interactive Roles of Microbial and Spartina Populations in Mercury Methylation Processes in Bioremediation of Contaminated Sediments in Salt-Marsh Systems
R825513C026 Evaluation of Physical-Chemical Methods for Rapid Assessment of the Bioavailability of Moderately Polar Compounds in Sediments
R825513C027 Freshwater Bioturbators in Riverine Sediments as Enhancers of Contaminant Release
R825513C028 Characterization of Laguna Madre Contaminated Sediments.
R825513C029 The Role of Competitive Adsorption of Suspended Sediments in Determining Partitioning and Colloidal Stability.
R825513C030 Remediation of TNT-Contaminated Soil by Cyanobacterial Mat.
R825513C031 Experimental and Detailed Mathematical Modeling of Diffusion of Contaminants in Fluids
R825513C033 Application of Biotechnology in Bioremediation of Contaminated Sediments
R825513C034 Characterization of PAH's Degrading Bacteria in Coastal Sediments
R825513C035 Dynamic Aspects of Metal Speciation in the Miami River Sediments in Relation to Particle Size Distribution of Chemical Heterogeneity