Laboratory experiments with heterogeneous reactions in mixed porous media
- Armstrong Lab., Tyndall AFB, FL (United States). Environmental Research Lab.
- Univ. of Florida, Gainesville, FL (United States). Dept. of Civil Engineering
- EPA, Athens, GA (United States). Environmental Research Lab.
The limited success and high cost of traditional active ground-water-contaminant plume management efforts (i.e., pump-and-treat systems) has stimulated a search for less expensive passive plume interception and in-situ treatment technologies. The funnel/gate system, which uses heterogeneous (surface-mediated) reactions on porous media to degrade dissolved contaminants, is one passive technology under consideration. Research on a heterogeneous reaction is presented in this paper, which can be extended to facilitate the design of engineered porous media systems (i.e., funnel/gates). Results are examined from batch and flow-through column experiments involving nitrobenzene degradation in a surface-mediated reaction with granular metallic iron. A nonequilibrium transport model that incorporates solute mass-transfer resistance near reactive iron surfaces is shown to simulate breakthrough curves (BTCs) from column systems, using model parameters estimated from batch systems. The investigation shows pseudo first-order degradation-rate coefficients increasing with higher solid:liquid ratios and with greater iron concentrations. In addition, nitrobenzene degradation is found to be faster in batch systems than in comparable column systems, indicating the presence of mass-transfer limitations in the flow-through systems. Finally, the present study provides insights on conditions pertinent to the design of engineered in-situ treatment zones, such as how mass-transfer, hydraulic, and reaction kinetic conditions affect ground-water-contaminant fate and transport through reactive porous media.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 287534
- Journal Information:
- Journal of Environmental Engineering, Vol. 122, Issue 8; Other Information: PBD: Aug 1996
- Country of Publication:
- United States
- Language:
- English
Similar Records
Funnel-and-gate design method. Final report, July 1995--April 1997
In situ remediation of contaminated ground water: The funnel-and-gate system