Identifier

etd-07142005-104310

Degree

Master of Science in Civil Engineering (MSCE)

Department

Civil and Environmental Engineering

Document Type

Thesis

Abstract

Knowledge of the fate and transport of chlorinated benzenes is necessary at certain sites for effective remediation of contaminated soils using plants. Current research is examining the capability of wetland plants to catalyze degradation or attenuate migration, but again requires knowledge of the uptake of contaminants from an aqueous environment. A two stage model was used to estimate the rate of uptake of contaminants from sediments. The first stage of the model predicts pollutant leaching rates from sediments to the overlying water, which would then be fed into the plant or bioreactor model systems. In this study the flux from contaminated sediments into the overlying water is simulated by using a diffusive transport model. This flux is used to calculate the aqueous phase concentration, coming out of the bed, then fed into a plant reactor. Concentrations coming out of the bed and plant reactor are both measured. A mathematical model was suggested and developed for the plant or bio-reactor which incorporates the transport model thus being able to accurately predict the buffering potentials of willows on chlorinated benzenes. This model was used to estimate the buffering effect of willows on sediments contaminated with lower chlorinated benzenes in Baton Rouge Bayou, near the Petro Processors, Inc. Superfund site. The model predictions were calibrated and verified against laboratory work. This model is then scaled up to determine the uptake. Uptake rates for willows based on retention times were estimated for different flow conditions of bayou (slow, fast and cyclic). The uptake rate for 1.34 acres of the study area was found to be 3.8 kg/year, highest for fast flow conditions while for slow and cyclic flows it was found to be 3.62 and 3.01 kg/year. The average total contaminant uptake for 100 acres for 20 years is estimated to be around 1.56 tons/year. The models used here adequately fit the lab data based on paired t test and correlation coefficient. This model can be used at similar sites in other places and for different compounds.

Date

2005

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

W. David Constant

DOI

10.31390/gradschool_theses.2939

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