Biokinetics and bioavailability protocol for organic pollutants in soil to enhance bioremediation
- Environmental Protection Agency, Cincinnati, OH (United States)
- Univ. of Cincinnati, OH (United States). Dept. of Chemical Engineering
Bioremediation of polluted soil requires a fundamental understanding of biodegradation kinetics and the physicochemical factors that control the rate of biodegradation. A systematic multi-level protocol based on three types of bioreactor systems, was developed to determine the biokinetic parameters of the suspended and immobilized microbiota and the transport and diffusivity parameters of soil contaminants and oxygen in the soil matrix. In the soil slurry reactor, significant biodegradation occurs in the aqueous phase by the suspended and immobilized microbiota and to some extent by the soil immobilized biofilms. The soil slurry reactor data were used to derive the biokinetic parameters for the suspended and immobilized microorganisms. The wafer reactor data were used to obtain additional information on biokinetic and transport parameters with oxygen limitation. The porous tube reactor data provided quantitative determination of oxygen diffusivity. In the soil tube reactor, oxygen limitation occurs inside the tube due to the diffusional resistance and oxygen consumption due to biodegradation. Soil slurry, soil wafer and soil tube reactor systems are used in conjunction with respirometers to quantitatively assess biodegradation rates in dispersed and intact soil systems. Modeling procedures, applied to the 3 experimental schemes proved useful for determining the biokinetic, transport and diffusivity parameters for phenol and polycyclic aromatic hydrocarbons (PAHs) in soil. Heterogeneous solid phase diffusion models developed for predicting adsorption and desorption rates of PAHs in low and high organic carbon soils were shown to be superior to the homogeneous surface diffusion models. Adsorption and desorption experiments were conducted to obtain nonlinear isotherms described by the Freundlich isotherm equation. A dual mode isotherm was used to describe adsorption in high organic soils.
- OSTI ID:
- 191285
- Report Number(s):
- CONF-9511137--; ISBN 1-880611-03-1
- Country of Publication:
- United States
- Language:
- English
Similar Records
Development of a multi-level protocol for determination of biodegradation kinetics and bioavailability of organic compounds to enhance in-situ bioremediation
Bioavailability and biodegradation kinetics protocol for polycyclic aromatic hydrocarbons in soil to enhance bioremediation and to achieve environmentally acceptable endpoints during treatment