PROTOCOL FOR DETERMINING BIOAVAILABILITY AND BIODEGRADATION KINETICS OF TOXIC ORGANIC SOIL POLLUTANTS TO ENHANCE IN-SITU BIOREMEDIATION

A systematic protocol involving three types of soil reactors has been developed to quantify soil bioremediation rates. Measuring biodegradat ion kinetic rates in soil systems is useful in evaluating the efficacy of bioremediation and in developing accurate cost models to compare b ioremediation technology with other physical/chemical treatment method s. The approach presented in this paper involves the use of three type s of bioreactor systems: soil slurry, soil wafer, and soil tube reacto rs. Phenol was used as the test compound. The protocol was developed s o that the experimental schemes which were used grew in complexity tow ard the actual in situ case, but remained simple enough to allow them to be adequately modeled. The data gained for each of the schemes agre ed with expectations. Both the rate and extent of biodegradation of ph enol were found to decrease with increasing complexity of the soil sys tems in the experimental schemes. Modeling procedures applied to the t hree experimental schemes proved useful for determining the biokinetic parameters for the degradation of phenol. Model predictions were foun d to agree very well with experimental data. A bioavailability index i s defined which can be obtained using cumulative oxygen uptake data. T he application of this protocol to other chemicals should be feasible with only minor alterations in the methodology presented in this paper .