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The soil distribution coefficient for highly concentrated TNT soil is determined. Different amounts of TNT soil are shaked with 250 ml of distilled water, and the concentration of TNT in water is monitored throughout the experiment. At the conclusion of the experiment, the remainder of TNT in the soil is determined. The soil distribution coefficient is calculated by dividing the concentration of TNT in the soil by the concentration of TNT in the water phase. The average soil distribution coefficient is found to be 4.86 L/kgThe mass transfer coefficient was determined under static conditions. This experiment involves a comprehensive study of distribution profiles for TNT in the soil and solvent phases. The experiment was conducted under a controlled temperature environment, for extensive periods of time. Samples were collected on a regular basis and were analyzed promptly. The average value of the mass transfer coefficient was determined to be 3.4×10-3 hr-1.

This paper investigates the presence of THM's in wastewater in and from various types of treatment plants and evaluates the efficiency of selected techniques for THM removal. Activated Sludge, Trickling Filters, and Rotating Biological Contactors, are the main processes in the two treatment plant systems that are considered for the purpose of this study. Samples of wastewater were collected from various points such as before chlorination, and after chlorination and in the effluent channel and analyzed for THM's using Gas Chromatography. The results have shown that chlorination process contributes significantly to THM formation. Chloroform removal efficiency were excellent by air stripping using either mechanical or diffused aeration (98%) and by using Activated Carbon as adsorber, which has achieved similar efficiency.

A reasonable field-scale operational scenario was developed as the hypothetical TNT bioremediation unit. II is described in Appendix A and termed the Riffle-Pool Reactor. The two-stage system consists of TNT leach-bed followed by a plant-pool bioreactor. Water is recirculated either continuously or intermittently over the riffle-bed TNT extractor and into the plant-pool reactor. A previously published manuscript entitled “Aquatic Plant Augmented TNT Degradation - Analysis of Reactor's Kinetics”; contains the kinetic parameter estimates needed to estimate equipment design and operating parameters. This include the Monod rate constant, dissolution constants and other kinetic parameters. This manuscript demonstrates how that basic information is incorporated into the design of the pilot, field-scale demonstration unit.

The purpose of this paper is to evaluate and analyze the kinetic data from both the laboratory and the field, and relate it to the Trinitrotoluene transport and biotransformation in the overall bioremediation process. Laboratory batch experiment results indicate that TNT dissolution mass transfer coefficients from TNT nuggets is 4.13 cm/h. The TNT desorption mass transfer coefficient from soil is 0.28 cm/h, and the TNT biotransformation rate constant in presence of Stonwort plant is 1.1 1/h.wt. In the field pool study the TNT biotransformation coefficient values fluctuate between 1.4-180 1/h.wt in presence of parrot feather plant. It has been found that the TNT dissolution and desorption rates are slower than biotransformation rate which leads to the main conclusion that TNT transport is controlling the overall bioremediation process.

Remediation of TNT contaminated soil by phytoremediation and bioremediation in aqueous medium is often limited by TNT desorption from the soil. Understanding the desorption of TNT from the contaminated soil is needed in order to employ effective soil remediation strategies. TNT (2,4,6-Trinitrotoluene) desorption was investigated using a flat sheet flow leaching bed reactor in the laboratory. Deionized water advective flow was pumped over the contaminated soil matrix in the form of a sheet flow. Concentrations of TNT in the collected water samples was determined by HPLC. The result is presented as the flux of TNT from the soil matrix to the water phase.The results showed a decrease in TNT concentration and flux with time. The rates of leaching were compared to the prediction of a simple mathematical model that was developed for this type of the reactors. The model accurately fits the rate of removal of TNT from soil under various experimental conditions. The effective diffusivity was calculated by fitting the developed mathematical model against the experimental data and was found to be 2.33×10-6 cm2/s. Consequently this resulted in a molecular diffusivity of 6.54×10-6 cm2/s. Diffusion is the limiting factor in leaching of TNT from the soil, as was apparent from the experimental results of decreasing flux with time and the TNT concentration gradient profiles within the soil bed, both during and after leaching experiment. This means that the diffusion of TNT is the limiting process in the overall TNT transport from soil into water.