Abstract: Methods for enhancing bioremediation of ground water contaminated with nonaqueous halogenated solvents are disclosed. An illustrative method includes adding an electron donor for microbe-mediated anaerobic reductive dehalogenation of the halogenated solvents, which electron donor enhances mass transfer of the halogenated solvents from residual source areas into the aqueous phase of the ground water. Illustrative electron donors include C2-C4 carboxylic acids and hydroxy acids, salts thereof, esters of C2-C4 carboxylic acids and hydroxy acids, and mixtures thereof, of which lactic acid, salts of lactic acid—such as sodium lactate, lactate esters, and mixtures thereof are particularly illustrative. The microbes are either indigenous to the ground water, or such microbes can be added to the ground water in addition to the electron donor.

Abstract: A method for treating contamination in subsurface formations includes fracturing the soil to produce a network of fractures in the formation and simultaneously injecting a slurry containing an optional proppant and a solid-phase or nonaqueous-phase treatment agent into the network of fractures. The proppant is for keeping the fractures open, and the treatment agent accelerates conversion of the contaminants into immobile or less toxic forms. Chitin is an illustrative solid-phase treatment agent, which functions as an electron donor for anaerobic reductive dechlorination mediated by dechlorinating bacteria.

Abstract: Methods for enhancing bioremediation of ground water contaminated with nonaqueous halogenated solvents are disclosed. An illustrative method includes adding a composition to the ground water wherein the composition is an electron donor for microbe-mediated reductive dehalogenation of the halogenated solvents and enhances mass transfer of the halogenated solvents from residual source areas into the aqueous phase of the ground water. Illustrative compositions effective in these methods include surfactants such as C2–C4 carboxylic acids and hydroxy acids, salts thereof, esters of C2–C4 carboxylic acids and hydroxy acids, and mixtures thereof. Other illustrative compositions according to the present invention include oleyl lactylic acid and, optionally, oleic acid and lactic acid or salts thereof. Especially illustrative compositions for use in these methods include lactic acid, salts of lactic acid, such as sodium lactate, lactate esters, and mixtures thereof.

Abstract: A method for in situ bioremediation of contaminants in the environment is described. The method includes adding an electron donor to ground water in an amount sufficient for a microbe in the ground water to use the electron donor for reducing the contaminant into an innocuous derivative thereof. Illustratively, the electron donor contains about 0.1 to 75% by weight of chitin, such as crustacean shell, partially deproteinized crustacean shell, ground mushrooms, or a fungal fermentation broth. The chitinous electron donor can be added to the ground water as a particulate solid or aqueous slurry.

Abstract: Methods for enhancing bioremediation of ground water contaminated with nonaqueous halogenated solvents are disclosed. An illustrative method includes adding a composition to the ground water wherein the composition is an electron donor for microbe-mediated reductive dehalogenation of the halogenated solvents and enhances mass transfer of the halogenated solvents from residual source areas into the aqueous phase of the ground water. Illustrative compositions effective in these methods include surfactants such as C2-C4 carboxylic acids and hydroxy acids, salts thereof, esters of C2-C4 carboxylic acids and hydroxy acids, and mixtures thereof. Other illustrative compositions according to the present invention include oleyl lactylic acid and, optionally, oleic acid and lactic acid or salts thereof. Especially illustrative compositions for use in these methods include lactic acid, salts of lactic acid, such as sodium lactate, lactate esters, and mixtures thereof.