Method for in-situ bioremediation of contaminated ground water

Abstract

A method for in-situ bioremediation of contaminated ground water and surface water using a porous wall filled with porous inorganic support spheres such as diatomaceous earth pellets treated by inoculation with selected non-pathogenic microbes, ie. bacteria, for destroying or converting the contaminant. The contaminants may be petroleum hydrocarbons, chlorinated hydrocarbons and other chemicals. The porous cells of the diatomaceous earth pellets provide a home not only for the microbes but also for oxygen, water and nutrients to help sustain the life of the augmented colonies of microbes introduced in the pellets. The method, in one embodiment, includes the digging of a trench perpendicular to the movement of the ground water and downstream from the contamination. The trench is dug below the level of the contaminated ground water and is filled with the porous inorganic support spheres creating the porous wall. Aeration pipes are installed at the bottom of the trench and gravel is used to fill the top of the trench. Also vent pipes may be installed in the trench for monitoring volatile contaminants emanating from the porous wall to monitor the progress of the bioremediation. Nutrients may be added in the form of aqueous solutions that are poured into the trench. The nutrients move by gravity downwardly feeding the microbes in the inorganic support spheres. Also, nutrients may be fed into the trench using the aeration tubes.