Abstract: A method to remediate a contaminated groundwater zone by shielding electron acceptors contained in groundwater flow that interfere with beneficial anaerobic reactions in the contaminated groundwater zone. Examples of such interfering electron acceptors include dissolved oxygen, nitrate, and sulfate. The method prevents electron acceptor-rich groundwater located upgradient from a contaminated zone from flowing into the contaminated groundwater zone. By diverting acceptor-rich groundwater around a contaminated zone, beneficial anaerobic reactions are enhanced that either biodegrade the contaminants, or change the subsurface geochemical environment so that contaminants are immobilized. Methods to establish a groundwater diversion system include constructing physical barriers to block clean groundwater flowing into a contamination zone, or creating a stagnant zone hydraulically by pumping clean groundwater upgradient of the contaminated zone or injecting clean water downgradient of the contaminated zone.

Abstract: A method is provided for reducing the concentration of radioactive materials or other trace contaminants in fluids withdrawn from subterranean reservoirs and also fluids in reservoirs. The method involves deposition of sorbent solids including, but not limited to, fine ion exchange resins, within the reservoir matrix surrounding a production well to act as an in-situ filter for dissolved radionuclides or other contaminants present in reservoir pore waters. For this purpose, the sorbent solid is either a) precipitated within the reservoir matrix by the reaction of ions or molecules of two or more carrier solutions or b) directly introduced into the reservoir as a solid component of a solid-liquid slurry using high-pressure injection techniques.

Abstract: The present invention provides a method for stimulating in-situ microbial biodegradation of halogenated organic compounds in an aqueous subsurface environment comprising the delivery of hydrogen, in the absence of nutritional factors, into the subsurface environment.

Abstract: A method is provided for reducing the radioactive material content of fluids withdrawn from subterranean reservoirs. The method involves deposition of sorbent solids within the reservoir matrix surrounding a production well to act as an in-situ filter for dissolved radionuclides present in reservoir pore waters. For this purpose, the sorbent solid is either a) precipitated within the reservoir matrix by the reaction of two or more carrier solutions or b) directly introduced into the reservoir as a solid component of a solid-liquid slurry using high-pressure injection techniques. Thereafter, fluids produced by the well contain significantly lower concentrations of radionuclides (e.g., principally radium and uranium ions), as radionuclides are removed from the inflowing reservoir fluids by means of ion exchange, adsorption, chelation, chemisorption, or coprecipitation with the in-situ filter medium.