Situ treatment of contaminated groundwater

US6214202A · kind A · utility

Assignee

• The Regents of the University of California · US

Inventors

• Walt W. McNab, Jr. · Concord, US
• Roberto Ruiz · Tulsa, US
• Tristan M. Pico · Livermore, US

Key dates

• Filing date: Jun 19, 2000
• Grant date: Apr 10, 2001
• Expiry date: Jun 19, 2020

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C02F2103/06
• WIPO field: Environmental technology
• WIPO sector: Chemistry

Abstract

A system for treating dissolved halogenated organic compounds in groundwater that relies upon electrolytically-generated hydrogen to chemically reduce the halogenated compounds in the presence of a suitable catalyst. A direct current is placed across at least a pair, or an array, of electrodes which are housed within groundwater wells so that hydrogen is generated at the cathode and oxygen at the anode. A pump is located within the well housing in which the cathode(s) is(are) located and draws in groundwater where it is hydrogenated via electrolysis, passes through a well-bore treatment unit, and then transported to the anode well(s) for reinjection into the ground. The well-bore treatment involves a permeable cylinder located in the well bore and containing a packed bed of catalyst material that facilitates the reductive dehalogenation of the halogenated organic compounds by hydrogen into environmentally benign species such as ethane and methane. Also, electro-osmatic transport of contaminants toward the cathode also contributes to contaminant mass removal. The only above ground equipment required are the transfer pipes and a direct circuit power supply for the electrodes. The ele…