Method and device for the in-situ elimination of hazardous substances from the groundwater and perched water

US6321837A · kind A · utility

Inventors

• Falk Doering · Stuttgart, DE
• Niels Doering · Stuttgart, DE

Key dates

• Filing date: May 22, 2000
• Grant date: Nov 27, 2001
• Expiry date: May 22, 2020

Classification

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

Abstract

An in-well method removes hazardous organic substances including oily phases topping the groundwater (LNAPL) and dense liquid non-aqueous phases (DNAPL) occurring on top of the aquitard, irrespective of the viscosity of the pollutants, from groundwater and/or the perched water. In one embodiment, volatile organic pollutants are stripped from the contaminated water by an injected gas stream inside the well. In a second embodiment, the well acts as an electrode. By imparting an electrolytic current between the electrode well and a counter electrode, the organic pollutants are electrochemically degraded while at the same time within the well the degraded pollutants are stripped from the water. By the same arrangement metal ions and colloids can be caused to precipitate onto the well casing. Apparatus for carrying out these methods is also disclosed. In distinction from hitherto known solutions, the method and apparatus are applicable to low performing wells having a low natural throughput, shallow aquifers and in fizzurized rock.