Abstract: The invention relates to a method for removing inorganic compounds from a section of soil. By regulating an electric voltage applied between two or more electrodes (1, 2) disposed in the section of soil (3) to values equal or below the electrokinetic point (61), inorganic compounds are electrochemically modified in situ in such a manner that they are electrokinetically mobilized and can be directly deposited on the electrodes (1, 2). According to the invention, the electrokinetic point (61) is adjusted and reached by applying a voltage to the electrodes (1, 2) and controlling it, once, after passing a first current/voltage zone (62) of a first gradient, a second current/voltage zone (63) of a second gradient that is smaller than the first gradient is reached.

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.