摘要:
The invention refers to a device for creating in an aquifer an oxidation and precipitation zone or a reduction zone between a number of injection wells arranged around one or more extraction wells for purified water, said injection wells each comprising an outer water-pervious tube (1). For preventing such a device from being clogged the invention suggests that at the upper end of the outer tube (1) is mounted a circulation vessel (2) from which extends downwardly within the outer tube (1) a first conduit (3), ending at the height of the upper portion of the aquifer and provided with a pressure inlet means (5) so as to form an upper ejector, and a second conduit (4), which at its lower end supports an externally sealingly mounted balloon body (7), which is inflatable into sealing engagement with the inner surface of the outer tube (1), said second conduit closely above said body carrying a pressure inlet means (6), so as to form a second ejector.