Abstract: A process for the purification of ground water is disclosed which comprises injecting conditioned water into a recharge well, simultaneously withdrawing water from an adjacent recharge well in order to create a purification zone therebetween, and withdrawing purified water from a supply well in an aquifer.

Abstract: The invention relates to a process for decreasing the content of nitrate in ground water, artificial ground water, that is infiltrated surface water, or surface water flowing through an aquifer or through a basin or a filter containing naturally occurring filter material. Water containing denitrification organisms and/or substrate therefore is introduced intermittently through a number of injection wells or injection pipes arranged around one or more extraction wells or extraction pipes for purified water. During each introduction of water containing denitrification organisms and/or substrate therefore said water is fed to only some of said injection wells or pipes and simultaneously water is drawn from nearby, adjacent or intervening injection wells or pipes for the purpose of creating a denitrification zone at a distance sufficiently far from the extraction well or extraction pipe.

Abstract: A procedure for separating and recovering marsh gas from bog mud. The marsh gas is separated from the mud by conducting the mud into a separating space carrying a pressure lower than the pressure prevailing in the bog, and from which said space the gas separating from the mud is conducted to a place of storage or of use.