Abstract: The invention relates to a device for combating the varroa mite in a bee brood, comprising at least one middle wall that can be inserted in particular into a beehive and that is provided with brood cells for female bees, the device having an electrical heating device that has a resistance heating element embedded in the middle wall and a control device connected to the latter which is designed such that an automatically running heating process can be initiated with a temporally pre-determined heat-up phase that lasts until a temperature of 39° C. to 45° C., preferably 39° C. to 42° C., is reached at the bottom of the brood cells in the region of the resistance heating element and then with a subsequent phase of maintaining this temperature for a predetermined period of time.

Abstract: The invention relates to a device for combating the varroa mite in a bee brood, comprising at least one middle wall that can be inserted in particular into a beehive and that is provided with brood cells for female bees, the device having an electrical heating device that has a resistance heating element embedded in the middle wall and a control device connected to the latter which is designed such that an automatically running heating process can be initiated with a temporally pre-determined heat-up phase that lasts until a temperature of 39° C. to 45° C., preferably 39° C. to 42° C., is reached at the bottom of the brood cells in the region of the resistance heating element and then with a subsequent phase of maintaining this temperature for a predetermined period of time.

Abstract: The present invention relates to an artificial aquifer for decreasing the contents of metals, metalloids, nitrate, nitrite, pesticides and organic micro contaminants in natural ground water or artificial infiltrated groundwater from surface water. The system comprising a basin of filling material creating a reaction zone, a feeding line, one or more satellite wells, at least one main well and a pumping well, whereby the feeding line is applied in the upper outer periphery of the basin and wherein the main well is connected to a pumping well via a bottom outflow provided with a regulating valve to maintain a given level of water in the aquifer. The invention further relates to a method for purifying water.

Abstract: The invention relates to a method for gassing liquids, in particular for aerating water, wherein gas is fed to a mixing tube (2) via a gas inlet (7) and liquid via a liquid inlet (13) such as to form a mixture of gas and liquid, which is characterised in that the liquid is introduced centrally via a feed pipe (12) and the mouth opening (13) of the latter into the mixing pipe (2) and is spread in the region of the mouth opening (13) by means of an impact onto a spreader (18).

Abstract: The present invention relates to an artificial aquifer for decreasing the contents of metals, metalloids, nitrate, nitrite, pesticides and organic micro contaminants in natural ground water or artificial infiltrated groundwater from surface water. The system comprising a basin of filling material creating a reaction zone, a feeding line, one or more satellite wells, at least one main well and a pumping well, whereby the feeding line is applied in the upper outer periphery of the basin and wherein the main well is connected to a pumping well via a bottom outflow provided with a regulating valve to maintain a given level of water in the aquifer. The invention further relates to a method for purifying water.

Abstract: The invention relates to a method for gassing liquids, in particular for aerating water, wherein gas is fed to a mixing tube (2) via a gas inlet (7) and liquid via a liquid inlet (13) such as to form a mixture of gas and liquid, which is characterised in that the liquid is introduced centrally via a feed pipe (12) and the mouth opening (13) of the latter into the mixing pipe (2) and is spread in the region of the mouth opening (13) by means of an impact onto a spreader (18).