Abstract: The present invention relates to a method for carrying out biological purification of wastewater with the aid of activated sludge in a sewage treatment plant, the sewage treatment plant comprising: an activated sludge tank that can be ventilated (B tank), at least two sedimentation and recirculation tanks (SU tanks), and a tank for biological phosphor elimination (P tank), wherein the P tank is hydraulically connected with the B tank via one or more openings, wherein the B tank is divided into two tanks B1 and B2 (B1 tank and B2 tank) which are hydraulically connectable via the P tank, wherein each of the B1 tank and the B2 tank is continuously connected hydraulically to at least one SU tank, wherein the P tank comprises closure means to cut off the hydraulic connection between the P tank and the B1 tank and/or the B2 tank, and wherein each of the SU tanks comprises an overflow unit for draining the excess water in the sewage treatment plant, wherein in the event of an emergency, the hydraulic connection betw

Abstract: The invention relates to a method for carrying out biological purification of wastewater with the aid of activated sludge, in which the wastewater is introduced into a tank for phosphor elimination (P tank), then into an activated sludge tank (B tank) and then into at least one sedimentation and recirculation tank (SU tank), in which a number of operating cycles are carried out, including a sludge return phase, a recirculation phase, a pre-sedimentation phase and a draw-off phase (S phase, U phase, V phase, and A phase respectively), wherein the method further includes the elimination of settleable solids of the inflow, the storage of the produced primary and excess sludge and the reduction of the rising of the water level in the wastewater purification system by using an additional tank (S tank), wherein the S tank is hydraulically connected with the P tank, the P tank with the B tank, and the B tank with the at least one SU tank, wherein the wastewater is first introduced into the S tank, then into the P ta

Abstract: The invention relates to a method for carrying out biological purification of wastewater with the aid of activated sludge, in which the wastewater is introduced into an activated sludge tank (B tank) and then, in alternation, into one of a number of sedimentation and recirculation tanks (SU tanks) continuously connected hydraulically to the B tank and in which a number of operating cycles are carried out, including a sludge return phase, a mixing phase, a sedimentation phase and a draw-off phase (S phase, U phase, V phase, and A phase respectively), wherein the method further includes elimination of phosphor by using a tank for biological phosphor elimination (P tank), wherein the P tank is hydraulically connected with the B tank via one or more openings, wherein the wastewater is first introduced into the P tank and then subsequently transferred into the B tank, wherein in the S phase at least part of the thickened activated sludge is introduced from the SU tank into the P tank, and, wherein the volume of th

Abstract: The invention relates to a method for carrying out biological purification of wastewater with the aid of activated sludge, in which the wastewater is introduced into a tank for phosphor elimination (P tank), then into an activated sludge tank (B tank) and then into at least one sedimentation and recirculation tank (SU tank), in which a number of operating cycles are carried out, including a sludge return phase, a recirculation phase, a pre-sedimentation phase and a draw-off phase (S phase, U phase, V phase, and A phase respectively), wherein the method further includes the elimination of settleable solids of the inflow, the storage of the produced primary and excess sludge and the reduction of the rising of the water level in the wastewater purification system by using an additional tank (S tank), wherein the S tank is hydraulically connected with the P tank, the P tank with the B tank, and the B tank with the at least one SU tank, wherein the wastewater is first introduced into the S tank, then into the P ta

Abstract: The invention relates to a method for carrying out biological purification of wastewater with the aid of activated sludge, in which the wastewater is introduced into an activated sludge tank (B tank) and then, in alternation, into one of a number of sedimentation and recirculation tanks (SU tanks) continuously connected hydraulically to the B tank and in which a number of operating cycles are carried out, including a sludge return phase, a mixing phase, a sedimentation phase and a draw-off phase (S phase, U phase, V phase, and A phase respectively), wherein the method further includes elimination of phosphor by using a tank for biological phosphor elimination (P tank), wherein the P tank is hydraulically connected with the B tank via one or more openings, wherein the wastewater is first introduced into the P tank and then subsequently transferred into the B tank, wherein in the S phase at least part of the thickened activated sludge is introduced from the SU tank into the P tank, and, wherein the volume of th

Abstract: The present invention relates to the biological purification of wastewater by means of activated sludge, wherein the wastewater is first introduced into an activated-sludge tank (B tank) that can be ventilated and then is introduced into one of two sedimentation and recirculation tanks (SU tanks) in alternation, the sedimentation and recirculation tanks being continuously connected hydraulically to the B tank. In the sedimentation and recirculation tanks, the activated sludge and the treated water are separated by sedimentation (V phase), and thereafter activated sludge is fed back into the B tank (S phase). Then the contents of the SU tank are mixed (U phase). Finally, the treated water is drawn off (A phase).

Abstract: The invention relates to a method of biological treatment of wastewater by means of activated sludge, wherein the wastewater is introduced first into an aerated activated sludge tank (B tank) and then by turns into one of several sedimentation and recirculation tanks (SU tanks), which are permanently linked with said B tank and in which a separation of activated sludge and clear water occurs, and after separation activated sludge is returned to the B tank and clear waters is drawn off; several times a day, in the SU tanks an operating cycle proceeds comprising a stirring phase (R phase), a pre-settling phase (V phase) and a discharge phase (A phase). In the R phase the activated sludge is remixed with the water, in the V phase the activated sludge settles down and in the A phase clear water is drawn off (single basin technique).

Abstract: The invention relates to a method of biological treatment of wastewater by means of activated sludge, wherein the wastewater is introduced first into an acrated activated sludge tank (B tank) and then by turns into one of several sedimentation and recirculation tanks (SU tanks), which are permanently linked with said B tank and in which a separation of activated sludge and clear water occurs, and after separation activated sludge is returned to the B tank and clear waters is drawn off; several times a day, in the SU tanks an operating cycle proceeds comprising a stirring phase (R phase), a pre-settling phase (V phase) and a discharge phase (A phase). In the R phase the activated sludge is remixed with the water, in the V phase the activated sludge settles down and in the A phase clear water is drawn off (single basin technique).

Abstract: In a method of constructing a filter well by forming a cavity, such as a bore, in the ground down to the level of the liquid-bearing zone of the strata and filling said cavity with a filtering medium such as filter gravel, the cavities are disposed so as to intersect along their length such that each cavity is in communication with at least one other cavity. In a preferred method, the cavity is formed and provided with a liner, and the liner is withdrawn as the filter medium is installed. Preferred arrangements of the cavities include single lines, intersecting lines, closed figures and especially circles occupied entirely by cavities, and lines radial to a central cavity.