Abstract: A treatment plant and method for controlling a treatment plant suitable for treatment of wastewater. The treatment plant includes a circulation channel housing liquid, a submersible flow generating machine arranged in the circulation channel and generating a liquid flow along the circulation channel, and a control unit that is operatively connected to the flow generating machine. The flow generating machine is driven in operation by the control unit. The method includes the steps of: driving the flow generating machine at a nominal speed, decreasing the rotational speed of the flow generating machine from the set nominal speed, detecting the rotational speed at which the torque of the flow generating machine is equal to a predetermined threshold, and determining the flow velocity of the liquid at the flow generating machine based on a predetermined relationship between the rotational speed of the flow generating machine and the flow velocity of the liquid.

Abstract: A treatment plant and method for controlling a treatment plant suitable for treatment of wastewater. The treatment plant includes a circulation channel housing liquid, a submersible flow generating machine arranged in the circulation channel and generating a liquid flow along the circulation channel, and a control unit that is operatively connected to the flow generating machine. The flow generating machine is driven in operation by the control unit. The method includes the steps of: driving the flow generating machine at a nominal speed, decreasing the rotational speed of the flow generating machine from the set nominal speed, detecting the rotational speed at which the torque of the flow generating machine is equal to a predetermined threshold, and determining the flow velocity of the liquid at the flow generating machine based on a predetermined relationship between the rotational speed of the flow generating machine and the flow velocity of the liquid.

Abstract: A method for controlling a treatment apparatus arrangement in a treatment plant, the treatment plant including a basin housing a liquid and solid matter. The operating condition in the basin is anoxic and/or anaerobic, and the treatment apparatus arrangement includes at least one mixer machine located in the basin and a variable speed drive operatively connected to the mixer machine. The variable speed drive operates the mixer machine alternately in a Normal Operation Mode, in which an operational speed of the mixer machine is at least the greater of a suspension speed and a process speed, and a Reduced Operation Mode, in which the operational speed of the mixer machine is below the suspension speed. Also described is a treatment apparatus arrangement and a treatment plant, respectively.

Abstract: A treatment plant and a method for controlling such a treatment plant suitable for treatment of waste water. The treatment plant includes a circulation channel adapted to house a liquid, an aeration arrangement adapted to supply a gas flow Q including oxygen to the liquid, at least one flow generating machine arranged in the circulation channel and adapted to generate a liquid flow along the circulation channel, and a control unit.

Abstract: A plant and method for controlling such a plant suitable for treatment of waste water. The plant includes a basin, a flow generating machine adapted to generate a liquid flow in the basin, equipment in the basin that effects the momentum of the liquid flow, and a control unit. The method includes the steps of: storing a predetermined relationship between the operational speed N of the flow generating machine and an operational parameter P from which the torque M of the flow generating machine may be derived, determining the operational speed N, determining a set value of the operational parameter P of the flow generating machine, determining a real value of the operational parameter P of the flow generating machine, and adjusting the operational speed N if the real value of the operational parameter P is different than the set value of the operational parameter P.

Abstract: A method for controlling a treatment apparatus arrangement in a treatment plant, the treatment plant including a basin housing a liquid and solid matter. The operating condition in the basin is anoxic and/or anaerobic, and the treatment apparatus arrangement includes at least one mixer machine located in the basin and a variable speed drive operatively connected to the mixer machine. The variable speed drive operates the mixer machine alternately in a Normal Operation Mode, in which an operational speed of the mixer machine is at least the greater of a suspension speed and a process speed, and a Reduced Operation Mode, in which the operational speed of the mixer machine is below the suspension speed. Also described is a treatment apparatus arrangement and a treatment plant, respectively.

Abstract: A plant and method for controlling such a plant suitable for treatment of waste water. The plant includes a basin, a flow generating machine adapted to generate a liquid flow in the basin, equipment in the basin that effects the momentum of the liquid flow, and a control unit. The method includes the steps of: storing a predetermined relationship between the operational speed N of the flow generating machine and an operational parameter P from which the torque M of the flow generating machine may be derived, determining the operational speed N, determining a set value of the operational parameter P of the flow generating machine, determining a real value of the operational parameter P of the flow generating machine, and adjusting the operational speed N if the real value of the operational parameter P is different than the set value of the operational parameter P.

Abstract: A treatment plant and a method for controlling such a treatment plant suitable for treatment of waste water. The treatment plant includes a circulation channel adapted to house a liquid, an aeration arrangement adapted to supply a gas flow Q including oxygen to the liquid, at least one flow generating machine arranged in the circulation channel and adapted to generate a liquid flow along the circulation channel, and a control unit.

Abstract: A treatment plant for waste water treatment, including a circulation tank, which is arranged to accommodate waste water up to a predetermined filling height, and at least one aerator section arranged at the bottom of the circulation tank, which aerator section is arranged to supply gas bubbles to the waste water, the circulation tank having a predetermined direction of flow along which the waste water is arranged to flow. The treatment plant includes a partition wall arranged transversely to the circulation tank downstream the aerator section, which partition wall has an upper end that in the vertical direction is situated at a height that is lower than 25% of the above-mentioned filling height.