Biological purification apparatus for effluent, has return flow of effluent to reactor regulated according to measured redox potential

摘要

The return flow (A-C) of effluent to the reactor vessel (R1-R4, S) is regulated using a control device comprising a measuring device for the redox potentional in the vessel and a controller for periodically obtaining redox potential values from the measuring device and using these values as a basis for regulating the pump adjustment system. An apparatus for the removal of phosphates and nitrogen compounds (especially nitrates and ammonia) from effluent (especially active sludge) via a biological method comprises at least one reactor and at least one control device for the return flow of effluent to the reactor vessel. The reactor vessel has an inlet, an outlet and a return flow inlet connected to a return pipe for supplying effluent to the vessel from a point in the apparatus located downstream from the reactor. A pump connected to the return pipe is used to generate the return flow and is provided with an adjustment system for altering the return flow rate. The control device comprises a device for measuring the redox potentional in the reactor vessel and a controller for periodically obtaining redox potential values from the measuring device and using these values as a basis for regulating the pump adjustment system. The controller includes a device for determining the difference between two redox potentials over a given time period and a control device for supplying adjustment parameters for the pump adjustment system on the basis of the redox potential difference. Independent claims are also included for the following: (1) Software for use in combination with the apparatus; (2) Carrier medium for the software; (3) Control device for the return flow rate in the apparatus; and (4) Control method for the return flow rate in the apparatus.