Patent FR-2996546-A1 (FR)
Title: Regulating the performances of a station of biological and/or physicochemical treatment of waste water, comprises adjusting e.g. cycles of ventilation of a sewage treatment plant according to information obtained from external parameters
Inventor: GRAU GUILLEM RENE JOSEPH
IPC: B01D46/46
Filed: 2012-10-05
Abstract: The method comprises: regulating external parameters at a treatment station (E) provided by transmitters and/or receivers, which communicate with a control unit (C) of the station; and adjusting, by the control unit, cycles of ventilation of a sewage treatment plant and/or proportioning of treatment reagents and/or the operation of consuming energy devices of the station, according to information obtained from the external parameters. The external parameters comprise analyses and short-term forecasts of a hydraulic load and pollution to be treated by the station. The method comprises: regulating external parameters at a treatment station (E) provided by transmitters and/or receivers, which communicate with a control unit (C) of the station; and adjusting, by the control unit, cycles of ventilation of a sewage treatment plant and/or proportioning of treatment reagents and/or the operation of consuming energy devices of the station, according to information obtained from the external parameters. The external parameters comprise: analyses and short-term forecasts of a hydraulic load and pollution to be treated by the station; a state of an environment receiver continuously analyzed by a sensor array situated near a discharge of the treated water; conditions of the energy market to adapt the flexibility of consumption of the plant to the availability and the cost of kWh; and weather forecasting including air temperature, precipitations, speed and direction of the wind, and periods of sunshine. The regulation step comprises: directly and continuously measuring physicochemical parameters such as pH, temperature, conductivity, dissolved oxygen, turbidity, nitrates and total organic carbon; detecting in line of priority substances; and measuring pollution integrated in time by passive samplers. The regulation step takes into account nitrogenized and/or cogitated parameters, and establishes a circadian cycle of oxygen level and/or oxygen saturation and/or pH by sensors placed in a receiving medium. The control of the equipment of the sewage treatment plant is adapted when one of the following events occurs: overrun of the maximum permissible amplitude of a circadian cycle of oxygen level and/or oxygen saturation and/or pH; and crossing a threshold (minimal or maximum) of the oxygen level and/or the oxygen saturation and/or the pH, or overrun of a slope of the amplitudes of circadian cycle on consecutive days, where the progressive drift of the amplitude of the circadian cycle is a sign of an increased sensitivity of the medium. The regulation step further comprises: measuring the oxygen level, the pH, contents of nutrients, flow rate, temperature, and/or luminosity, provided by transmitters installed in the receiving medium downstream from the station of treatment; and measuring, in a receiving natural environment, the physicochemical parameters representative of its health status. The method further comprises: maintaining the discharge below a permanent minimal discharge instruction for the periods of increased sensitivity of the receiving medium and ensuring the minimal instruction in normal periods for the permanent minimal discharge instruction; and modulating the level of discharge around the minimal instruction, according to the normal periods, sensitive and insensitive for an expressed minimal instruction in annual or periodic medium. The regulation step takes into account market conditions and adapts energy operating range of the energy consuming devices based on their flexibility, so that a minimum number of energy consuming devices is used during periods with constraints. The economic output of the station is improved by: treating a buffer water tank; increasing the volume of water treated during hours when energy is cheaper; reducing the volume during hours when the energy is more expensive, where the total volume processed for given period of time is equal to that of the desired period of time; taking into account the weather forecast to increase the volume of treated water for periods of normal or low rainfall; and maintaining the volume of treated water equal to the optimal range during periods of heavy rain. The regulation step takes into account the weather parameters to ensure a regulation of reagents for deodorization and treatment of smoke according to the speed and the direction of the wind, while remaining in emission standards, to further protect the surrounding areas, using the phenomena of dispersion and fallen treated gases. An independent claim is included for a station of biological and/or physicochemical treatment of waste water.