Abstract: The invention concerns a method for regulating a wastewater or sludge treating plant. Ponds and cells provided with aerating means are used for eliminating carbonaceous, nitrogenous, and phosphate pollutants. The invention is characterized in that an automaton uses periods during which the plant is underloaded to impose on it abnormal operating conditions. The automaton analyses the response of the plant to the abnormal operating conditions to simulate and optimize the plant operating parameters for heavy-load periods, by automatically adjusting the parameters of the automaton logic.

Abstract: The invention concerns a method for regulating an effluent treating plant, in particular for waste water or sludge derived from that type of treatment, using in particular ponds and cells provided with aerating means, for eliminating carbonaceous, nitrogenous, phosphate pollutants and a regulating automaton operating on the analysis of the evolution of predetermined operating parameters of the plant. The invention is characterised in that: the automaton uses periods during which the station is under-loaded-to impose on it abnormal operating conditions, and the automaton analyses the response of the plant to said abnormal operating conditions to update and optimise the plant operating parameters for heavy-load periods, by automatically adjusting the parametering of the automaton logic. In the implementing example, the method is used for controlling the aeration of a purification plant.

Abstract: A method for estimating incoming pollution loads during operation of a municipal wastewater treatment plant involves the step of continuously measuring the conductivity and turbidity of the raw water to be treated. The concentration of a pollutant in the raw water to be treated is estimated as a function of the measured conductivity and turbidity. The flow rate of the raw water to be treated is also continuously measured. The load of the pollutant in the raw water to be treated is estimated as a function of the estimated concentration of the pollutant and the measured flow rate. The estimated pollutant load allows adjustment of downstream treatment for eliminating the estimated total load of the pollutant.

Abstract: The oxidoreduction potential is measured on each of a number of tanks. A data processing system analyzes the oxidoreduction potential evolution and establishes a diagnosis of the aeration/biology couple to ensure the degradation reactions of the carbonaceous and nitrogenous pollution. It is then determined whether to start, to continue, or to stop aeration in the tanks, depending on the required degree of purification. In the first tanks, priority is given to the treatment of carbonaceous pollution with specific parameter representation of the oxidoreduction potential threshold values. In the last tank, fine-tuning the treatment of the carbonaceous and nitrogenous pollution is accomplished by managing the aeration.

Abstract: A method of purifying waste water biologically, in which at least one biological reaction is performed in at least one biological reactor containing microorganisms in activated sludge, and the waste water is separated from the activated sludge in a clarification basin, with at least a fraction of the activated sludge from said biological reactor being recirculated, wherein, prior to admitting the waste water to be treated into said biological reactor, at least a fraction of the polluting particles in suspension therein are separated out therefrom, the separated polluting particles are sent to a sludge activation reactor that is separate and disposed in parallel, the separating polluting particles are used as the main substrate for the development of microorganisms in strict aerobiosis, and the superactivated sludge obtained in this way is injected into the biological reactor(s).

Abstract: A method of regulating aeration in biological treatment of wastewater by implementing a step of eliminating carbon in aerobiosis, a step of nitrification in aerobiosis, and a step of denitrification in an anoxia, in which method the oxidation-reduction potential is continuously measured in a treatment system, a curve is established of variation in oxidation-reduction potential as a function of time, and the derivative thereof is calculated, wherein, when the derivative tends towards zero, the derivative and the value of the oxidation-reduction potential are correlated to determine whether aeration should be started, continued, or stopped.

Abstract: A method of biologically purifying liquids that are heavily contaminated with organic or inorganic impurities, by using bacteria in the presence of a solid support on which bacteria can be fixed, comprises the following steps: the liquid to be purified is continuously injected without prior filtering into a reactor in which a solid support having grain size lying in the range 1 mm to 5 mm and density lying in the range 1.01 g/cm.sup.3 to 1.3 g/cm.sup.3 has been put into turbulent motion by blowing in gas in the presence of bacteria and while satisfying the conditions required by the metabolism of the bacteria; and the treated liquid is taken continuously from the reactor after a transit time that is long enough to ensure purification of the impurities contained in the liquid to be purified.

Abstract: A method of treating water with activated sludge, comprising a process for depolluting said water including a stage in which carbon pollution is oxidized, a nitrification stage which may optionally be associated with a denitrification state and/or a dephosphating stage, and a sludge ageing process. The method further includes a sludge concentration stage, said stage being performed upstream from the sludge ageing stage, said concentration being performed by phase separation using compressed air, e.g. in a flotation tank (3), and the concentrated sludge being recycled via the sludge ageing stage.