Abstract: A method for treating waste water uses a membrane bioreactor that produces excess biological sludge and treated water components. This is achieved by extracting the biological sludge from the bioreactor then causing contact between the biological sludge and dewatered effluent to form two resulting products. The first product contains polyclectrolyte loaded sludge. Polyelectrolyte is continually added to the polyelectrolyte loaded sludge during dewatering to separately form dewatered sludge and the dewatered effluent. This is followed by extracting, as a second product, polyelectrolyte free effluent. The polyelectrolyte free effluent is recycled to the bioreactor.

Abstract: The invention relates to a membrane bioreactor waste water treatment method comprising a sludge dewatering step and a step involving the recycling of the liquid effluent originating from the sludge dewatering step, which is performed at the head of the bioreactor. The invention is characterised in that: the biological sludge extracted from the bioreactor (1) is brought into contact with the liquid effluent from the sludge-dewatering step such that the residual polyelectrolyte content in said effluent, which was used for sludge conditioning during the dewatering step (4), moves towards the biological sludge; the biological sludge is separated from the liquid effluent such as to produce a polyelectrolyte-free liquid effluent and a polyelectrolyte-loaded biological sludge; the polyelectrolyte-free liquid effluent is recycled at the head of the membrane bioreactor, and the polyelectrolyte-loaded biological sludge is conveyed towards the dewatering step.

Abstract: The invention concerns a method for purifying aqueous effluents, in particular polluted water, by catalytic oxidation using a three-phase reactor comprising two communicating chambers. The invention is characterised in that it consists in: maintaining the catalyst suspended and continuously circulating it between the two chambers of said reactor, by entrainment under the effect of carrier gas injected into one of said chamber, and in oxidizing the pollutants in contact with the in the other chamber, by injecting a reactive oxidizing gas in said other chamber.

Abstract: A single enclosed chamber includes a lower destabilizing area, a central filtering and coalescence area containing coalescence material, and an upper flotation and separation area. Emulsion is introduced into the lower destabilizing area and is destabilized therein. The emulsion is then passed upwardly into the central filtering and coalescence area. The dispersed phase of the emulsion is attracted to the coalescence material in the form of droplets, and as the emulsion continues to pass upwardly therethrough the droplets grow in size. During passage of the emulsion through the filtering and coalescence material, matter in suspension is filtered from the emulsion. Within the flotation and separation area is located a separation device including a lower convergent portion and an upper divergent portion.