The system (1) for accelerating settling in a settling tank (2) by recirculation of slowly sedimenting fine particles uses the Venturi effect caused by coaxial deflectors (14, 14′, 15, 24) promoting the agglomeration of particles in laminar currents (F1-F4) bringing them into contact with the sludge (3) of the main current (C1) entering into the system (1), which is entrained by the centripetal counter currents (C3) generated within the settling tank (2) towards the bottom (7) of the settling tank.

Various aspects of the present disclosure are directed to sewage treatment plants and methods of operating sewage treatment plants. In one example embodiment, the sewage treatment plant includes a clarifier having an aeration region with a vent opening to blow in oxygenous gas for mixing water to be clarified and a settling region with an outlet. The sewage treatment plant further includes a wall system that delimits the at least one aeration region from the at least one settling region by the wall system. The wall system has a channel system which has at least one first opening leading to the aeration region in the region of the water level and a sludge removal device of the channel system in the region of a lower wall of the clarifier for transporting solids-rich water from the settling region into the aeration region.

Systems and methods for enabling dynamic volumetric transitioning and segmentation of treatment conditions are disclosed. Such treatment conditions may include, by way of example, systems and methods for dynamically transitioning treatment environments within a reactor for activated sludge treatment processes. Such environments may include anaerobic, anoxic, fermentation, suboxic, and aerobic environments.

An apparatus for degrading the organic fraction of sewage by means of active biomass, in particular active sludge particles, comprising: —at least one tank (1) adapted to contain the sewage and said active biomass; —at least one hollow structure (6, 106, 206), adapted to be at least partially immersed in the sewage, provided with at least one first opening (61) for letting in the sewage and with at least one second opening (62) for letting out the sewage, wherein the ratio between the area of the at least one first opening (61) and the area of the at least one second opening (62) is equal to at least 5:1; —air delivery means (7, 70) adapted to introduce air inside said at least one structure (6, 106, 206); wherein said at least one first opening (61) is proximal to said air delivery means (7, 70) and said at least one second opening (62) is distal from said air delivery means (7, 70), so that the air delivery means (7, 70) are adapted to generate a flow of sewage from said at least one first opening (61) to said at least one second opening (62).

An apparatus and method for selecting and retaining solids in an activated sludge process for the improving wastewater treatment using screens. The screens can be used to separate and retain solids based on size or compressibility. The screens are used to separate and select for slow growing organisms, faster settling organisms, or materials added to absorb, treat or remove constituents in the activated sludge process.

A process for the biological treatment of wastewater in which the performance of a conventional activated sludge system is improved by adding an aerobic granular biomass system in a hybrid parallel process configuration. Waste biomass and suspended material from the aerobic granular biomass system is introduced into the conventional activated sludge system for this purpose. In the hybrid process configuration the advantages of both systems are combined to produce new advantages, while drawbacks of the individual systems are reduced to great extent.

A wastewater treatment system includes a biological treatment plant and an auxiliary, non-biological treatment plant. The auxiliary plant receives overflow, which can be sanitary sewer overflow, combined sewer overflow or strictly storm overflow. Treatment is by coagulation and membrane separation, removing most bacteria. Following treatment the outflow can be discharged to streams.

The present invention relates to an efficient and cost effective wastewater treatment process that aims to reduce the concentration of soluble and colloidal and particular organic material upstream of a biological treatment process. In particular, the wastewater treatment process described includes a pre-treatment process that relies on biosorption and filtration to reduce the concentration of soluble and insoluble organic matter.

The present invention relates to a testing method for testing a state of an aeration tank in a wastewater treatment facility that uses activated sludge. The testing method comprises obtaining a difference between: a sedimentation amount when a given period of time has elapsed after an activated sludge mixed liquid collected from the aeration tank and water having a higher dissolved oxygen concentration than the activated sludge mixed liquid are poured into the same container and mixed together; and a sedimentation amount when a period of time equal to the given period of time has elapsed after the activated sludge mixed liquid collected from the aeration tank and water having a lower dissolved oxygen concentration than the activated sludge mixed liquid are poured into the same container and mixed together.

The present disclosure belongs to the technical field of sewage treatment, and discloses a method and system for enhanced culture of aerobic granular sludge. The system includes a reaction tank, a water inlet and outlet unit, an aeration unit, and a sludge discharge unit. The water inlet and outlet unit includes a water inlet pump, a water inlet electric valve, a liquid flowmeter, a sewage uniform distribution treatment device, buffers, a water drainage pipe, and a water drainage electric valve. The aeration unit includes a blower, microporous aerators, and a gas flowmeter. The sludge discharge unit includes sludge discharge pumps, a sludge discharge pipe, a sludge discharge electric valve, and a sludge concentration meter. In the present disclosure, a multi-point uniform water distribution method is used. When the flow rate of influent water is adjusted, sewage slowly and uniformly flows through a sludge layer from the bottom of the system, so that the concentration of organic matter in raw water is prevented from being rapidly reduced by rapid single-point water intake, the utilization rate of the organic matter in the sewage is increased to the maximum extent, and the efficiency of the system is improved.