The invention in one form is directed to an airlift pump that is optimized to transfer large volumes of water using very low pumping head. Specifically, the airlift pump is comprised of a pump inlet and outlet which are both located below pond's surface. The pumping force driving the water flow is supplied by the weight of the volume of water displaced by pressurized air into a vertical pipe, and this energy is dissipated by the friction of the rising bubbles pipe entrance head, plus the frictional effects of the inner pipe wall and the energy contained in the water's exit velocity.

Disclosed is a method for managing the operation of an apparatus for injecting oxygen into a purification basin. The oxygen notably being used by the biomass present in the purification basin to consume the pollution present in an effluent feedstock contained in the basin. The method comprises varying a rotational speed of the shaft by using a frequency variator, wherein an applied variation in speed is between plus 15% and minus 15% of the nominal speed of the shaft.

Disclosed is a method for managing the operation of an apparatus for injecting oxygen into a purification basin. The oxygen notably being used by the biomass present in the purification basin to consume the pollution present in an effluent feedstock contained in the basin. The method comprises varying a rotational speed of the shaft by using a frequency variator, wherein an applied variation in speed is between plus 15% and minus 15% of the nominal speed of the shaft.

The present invention relates to an apparatus for collecting and treating wastewater (1) based on biodegradation-recombination-biodegradation process, comprising: a shell (1.1), the space inside the shell is divided into a first chamber (1.2) and a second chamber (1.3) by a divider wall (1.4), wherein: the first chamber (1.2) contains biological medium suitable for heterotrophic microorganisms growth; the second chamber (1.3) contains biological medium suitable for autotrophic microorganisms and heterotrophic microorganisms growth. The present invention also relates to a system for collecting and treating wastewater combining rainwater drainage used for building, comprising: at least one wastewater treatment apparatus (1) above; a indoor pipe system for collecting and transfering wastewater, rainwater comprising a main vertical pipe (2), substantially horizontal branch pipes; and a outdoor pipe system for transfering wastewater combining rainwater drainage comprising a horizontal pipe (3) for connecting the indoor pipe system for collecting and transfering wastewater, rainwater to at least one wastewater treatment apparatus (1) above.

A self-deploying float assembly to support mechanical equipment such as aerators and mixers for use in water, wastewater and process water stream treatment basins and a method of installing same.

A self-deploying float assembly to support mechanical equipment such as aerators and mixers for use in water, wastewater and process water stream treatment basins and a method of installing same.

A device and method for injection of oxygen-rich gas into a body of liquid with oxygen recycling are disclosed. The device comprises a rotary hollow shaft vertically passing through a float partially immersed in the liquid, an impeller attached to the lower end of the rotary hollow shaft, a columnar structure, surrounding the rotary hollow shaft, mounted on the bottom side of the float and vertically extending into the liquid, a gas diffusion chamber formed by the columnar structure, the float and the liquid surface under the float, and a gas injection conduit passing through the float for delivering the oxygen gas into the gas diffusion chamber, wherein a vacuum is generated in the body of the liquid around the impeller when the impeller is driven to rotate, so that the oxygen-rich gas in the gas diffusion chamber is sucked into the body of the liquid and mixed therein.

A device and method for injection of oxygen-rich gas into a body of liquid with oxygen recycling are disclosed. The device comprises a rotary hollow shaft vertically passing through a float partially immersed in the liquid, an impeller attached to the lower end of the rotary hollow shaft, a columnar structure, surrounding the rotary hollow shaft, mounted on the bottom side of the float and vertically extending into the liquid, a gas diffusion chamber formed by the columnar structure, the float and the liquid surface under the float, and a gas injection conduit passing through the float for delivering the oxygen gas into the gas diffusion chamber, wherein a vacuum is generated in the body of the liquid around the impeller when the impeller is driven to rotate, so that the oxygen-rich gas in the gas diffusion chamber is sucked into the body of the liquid and mixed therein.

In one embodiment, a method of reducing at least one of nitrogen, carbon and phosphorous in a lagoon that includes at least three cells.

In one embodiment, a method of reducing at least one of nitrogen, carbon and phosphorous in a lagoon that includes at least three cells.