Abstract: A pump for aerating and circulating water in a facultative lagoon includes a cylindrical pump housing with a housing wall, a concentrically aligned pump cylinder having an outer surface, inner surface, pump cavity, an upper cover with a center opening, and lower openings through the pump cylinder's lower portion. A bubble tube aligns concentrically inside the pump cylinder with the upper cover's center opening, the bubble tube being shorter than the pump cylinder. The pump includes a diffuser coil extending spirally adjacent the pump cylinder's outer surface, a first air inlet connected to the diffuser coil, a second air inlet with an air conduit terminating in the pump cavity, a concrete cavity below the pump cylinder, and vertical slots along the cylindrical pump housing's upper perimeter.

Abstract: 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.

Abstract: 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.