Abstract: A bubble generator including a container having a side wall and a top wall defining a cavity. An insert is located within the cavity defining a gas path with a trap portion. The gas path being in communication with an exit in the container. The cavity including an opening receiving a gas accumulating within the cavity, the gas path allowing the accumulating gas to escape through the exit once the accumulating gas reaches a predetermined level proximate the trap portion.

Abstract: A bubble generator including a container having a side wall and a top wall defining a cavity. An insert is located within the cavity defining a gas path with a trap portion. The gas path being in communication with an exit in the container. The cavity including an opening receiving a gas accumulating within the cavity, the gas path allowing the accumulating gas to escape through the exit once the accumulating gas reaches a predetermined level proximate the trap portion.

Abstract: A wastewater treatment system includes a blower providing air to an aerator and a low pressure pulsed air mixer. The invention generally relates to a wastewater treatment system and more particularly to a wastewater treatment system to eliminate biological and nutrient contaminants from wastewater.

Abstract: A BOD-containing wastewater also containing unacceptable levels of phosphorous, nitrogen or mixtures thereof is introduced into and mixed with recycled activated sludge in a first aeration zone including at least one partially submerged rotatable biological contactor under conditions whereby the overall dissolved oxygen content of the mixed liquor in the first aeration zone is about 0.7 to about 1.5 mg/l so as to cause microorganisms capable of storing phosphates under oxidizing conditions to release soluble phosphates into the mixed liquor, the mixed liquor from the first aeration zone is transferred to a subsequent aeration zone and aerated under conditions whereby the overall dissolved oxygen content of the mixed liquor is greater than about 1.