Patent ID: 8808544

Claim:
A wastewater treatment system comprising: a contact tank having an first inlet configured to receive wastewater to be treated, a second inlet, and an outlet, the contact tank configured to mix the wastewater to be treated with activated sludge to form a first mixed liquor; a dissolved air flotation unit having an inlet in fluid communication with the outlet of the contact tank and a gas inlet configured to introduce gas into the dissolved air flotation unit to facilitate the flotation of suspended matter from the first mixed liquor and the removal of the suspended matter from the dissolved air flotation unit, the dissolved air flotation unit configured to separate the suspended matter from a portion of the first mixed liquor to form a solids-lean dissolved air flotation unit effluent and waste solids, to output the waste solids through a solids outlet of the dissolved air flotation unit, and to output the solids-lean dissolved air flotation unit effluent through an effluent outlet of the dissolved air flotation unit; a biological treatment unit having a first inlet in fluid communication with the outlet of the contact tank, a second inlet, a third inlet in fluid communication with the effluent outlet of the dissolved air flotation unit, and an outlet, the biological treatment unit configured to biologically break down organic components of the first mixed liquor and of an effluent from the dissolved air flotation unit to form a second mixed liquor; a clarifier having an inlet in fluid communication with the outlet of the biological treatment unit, an effluent outlet, and a return activated sludge outlet, the clarifier configured to output a clarified effluent through the effluent outlet and a return activated sludge though the return activated sludge outlet; a dissolved air flotation unit effluent conduit extending between the effluent outlet of the dissolved air flotation unit and the third inlet of the biological treatment unit; a mixed liquor conduit extending between the outlet of the contact tank and the first inlet of the biological treatment unit; a first return activated sludge conduit extending between the return activated sludge outlet of the clarifier and the second inlet of the contact tank; and a second return activated sludge conduit extending between the return activated sludge outlet of the clarifier and the second inlet of the biological treatment unit.