US Patent 7811449 Flow equalized rotating biological contactor

A wastewater treatment system is provided that utilizes an equalization tank that stores hydraulic surge flows from the collection system and uses a waterwheel to transfer a maximum flow equal to plant design flow to the downstream treatment systems. The waterwheel aerates the raw wastewater in the equalization tank and prevents it from going septic and causing unacceptable odors. Because the waterwheel cannot transfer more than plant design flow to the downstream treatment elements, these elements will never experience a hydraulic overload.