Wastewater treatment system and method

A method for removing contaminants from raw wastewater, using an apparatus including first and second tank units, wherein each of said tank units includes a tank, skimming means for removing floating contaminants from at least a portion of the surface of the wastewater, dredging means for removing settled contaminants from at least a portion of the bottom of the tank, a plurality of partitions and openings in the tank for directing the flow and changing the velocity of the wastewater as it flows through the tank, and air curtain means located near the bottom of the tank for forming a curtain of air bubbles which move opposite to the flow of wastewater through at least a portion of the tank, first and second mixing chambers, said first mixing chamber receiving raw wastewater, at least one treatment chemical and pressurized air, and providing for mixing of the raw wastewater with the at least one treatment chemical and air by agitation thereof by the pressurized air to form a first aerated mixture, said first aerated mixture being supplied to said first tank unit, said second mixing chamber receiving a first treated water output of said first tank unit, at least one treatment chemical and pressurized air, and providing for mixing of the treated water, air and at least one treatment chemical by agitation thereof by the pressurized air to form a second aerated mixture, said second aerated mixture being supplied to said second tank unit, pumping means for supplying raw wastewater under pressure to said first mixing chamber, treatment chemical supply means for supplying said at least one treatment chemical to at least each of said first and second mixing chambers, and a source of pressurized air for supplying pressurized air to at least each of said air curtain means of said first and second tank units and to said first and second mixing chambers for agitating and aerating the contents thereof, whereby raw wastewater containing contaminants is pumped to said first mixing chamber, mixed with air and the at least one treatment chemical to form the first aerated mixture which flows through said first tank unit where a substantial portion of the contaminants are removed via settling and flotation facilitated by the at least one treatment chemical and the air curtain means to form the first treated water output which flows to said second mixing chamber where it is mixed with air and the at least one treatment chemical to form the second aerated mixture which flows through said second tank unit where a substantial portion of the contaminants remaining in said first treated water output are removed by flotation and settling facilitated by said at least one treatment chemical and the air curtain means to form a second treated water output which can be recycled or disposed of in a municipal sewer.