Patent ID: 9708197
Date: 2017-07-18
CPC Classifications: B01D,B03D,C02F

Claim:
1. A water or wastewater treatment system or apparatus characterised by: two or more dissolved air flotation chambers each including a submerged contact chamber for directing water entering the contact chamber to the surface of the dissolved air flotation chamber; a first discharge pipework for float material associated with said two or more dissolved air flotation chambers; a feed pump means to move water or wastewater into each contact chamber at substantially equal flow rates via a feed line, wherein the water or wastewater entering the contact chambers via the feed line includes suspended matter; a pressurised dissolver for saturating water with air; a recirculation pump means to move treated water via a recirculation line from each of the dissolved air flotation chambers to the pressurised dissolver at substantially equal flow rates, and then back into the contact chambers, whereby air-saturated water from the dissolver degasses upon entry into the contact chambers and forms bubbles which adhere to said suspended matter causing the suspended matter to float to the surface of each chamber to form a layer of float material; and a second discharge pipework for treated water associated with said two or more dissolved air flotation chambers, said second discharge pipework including a control valve which when closed prevents flow of treated water from the dissolved air flotation chambers for a predetermined time to thereby cause a liquid level in the chambers to rise and said float material to be discharged through said first discharge pipework, wherein said recirculation line branches into individual lines that feed each contact chamber with said air-saturated water, each said branched recirculation line including a flow restricting device enabling uniform flow into each contact chamber.