Patent ID: 11970412
Assignee: DOOSAN ENERBILITY CO., LTD.
Field: Environmental technology (Chemistry)
Classification: CPC C | IPC C

Claim 8:
9. A dissolved air flotation water treatment system comprising:
a mixing-and-coagulation basin in which a mixture of feed water and coagulant flows in and agitates the mixture to form and grow floes in raw flocs water,
a flotation basin in which micro-bubbles are injected into the raw flocs water supplied from the mixing-and-coagulation basin so that the flocs are raised; and
at least two plasma discharge devices including a first plasma discharge device and a second plasma discharge device, the at least two plasma discharge devices disposed underwater in the flotation basin to generate plasma and the micro-bubbles through underwater electric discharge,
wherein each of the at least two plasma discharge device comprises:
a reactor having an input port through which the mixture flows in and an output port through which treated mixture flows out;
a ground electrode disposed in a first side of the reactor; and
a plasma electrode module disposed in a second side of the reactor,
wherein the plasma electrode module includes a conductive substrate including a plurality of holes, a ceramic layer surrounding a portion of an outer surface of the conductive substrate, and a plasma electrode disposed in each of the plurality of holes,
wherein the plasma electrode has a multilayer structure in which a cylindrical ground portion, a fixed portion, and a discharge portion are sequentially stacked,
the ground portion is in contact with the conductive substrate and the plasma and the micro-bubbles are generated on the discharge portion, and
wherein the flotation basin is divided into a contact region and a separation region by a partition, and the first plasma discharge device is installed in the contact region, and the second plasma discharge device is installed in the separation region,
wherein the contact region allows the flocs in the raw flocs water to collide and combine with the micro-bubbles generated by the first plasma discharge device, thereby forming a first bubble-floc agglomerate, and provide treated raw flocs water containing the first bubble-floc agglomerate therein to the separation region over the partition, and,
wherein the separation region receives the treated raw flocs water containing the first bubble-floc agglomerate provided from the contact region, allows flocs in the treated raw flocs water that have grown late and have not yet formed a bubble-floc agglomerate to collide with and combine with micro-bubbles generated by the second discharge device to form a second bubble-floc agglomerate, and allows the first and second bubble-floc agglomerates to be removed.