US 11,945,744 B2
Method and apparatus for reusing wastewater
Seok Hwan Hong, Seoul (KR); Dae Soo Park, Seoul (KR); Seung Joon Chung, Seoul (KR); Yong Xun Jin, Seoul (KR); Jae Hyung Park, Seoul (KR); Jae Hoon Choi, Seoul (KR); Jae Dong Hwang, Seoul (KR); Jong Keun Yi, Hwaseong (KR); Su Hyoung Cho, Hwaseong (KR); Kyu Won Hwang, Hwaseong (KR); June Yurl Hur, Hwaseong (KR); Je Hun Kim, Hwaseong (KR); and Ji Won Chun, Hwaseong (KR)
Assigned to SAMSUNG ENGINEERING CO., LTD., Seoul (KR); and SAMSUNG ELECTRONICS CO., LTD, Gyeonggi-Do (KR)
Filed by Samsung Engineering Co., Ltd., Seoul (KR); and Samsung Electronics Co., Ltd., Suwon (KR)
Filed on Apr. 14, 2023, as Appl. No. 18/134,906.
Claims priority of application No. 10-2022-0094723 (KR), filed on Jul. 29, 2022.
Prior Publication US 2024/0034658 A1, Feb. 1, 2024
Int. Cl. C02F 9/00 (2023.01); B01D 61/02 (2006.01); B01D 61/14 (2006.01); B01D 61/58 (2006.01); B01D 65/02 (2006.01); C02F 1/52 (2023.01); C02F 1/56 (2023.01); C02F 1/66 (2023.01); C02F 1/00 (2023.01); C02F 1/20 (2023.01); C02F 1/44 (2023.01); C02F 1/50 (2023.01); C02F 3/12 (2023.01); C02F 3/30 (2023.01); C02F 3/34 (2023.01); C02F 5/08 (2023.01); C02F 101/14 (2006.01); C02F 101/16 (2006.01); C02F 101/30 (2006.01); C02F 103/08 (2006.01)
CPC C02F 9/00 (2013.01) [B01D 61/025 (2013.01); B01D 61/145 (2013.01); B01D 61/147 (2013.01); B01D 61/58 (2013.01); B01D 65/02 (2013.01); C02F 1/5236 (2013.01); C02F 1/56 (2013.01); C02F 1/66 (2013.01); B01D 2317/025 (2013.01); C02F 2001/007 (2013.01); C02F 1/20 (2013.01); C02F 1/441 (2013.01); C02F 1/444 (2013.01); C02F 1/50 (2013.01); C02F 3/1268 (2013.01); C02F 3/30 (2013.01); C02F 3/342 (2013.01); C02F 5/08 (2013.01); C02F 2101/14 (2013.01); C02F 2101/16 (2013.01); C02F 2101/30 (2013.01); C02F 2103/08 (2013.01); C02F 2301/046 (2013.01); C02F 2303/04 (2013.01); C02F 2303/16 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A method for reusing wastewater, the method comprising:
producing a mixed wastewater by mixing multiple types of wastewater (S20);
performing a first purification by passing the mixed wastewater through a flocculation-sedimentation unit (S40);
performing a second purification by passing an effluent of the flocculation-sedimentation unit through a membrane bioreactor (MBR) (S60);
performing a third purification by passing an effluent of the MBR through a reverse-osmosis membrane unit (S80); and
reusing an effluent of the reverse-osmosis membrane unit as a cooling water or industrial water (S100),
wherein the mixed wastewater refers to wastewater containing a mixture of hydrofluoric acid wastewater, other acidic wastewater, and alkaline wastewater produced from the semiconductor manufacturing process, or display manufacturing process, a total phosphorus (T-P) concentration in the mixed wastewater is 10 mg/L or less,
wherein the step (S40) comprises:
producing a first treated water by passing the mixed wastewater through a first flocculation reactor (S40-2);
producing a third treated water by passing either the first treated water or a second treated water through a third flocculation reactor, wherein the second treated water is obtained by passing the first treated water through a second flocculation reactor (S40-4);
producing a fourth treated water by passing the third treated water through a fourth flocculation reactor (S40-6); and
producing a fifth treated water and a sludge by passing the fourth treated water through a sedimentation tank (S40-8),
wherein a first chemical and a second chemical are introduced into the first flocculation reactor, a third chemical is introduced into the third flocculation reactor, and a fourth chemical is introduced into the fourth flocculation reactor,
wherein the first chemical comprises slaked lime, the second chemical comprises a hydrogen peroxide scavenger, the third chemical comprises a pH control agent, and the fourth chemical comprises an anionic polymer flocculant,
wherein a pH of the first flocculation reactor is 10.0 to 11.5, and a pH of the third flocculation reactor is 6.5 to 7.5, wherein the effluent of the MBR is adjusted to a pH of 5.8 to 6.5 and then supplied to the reverse-osmosis membrane unit,
wherein the step (S60) comprises:
producing a sixth treated water by passing the fifth treated water through an anoxic tank (S60-2);
producing a seventh treated water by passing the sixth treated water through an aerobic tank (S60-4);
producing an eighth treated water by passing the seventh treated water through a separation membrane tank (S60-6);
wherein the step (S60) further comprises step (S60-8) of passing an unfiltered water remaining in the separation membrane tank through a deaeration tank, and step (S60-10) of passing an effluent of the deaeration tank through the anoxic tank.