Countercurrent-cocurrent dissolved air flotation process system

A countercurrent-cocurrent dissolved air flotation (CCDAF) process system, comprising an air flotation tank body (1), wherein a chemical dosing zone (101), a counter-current contact zone (102), a co-current contact zone (103), a separation zone (104), and a clarified effluent zone (105) are sequentially arranged in the air flotation tank body (1) from left to right;

• and a top of the counter-current contact zone (102) is communicated with the chemical dosing zone (101), a bottom of the counter-current contact zone (102) is communicated with the co-current contact zone (103), a top of the separation zone (104) is communicated with the co-current contact zone (103), and a bottom of the separation zone (104) is communicated with the clarified effluent zone (105);
• a wastewater inlet (2) and a chemical dosing port (3) are arranged at a bottom of the chemical dosing zone (101), and a motorized valve (4) is arranged on the chemical dosing port (3);
• an agitator (5) and a fluorescence sensor (6) are arranged in the chemical dosing zone (101), the fluorescence sensor (6) is electrically connected to a first controller (7), and the first controller (7) controls opening and closing operations of the motorized valve (4);
• a counter-current dissolved air releaser (8) is arranged at the bottom of the counter-current contact zone (102), a co-current dissolved air releaser (9) is arranged at a bottom of the co-current contact zone (103), the counter-current dissolved air releaser (8) and the co-current dissolved air releaser (9) are connected to a high-pressure dissolved air water device (10), high-pressure nozzles (11) are arranged at upper portions of the counter-current dissolved air releaser (8) and the co-current dissolved air releaser (9), and the high-pressure nozzles (11) are connected to a first water supply pipeline (12);
• and protective guards (23) are arranged at upper portions of the high-pressure nozzles (11), and high-pressure water is sprayed from the high-pressure nozzles (11) to surfaces of the dissolved air releasers;
• a reciprocating moving device (13) is arranged at an upper portion of the top of the separation zone (104), with a vertically movable skimmer plate device (14) arranged on the reciprocating moving device (13);
• a left oil storage groove (15) and a left pressure sensor (16) are arranged at a left side of the top of the separation zone (104), and a right oil storage groove (17) and a right pressure sensor (18) are arranged at a right side of the top of the separation zone (104);
• the left pressure sensor (16) and the right pressure sensor (18) are electrically connected to a second controller (19), and the second controller (19) regulates vertical movement of the skimmer plate device (14);
• and an inclined plate device (20) is arranged at the bottom of the separation zone (104);
• and
• a filter membrane device (21) is arranged in the clarified effluent zone (105), and a clarified water outlet (22) is connected to a top of the clarified effluent zone (105).