METHOD FOR TREATMENT OF SEWAGE WATER OF PRODUCTION OF PRINTED CIRCUIT BOARDS CONTAINING WATER-ALKALI DRY-FILM PHOTORESIST AND DEVICE FOR ITS EMBODIMENT Russian patent published in 1996 - IPC

FIELD: treatment of sewage waters. SUBSTANCE: sewage water is subjected to electrochemical treatment in diaphragm electrolyzer by acidification of sewage water up to pH 2-4 in anode chamber of the three-chamber electrolyzer in the presence of Na₂SO₄, introduced in the amount of 100-500 mg/l and dispersed part is separated by electroflotation in the presence of anionic flocculant in the amount of 0.05-1.0% of photoresist mass. Electrochemical treatment is conducted at ratio of volume densities of current in electrolyzer and electroflotator of (0.2-2.0):(0.065-0.20), respectively. The device for embodiment of the offered method has body separated into diaphragm electrolyzer with ion-exchanger membrane and water inlets and outlets, electroflotator with a set of nonsoluble horizontal electrodes, purified water outlet and slime collector. Electrolyzer and electroflotator separated from each other by overflow partition with height of 0.85-0.95 of the height of water level in the electroflotation cell. Electrolyzer is three-chamber unit whose anode chamber is located between symmetrical cathode chambers and separated from them by parallel cation-exchange membranes. Electroflotator has partition whose height exceeds the water level by 0.05. The partition separates electroflotator into two sections, each furnished with a set of nonsoluble electrodes. Volumes of both cathode chambers, anode chamber and electroflotator relate to one another as 1:(2-3):(2-6), respectively. EFFECT: higher efficiency. 3 dwg