摘要 |
FIELD: treatment of sewage water from various pollutions; applicable in rendering harmless of sewages of electroplating, metallurgical and chemical industries. SUBSTANCE: method of treatment of industrial fluoride sewage water includes their treatment in field of galvanic couple from crushed graphite and iron chips with execution of vibratory motions and air supply with subsequent separation of solid phase by filtering, chromium fluoride sewage water containing chromium (VI) and chromium (III) are directed for their successive precipitation with solutions of alkali metal hydroxider to produce alkali metal fluosilicates at pH 3-6.5, and chromium hydroxide at pH 8.5-9.0, and precipitating of fluorine ions with alkali-earth metal nitrates and successive separation of products by filtering, with separation in filtrate of sodium nitrate. Graphite is used in form of its used wastes. Vibratory motions of galvanic couple components are executed at amplitude of ±90° and duration of contact of sewage water with galvanic couple for 10-15 min. Device for treatment of industrial fluoride sewages includes vertical cylindrical body accommodating crushed graphite with iron chips and installed for execution of vibratory motions, check grate, means for air supply and branch pipes for intake of sewage water and discharge of treated water. Device body is made of corrosion-resistant material. It additionally accommodates four sections of holders. Device body is secured to axle of oscillation installed on supports for vibratory motions with amplitude of ±90°. Air supply means disperser is made in form of jet aerator with perforated grate bars installed in front of aerator and distributor of sewage water flow. EFFECT: reliable and efficient treatment of chromium fluoride sewage water of semiconductor industry. 7 cl, 3 dwg
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