METHOD AND APPARATUS FOR PURIFYING SEWAGE WATER FROM METAL SALTS Russian patent published in 2002 - IPC

FIELD: purification of industrial sewage water of coke industry, mechanical engineering etc from metal salts. SUBSTANCE: method involves subjecting sewage to aeration in cation exchanger and to oxidation in anion exchanger, with air being used for aeration in cation exchanger and ozone or chlorinated water being used for oxidation in anion exchanger; directing sewage water through cation exchanger and anion exchanger at velocity of 0.1-30 m/hour. Apparatus has sequentially arranged cation exchanger containing charge in the form of granular peat and anion exchanger with charge. Charge is arranged in cation exchanger in successive layers formed from nonwoven fibrous material based on natural fibrous substances and dried granular peat arranged between layers of nonwoven fibrous material. In anion exchanger charge is made from nonwoven fibrous material and filtering granular charge arranged beneath nonwoven fibrous material. Dried granular peat is preliminarily treated with 0.01-1% mineral acid solution, with following successive laying of materials. Height of dried granular peat in cation exchanger is 40-4,000 mm and height of each layer of fibrous material is 2-40 mm, peat granule size is 1-10 mm. In anion exchanger height of fibrous material layer is 2-2,000 mm, height of filtering charge layer is 10-4,500 mm. Filtering charge is quarts sand, gravel, crushed granite, hard coal or claydite, or ground burnt rocks with particle diameter of 0.2-70 mm. Fibrous material of fractal structure is produced by settling suspension of natural fibrous substances, for example wood cellulose of sulfite or sulfate cooking, cotton lint, worsted knop. EFFECT: increased efficiency and improved filtering cycle of ion-exchange filters. 12 cl, 1 dwg, 1 tbl