CLARIFIED WATER PRODUCTION PROCESS Russian patent published in 2007 - IPC B01D61/14 C02F9/08 C02F1/52 

FIELD: water treatment.

SUBSTANCE: invention relates to treating water and effluents and can be used to produce clarified water for feeding water-rotation cycles in ammonia production. Process comprises taking initial water, clearing it on 200-μm gauze filters, flocculation, clarification, and supplying clarified water to plant, wherein demineralized water is produced via nanofiltration and reverse osmosis. Initial water can be biologically purified chemical enterprise waste waters, storm flows, mine effluents, and other effluents or mixtures thereof having total salt contents 3-4 g/L, suspended substances content up to 50 mg/L, total microbial number up to 10 thousand units in ml, and total hardness up to 15 mg-eq/L. Clarification of water is accomplished through ultrafiltration to separate dissolved impurities on ultrafiltration membranes characterized by filtration spectrum from 50 to 1000 Å under pressure 0.05 to 0.5 MPa to achieve full elimination of suspended substances in permeate and detention of all microbiological impurities. Prior to performing clarification, water is supplemented by flocculant, in particular 14% of FeCl₃. As membrane elements are becoming polluted, they are being cleaned by receiving cleaning solutions: 50% sulfuric acid and 42% alkali or 20% sodium hypochlorite, followed by ageing for a specified time.

EFFECT: enabled full removal of microbiological impurities and suspended particles to provide water suitable for nanofiltration and reverse-osmosis plants.

1 dwg, 4 tbl, 3 ex