PROCESS OF TREATMENT OF SEWAGE IN ION-EXCHANGE DEMINERALIZATION PLANTS Russian patent published in 2003 - IPC

FIELD: neutralization and softening of acidic and alkaline sewage formed by regeneration of filters in ion-exchange demineralization plants. SUBSTANCE: invention can be utilized in development of low-waste water preparation processes used in heat power industry, in ferrous and non-ferrous metallurgy, in chemical and petroleum refining industry. Process of treatment of sewage in ion-exchange demineralization plants is realized by way of passage of sewage through carboxyl cationic exchanger. After passage through carboxyl cationic exchanger acidic sewage is separated from gypsum sediment and is mixed with alkaline sewage. Mixture is separated from magnesium hydroxide and is passed through same carboxyl cationic exchanger. Alkalinity of mixture is kept in range of hardness ±3 mg-eq/l. Process of sedimentation of gypsum is conducted in suspended layer of sediment precipitated before. If alkalinity in mixture of sewage is in deficit this suspended layer is injected with quicklime in process of precipitation of gypsum. EFFECT: reduced hardness and mineralization of regenerated sewage in process of its neutralization. 4 cl, 1 dwg, 1 tbl