METHOD OF PROCESSING NATURAL BRACKISH WATERS WITH PRODUCTION OF SOLUTIONS OF MINERAL FERTILIZERS, PLANT FOR REALIZING SAID METHOD AND ION-EXCHANGE UNIT

FIELD: agriculture.SUBSTANCE: group of inventions relates to processing of natural brackish waters with production of solutions of mineral fertilizers intended for fertigation: irrigation and simultaneous application of fertilizers during cultivation of crops, and can be used in agriculture. Method of processing natural brackish water to obtain solution of complex mineral fertilizer involves use for processing of initial water three series-arranged ion-exchange columns, two of which contain ionite in form of cationic component of obtained fertilizer, and one - in form of anionic component. Solution from the output of the second cation column in the direction of flow is directed into the nanofiltration unit to obtain a concentrate and a permeate. One part of the permeate is fed into the column with an anionite to obtain solution of complex mineral fertilizer at its outlet, and the other part to the distiller to obtain desalinated water simultaneously with fertilizer for preparation of fertigation solution. Salt concentrate after desalination is used for regeneration of cationite in the above column. Regenarate of this column together with salt containing cationic component of obtained fertilizer - for regeneration of cationite of the first along flow column. In the column with anionite regeneration of ionite is carried out using a salt containing an anion component of the obtained fertilizer. In addition, three same columns are used, as said, forming pairs with them. In the second columns of these pairs, regeneration of ionites is performed at the time when the treated water is passed through the first columns, and vice versa. Plant for processing of natural brackish water with production of complex mineral fertilizer includes three ion-exchange units, having each two columns (C01, C02), reservoirs (R01, R02) for external regenerating solution and such solution displaced from free volume of column, as well as switches flows (F01, F02, F03).EFFECT: inventions enable to ensure use of low-grade initial fertilizers with prevention of ingress of agrotechnically hazardous components into the obtained complex mineral fertilizer and disturbance of the desalter operation, improve environmental safety, as well as provide formation of insoluble precipitation in columns and waste solutions, increase productivity and ensure continuity of production of complex mineral fertilizer with reduction of consumption of simple fertilizers and volume of waste solutions.16 cl, 6 dw