METHOD OF FRYING WATER FROM STRONG ACID ANIONS Russian patent published in 2004 - IPC

FIELD: water treatment.

SUBSTANCE: invention relates to ion-exchange purification methods and to production of highly desalted water, which can be applied on chemical water-purification plants of industrial enterprises, heat-and-power stations, and other enterprises requiring high-purity chemically cleaned water. Water to be freed from strong acid anions (chloride, sulfate, and nitrate anions) is passed through mixed-basicity porous anionite prepared via consecutive chloromethylation and amination reactions of macroporous styrene/divinylbenzene copolymer wherein contents of low- and high-basicity groups are interrelated as (9-17):1 and pH value of water to be treated should not exceed 5.0. Above anionite is characterized by high value of dynamic exchange capacity (regarding strong acid anions) for water with low pH values and is mainly designed to be placed in the first step of OH^- anionation.

EFFECT: increased duration of the filtration cycle of the first step of anionite filter and reduced water production expenses.

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