The article is devoted to the use of natural minerals in water treatment. The paper presents the results of a study of the sorption properties of the opoka. The study showed the advantages of flask membranes compared to those deposited with silicic acid. The optimal conditions for the modification of the flask were determined, which make it possible to purify water from metal impurities to the required level.

Keywords: groundwater, water purification, deferrization, membrane, deposited membrane, sorption methods, flask, polyacrylamide