METHOD FOR OBTAINING MODIFIED SORBENT FOR EXTRACTION OF HEAVY METAL IONS FROM AQUEOUS SOLUTIONS Russian patent published in 2023 - IPC B01J20/30 B01J20/24 B01J20/02 C08B37/08 

FIELD: chemical industry.

SUBSTANCE: methods for producing sorbents containing chitosan, intended for the extraction of heavy metal ions by sorption from solutions of various compositions resulting from various production processes, used to improve membrane and sorption techniques, in water treatment, in the development of methods for the utilization of heavy metal ions from aqueous solutions and wastewater of different nature. A method for obtaining a modified sorbent for the extraction of heavy metal ions from aqueous solutions is described, which consists in obtaining a solution of chitosan in 1 vol.% acetic acid, intensive stirring and ultrasonic treatment for 20-40 minutes to obtain a homogeneous gel, gradual addition of epichlorohydrin as a cross-linker agent and stirring until it is completely included in the reaction mixture to obtain a cross-linked chitosan gel, subsequent dropwise introduction of the prepared gel into an aqueous alkaline solution with stirring, keeping the formed chitosan granules in it, followed by their separation from the dispersion medium, thorough washing with distilled water to neutral pH and modification in an aqueous solution containing 2-ethylimidazole and a metal salt in a molar ratio of 2-ethylimidazole/metal equal to 2:1-8:1, in the presence of a surfactant, while dropwise introduction of the prepared cross-linked chitosan gel is carried out into an aqueous hydroxide solution sodium with a concentration of 1-2 M, and the modification of chitosan granules is carried out in an aqueous solution containing sodium dodecyl sulfate as a surfactant, and copper sulfate as a metal salt.

EFFECT: increasing the sorption capacity of the sorbent with respect to heavy metal ions.

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