METHOD OF PRODUCING MODIFIED SORBENT FOR EXTRACTING HEAVY METAL IONS FROM AQUEOUS SOLUTIONS Russian patent published in 2022 - IPC B01J20/24 B01J20/30 

FIELD: chemistry.

SUBSTANCE: invention relates to methods of producing sorbents. Described is a method of producing a modified sorbent for extracting heavy metal ions from aqueous solutions, which consists in producing a solution of chitosan in 1 % acetic acid, intensive mixing, gradual addition of epichlorohydrin as a cross-linking agent and stirring until it is completely included in the reaction mixture, followed by drop-by-drop introduction of the prepared mixture into the aqueous alkaline solution while stirring, holding the formed granules in it, followed by their separation from the dispersion medium and thorough washing with distilled water to neutral pH, wherein the chitosan gel is homogenised by ultrasonic treatment for 20–40 minutes, drop introduction of the prepared gel of cross-linked chitosan is carried out in an aqueous solution of sodium hydroxide with concentration of 1 M, in which the formed granules are held for 20–50 minutes, followed by washing with distilled water, and modification of chitosan granules is carried out in an aqueous solution containing 2-ethylimidazole and nickel chloride in molar ratio 2-ethylimidazole/Ni²⁺, equal to 2:1–8:1, in the presence of dodecyldimethylamine-N-oxide.

EFFECT: increased sorption capacity of sorbent in relation to heavy metal ions.

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