METHOD OF MODIFYING SORBENTS FOR EXTRACTION OF HEAVY METAL IONS FROM AQUEOUS SOLUTIONS Russian patent published in 2023 - IPC B01J20/24 B01J20/32 C08B15/00 C02F1/28 C02F1/62 

FIELD: chemical industry.

SUBSTANCE: invention relates to the chemical industry and may be used to improve membrane and sorption technologies, in water treatment, in the development of technologies for the utilization of heavy metal ions from aqueous solutions and wastewater of various origin. A method for modifying sorbents for the extraction of heavy metal ions from aqueous solutions is presented, the method consisting in bringing them into contact at room temperature with modified polymeric sorbents based on cellulose at a solution/sorbent modulus of 50-200 during 20-30 min, wherein modifying of sorbents is carried out by depositing carbon nanotubes (CNTs) Taunit M on them, the tubes being pre-oxidized with concentrated nitric acid at a modulus of 50-100 at room temperature during 60-90 minutes or with solutions of potassium dichromate or potassium permanganate at pH 2-4, the modulus of the solution being 50-100 and temperature 50-60°C during 20-30 min, then the nanotubes are separated, washed with distilled and dried, then the modification of cellulose-based sorbents is carried out with treated carbon nanotubes in an amount of 10-20% of the mass of the sorbent in toluene at a toluene/sorbent modulus of 1-2 at room temperature during 1-2 hours, then the finished sorbent is separated from toluene by centrifugation, washed with distilled water and dried, wherein the cellulose sorbents treated in an alkali solution are treated with a mixture of epichlorohydrin and ethyl alcohol at a ratio of 1:2, a temperature of 50-70°C for 2-3 hours at a modulus of 15, followed by washing with distilled water and ethyl alcohol to pH 7, then treated with ethylenediamine at a temperature of 75-80°C under reflux during 2.5-3.5 h at ethylenediamine/sorbent 2 module, followed by washing with distilled water and drying to permanent weight.

EFFECT: invention provides an increase in the degree of extraction of heavy metal ions.

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