METHOD FOR MODIFYING SORBENTS FOR EXTRACTING HEAVY METAL IONS FROM AQUEOUS SOLUTIONS Russian patent published in 2022 - IPC B01J20/24 B01J20/32 C02F1/28 

FIELD: technological processes.

SUBSTANCE: invention relates to methods of extracting heavy metal ions by sorption. Described is a method of modifying sorbents for extracting heavy metal ions from aqueous solutions, which consists in contacting them at room temperature with modified polymer sorbents based on cellulose with a solution/sorbent modulus of 50–200, wherein modification of sorbents is carried out by applying carbon nanotubes (CNT) thereon, wherein carbon nanotubes are pre-oxidized with concentrated nitric acid at modulus 50–100 at room temperature for 60–90 minutes or solutions of potassium bichromate or potassium permanganate at pH 2–4, solution modulus of 50–100 and temperature of 50–60°C for 20–30 minutes, then carbon nanotubes are separated, washed with distilled water, dried and treated with thionyl chloride at a module of thionyl chloride/CNT 30–50 while heating with a reflux condenser at temperature of 75–80°C for 15–20 minutes, followed by washing, squeezing and drying to constant weight, after which cellulose-based polymer sorbents are modified with treated carbon nanotubes in amount of 10–20% of the sorbent weight in toluene with a toluene/sorbent modulus of 1–2 at room temperature for 1–2 hours, then the finished sorbent is separated from toluene by centrifugation, washed with distilled water and dried, and their contact with modified polymer sorbents based on cellulose is carried out for 20–30 minutes.

EFFECT: high degree of extraction of heavy metal ions and simplified processing of sorbents.

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