METHOD OF MODIFYING SORBENTS BASED ON CELLULOSE FOR EXTRACTING HEAVY METAL IONS FROM AQUEOUS SOLUTIONS Russian patent published in 2024 - IPC B01J20/24 B01J20/32 C02F1/28 C02F1/62 

FIELD: chemistry.

SUBSTANCE: invention relates to chemical industry and specifically to methods of extracting heavy metal ions by sorption on natural cellulose-containing sorbents. Method of modifying polymer sorbents based on cellulose consists in depositing carbon nanotubes (CNT) on them, which are preliminarily oxidised, washed with distilled water, dried and treated with thionyl chloride. CNTs are oxidised with concentrated sulphuric acid. After treatment with thionyl chloride, CNTs are additionally treated with ethylenediamine at ethylenediamine/CNT module of 50-200 at temperature of 60-80 °C for 1-3 hours, followed by washing with distilled water and ethyl alcohol, squeezing and drying to constant weight. Sorbents are pretreated with citric acid solution with concentration of 0.3-0.5 M at acid solution/sorbent modulus of 10-20 at temperature of 110-130 °C for 2-4 hours. Modification with treated CNTs in amount of 10-20% of sorbent weight is carried out in toluene.

EFFECT: high degree of extraction of heavy metal ions from aqueous solutions.

1 cl, 1 tbl, 9 ex