METHOD FOR MODIFYING CELLULOSE-BASED SORBENTS FOR EXTRACTING HEAVY METAL IONS FROM AQUEOUS SOLUTIONS Russian patent published in 2020 - IPC B01J20/30 B01J20/24 C02F1/28 C02F1/62 

FIELD: chemistry.

SUBSTANCE: invention relates to chemical industry, specifically to methods of modifying natural cellulose-containing sorbents intended for extraction of heavy metal ions by sorption from solutions of different composition. Method of modifying cellulose-based sorbents involves two-step treatment of a sorbent selected from cotton or wood pulp, short linen fiber, sawdust or girasol stems, modifying agents followed by washing with water after each step. At the first step, treatment is carried out with a solution of an oxidising agent selected from sodium metaperiodate, iodic acid or sodium hypochlorite, with concentration of oxidant of 0.1–0.3 M, with solution pH of 2.5–4.5, with a solution/sorbent module of 15–50, at temperature 25–55 °C for 4–6 hours to content of aldehyde groups (sorbent) 10–12 %. At the second stage, treatment is carried out with 1–10 % aqueous or alcohol solution of polyethylene polyamine at solution pH of 9–11 at room temperature, with solution/sorbent module 15–50 for 30–60 minutes while stirring.

EFFECT: higher degree of heavy metal ions extraction.

1 cl, 1 tbl, 5 ex