METHOD OF MODIFYING SORBENTS FOR EXTRACTING HEAVY METAL IONS FROM AQUEOUS SOLUTIONS Russian patent published in 2024 - IPC C08B15/00 C02F1/28 C02F1/62 

FIELD: chemical industry.

SUBSTANCE: invention relates to chemical industry, namely to methods of extracting heavy metal ions by sorption on natural cellulose-containing sorbents from solutions of different composition. Method of modifying sorbents based on cellulose for extracting heavy metal ions from aqueous solutions consists in depositing oxidised and treated with thionyl chloride carbon nanotubes (CNT), wherein the amount of CNT is 10–20 % of the weight of the sorbent. CNT is oxidised with concentrated sulfuric acid at modulus of 50–100 at room temperature for 1.5–2 hours, washed with water and dried. Then, the oxidised CNT are successively treated with thionyl chloride at modulus 50 at room temperature for 2–4 hours and ethylenediamine at modulus 200 at 70 °C for 2–3 hours. Obtained modified CNT are then washed several times in turn with distilled water and ethanol to pH 7. Polymer sorbents based on cellulose are pre-treated with a solution of an oxidant selected from sodium metaperiodate, iodic acid or sodium hypochlorite, with oxidant concentration of 0.1–0.3 M, with solution pH 2.5–4.5, with solution/sorbent modulus of 15–50, at temperature of 40–55 °C, for 2–4 hours, to content of aldehyde groups in sorbent 10–12 %.

EFFECT: disclosed invention increases degree of extraction of heavy metal ions from aqueous solutions.

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