METHOD OF EXTRACTING HEAVY METAL IONS FROM AQUEOUS SOLUTIONS Russian patent published in 2018 - IPC C02F1/28 B01J20/24 B01J20/22 B01J20/30 

FIELD: technological processes.

SUBSTANCE: invention relates to processes for extracting heavy metal ions by sorption. Method for extracting heavy metal ions from aqueous solutions consists in passing the solution through a fixed layer of a swollen granular adsorbent derived from a cellulose-containing material (CCM), taken from sawdust or a short flax fiber fraction of 0.5–1 mm. CCM is dried to constant weight, treated with a 2–3 % solution of hydrochloric acid, washing with acid solution with distilled water to pH 5, wringing to 50 % humidity. Next, the resulting mass is sequentially treated with a solution of chitosan in acetic acid, a solution of glutaraldehyde and a solution of aminoacetic acid, carried out in molar ratio of CCM : chitosan : glutaraldehyde : aminoacetic acid, equal to 1:(0.3–0.4):(0.2–0.3):(0.05–0.1). Resulting mixture is granulated.

EFFECT: preventing the destruction of swollen adsorbent granules, improving the filterability of the adsorbent layer during water purification, increasing the protective action time of the adsorbent layer.

1 cl, 1 tbl, 6 ex