FIELD: paper-and-pulp industry. SUBSTANCE: highly oxidized cellulose that may be used for recovering especially toxic substances, such as strontium, antimony, mercury, lead, rare-earth metals, is prepared by two-stage oxidation of cellulose successively with iodine-containing compound and nitrogen oxides followed by washing with purified water and ethyl alcohol and drying. First-stage oxidation is carried out in 5-11% sodium periodate solution at pH 2.5-4.5 and 40-60 C and then washed with water and sulfuric acid solution. Second-stage oxidation is effected with 15-30% solution of nitrogen oxides in carbon tetrachloride for 30-40 min at 2-10 C and pressure 0.2 to 2.0 atm, after which intermediate product is separated from solution and held for 3-5 hr at 25-40 C and pressure 3.2 to 5.0 atm. EFFECT: increased degree of cellulose oxidation to give product suitable for use as nontoxic radioprotective, hemostatic, antimicrobial, and wound-healing agents. 3 cl, 4 tbl
