Akira Hamaguchi

Preparation of dithiocarbamatecellulose derivatives and their adsorption properties for trace elements

Tosylcellulose was treated separately with aniline, benzylamine, n-butylamine and piperazine to give four different aminocelluloses which were further treated with carbon disulfide to furnish four dithiocarbamatecelluloses (AND, BZD, BUD and PID). A comparative study was made of their performance as adsorbents for several kinds of metal ions. PID, which has the highest degree of substitution of the dithiocarbamate group of the four derivatives obtained, was investigated for its adsorption behavior towards Ag+, As5+, Cd2+, Co2+, Cr3+, Cr6+, Cu2+, Fe3+, Hg2+, Mn2+, Pb2+, Sb5+; Se4+, Te4+ and Zn2+. PID showed good adsorption characteristics with relatively large capacities for Ag+, Cr6+, Cu2+, Hg2+, Pb2+ and Se4+ ranging from 9.5 to 370 mg g-1 of resin.

Sorption of uranium by cellulose derivatives

The sorption behaviour of uranium was investigated by batch and column methods using four cellulose derivatives, two having an amino group and two having an amino group plus a dithiocarboxylate group. All four derivatives showed maximum uranium sorption from pure water in the neutral region or from artificial sea water in the acidic region. In the batch method, quantitative removal of 100 µg of uranium from 50 ml of water at pH 5.0 was achieved by equilibration with 50 mg of any of the four sorbents. The percentage removal under these conditions decreased gradually with increasing concentration of uranium above 100 µg per 50 ml. A similar high percentage removal of uranium was achieved using artificial sea water. In the column method, quantitative removal of 5 µg of uranium from 1 l of water at pH 6.7 was achieved with 200 mg of either of the two sorbents. Similar quantitative removal of uranium was achieved from 1 l of artificial sea water at pH 5.4 with 500 mg of either of the two sorbents. Several 1-and 10-l portions of natural sea water, adjusted to pH 5.0, were passed through the column, which was packed with a mixture of 500 mg of either of the two sorbents and 1 g of cellulose powder. The results indicated that uranium was quantitatively removed from the 1-l portions, while approximately 50% was removed from the 10-l portions.