Actuality the problem of iodine deleting from wastewaters is that iodine often gets into water from the treatment facilities including radioactive isotopes. Radioactive iodine is a widespread by-product of nuclear splitting and pollution at nuclear disasters. Іons of radioactive iodine have a special danger. In Ukraine radioactive iodine in wastewaters represents ecological danger yet.
The purpose of this work was to select the effective adsorbent for absorption iodine ion from water by comparison the adsorption capacity of different types of activated carbon toward iodine anions.
For this purpose the industrial activated carbon Filtrasorb 400 (F400) produced by Calgon Corp. was studied. F400 was oxidized with concentrated nitric acid and sample F400ox was obtained. Also F400 was modified with silver nitrate and sample F400mod was obtained and oxidized carbon F400ox+mod which was additionally modified by silver nitrate was obtained too.
Investigation of their adsorption activity was carried out by a static method with using of 0.1 m KI solution, to 100 cm3 of which 1.0 g of the investigated active carbon was added. The initial and equilibrium concentrations of solutions were determined by the results of titration by Foolgard method. Then the adsorption degree (X, %) and adsorption capacity (G, mmol/g) were calculated. The results of this study are present in Fig. 1.
Figure 1 − The adsorption degree and adsorption capacity of investigated activated carbon samples.
It is seen from Fig. 1 that the most effective is the sample oxidized carbon is additionally modified by silver nitrate the adsorption degree for which was 33,5%. And adsorption capacity was 3,35 mmol/g.
Thus, modification of the surface of production activated carbon contributes to increase of adsorption capacity toward iodine ions. This study prognosticates further receiving new highly effective modified activated carbon with increased adsorption activity toward radioactive anion of iodine.