CONTINUOUS ADSORPTION AND DESORPTION OF CHROMIUM IONS BY SPHAGNUM MOSS FEAT

Irish sphagnum peat was used for the continuous adsorption of hexavalent chromium from acidic solutions. At an initial pH of 2.0, there is an appreciable formation of trivalent chromium, which is not adsorbed as readily as the hexavalent form. This did not occur when the initial pH was 2.5. The values of the adsorption capacities thus depend both on the pH and whether they are quoted in terms of total or hexavalent chromium. However, the capacities of the Irish peat are greater than Chinese peat, indicating that it has considerable potential asa commercial low-cost adsorbent for chramium. The exhausted peat can be regenerated in situ with 1 M sodium hydroxide but the regeneration efficiencies are low (< 40%).