CONTINUOUS ADSORPTION AND DESORPTION OF CHROMIUM IONS BY SPHAGNUM MOSS FEAT

Irish sphagnum peat was used for the continuous adsorption of hexavale nt chromium from acidic solutions. At an initial pH of 2.0, there is a n appreciable formation of trivalent chromium, which is not adsorbed a s 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 o n the pH and whether they are quoted in terms of total or hexavalent c hromium. However, the capacities of the Irish peat are greater than Ch inese peat, indicating that it has considerable potential asa commerci al low-cost adsorbent for chramium. The exhausted peat can be regenera ted in situ with 1 M sodium hydroxide but the regeneration efficiencie s are low (< 40%).