ASTURIAN FLY-ASH AS A HEAVY-METALS REMOVAL MATERIAL

Coal-burning plants produce large amounts of fly ash as a residue. Fly ash has been used in construction, agriculture, metal recovery and wa ter pollution control. This paper considers the efficiency of fly ash in the removal of heavy metals (Cd and Cu). The fly ash is shown to be an effective metal adsorbent for these two metals. Adsorption capacit y increases as metal initial concentration decreases. The removal phen omenon appears to be that the fly ash neutralises the metal solution d ue to its alkaline nature. The presence of high ionic strength, or app reciable quantities of Ca and Cl ions does not have a significant effe ct on the adsorption of these metals by fly ash. (C) 1998 Elsevier Sci ence Ltd. All rights reserved.