THE CONCENTRATIONS AND PARTICLE-SIZE RELATIONSHIPS OF SELECTED TRACE-ELEMENTS IN FLY ASHES FROM UK COAL-FIRED POWER-PLANTS AND A REFUSE INCINERATOR

Fly ash samples from 11 coal-fired power plants and a refuse incinerator in the U. K. were analyzed for total arsenic, cadmium, lead and selenium. Enrichment factor (EF) values calculated with respect to crustal abundance (EF//c//r//u//s//t) were highest for cadmium and lead in refuse fly ash, with EFs of 2500 and 740, respectively. Enrichment factors for selenium were similar in both fly ash types; only arsenic was more enriched in coal fly ash compared with refuse fly ash. Despite the high EF//c//r//u//s//t values of certain elements in the two fly ash types, the same elements showed EF values of about unity when expressed with respect to the starting material. The EF//c//r//u//s//t values estimated for arsenic, lead and selenium in suspended particulates from a refuse incinerator were similar to those calculated for the urban atmospheric aerosol, whereas cadmium was 10 times more enriched in the suspended particulates. Scanning electron microscopy revealed a marked contrast in the morphological features of the two fly ash types.