CHEMICAL SPECIATION OF HEAVY-METALS IN POWER-PLANT ASH POND LEACHATE

Soil attenuation of heavy metals from industrial leachates is dependent upon many factors. Data in this paper are based on field measurements from an active power plant fly ash disposal site and are organized via a thermodynamic approach which is facilitated by computer solutions to the equilibrium situation. Results for the site studied show that adsorption onto hydrous iron and manganese oxides is the major solubility control for cadmium, nickel, and zinc while precipitation of discrete phases controls for chromium, copper, and lead. The partitioning of heavy metals between solution and particulate phases is most affected by pH, p(FeOOH), p(MnOx), andp(SO42-). © 1979, American Chemical Society. All rights reserved.