Elemental Characterization of Municipal Solid Waste Incinerator Ash and Its Leachates Using Neutron Activation Analysis and Inductively Coupled Plasma Atomic Emission Spectroscopy

328 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1993.Incineration of municipal solid waste (MSW) is an increasingly attractive option for dealing with the burgeoning quantity of solid waste generated in the West. A combination of neutron activation analysis (NAA), inductively coupled plasma (ICP), and x-ray fluorescence (XRF) are used to analyze a wide range of elements in a variety of ash and extraction fluids, facilitating a detailed assessment of the hazards posed by the ash produced from MSW incineration.Samples of bottom, fly and combined ash were analyzed using NAA and XRF. Epithermal NAA in conjunction with a Compton suppression system were especially helpful in reducing the detection limits of As, Au, Cd, Mo and Sb. The distribution of elements varied with the size of fly ash particles, with most volatile heavy metals except Hg being concentrated on the smallest ash particles. Since the smallest particles are those most likely to escape in emissions, elements occurring at concentrations 100-10000 times those typically found in soil (Ag, Au, Br, Ce, Cd, Cl, Hg, In, Pb, Sb, Ta and Zn) can be used to develop an aerosol source signature for MSW incinerators.In addition to the regulatory TCLP test, water batch and sequential extractions were completed on each ash and analyzed by ICP and NAA. The smallest particles in the fly ash, which account for 75% of its mass, have the greatest buffering capacity and maintain the alkaline nature of the ash. The pH of the leaching solution, rather than the concentration of the metals in the ash, governs the metal concentrations in the leachates. Based on the results of the water batch and sequential extractions, elements easily leached from the ash with the first washing create a concentration spike which is more important than the slow release of more tightly bound forms attacked in TCLP. Liquid-to-solid ratios of 200 in the water batch extraction have no effect on the chemical behavior of the ash, implying that fears of the acidification of ash monofills by rain are grossly exaggerated.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD