Landfill Disposal of Limestone Dual Alkali Flue Gas Desulfurization Waste

摘要

A landfill disposal test program was undertaken to demonstrate the addition of fly ash and lime to calcium sulfite-sulfate flue gas desulfurization (FGD) wastes and to establish design and operating guidelines for an environmentally acceptable waste disposal system. A lined, diked landfill disposal site was partially filled with waste mixtures of FGD filter cake, fly ash, and lime. Field samples were assessed in terms of engineering properties and leachate quality. Laboratory mixtures were analyzed for comparison with field samples. Revegetation studies were performed with laboratory mixtures to determine how fly ash and FGD sludge affect plant growth and to identify candidate species for on-site testing.\nFixation and stabilization improved the shear strength and reduced the compressibil¬ity of the laboratory mixtures tested. Laboratory testing of the properties of fixed filter cake indicated that mixtures of filter cake with a solids content of 56％, a fly ash-to-filter cake ratio of 1:1, and a lime content of 3％ have a natural water content below the liquid limit and appear to be suitable for landfill.