Mass Transport Release of Heavy Metal Oxyanions from Solidified/Stabilized Co-Disposed Flue Gas Desulfurization Brine and Coal Fly Ash Monoliths

摘要

The United States(US)coal-fired power industry is facing increasing pressure to improve wastewater disposal practices.One of the most pressing waste disposal issues is the treatment of flue gas desulfurization(FGD)wastewater.Zero liquid discharge(ZLD)strategies are gaining significant interest in the industry and can include the coupling of a brine concentrator and solidification/stabilization(S/S)process.This current project evaluated the mass transport release of heavy metal oxyanions(As,Cr,and Se)from solids produced by this process utilizing a United States Environmental Protection Agency(USEPA)Method 1315 evaluation.Ferrous sulfate(FS)addition significantly decreased release of oxyanions As,Cr,and Se.The results indicate that FS addition could increase the likelihood of successful long-term disposal of S/S solids of concentrated FGD brines containing these heavy metal oxyanions.