Fly Ash

Frontier GeoSciences recently concluded an exhaustive 2 year study with the US Department of Energy to develop methods for assessing Coal Combustion Products (CCPs). Our study included fly ash and flue gas desulfurization in solids and slurries. Take advantage of our deep understanding of fly ash issues to help protect your organization!

Mercury control technologies can change the quality of CCP. We have found that many combustion products see an increase in total metals after implementation of control technologies. However, the relative availability and mobility of metals is reduced following mercury control technology additions. The quality changes can be affected by various factors such as coal sources, plant operation, and the type of control technology used. Changes in total metals or leaching of metals in CCPs can change the ability for use in asphalt, cement, or wallboard manufacturing and can sometimes even limit non hazardous landfill disposal.

Traditional testing such as toxicity characteristic leaching procedure (TCLP), synthetic precipitation leaching procedure (SPLP), and ASTM D3987 leaching procedure to characterize metals leaching in CCPs are performed for under 18 hours and cannot simulate long term leaching characteristics of CCPs. In addition, there are no common commercially available techniques to characterize reemission or microbial leaching of trace metals in CCPs.Based on recent events, we’ve received many emails and phone calls regarding Frontier GeoSciences recently concluded studies with the US Department of Energy.

Frontier GeoSciences has developed several methods for assessing Coal Combustion Products (CCPs), including fly ash and flue gas desulfurization (FGD) solids and slurries. These tests were designed to mimic specific end uses for CCPs in order to better understand the potential mobility of mercury and other trace metals from CCPs into the environment.

Testing Available for CCPs
Test	Purpose
Low temperature metal volatility	Metals can be potentially re-emitted in products after coal combustion. This testing procedure estimates the re-emission of trace metals after landfill disposal or use as soil fill.
Volatilization - mid temp	Metals can be potentially re-emitted in products after coal combustion. This testing procedure estimates the re-emission of trace metals during asphalt or wallboard manufacturing.
Volatilization - high temp	Metals can be potentially re-emitted in products after coal combustion. This testing procedure estimates the re-emission of trace metals during cement manufacturing.
Microbial Methylation	Microbial activity can have a profound effect on the mobility, toxicity, and environmental impact of trace metals after soild fill use or landfill disposal. This testing procedure estimates the mobility of trace metals in CCPs after microbial activity. It also simulates the methylation potential of mercury in soil and landfill applications.
Chemical Leaching	Chemical leaching is necessary to determine whether CCPs can be classified as hazardous waste. In addition to TCLP testing protocol this testing mimics the amount of trace metals that are leached from CCPs following precipitation events.

Dr. Amy Dahl’s recently presented her research at the 2008 MEGA Symposium in Baltimore, MD titled: The Impact of Hg Control Technologies on Mobility Pathways of Hg, Ni, As, Se, Cd and Pb from Coal Utilization Byproducts. You can download a copy of the paper from the MEGA website here.

Coal Ash Mobility Research

Read about the research that we have been working on concerning mobility pathways of trace metals from coal utilization by-products.