Journal of Environmental Protection, 2016, 7, 1592-1604 http://www.scirp.org/journal/jep ISSN Online: 2152-2219 ISSN Print: 2152-2197 DOI: 10.4236/jep.2016.711131 October 28, 2016 Liming Characteristics of a High-Calcium Dry Flue Gas Desulfurization By-Product and a Class-C Fly Ash Jason R. Burgess-Conforti 1* , David M. Miller 1 , Kristofor R. Brye 1 , Lisa S. Wood 1 , Erik D. Pollock 2 1 Department of Crop, Soil, and Environmental Sciences, University of Arkansas, Fayetteville, AR, USA 2 Stable Isotope Laboratory, University of Arkansas, Fayetteville, AR, USA Abstract Due to coal’s availability and low cost, coal combustion continues to be the United States’ primary energy source. However, coal combustion produces large quantities of waste material. Some coal combustion by-products (CCBs) have chemical and physical characteristics that make them potentially useful as soil amendments. The objectives of this study were to characterize a relatively new, high-calcium dry flue gas desulfurization (DFGD) by-product and compare its agronomic liming potential to a Class-C fly ash (FA) and reagent-grade calcium carbonate (CaCO 3 ). Calcium carbonate equivalence (CCE), degree of fineness (DOF), and effective neutralizing value (ENV) for each CCB were determined using standard methods. The CCBs and CaCO 3 were also incubated with an acidic (~4.5) clay sub-soil at application rates equivalent to 0, 0.5, 1, and 2 times the soil’s lime requirement and compared to an unamended control. Soil pH was then measured periodically during a 40-day incuba- tion. The ENV of 79.4% for the DFGD by-product and 57.3% for the FA were com- parable to those of commercially available liming materials, but were significantly lower (P < 0.05) than that of reagent-grade CaCO 3 . After 40 days of incubation at the 0.5× application rate, both CCBs raised the pH of the clay soil to only 5.0, while the CaCO 3 raised the pH to 6.5. After 40 days at the 1× rate, all three materials had raised the soil pH to between 6.5 and 7.0, although the FA increased the soil pH more slowly than did the other two materials. At the 2× rate, both CCBs increased the soil pH to between 7.5 and 8.0, while the CaCO 3 increased the soil pH to only 7.0. Both CCBs appear to be useful as soil liming materials, although care should be taken to avoid over-application, as this may make the soil too alkaline for optimum plant growth. How to cite this paper: Burgess-Conforti, J.R., Miller, D.M., Brye, K.R., Wood, L.S. and Pollock, E.D. (2016) Liming Characte- ristics of a High-Calcium Dry Flue Gas Desulfurization By-Product and a Class-C Fly Ash. Journal of Environmental Protec- tion, 7, 1592-1604. http://dx.doi.org/10.4236/jep.2016.711131 Received: September 19, 2016 Accepted: October 25, 2016 Published: October 28, 2016 Copyright © 2016 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY 4.0). http://creativecommons.org/licenses/by/4.0/ Open Access