Chemical properties of acid soil treated with coal combustion by‐products and leached

Abstract

Abstract Application of coal combustion by‐products (CCBs) to acid soils can have beneficial or detrimental effects. A column study was conducted to determine the effects of CCBs on mitigating acid soil properties after leaching with 138 cm deionized water. Columns containing 105 cm acidic Lily soil (Typic Hapludult) had mixed in the top 15 cm the following treatments (g/kg soil): no CCB or limestone (check); dolomitic limestone (lime) at 3.98; high‐calcium sulfate (CaSO4) flue gas desulfurization (FGD) by‐product (BP) at 15.88; combination of lime+FGD at rates given; high‐CaSO4 FGD BP enriched with Mg (FGD+Mg) at 15.88; and fluidized bed combustion (FBC) BP at 6.45. After being leached for 39 days, the columns of acid soil treated with high‐CaSO4 by‐products showed higher subsurface pH, calcium (Ca), and sulfur (S) and lower aluminum (AI) and manganese (Mn). In contrast, the lime alone treatment had little effect on subsurface soil properties. Use of dolomitic limestone to supply magnesium (Mg) in conjunction with the CaSO4 treatments was more effective than supplementation with Mg(OH)2, where97% of the added Mg leached from the top layer. Substances leached from the CCBs studied were effective in reducing problems associated with subsurface soil acidity.