Potential of Spray Dry Absorber Calcium Sulfite By-Product As an Agricultural Amendment.

Power generation waste disposal is a limiting factor in the projected lifetime of a power plant because of landfill quantity restrictions. Therefore, finding new ways to distribute waste is of great to concern to operators. Some power plants produce Spray Dry Absorber (SDA) Calcium Sulfite (CaSO3) waste where CaSO3 has more potential harmful issues to common agricultural crops than the more common waste product flue gas desulfurization (FGD) gypsum (CaSO4). A three year study was conducted at the Arlington Agricultural Research Station on a Plano silt loam to determine the effect of land application on crop yield, soil pH, heavy metal content, and the rate of chemical conversion of SDA from CaSO3 to CaSO4. Plots measured 3.0 × 10.7m and treatments included three application timings, two application rates and a non-treated control in a randomized complete block design. Application timings were early spring (April), late spring (late May or early June), and fall (October) for corn and soy, and after first cut (~1 June) and fall (October) for alfalfa. Application rates were 2.24 dry Mg ha-1 and 4.48 dry Mg ha-1. No significant reduction in yield for corn, soy, or alfalfa was observed in either 2015 or 2016. Small increases in soil arsenic concentration were measured in corn soil and corn grain at the end of 2016 compared to the non-treated control. The second cut of alfalfa plant tissue had increased lead in the spring high rate treatment in 2016. No significant differences in heavy metals were seen in any tissue or soil in 2015. Significant increases in pH were observed in high rate treatments in 2016 No significant differences were observed in the rate of conversion of CaSO3 to CaSO4 between treated plots. Sulfate and Sulfite contents were higher in treated plots aver the control.