Using Flue Gas Desulfurization (FGD) Gypsum, By-Product of Coal-Fired Power Plants in Agriculture

Abstract

Gypsum is a non-metallic mineral sulphate in natural form of salt. Its structure consists of calcium ion (Ca²⁺), sulphate ion (SO₄^2-) and molecules of water (H₂O). Its formula is CaSO₄•2H₂O, found in nature and synthesis in various processes including gypsum as a by-product of scrubbing sulfur from combustion gases at coal-fired power plants, called Flue Gas Desulfurization Gypsum or FGD Gypsum. It can be used in agriculture, as well as other types of gypsum, as a conditioner to improve soil physical properties, and water infiltration and storage; to reduce compaction in soil, nutrient movement to surface water (run off), and erosion. Moreover, it also helps to balance the sodium content of saline soils; to decrease aluminum toxicity in acid soil. In addition, calcium and sulfur in FGD Gypsum are also essential nutrients for plant growth and yield. Currently, there are some concerns about heavy metal contamination of FGD Gypsum derived from synthetic process. However, some researchers reported that using appropriate rate of FGD gypsum would not cause on environmental impacts. Therefore, gypsum, a manufactured by-product of the coal-fired combustion process in power plants, is an alternative way to help farmers solve the problem of land degradation, improves soil structure, and increase agricultural profit effectively and sustainably.