ABSTRACT
Flue Gas Desulfurization (FGD) gypsum is one of the synthetic by-products of a coal-fired power generation plant. It is created by forced oxidation scrubbers in coal-fired power plants, which remove sulfur dioxide (SO2) emissions from the flue gas stream. It has several beneficial applications in building industry and road construction, and in agricultural practice as a soil amendment due to its abundance, particle size, chemical and physical similarities to mined gypsum and the purity of material. Due to the high Ca2+ and SO4 2- content and the alkaline behavior of FGD gypsum, it can be used as a soil conditioner to improve physical and chemical properties by promoting better aggregation, increasing water infiltration rate and movement through the profile, reclaiming sodic soils and reducing soil and soluble phosphorus loss from agricultural fields. It is moderately soluble in soil and takes multiple years after application of the amendment before measurable benefits are observed. There is no report of negative effects due to FGD gypsum application, but a good understanding of its composition and properties is very essential to know and avert the possible environmental risks. The selection of appropriate application rates, timing and methods also should be taken into consideration for economic use of FDG gypsum. FGD technology is promising in terms of transforming waste product into a beneficial product that increases crop production and improves soil quality in an economically and environmentally sustainable manner.
