title: Influence of Flue Gas Desulfurization Gypsum Amendments on Heavy Metal Distribution in Reclaimed Sodic Soils.
abstract: Although flue gas desulfurization (FGD) gypsum has become an effective soil amendment for sodic soil reclamation, it carries extra heavy metal contamination into the soil environment. The fate of heavy metals introduced by FGD gypsum in sodic or saline-alkali soils is still unclear. This work aims to investigate the effects of FGD gypsum addition on the heavy metal distributions in a sodic soil. Original soil samples were collected from typical sodic land in north China. Soil column leaching tests were conducted to investigate the influence of FGD gypsum addition on the soil properties, especially on distribution profiles of the heavy metals (Pb, Cd, Cr, As, and Hg) in the soil layers. Results showed that pH, electrical conductivity, and exchangeable sodium percentage in amended soils were significantly reduced from 10.2 to 8.46, 1.8 to 0.2 dS/m, and 18.14% to 1.28%, respectively. As and Hg concentrations in the soils were found to be positively correlated with FGD gypsum added. The amount of Hg in the leachate was positively correlated with FGD gypsum application ratio, whereas a negative correlation was observed between the Pb concentration in the leachate and the FGD gypsum ratio. Results revealed that heavy metal concentrations in soils complied well with Environmental Quality Standard for Soils in China (GB15618-1995). This work helps to understand the fate of FGD gypsum-introduced heavy metals in sodic soils and provides a baseline for further environmental risk assessment associated with applying FGD gypsum for sodic soil remediation.
authors.affiliation: Research Center for Saline-Alkali Soil Rectification and Carbon Fixation, Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University , Beijing, China .
authors.forename: Qun
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Research Center for Saline-Alkali Soil Rectification and Carbon Fixation, Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University , Beijing, China .
authors.forename: Shujuan
authors.initials: S
authors.lastname: Wang
authors.affiliation: Research Center for Saline-Alkali Soil Rectification and Carbon Fixation, Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University , Beijing, China .
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Research Center for Saline-Alkali Soil Rectification and Carbon Fixation, Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University , Beijing, China .
authors.forename: Ning
authors.initials: N
authors.lastname: Zhang
authors.affiliation: Research Center for Saline-Alkali Soil Rectification and Carbon Fixation, Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University , Beijing, China .
authors.forename: Bo
authors.initials: B
authors.lastname: Zhao
authors.affiliation: Research Center for Saline-Alkali Soil Rectification and Carbon Fixation, Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University , Beijing, China .
authors.forename: Yuqun
authors.initials: Y
authors.lastname: Zhuo
authors.affiliation: Research Center for Saline-Alkali Soil Rectification and Carbon Fixation, Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University , Beijing, China .
authors.forename: Changhe
authors.initials: C
authors.lastname: Chen
keywords: FGD gypsum; environmental impact; heavy metals; sodic soil remediation; soil column-leaching experiment