title: Recycling flue gas desulphurization (FGD) gypsum for removal of Pb(II) and Cd(II) from wastewater.
abstract: The present study aims to verify the feasibility of directly reusing the flue gas desulphurization (FGD) gypsum generated from coal-fired power plants to adsorptively remove Pb(II) and Cd(II) from wastewater. The Toxicity Characteristic Leaching Procedure (TCLP) test was conducted to evaluate the leachability of toxic heavy metals from FGD gypsum. The adsorption behaviors of FGD gypsum for Pb(II) and Cd(II) such as pH impact, sorption kinetics, sorption isotherms and sorption thermodynamics were studied in a series of batch experiments. The pH studies indicated that the adsorption of Pb(II) and Cd(II) had their best adsorption amounts both at the pH values from 5.0 to 7.0. The kinetic analysis displayed that the adsorption processes both followed the pseudo-second order model well, and the FGD gypsum provided a higher sorption rate for Pb(II). Equilibrium studies showed that the adsorption of Pb(II) and Cd(II) could be properly described by Langmuir isotherms model, and the predicted maximum adsorption capacities were even greater than some specially prepared adsorbents. The thermodynamic investigation confirmed that the removal of Pb(II) and Cd(II) from aqueous medium could carry out spontaneously, and the higher temperature favored the processes. The instrument analysis techniques were also employed to deeply understand the mechanism involved in Pb(II) and Cd(II) removal by FGD gypsum. Overall, good sorption performance together with cost-effective characteristic makes FGD gypsum potentially attractive material for the Pb(II) and Cd(II) removal in industrial wastewater.
authors.affiliation: Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
authors.forename: Yubo
authors.initials: Y
authors.lastname: Yan
authors.affiliation: Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
authors.forename: Qiao
authors.initials: Q
authors.lastname: Li
authors.affiliation: Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China. Electronic address: sunxyun@njust.edu.cn.
authors.forename: Xiuyun
authors.initials: X
authors.lastname: Sun
authors.affiliation: Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
authors.forename: Zhiyuan
authors.initials: Z
authors.lastname: Ren
authors.affiliation: Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
authors.forename: Fei
authors.initials: F
authors.lastname: He
authors.affiliation: Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
authors.forename: Yalun
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China. Electronic address: wanglj@njust.edu.cn.
authors.forename: Lianjun
authors.initials: L
authors.lastname: Wang
mesh_terms: D002104:Cadmium / Q000737:chemistry / Q000302:isolation & purification*; D002133:Calcium Sulfate / Q000737:chemistry*; D005740:Gases / Q000737:chemistry*; D007854:Lead / Q000737:chemistry / Q000302:isolation & purification*; D010316:Particle Size; D013499:Surface Properties; D013816:Thermodynamics; D062065:Wastewater / Q000737:chemistry*
chemical_list: D002104:Cadmium; D002133:Calcium Sulfate; D005740:Gases; D007854:Lead; D062065:Wastewater
keywords: Adsorption; Cd(II); FGD gypsum; Mechanism; Pb(II)