title: Thermodynamic parameters for adsorption equilibrium of heavy metals and dyes from wastewaters: Research updated.
abstract: The standard Gibbs free energy, enthalpy and entropy change data for adsorption equilibrium reported in biosorption literature during January 2013-May2016 were listed. Since the studied biosorption systems are all near-equilibrium processes, the enthalpy and entropy change data evaluated by fitting temperature-dependent free energy data using van Hoff's equation reveal a compensation artifact. Additional confusion is introduced with arbitrarily chosen adsorbate concentration unit in bulk solution that added free energy change of mixing into the reported free energy and enthalpy change data. Different standard states may be chosen for properly describing biosorption processes; however, this makes the general comparison between data from different systems inappropriate. No conclusion should be drawn based on unjustified thermodynamic parameters reported in biosorption studies.
authors.affiliation: Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan.
authors.forename: Yingju
authors.initials: Y
authors.lastname: Chang
authors.affiliation: R&D Center for Membrane Technology, Department of Chemical Engineering, Chung Yuan Christian University, Chungli, Taiwan.
authors.forename: Juin-Yih
authors.initials: JY
authors.lastname: Lai
authors.affiliation: Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan; R&D Center for Membrane Technology, Department of Chemical Engineering, Chung Yuan Christian University, Chungli, Taiwan; Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan. Electronic address: djlee@ntu.edu.tw.
authors.forename: Duu-Jong
authors.initials: DJ
authors.lastname: Lee
mesh_terms: D000327:Adsorption; D004396:Coloring Agents / Q000737:chemistry* / Q000302:isolation & purification; D019216:Metals, Heavy / Q000737:chemistry* / Q000302:isolation & purification; D012996:Solutions / Q000737:chemistry; D013696:Temperature; D013816:Thermodynamics; D062065:Wastewater / Q000737:chemistry*
chemical_list: D004396:Coloring Agents; D019216:Metals, Heavy; D012996:Solutions; D062065:Wastewater
keywords: Adsorption; Dye; Equilibrium; Heavy metal; Low-cost adsorbent; Thermodynamics