TY - JOUR
T1 - Thioglycolate-based task-specific ionic liquids: Metal extraction abilities vs acute algal toxicity
AU - Platzer, Sonja
AU - Leyma, Raphlin
AU - Wolske, Sara
AU - Kandioller, Wolfgang
AU - Heid, Esther
AU - Schroeder, Christian
AU - Schagerl, Michael
AU - Krachler, Regina
AU - Jirsa, Franz
AU - Keppler, Bernhard K.
N1 - Publisher Copyright:
© 2017 The Authors
PY - 2017/10/15
Y1 - 2017/10/15
N2 - We studied the extraction behavior of two thioglycolate-based ionic liquids (ILs), for heavy metals from aqueous solutions; substances of interest were methyltrioctylammonium S-hexyl thioglycolate [N
1888][C
6SAc] and methyltrioctylphosphonium S-hexyl thioglycolate [P
1888][C
6SAc]. Theses ILs previously have shown very good extraction abilities towards cadmium and copper, therefore we investigated time-dependent metal removal experiments with aqueous solutions of cobalt(II), nickel(II) and zinc(II). The highest distribution ratio (R
IL/Water) was determined for zinc (R
IL/Water = 2000). Recovery studies for zinc after extraction were performed with different stripping agents showing a successful recycling. Additionally, the two ILs were immobilized on active charcoal, displaying great potential for solid-liquid extraction. Regarding the extraction mechanism, quantum-mechanical calculations were included, which indicate that the metal extraction depends on the stability of the metal-water cluster. Ligands (water as well as ILs) are planar coordinated in nickel complexes but showed a tetrahedral configuration for zinc. As a first estimate of the ecotoxicity of the ILs, in vivo tests toward three freshwater green algae species Tetradesmus obliquus, Desmodesmus armatus and Raphidocelis subcapitata were carried out. The EC
50 values (effective concentration after 72 h) confirm high toxicity of all tested ILs to all species, displaying only small differences between the species and EC
50ies.
AB - We studied the extraction behavior of two thioglycolate-based ionic liquids (ILs), for heavy metals from aqueous solutions; substances of interest were methyltrioctylammonium S-hexyl thioglycolate [N
1888][C
6SAc] and methyltrioctylphosphonium S-hexyl thioglycolate [P
1888][C
6SAc]. Theses ILs previously have shown very good extraction abilities towards cadmium and copper, therefore we investigated time-dependent metal removal experiments with aqueous solutions of cobalt(II), nickel(II) and zinc(II). The highest distribution ratio (R
IL/Water) was determined for zinc (R
IL/Water = 2000). Recovery studies for zinc after extraction were performed with different stripping agents showing a successful recycling. Additionally, the two ILs were immobilized on active charcoal, displaying great potential for solid-liquid extraction. Regarding the extraction mechanism, quantum-mechanical calculations were included, which indicate that the metal extraction depends on the stability of the metal-water cluster. Ligands (water as well as ILs) are planar coordinated in nickel complexes but showed a tetrahedral configuration for zinc. As a first estimate of the ecotoxicity of the ILs, in vivo tests toward three freshwater green algae species Tetradesmus obliquus, Desmodesmus armatus and Raphidocelis subcapitata were carried out. The EC
50 values (effective concentration after 72 h) confirm high toxicity of all tested ILs to all species, displaying only small differences between the species and EC
50ies.
KW - Ionic liquids
KW - Metal extraction
KW - DFT calculation
KW - Algal toxicity
KW - Immobilization
KW - PSEUDOKIRCHNERIELLA-SUBCAPITATA
KW - ACTIVATED CARBON
KW - IMMOBILIZATION
KW - IMIDAZOLIUM
UR - http://www.scopus.com/inward/record.url?scp=85023612135&partnerID=8YFLogxK
U2 - 10.1016/j.jhazmat.2017.06.053
DO - 10.1016/j.jhazmat.2017.06.053
M3 - Article
VL - 340
SP - 113
EP - 119
JO - Journal of Hazardous Materials
JF - Journal of Hazardous Materials
SN - 0304-3894
ER -