Effect of glutamic acid on copper sorption onto kaolinite - Batch experiments and surface complexation modeling.
High carbonate content of the European Kupferschiefer ore deposits is a challenge for acid copper leaching (pH ≤ 2). Therefore investigating the mobility behavior of Cu(II) under conditions related to an alternative, neutrophil biohydrometallurgical Cu(II) leaching approach is of interest. As glutamic acid (Glu) might be present as a component in the growth media, we studied its effects on the adsorption of Cu(II) onto kaolinite. The binary and ternary batch sorption measurements of Cu(II) and Glu onto kaolinite were performed in the presence of 10 mM NaClO4as background electrolyte and at a pH range from 4 to 9. Sorption experiments were modeled by the charge-distribution multi-site ion complexation (CD-MUSIC) model by using single sorption site (≡SOH) and monodentate surface complexation reactions. Glu sorption on kaolinite is weak (<10%) and independent of pH. Furthermore, Glu slightly enhances the Cu(II) sorption at low pH but strongly hinders (up to 50%) the sorption at higher pH and therewith enhances copper mobility. The results of isotherms show that Cu(II)-Glu sorption onto kaolinite mimics the Freundlich model. The proposed CD-MUSIC model provides a close fit to the experimental data and predicts the sorption of Cu(II), Cu(II)-Glu and Glu onto kaolinite as well as the effect of Glu on Cu(II) mobility.
Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Permoserstr. 15, 04318 Leipzig, Germany. Electronic address: l.karimzadeh@hzdr.de.
Lotfollah
L
Karimzadeh
Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Permoserstr. 15, 04318 Leipzig, Germany. Electronic address: r.barthen@hzdr.de.
Robert
R
Barthen
Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Permoserstr. 15, 04318 Leipzig, Germany. Electronic address: m.stockmann@hzdr.de.
Madlen
M
Stockmann
Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Permoserstr. 15, 04318 Leipzig, Germany. Electronic address: m.gruendig@hzdr.de.
Marion
M
Gruendig
Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Permoserstr. 15, 04318 Leipzig, Germany. Electronic address: k.franke@hzdr.de.
Karsten
K
Franke
Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Permoserstr. 15, 04318 Leipzig, Germany. Electronic address: j.lippmann-pipke@hzdr.de.
Johanna
J
Lippmann-Pipke
D000327:Adsorption; D003300:Copper / Q000737:chemistry / Q000302:isolation & purification*; D052918:Environmental Restoration and Remediation / Q000379:methods; D018698:Glutamic Acid / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007616:Kaolin / Q000737:chemistry*; D008956:Models, Chemical
D007616:Kaolin; D018698:Glutamic Acid; D003300:Copper
Copper mobility; Glutamic acid; Kaolinite; Sorption; Surface complexation modeling