Nanoscale zero-valent iron for the removal of Zn2+, Zn(II)-EDTA and Zn(II)-citrate from aqueous solutions.
The parameters which influence the removal of different zinc (Zn) species: Zn(2+), Zn(II)-EDTA and Zn(II)-citrate from aqueous solutions by nanoparticles of zero-valent iron (nZVI) were investigated at environmental relevant pH values. Untreated, surface modified and silica-fume supported nZVI were applied at different iron loads and contact times to Zn solutions, which were buffered to pH 5.3, 6.0 and 7.0. The results revealed that pH, the type of nZVI, the iron load, the contact time, and the Zn species all had a significant influence on the efficiency of removal. Zn(2+), Zn(II)-EDTA and Zn(II)-citrate were the most effectively removed from aqueous solutions by untreated nZVI. Zn(2+) removal was governed mainly by adsorption onto precipitated iron oxides. Complete removal of Zn(2+) and Zn(II)-citrate was obtained at all pH values investigated. The removal of strong Zn(II)-EDTA complex was successful only at acidic pH, which favored degradation of Zn(II)-EDTA. Consequently, the released Zn(2+) was completely removed from the solution by adsorption onto iron oxides.
Slovenian National Building and Civil Engineering Institute, Dimičeva ulica 12, 1000 Ljubljana, Slovenia.
Nina
N
Kržišnik
Slovenian National Building and Civil Engineering Institute, Dimičeva ulica 12, 1000 Ljubljana, Slovenia.
Ana
A
Mladenovič
Slovenian National Building and Civil Engineering Institute, Dimičeva ulica 12, 1000 Ljubljana, Slovenia.
Andrijana Sever
AS
Škapin
Slovenian National Building and Civil Engineering Institute, Dimičeva ulica 12, 1000 Ljubljana, Slovenia.
Luka
L
Škrlep
Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia.
Janez
J
Ščančar
Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia. Electronic address: radmila.milacic@ijs.si.
Radmila
R
Milačič
D000327:Adsorption; D002951:Citrates / Q000737:chemistry; D004492:Edetic Acid / Q000737:chemistry*; D007501:Iron / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*; D018508:Water Purification / Q000379:methods; D015032:Zinc / Q000032:analysis / Q000737:chemistry*
D002951:Citrates; D014874:Water Pollutants, Chemical; D004492:Edetic Acid; D007501:Iron; D015032:Zinc
Aqueous solutions; Nanoparticles of zero-valent iron; Remediation; Zn(2+); Zn(II)–EDTA; Zn(II)–citrate