Structural study of the incorporation of heavy metals into solid phase formed during the oxidation of EDTA by permanganate at high pH.
Properties of solid phases formed during the oxidation of EDTA by permanganate in a high-pH, high-ionic strength solution, and the retention of Cu2+, Ni2+, and Zn2+ by them were examined. Morphologically, the solids were agglomerates of particles with sizes <100 nm. X-ray absorption spectroscopy (XAS) analysis indicated that these particles were birnessite. Its precipitation was accompanied by the removal of Zn2+ and Cu2+ released as a result of the breakdown of their complexes with EDTA. However, Ni2+ was not removed from the supernatant. Cu2+ was strongly bound by birnessite and exhibited little mobility in the pH range from 3 to 14. Zn2+ was more mobile, especially at pH > 12. XAS showed that Cu2+ binding sites were located within MnO6 octahedra-comprised sheets that constitute birnessite while Zn2+ was positioned between them.
Korshin
Gregory V
GV
Department of Civil and Environmental Engineering, Box 352700, University of Washington, Seattle, Washington 98115-2700, USA. Korshin@u.washington.edu
Chang
Hyun-Shik
HS
Frenkel
Anatoly I
AI
Ferguson
John F
JF
D004492:Edetic Acid / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D017895:Manganese Compounds / Q000737:chemistry*; D019216:Metals, Heavy / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D044367:Phase Transition; D013054:Spectrophotometry, Atomic; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D014961:X-Ray Diffraction
D017895:Manganese Compounds; D019216:Metals, Heavy; D010087:Oxides; D014874:Water Pollutants, Chemical; C048856:permanganic acid; D004492:Edetic Acid