Titanium dioxide mediated photocatalysis of Pb(II)- and Co(II)-EDTA complexes
- Univ. of Maryland, College Park, MD (United States)
The photocatalysis of lead and cobalt(II) complexed to EDTA was evaluated under a variety of experimental conditions. Adsorption characteristics of the metals and the metal complexes were also determined. A recirculating batch system was used to quantify photocatalytic oxidation rates. EDTA mineralization and total dissolved metal were monitored. Separations of Co(II*), Co(II)-EDTA, and Co(III)-EDTA were made with a method using Dowex cation exchange resin. Adsorptions of Pb(II), Co(II), EDTA, and the corresponding metal complexes was examined using concentrations of 10{sup -}{sup 5} to 10{sup -}{sup 3} M in 2 g/L TiO{sub 2}. After purging and pH adjustment, the samples were shaken overnight. The final pH and metal and TOC concentrations were determined. Results showed that the photocatablytic oxidation of metal-EDTA complexes is independent of pH from 5 to 7. This contrasts with the adsorption of these species onto TiO{sub 2}, which decreases at neutral-high pH, suggesting that adsorption is not a prerequisite to photocalysis. For Co(II)-EDTA, a competing pH dependent conversion to Co(III)-EDTA is noted.
- OSTI ID:
- 210237
- Report Number(s):
- CONF-9509139--
- Country of Publication:
- United States
- Language:
- English
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