ATR-FTIR investigation of molybdenum cycling in the presence of organics

CHED 1062

Kelly Murphy, jennifer.morford@fandm.edu and Jennifer L. Morford, jennifer.morford@fandm.edu. Department of Chemistry, Franklin & Marshall College, P.O. Box 3003, Lancaster, PA 17604-3003
This study investigates the importance of organic molecules (salicylic acid and protocatechuic acid) for molybdenum removal from the aqueous phase. Various combinations (molybdate; organic; molybdate and organic) were combined with solid aluminum oxide at a constant ionic strength, equilibrated, and analyzed using ATR-FTIR. In order to determine organic species' changes in the presence of molybdenum, spectral comparisons of the supernatant and solid were performed. These suggest that salicylic acid forms a different surface complex via its carboxylic group in the presence of molybdenum; molybdenum interacts with the phenolic group on salicylic acid. The shift and formation of new peaks in the molybdenum region implies that organic interactions influence molybdenum adsorption. Molybdenum has no effect on the adsorption of phenolic groups of protocatechuic acid to the solid surface as evidenced by a lack of change in the spectra. Analysis of the supernatant showed the formation of an aqueous molybdenum-organic complex.