Adsorption studies of Mo and V onto ferrihydrite

In this paper, the kinetics of Mo and V (100 mu M) uptake oil ferrihydrite (FHY) were evaluated in batch. mono-sorbate systems at pH between 4 and 9, and in bi-sorbate systems in the presence of P (100 mu M) at pH 7. In the Mo and V single-sorbate experiments, 100% adsorption was observed at pH values below 6 and 9, respectively. Above the point of zero charge (PZC = 7.97) of FHY, the adsorption efficiency for Mo dropped dramatically (20% at pH 8) while V showed high uptake efficiencies even at pH 9 (60% efficiency). The results from the bi-sorbate experiments (Mo-P and V-P) showed that at pH 71 P out-competed (97%) Mo for binding sites on FHY, while in the V-P binary system only similar to 44% of the binding sites are occupied by P with the remaining sites being occupied by V.