Abstract
Oxygen isotope(<18>^O and<16>^O)effect between dissolvedand adsorbed phosphate anion (P0_4^3 )on iron hydroxide was experimentally examined in the aqueous system using differential isotopemethod The chemical kinetics of adsorption density(μmole/m^2)suggested that the adsorption structure evolved from macropore(surface dffusion)to micropore diffusion. In the earlier process, no significant isotope fractionation on the macropore surface occurred but in the followed process,<18>^ bearing P0_4^3 was preferentially partitioned onto the surface site of micropore. An in situ laser Raman analysis distinguished these adsorption species and revealed that the formation of the FeP0_4 like structure dominated in the later adsorption process .
