Breakthrough curves show the concentration of byproducts from glyphosate oxidation generally follow the order: phosphate > glycine > AMPA > ammonium, with similar trends but lower concentrations detected in experiments with hausmannite, and at pH 7.2 (Figure and S7 and Table ). NH4 + was not detected with hausmannite. These results indicate that glycine is the dominant byproduct from glyphosate oxidation (at least initially) although AMPA concentrations increase with time suggesting favorability for the AMPA pathway at later times. BSA association significantly suppressed the formation of glycine on K-birnessite at pH 4.6 and 7.2 (Figure and Table ). Estimated rate constants (Table ) for glyphosate oxidation through the glycine (kr,1) and AMPA (kr,2) pathways and AMPA degradation (kr,3) suggests glycine formation occurs at the early stage of the transformation sequence, but the AMPA pathway is preferred at the late stage. This is in good agreement with pervious work where AMPA was found to be more resistant to degradation compared to glyphosate. Furthermore, our preliminary in-situ adsorptiondesorption experiments confirm that AMPA can bind to the surface of K-birnessite via its phosphonate groups (Figure ). Therefore, lower AMPA concentrations detected in effluents compared to glycine (Figure ), and low estimated kr,3 values may include the combined effects of adsorption and degradation of AMPA. The rate of transformations on Mn oxides follow the sequence: kr,1 >> kr,2 > kr,3. Notably, K-birnessite was able to degrade glyphosate with faster rates than hausmannite (kr,1 and kr,2), especially at pH 7.2 (Table ). BSA association enhanced all the transformation rate constants (kr,1, kr,2 , and kr,3), except at pH 7.2 for kr,1 (birnessite and hausmannite) and for kr,3 (birnessite).