Third, following the known mechanisms, oxidative defluorination is realized via a series of "spontaneous" pathways after the oxidants add an -OH to the fluorinated carbon. The pathways include HF elimination from -C(OH)F-, hydrolysis of -C(O)F, and hydrolysis of ester CF3CO-O-RF. Thus, all transformation products are expected to include a -COO -, being subject to further degradation by SO4 -•. In theory, 100% oxidative defluorination can be expected, but experimental results found limited defluorination of NBP-COOH (62.3%) and TP1 (68.1%) at a high S2O8 2- dose of 200:1 (Table , zones C and D). Even for the simple molecule TP2, the defluorination appeared to be limited at ~90% (Table , entries 7-10). Therefore, other unknown pathways and mechanisms exist for SO4 -• oxidation. This insight is further evidenced by the bigger gap of F atom balance for SO4 -• than for HO• (Table , zones B and C versus A).