Oxidation of nonylphenol using ferrate

Public concerns on nonylphenol (NP) and nonylphenol ethoxylates (NPEOs) are growing because they are frequently detected in the aquatic environment and proven endocrine disrupter compounds (EDCs). Since these compounds cannot be biologically completely degraded, chemical oxidation has been frequently applied to degrade NP and NPEOs. In this study, ferrate(VI) (Fe(VI)) was used to oxidize NP and its oxidation kinetics was evaluated. It should, however, be noted that the first order rate was evaluated using data collected only after the initial degradation phase, in which 50-70 % Np was degraded. In fact, the NP and Fe(VI) concentrations during the ID phase could not be quantified since the oxidation was too fast. The effect of hydrogen peroxide (H2O2) presence on the NP oxidation by Fe(VI) was also evaluated. In general, the initial destruction of NP by Fe(VI) at lower pH was more significant than higher pH (i.e., 26% at pH 9.0 and 71% at pH 6.0). H₂O₂ addition did not have much impact on the NP oxidation. When applied to oxidation of NP in natural water, Fe(VI) showed less removal efficiency possibly due to the presence of dissolved organics in the water.