It is also important to highlight that because of the weak affinity towards As(III) by several adsorbents, the arsenic treatment technologies require the pre-oxidation of As(III) to As(V) to allow the efficient uptake. Pre-oxidation is used in technologies employing iron coagulants, nanofiltration by thin-films, and membrane-integrated hybrid systems . These processes turn costly and time-consuming due to the operational complexity, using strong oxidants (H2O2 and KMnO4) or photocatalysts (TiO2) in the pre-oxidation process.