Abstract:
In this study, the effects of surface functional groups on the removal of 17α-methyltestosterone (MT) by adsorption on porous silicate adsorbent (Santababara Acid 15) were investigated. Surfaces of the adsorbents were modified by grafting five surface functional groups; silanol (SBA-15), 3-aminopropyltriethoxy (A-SBA-15), 3-mercaptopropyltriethoxy (M-SBA-15), triethoxyoctyl (O-SBA-15) and phenyltrimethoxy (P-SBA-15). From obtained results, the adsorption of MT onto all adsorbents was found to rapidly decrease and desorbed MT before reaching equilibrium, except A-SBA-15 which cannot adsorb MT. The MT adsorption did not follow both the pseudo-first-order and pseudo-second-order kinetic models. The hydrophobic adsorbents (O-SBA-15, M-SBA-15 and P-SBA-15) had higher MT adsorption capacities than hydrophilic adsorbents (SBA-15). The hydrophilic adsorbents (SBA-15) had higher MT desorption than the hydrophobic adsorbents (O-SBA-15, M-SBA-15 and P-SBA-15). The adsorption capacities of all adsorbents relate to hydrophobic interaction, London dispersion force, π-π electron donor-acceptor, ion-dipole electrostatic interaction and hydrogen bonding between MT molecule and surface functional groups. Mixing with Tannic acid can slightly enhance MT adsorption capacities. It might be caused by interaction between MT molecule and already adsorbed tannic acid on the surfaces.