Metal ion-supported mesoporous silica materials for the removal of sulfamethizole from water

The extensive use of sulfonamide antibiotics (SAs) proved to be harmful to humans and the environment; thus, the treatment of SAs in water is imminent. In this work, mesoporous SBA-15 silicon was modified using N-[3-(trimethoxysilyl)propyl]ethylenediamine (AAPTMS) through the formation of AAPTMS-SBA-15. The adsorption performance of AAPTMS-SBA-15 toward sulfamethizole (SIZ) was investigated in the absence and presence of various metal ions, and the results reveal that the introduction of Ni2+ substantially improved the adsorption capacity for SIZ. To maximize the adsorption performance toward SIZ, AAPTMS-SBA-15 was then combined with the heavy metal Ni2+ to prepare Ni-AAPTMS-SBA-15. Subsequently, the adsorption performance and behavior of Ni-AAPTMS-SBA-15 were studied in terms of pH, adsorbent dosage, kinetics, isothermal adsorption, and thermodynamics. SIZ exhibited spontaneous and exothermic adsorption on Ni-AAPTMS-SBA-15, which rapidly reached equilibrium within 2 min; the maximum adsorption capacity was 188.68 mg g−1 at pH = 5.0 and adsorbent dosage of 8 mg. The effective adsorption of SIZ was attributed to the combined mechanisms of electrostatic interaction, complexation and pore-filling.