Post-modification of nanoporous silica type SBA-15 by bis(3-triethoxysilylpropyl)tetrasulfide as an efficient adsorbent for arsenic removal

Abstract A silica-based mesoporous adsorbent, SBA-15-S 4 was synthesized through the surfactant method and modified by bis(3-triethoxysilylpropyl) tetrasulfide. The obtained sorbent was characterized by FT-IR, BET, TGA, XRD, SEM, TEM, SAXS and EDX. Further studies revealed that the new synthesis sorbent has a high capacity to adsorb As(III) ions. The main experimental factors affecting removal efficiency of the adsorbent including pH and concentration of the sample solution, contact time, type and quantity of the eluent were all optimized. Under the optimal conditions, the maximum adsorption capacity of the modified SBA-15 was calculated to be 322.6 mg g − 1 . The adsorption mechanism was also studied, and it was found that the Langmuir isotherm model well fitted in the obtained equilibrium data of adsorption process. The sorbent was successfully used in arsenic removal from three real water samples, including tap water, well water and lake water.