Fabrication Of Mesoporous Materials By Hard Template Method And Its Adsorptive Removal Of Cr⁶⁺

Chromium in waste water is hiding a huge security risk to human body, which raises significant demands on removing this toxic metal ions, Cr(VI) in particular.Various technologies have been developed in the past to tackle this problem, including the use of mesoporous molecular sieve as adsorbents. However, the performance of the adsorbent needs to be further improved, leading to the key objective of the current work.The work started with the preparation of Fe-modified SBA-15 which is a well-received mesoporous molecular sieves. The resulting products such as FeX/SBA-15/a,FeX/SBA-15/b,FeX/SBA-15/c,FeX/SBA-15/T1,FeX/SBA-15/T2 and FeX/SBA-15/T3 toward the removal of Cr(VI) were consciously investigated.The corresponding kinetics adsorption model and Isotherm adsorption models were also fitted based on experimental data.The characteristics of as-prepared FeX/SBA-15/a, Fe X/SBA-15/b,FeX/SBA-15/c were also revealed via BET measurement. The results indicated that FeX/SBA-15/a has the highest specific surface area; and its maximum adsorption capacity toward Cr(VI) reached up to 40mg/g. FeX/SBA-15/T3 showed its new profile in different initial concentration of potassium dichromate compared with FeX/SBA-15/T1, Fe X/SBA-15/T2 and FeX/SBA-15/T3. Adsorption capacity was mostly influenced by initial concentration of potassium dichromate and value of pH.The adsorption behavior fit well with pre-second kinetics adsorption model and Freundlich Isotherm adsorption model.Finally, the adsorbents were further characterized using X- ray diffraction and scanning electron microscopy(SEM) to reveal the composition and surface morphology. The findings are very helpful to establish the relationships between adsorbent structure and its adsorption mechanism. Overall, the experimental results demonstrated that the as-modified mesoporous materials is feasible and promising in the clarification of chromium-containing wastewater.