Adsorption Behavior and Mechanism of Arsenic on Mesoporous Silica Modified by Iron-Manganese Binary Oxide (Femnox/sba-15) from Aqueous Systems.

Iron-manganese binary oxides (FeMnOx) can remove contaminants from aqueous solutions with high efficiency, and mesoporous silica (SBA-15) is widely used as a supporting material due to its large specific surface area and good stability. In this study, SBA-15 was used to support FeMnOx in the synthesis of a novel arsenic (As) adsorbent (FeMnOx/SBA-15), and its characteristics under different reaction conditions, such as pH, temperature, presence of competing ions, and humic acid, were tested. The results showed that the contaminant adsorption efficiency of the novel adsorbent was better than that of bare FeMnOx, as the addition of SBA-15 decreased the agglomeration effect of FeMnOx. Additionally, FeMnOx/SBA-15 underwent calcination to further enhance its performance. The state of iron and manganese in FeMnOx/SBA-15 and the corresponding arsenic removal efficiency were improved by calcination at 350 degrees C with an FeMnOx/SBA-15 mass fraction of approximately 45%. Almost 90% of As (50 mL, 5.0 mg L-1) could be removed by 0.2 g L-1 of FeMnOx/SBA-15 (mass ratio of 45% and calcination temperature of 350 degrees C). The FeMnOx/SBA-15 could regenerate and still be used after four consecutive cycles. The high As sorption capacity, ability to regenerate, and reusability of FeMnOx/SBA-15 confirmed that this adsorbent is promising for treating As-contaminated drinking water.