Adsorption Kinetics of Acid Orange 7 on Nano-CeO₂–TiO₂ in Water

Abstract

To investigate the application of nano-CeO2-TiO2 as a sorbent in wastewater treatment, CeO2-TiO2 powder was prepared by the solvothermal method and then characterized. The adsorption kinetics of the adsorption of acid orange 7 (AO7) on CeO2-TiO2 were investigated under various conditions, such as initial concentration, temperature, and pH of the AO7 solution. Kinetic analyses were conducted with both Lagergren pseudo-first and pseudo-second order models. The results showed that the CeO2-TiO2 powder was composed of cubic CeO2 and anatase TiO2 with a specific surface area of 140.42 m2 x g(-1). The adsorption capacity of AO7 on CeO2-TiO2 increased with increasing starting concentration of AO7, but decreased with increasing temperature. The most favorable pH range of the A07 solution was 3-8 for the adsorption of AO7 on CeO2-TiO2. The results revealed that the adsorption kinetics of AO7 on CeO2-TiO2 matched the pseudo-second order model very well. The results indicate that CeO2-TiO2 has a potential application in the removal of AO7 from wastewater.

Magnetic MOF for AO7 Removal and Targeted Delivery

“…As shown in Figure 5a, the adsorption of Fe 3 O 4 @UiO-66 with a very fast growth rate was complete within 5 h, and with the passage of time, the adsorption rate of Fe 3 O 4 @UiO-66 slowed down and reached a plateau at 140 mg/g. AO7 [39,40] is an acidic dye, the composite mainly relies on Lewis acid-base interaction between AO7 and Zr-based MOFs [34]. Figure 5c shows the release profile of Fe 3 O 4 @UiO-66 with AO7, which is quite fast and releases 60% within 5 h which is affected by natural diffusion [34,41].…”