1.Surface Area and Pore Structure of active alumina:

The presence of oxidized iron can alter the surface area and pore structure of active alumina. However, this change in surface properties can affect the adsorption capacity and selectivity of the material for fluoride ions.

2.Charge Density:

Oxidized iron can introduce additional positive charge onto the surface, which can enhance the electrostatic attraction between the material and negatively charged fluoride ions. Moreover, this increased charge density can lead to improved fluoride adsorption performance.

3.Chemical Reactivity:

The presence of oxidized iron can increase the chemical reactivity of activated alumina, promoting the formation of stronger chemical bonds with fluoride ions. This enhanced chemical interaction can result in better fluoride adsorption performance. 

4.Catalytic Activity of active alumina:

Oxidized iron can act as a catalyst, facilitating the adsorption of fluoride ions onto the surface of active alumina. By lowering the activation energy required for the adsorption process, the presence of oxidized iron can improve the overall fluoride adsorption performance.

5.Stability and Durability:

The incorporation of oxidized iron into activated alumina can enhance the stability and durability of the material under various operating conditions. This improved stability can contribute to maintaining the high fluoride adsorption performance of the material over time.