ازالة صبغتيAzure A و Coomosie brilliant blue G -250من محاليلها المائية بأستخدام أوكسيدين متراكبين نانويين نوع سباينل MnFe2O4و MnFe2O4-MgO كسطحين مازين

Removal of Azure A and Coomosie brilliant blue G-250 dyes from aqueous solutions using MnFe2O4 and MnFe2O4-MgO nanocomposite spinel oxides as coating surfaces

The study in this thesis included the preparation of two spinel surfaces consisting of manganese and iron oxides in the form of spinel structure MnFe2O4 which loaded on magnesium oxide MnFe2O4-MgO to remove the dyes(Azure A) and CBBG-250 by the adsorption process, prepare the two adsorbent surface MnFe2O4 and MnFe2O4-MgO by co-precipitation method, and then subjected using infrared technique (FT-IR), X-ray diffraction (XRD), and scanning electron microscopy (FESEM), and Atomic force microscope diagnosis of (AFM).
A study was also conducted to determine the best conditions for the adsorption process, which included (equilibrium time, adsorbent surface weight, acidity pH, effect of ionic strength, effect of temperature (isotherms),The results showed that equilibrium occurs for theCBBG-250 dye at an equilibrium time of 5 min. The weight of the adsorbent surface is 0.01g and at pH = 2 for the adsorbent surface MnFe2O4, while the equilibrium time was 5min. The weight of the adsorbent surface is 0.008g and at pH=2 for the adsorbent surface bearing MnFe2O4-MgO.
As for the Azure A dye, the results showed that equilibrium occurs at a time of 10 minutes. The weight of the adsorbent surface is 0.01g, and the acidity function pH=8 for the adsorbent surface is MnF2O4, while the equilibrium time was 5min. The weight of the adsorbent surface is 0.005 g at pH=8 for the MnFe2O4-MgO loaded adsorbent surface.
The ionic strength had a clear effect on the adsorption process, as it became clear that the adsorption capacity decreased with increasing the concentration of the ionic strength for both dyes.
The removal of theAzure A and CBBG-250 dyes was studied by using the MnFe2O4and MnFe2O4-MgO at different temperatures (298, 308, 318, 328, 338 K) to determine adsorption isotherms and thermodynamic functions.
use Langmuir, Freundlich and Temkin isotherm models to describe the experimental isotherms and isotherm constants, and the equilibrium data for Azure A and CBBG-250 dyes showed that they agree with the Freindlich and Temkin isotherm and were well equilibrium on the two surfaces MnFe2O4 and MnFe2O4-MgO and it does not apply to the Lanckmeyer isotherm, and the shape of the isotherm for both dyes takes the shape of the letter S according to the classification Giles.
The values of the thermodynamic functions were calculated, which are compressive energy ∆G, enthalpy ∆H and entropy ∆S. The results showed that the negative values of ∆G Azure A dye indicate that the adsorption process is spontaneous, and that the positive values of ∆H and ∆S indicate that the adsorption process is endothermic and an increase in Randomness as a result of its association on the adsorbent surface MnFe2O4and MnFe2O4-MgO while the values of the thermodynamic functions ∆G, negative ∆H and positive ∆S in CBBG-250 dye indicate the adsorption process is spontaneous, endothermic, and an increase in randomness as a result of its association with the MnFe2O4 adsorbent surface. As for the negative ∆G, ∆H, and ∆S positive values in CBBG-250 , they indicate that the adsorption process is spontaneous, endothermic, and the randomness increase in the system due to the loss of water that surrounds the dye molecules. MnFe2O4-MgO adsorbed on the surface..
A comparison was made between the use of both surfaces for the adsorption of Azure A and CBBG-250 dyes, and it was found that the adsorption of both dyes on the MnFe2O4-MgO adsorbent surface was better than using the MnFe2O4 adsorbent surface.