ازالة صبغتي Indigo carmine وMalachite green من محاليلها المائية بأستخدام أوكسيد متراكب نانوي نوع سباينل MnFe2O4و MnFe2O4-MgO كسطوح مازة

Removal of Indigo carmine and Malachite green from aqueous solution by using spinel nano composite oxides MnFe2O4 and MnFe2O4-MgO as adsorbent

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 Indigo carmine (IC) and Malachite green (MG) 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).
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 the IC dye at an equilibrium time of 20 min. The weight of the adsorbent surface is 0.01g and at pH = 2 for the adsorbent surface MnFe2O4, while the equilibrium time was 10min. The weight of the adsorbent surface is 0.005g and at pH=6 for the adsorbent surface bearing MnFe2O4-MgO.
As for the MG dye, the results showed that equilibrium occurs at a time of 20 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 the IC and MG 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 IC and MG dyes showed that they agree with the Freindlich 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 ∆ Gin Indigo carmine 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 Malachite green 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 Malachite green dye, 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 IC and MG 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.