Magnetic biocomposite synthesis of adsorbents and characterization: Methylene blue investigation of adsorption

With the increase in technology and population, people's needs have increased and there has been a rapid increase in textile industry activities. In order to meet these needs, the ability to dye industrial products has led to the consumption of dyestuffs. However, water containing dyestuffs discharged into water resources without treatment causes water pollution. Dyes have low biodegradability properties due to the aromatic rings and double bonds in their structures. They are also durable and permanent chemical substances. Therefore, if they are not purified appropriately and in sufficient quantities, they have a lethal effect on aquatic life. In this study, it was aimed to investigate the removal of methylene blue (MM) from aqueous media by synthesizing magnetic biocomposite adsorbents containing glutaraldehyde cross-linked chitosan-coated vegetal waste (olive tree leaves, walnut tree leaves and fig tree leaves). Time-dependent MM retention capacity, MM adsorption capacity at different initial concentrations, pH-dependent MM capacity, adsorption thermodynamics and adsorption isotherms of the synthesized biocomposites were examined. It was tried to determine its suitability for Langmuir, Freundlich and Temkin isotherms. In the adsorption process, magnetic chitosan-based olive tree leaf cross-linked with glutaraldehyde (nFe3O4-Kts-ZY), magnetic chitosan-based walnut tree leaf cross-linked with glutaraldehyde (nFe3O4-Kts-CY) and magnetic chitosan-based fig tree leaf cross-linked with glutaraldehyde (nFe3O4-Kts-İY). The optimum adsorbent dosage for biocomposites was found to be 6 g/L. In the MM removal process, the equilibrium time for all three biocomposite adsorbents was 120 min. It has been observed that . The most suitable pH for MM adsorption efficiency was found to be 6. Surface properties of nFe3O4-Kts-CY, nFe3O4-Kts-ZY and nFe3O4-Kts-İY adsorbents synthesized in the thesis before and after MM adsorption, elemental composition by SEM analysis, characterization of functional groups by SEM-EDX analysis, determination by FTIR method and structural analyzes by XRD technique. has been made. It has been proven that nFe3O4-Kts-CY, nFe3O4-Kts-ZY and nFe3O4-Kts-İY biocompocites prepared in this study are effective adsorbents for MM removal from aqueous solutions.