Synthesis and characterization of biochar and nano-biochar composites produced from tree fruit seeds and their applications in the removal of some cationic dyes from aqueous solutions

The use of synthetic dyes in the industry has caused pollution of water basins and it has gained importance in recent years to turn wastewater into usable water. Characterization of raw biomass, biochars and modified biochars have been carried out. In this study, fruit seeds of the Guilibris (Albizia julibrissin) tree and fruit seeds of the Popcorn (Colutea cilicica) tree were used as raw biomass. The synthesized biochars were modified with silver and iron loaded nanoparticles. Silver nanoparticles were obtained by green synthesis method. In this method, fresh green walnut shell (Juglans regia) was used as plant extract. In equilibrium and thermodynamic studies for the removal of methylene blue and malachite green dyes from aqueous solutions, the effect of adsorption parameters (pH, contact time, adsorbent amount and initial dye concentration) were investigated and optimum parameters for adsorption processes were determined. The experimental results were analyzed according to Langmuir, Freundlich and Temkin isotherms. Kinetic studies were carried out to study the effect of contact time on adsorption. By changing the temperature during the dye removal process, Gibbs free energy, enthalpy and entropy values were calculated and the appropriate operating temperature was determined. In this thesis study, it has been shown that biochars and modified biochars are adsorbents that can be used efficiently in the removal of dyes from aqueous solutions. It was concluded that the synthesized adsorbents will have an efficient role in the economic removal of dye pollutants from water resources.