Evaluation of the Iron (III) oxide/sawdust nanocomposite efficiency in COD removal from landfill leachate: optimization and evaluation of adsorption isotherms Research Areas :

One of the characteristics of municipal wastes is the high percentage of perishable organic matter, which is associated with a significant amount of leachate production. Waste leachate, whether fresh, compost or landfill leachate, has a variety of suspended and soluble organic and inorganic materials, and may also contain a variety of pathogens and heavy metal compounds. Therefore, the leachate can lead to many environmental problems. The purpose of this study is COD removal from landfill leachate using bio-magnetic iron (III) oxide/sawdust nanocomposite. First, Fe3O4/SD magnetic nanocomposite was synthesized by the chemical precipitation method and the structure and morphology of the synthesized nanocomposite were investigated using X-ray Diffraction (XRD) and Field Scanning Electron Microscopy (FE-SEM) technique. Then, the effect of influential variables on the adsorption process including pH, contact time, adsorbent amount, and temperature on the removal of COD were investigated. The results of effective parameters showed that the highest COD removal efficiency was observed at pH 7, the adsorbent amount of 0.4 g, the contact time of 45 minutes, and the temperature of 45°C with a removal efficiency of about 70%. Also, the isotherm studies confirmed that the removal process followed the Freundlich isotherm more closely (R2= 0.9243) and the heterogeneity and multilayers of the adsorption process were confirmed. Finally, the results showed that treatment of the landfill centers leachate's organic load is possible using the adsorption process of Fe3O4/SD magnetic nanocomposite and can be used as an efficient method in leachate treatment of landfill centers and compost plants.