Covalent Synthesis and Performance Evaluation of Graphene Oxide/y-Alumina Hybrid Nanocomposite for Industrial Wastewater Treatment

This study presents the synthesis, characterization, and wastewater treatment performance of a novel hybrid nanocomposite composed of graphene oxide (GO) and γ-alumina (γ-Al۲O۳). Functionalization achieved through silanization using ۳-glycidyloxypropyltrimethoxysilane (GPTMS) for GO and ۳-aminopropyltriethoxysilane (APTES) for γ-Al۲O۳, followed by covalent grafting via epoxy-amine linkage. FTIR spectroscopy confirmed successful grafting, with clear evidence of Si-O-Si stretching and reduction of epoxy ring vibrations. BET surface area analysis revealed that the GO/γ-Al۲O۳ hybrid retained a high specific surface area (۱۹۸.۰۸ m²/g), comparable to commercial γ-Al۲O۳, confirming that GO did not hinder porosity. UV-Vis spectroscopy demonstrated the hybrid's high affinity for silver ions, as indicated by a gradual decrease in AgNO۳ absorbance at ~۴۳۰ nm with increasing nanoparticle concentration (۱-۵%). Real-world wastewater from a metal industry source was treated with GO/γ-Al۲O۳ at various concentrations (۰%, ۳%, ۴%, and ۵%). Substantial reductions in chemical oxygen demand (COD), biological oxygen demand (BOD), and turbidity were observed. At ۵% nanoparticle dosage, COD and BOD were reduced from ۱۱۶۲ mg/L and ۴۸۰ mg/L to ۶۴ mg/L and ۱۱ mg/L, respectively, while turbidity decreased from >۱۱۰۰ NTU to ۱.۶۲ NTU. These findings suggest that the GO/γ-Al۲O۳ hybrid nanocomposite is a powerful multifunctional adsorbent capable of simultaneously removing heavy metals, reducing organic load, and improving water clarity. Its scalability, stability, and synergy between GO and γ-Al۲O۳ functionalities make it a promising material for industrial wastewater treatment applications.

کلیدواژه ها:

Graphene oxide (GO) ، γ-Alumina nanoparticles ، Hybrid nanocomposites ، Wastewater treatment ، Heavy metal adsorption