Ammonia removal from industrial effluent using zirconium oxide and graphene-oxide nanocomposites

The present study developed and evaluated nano-adsorbents based on zirconium oxide and graphene oxide (ZrO₂/GO) as a novel adsorbent for the efficient removal of ammonia from industrial effluents. Fourier transform infrared (FTIR) spectroscopy, Field Emission Scanning Electron Microscope, Energy-dispersive X-ray Spectroscopy, and X-ray diffraction were used to evaluate and identify the novel adsorbent in terms of morphology, crystallography, and chemical composition. The pH (7), adsorbent quantities (20 mg), adsorbent contact time (30 min) with the sample, and initial ammonia concentration were all tuned for ammonia uptake. To validate ammonia adsorption on the ZrO₂/GO adsorbent, several kinetic models and adsorption isotherms were also utilized. The results showed that the kinetics of ammonia adsorption are of the pseudo-second order due to high R² (>0.99) value as compared first-order (R² = 0.52). The chemical behavior and equilibrium isotherm were analyzed using the isotherm models and Langmuir model provided high R² (>0.98) as compared Freundlich (>0.96). Hence, yielding a maximum uniform equilibrium adsorption capacity of 84.47 mg g^-1. The presence of functional groups on the surface of graphene oxide and ZrO₂ nanoparticles, which interact efficiently with ammonia species and provide an efficient surface for good ammonia removal, is most likely to be responsible.