Remediation of malachite green in wastewater by ZIF-8@Fe/Ni nanoparticles based on adsorption and reduction

Area of Science:

• Materials Science
• Environmental Chemistry
• Nanotechnology

Background:

• Industrialization and urbanization generate significant dye-contaminated wastewater, posing a global environmental challenge.
• Malachite green (MG) is a common synthetic dye found in industrial effluents, known for its toxicity and persistence.
• Effective methods for removing MG from wastewater are crucial for environmental protection.

Purpose of the Study:

• To synthesize and characterize a ZIF-8@Fe/Ni composite material for the removal of malachite green (MG) dye.
• To investigate the adsorption and degradation mechanisms of MG removal by the ZIF-8@Fe/Ni composite.
• To evaluate the efficiency of ZIF-8@Fe/Ni in treating dye-contaminated wastewater.

Main Methods:

• Synthesis of ZIF-8@Fe/Ni composite.
• Characterization using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier-Transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS), and Gas Chromatography-Mass Spectrometry (GC-MS).
• Adsorption and degradation kinetic studies (pseudo-second-order and pseudo-first-order kinetics).

Main Results:

• ZIF-8@Fe/Ni composite successfully synthesized with stable ZIF-8 structure and presence of Fe/Ni nanoparticles.
• Achieved >99% removal of 50 mg L⁻¹ MG within 120 min at 318 K, with a high adsorption capacity of 151.520 mg g⁻¹.
• Identified two major MG degradation products and confirmed pseudo-second-order adsorption and pseudo-first-order reduction kinetics.
• Demonstrated 92% MG removal efficiency in simulated wastewater remediation.

Conclusions:

• ZIF-8@Fe/Ni composite is a highly effective material for the removal of malachite green dye from wastewater.
• The removal mechanism involves both adsorption and catalytic degradation.
• This material shows significant potential for practical application in industrial wastewater treatment.