0
Article Tier 2 Sign in to save

Efficient removal of aged microplastics from seawater using hydrophilic Fe3O4 nanoparticles: A multi-scale study based on macroscopic experiments and microscopic calculations

AI summary Read the abstract

Researchers tested unmodified hydrophilic iron oxide nanoparticles as a magnetic adsorbent for physically aged microplastics in seawater, achieving removal efficiencies above 80% at low dosage and confirming via density functional theory that electrostatic attraction combined with van der Waals forces drives adsorption, with performance improving further under saline conditions — offering a cost-effective approach for remediation of environmentally weathered MPs.

Study Type Environmental

Effective microplastics (MPs) remediation technologies are required to combat marine MPs pollution. Magnetic adsorption is a promising approach for MPs remediation. However, current strategies typically employ hydrophobic magnetic adsorbents to remove pristine hydrophobic MPs, overlooking the fact that environmental aging can enhance the hydrophilicity of MPs. This study investigated the adsorption performance of unmodified hydrophilic FeO nanoparticles (NPs) on six types of physically aged MPs through a multi-scale approach, combining macroscopic experimental observations with microscopic explanatory mechanisms. Results demonstrated that the removal efficiencies of aged MPs at high concentrations (at 4 g each) exceeded 80% at a low dosage of 5 mg hydrophilic FeO NPs. The adsorption capacities of MPs reached up to (6.716-7.359) × 10 mg/g. The optimal adsorption performance was achieved under neutral conditions (pH = 7), due to favorable electrostatic attraction between positively charged hydrophilic FeO NPs and negatively charged MPs. Increasing salinity enhanced adsorption by compressing the electrical double layer and promoting aggregation. Multivalent cations (e.g., Al) facilitated adsorption through charge neutralization and coagulation induced by their hydrolysis products. The applicability of hydrophilic FeO NPs was assessed in a practical nearshore seawater sample. Results indicated higher removal efficiencies (87.1-93.6%) for aged MPs compared to deionized water. Characterization, desorption tests and density functional theory calculations revealed that the adsorption was controlled by electrostatic interactions, combined with van der Waals forces. These findings provide insights into the interaction mechanism between hydrophilic magnetite NPs and aged MPs, validating a robust and cost-effective strategy for MPs remediation in complex marine environments.

More Papers Like This

Article Tier 2

Electrostatic Interactions Override Surface Area Effects in Size-Dependent Adsorptive Removal of Microplastics by Fe3O4 Nanoparticles

AI summary Read the abstract

This study investigated how the size and surface charge of magnetic nanoparticles affect their ability to adsorb and remove microplastics from water. Electrostatic interactions between particle surface charge and MP surfaces overrode simple surface area effects, providing design principles for more effective magnetic nanoparticle-based MP remediation.

Article Tier 2

Polystyrene microplastics removal from aqueous solutions by magnetic iron nanoparticles

AI summary Read the abstract

Researchers tested magnetic iron oxide (Fe₃O₄) nanoparticles for removing polystyrene microplastics from water, systematically optimizing concentration, dosage, contact time, and pH, and found effective microplastic removal through adsorption interactions that could be leveraged for environmental remediation.

Article Tier 2

Removal of microplastics from water by magnetic nano-Fe3O4

AI summary Read the abstract

Researchers developed a method for removing microplastics from water using magnetic iron oxide nanoparticles that attach to plastic surfaces, allowing the particles to be pulled out with a magnet. The technique achieved removal rates above 80% for common microplastic types in environmental water samples including river water, sewage, and seawater, suggesting a practical approach for water treatment.

Article Tier 2

Efficient magnetic capture of PE microplastic from water by PEG modified Fe3O4 nanoparticles: Performance, kinetics, isotherms and influence factors

AI summary Read the abstract

Researchers developed PEG-modified Fe3O4 magnetic nanoparticles that efficiently capture polyethylene microplastics from water with a maximum adsorption capacity of 2,203 mg/g, maintaining high removal efficiency across varying environmental conditions.

Article Tier 2

Effect of aggregation behavior on microplastic removal by magnetic Fe3O4 nanoparticles

AI summary Read the abstract

Researchers investigated how magnetic iron oxide nanoparticles can remove nanoscale microplastics from water. They found that 83 to 93 percent of the plastic particles could be captured within one hour, with removal efficiency strongly linked to how the nanoparticles and plastics clump together. The study shows that water acidity and salt levels significantly influence the process, offering practical guidance for deploying magnetic cleanup technologies.

Research digests by email

When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.

Email me about

Share this paper