Pb(II) uptake onto nylon microplastics: Interaction mechanism and adsorption performance

Area of Science:

• Environmental Science
• Materials Science
• Analytical Chemistry

Background:

• Heavy metals and microplastics are pervasive aquatic pollutants.
• Understanding pollutant interactions with microplastics is crucial for environmental remediation.

Purpose of the Study:

• To investigate lead(II) ion adsorption onto aged nylon microplastics.
• To determine the influence of various environmental factors on adsorption.
• To characterize the surface properties of microplastics affecting lead(II) uptake.

Main Methods:

• Batch adsorption studies were conducted varying pH, contact time, temperature, electrolyte, and fulvic acid concentrations.
• Surface characterization used SEM-EDAX, FTIR, TGA, XRD, and DSC.
• Adsorption kinetics and isotherms (Langmuir, Freundlich) were analyzed.

Main Results:

• Adsorption kinetics followed pseudo-second order, Elovich, and intraparticle diffusion models.
• Lead(II) uptake was spontaneous and endothermic.
• Adsorption was significantly affected by pH, sodium chloride, and fulvic acid concentrations.

Conclusions:

• Aged nylon microplastics demonstrate significant lead(II) adsorption capacity.
• Surface carboxyl groups on microplastics are critical for lead(II) adsorption.
• This research provides insights into the environmental fate of lead in microplastic-contaminated waters.