Abstract
Our study investigates the generation of nanoplastics (NPs) from real-world plastic waste and their capacity to adsorb heavy metal (HM) ions. NPs, synthesized from polyethylene terephthalate (PET), polystyrene (PS), and polypropylene (PP) using a milling method, were characterized using dynamic light scattering (DLS) and scanning electron microscopy (SEM), confirming particle sizes below 200 nm. Manganese (Mn(2+)), cobalt (Co(2+)), zinc (Zn(2+)), cadmium (Cd(2+)), and lead (Pb(2+)) at concentrations ranging from 50.0 parts per billion (ppb) to 2.0 ppm (ppm) were exposed to the NPs. Residual HM concentrations were measured using inductively coupled plasma mass spectrometry (ICP-MS). PP exhibited the highest adsorption capacities, with Langmuir maximum adsorption capacity (q(m) ) values of 90.91 μg per gram (μg/g) for Mn(2+), 114.94 μg/g for Co(2+), 101.01 μg/g for Zn(2+), and 107.53 μg/g for Cd(2+). Pb(2+) showed rapid adsorption, with over 99% adsorption within 5 min, with a capacity of 396.1 μg/g on PP, 390.6 μg/g on PET, and 393.2 μg/g on PS. Adsorption kinetics followed a pseudo-second-order model, suggesting chemisorption, while Langmuir and Freundlich isotherms supported monolayer adsorption.