Madhu Khatri

The environmental degradation of single‐use polyethylene (PE) bags poses a growing concern due to the release of microplastics (MPs) and nanoplastics (NPs). This study investigated the fragmentation behaviour of PE bags under simulated environmental conditions (mechanical shear stress, temperature, pH, and ultraviolet [UV] exposure) and evaluated the toxicity of resulting particles using zebrafish ( Danio rerio ) embryos. Shear stress alone caused up to 30.76% polymer deterioration and released approximately 4.7 × 10 ³ particles per microliter. The ideal fragmentation occurred at pH 6.5, 50°C, and 1‐h UV exposure, whereas minimal release was also observed at pH 6.5, 30°C, and 15‐h UV exposure. The MP/NP characterization revealed that MPs/NPs from PE bags were morphologically heterogeneous and chemically distinct from pure PE MPs/NPs, containing additives such as Si, Al, and Ti. Zebrafish exposure studies demonstrated dose‐dependent developmental toxicity, including pericardial oedema, spinal curvature, delayed hatching, and mortality up to 93% at the highest particle concentration. Compared to pure PE MPs/NPs, MPs/NPs released from PE bags showed higher toxicity, likely due to chemical degradation products. Hatching rates also declined significantly with increasing particle concentrations. The total ratio of normal zebrafish declined intensely from 60% at the lowest concentration to only 10% at the highest exposure level, confirming a strong concentration‐dependent toxic effect. This reduction in healthy larvae, with increase in malformations and mortality, shows the developmental toxicity induced by MPs/NPs. These findings highlight the critical environmental and biological risks of plastic pollution from disposable PE bags and emphasize the need for stricter waste management and regulatory oversight.

The widespread presence of microplastics (MPs) and nanoplastics (NPs) in the terrestrial and aquatic environments is posing a great threat globally. MPs/NPs pervade our environment in different forms and sizes. Their widespread presence can negatively affect aquatic organisms, soil, wildlife, birds, and humans. As a result, it becomes critical to develop remediation options for MPs/NPs. Among numerous materials, magnetic nanomaterials are one of the potential thrust areas for mitigating MP/NP pollution. In the present review, we discuss the recent developments in applying magnetic nanomaterials (such as nanoscale zero-valent iron, iron oxide nanoparticles, magnetic nanocomposites, spinel ferrites, and magnetic perovskites) for MP/NP removal from various matrices. Different methods including adsorption, coagulation removal, and degradation have been highlighted in detail to remediate MPs/NPs. Then, the performance comparison between different technologies and magnetic nanomaterials has been done to highlight their relative efficiencies, limitations, and suitability for MP/NP remediation. Finally, the limitations, practical challenges in real contaminated ecosystems, and future solutions for the use of magnetic nanomaterials are discussed. Graphical abstract

Purpose The presence of microplastics (MPs) and nanoplastics (NPs) in aquatic ecosystems has raised serious environmental and health concerns. Polystyrene is one of the most abundant plastic polymers found in the environment. Polystyrene MPs/NPs have harmful implications for human health and their removal from the environment has become a serious challenge. Methods In this study, we investigated the adsorptive uptake of polystyrene nanoplastics (PS NPs) from aqueous solutions using fly ash-loaded magnetic nanoparticles (FAMNPs) as the magnetic nano-adsorbent. During the factor screening study, the adsorption process was studied as a function of four variables namely pH (5–10), adsorption time (30–120 min), amount of FAMNPs (0.01–0.04 g), and stirring speed (50–200 rpm). Central composite design (CCD) and response surface methodology (RSM) were employed to establish the relationship between the variables. Furthermore, toxicity assessments of PS NPs were checked on a zebrafish model, shedding light on its potential ecological effects. Results Two variables namely the pH and amount of FAMNPs significantly influenced the adsorption capacity of FAMNPs and were further optimized for subsequent analysis. The optimum operational readings proposed by the model were pH (8.5), and the amount of FAMNPs (0.03 g), resulting in a good adsorption capacity of 29.12 mg/g for PS NPs. The adequacy of the proposed model was evaluated by analysis of variance (ANOVA). Zebrafish embryos exposed to PS NPs revealed physical deformations such as pericardial edema and malformed notochord. Conclusion The study demonstrates the effectiveness of FAMNPs in the adsorption of PS NPs from aqueous solutions, with optimal conditions identified at pH 8.5 and 0.03 g of FAMNPs using RSM. The adequacy of the model was confirmed through ANOVA analysis. Toxicity assessments on zebrafish embryos exposed to PS NPs revealed significant mortality and physical deformations, highlighting the importance of PS NPs removal for environmental health. Graphical Abstract