Identification and detection of label-free polystyrene microplastics in maize seedlings by Raman spectroscopy

Microplastics generation from flooring materials under UV exposure: A comprehensive analysis of microplastics emission and chemical deformation

To investigate the sources of microplastics (MPs) emissions in indoor environments, study analyzed the generation of MPs upon the degradation of flooring materials caused by walking friction and UV exposure from sunlight entering indoor spaces. Three common flooring materials, carpet tiles, laminate flooring, and polyvinyl chloride (PVC) flooring, were subjected to perform degradation experiments using a walking simulation device and a weathering chamber. The study analyzed the surfaces of the flooring materials, MPs concentrations, morphological characteristics, and chemical deformation. Surface analysis of the degraded flooring materials demonstrated the effects of walking-induced friction and UV exposure on material deterioration, confirming the potential for MPs generation. The concentration analysis revealed trends in MPs emissions based on the duration of UV exposure. Additionally, morphological analysis of MPs provided insights into their generation from flooring surfaces. Furthermore, chemical composition analysis indicated that the delta carbonyl index of MPs increased by 2.68, 20.00, and 4.03 times for carpet tiles, laminate flooring, and PVC flooring, respectively, after UV exposure. The study verifies MPs generation from flooring materials due to walking friction and UV exposure and offers insights into the chemical transformations of MPs.

Fate, characteristics, and potential threat of microplastics in sludge under various dewatering treatments

Microplastics (MPs), an emerging environmental pollutant, have been found in wastewater sludge with increasing frequency. Their occurrence, surface properties, and adsorption characteristics may be altered during various sludge dewatering processes. This study explored and compared the performance of four types of sludge dewatering processes (FeCl3 + CaO, Fe2+ + H2O2 + CaO, Fe2+ + peroxymonosulfate (PMS) + CaO, and Fe2+ + CaO2 + CaO) in improving sludge dewaterability, the fate and characteristics of MPs during treatments, and their effect on the adsorption of heavy metals by aged MPs. Results showed that iron-based advanced oxidation processes (Fe-AOPs) indicated superior performance in improving sludge dewaterability compared to conventional FeCl3 + CaO treatment, as evidenced by the water content of sludge cakes being reduced to below 54.0 % (w/t) in Fe-AOPs. Fe2+ + PMS + CaO and FeCl3 + CaO effectively reduced MPs concentrations in both dewatered sludge and filtrate, thereby mitigating potential environmental risks. The potential risk associated with heavy metal adsorption onto treated MPs was greater for Fe2+ + PMS + CaO than for FeCl3 + CaO. In summary, Fe2+ + PMS + CaO offered a feasible method for sludge dewatering and MPs removal, particularly suited to sludge with low heavy metal concentrations. FeCl3 + CaO treatment effectively mitigated co-toxicity between heavy metals and MPs, proving more suitable for sludge with high heavy metal content. This study offers new insights into the selection of appropriate sludge treatments regarding MPs.