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

Due to their resistance to degradation, wide distribution, easy diffusion and potential uptake by organisms, microplastics (MPs) pollution has become a major environmental concern. In this study, PEG-modified Fe3O4 magnetic nanoparticles demonstrated superior adsorption efficiency against polyethylene (PE) microspheres compared to other adsorbents (bare Fe3O4, PEI/Fe3O4 and CA/Fe3O4). The maximum adsorption capacity of PE was found to be 2203 mg/g by adsorption isotherm analysis. PEG/Fe3O4 maintained a high adsorption capacity even at low temperature (5°C, 2163 mg/g), while neutral pH was favorable for MP adsorption. The presence of anions (Cl-, SO42-, HCO3-, NO3-) and of humic acids inhibited the adsorption of MPs. It is proposed that the adsorption process was mainly driven by intermolecular hydrogen bonding. Overall, the study demonstrated that PEG/Fe3O4 can potentially be used as an efficient control against MPs, thus improving the quality of the aquatic environment and of our water resources.

Characterization of HDPE microparticles in sludge aerobic digestion and their influence on the process.

The occurrence of microplastics (MPs) in wastewater has been studied in the last years. The high efficiency of their removal from wastewater is linked to their transfer to the sludge. In this work, the effect of high-density polyethylene (HDPE) on aerobic digestion was evaluated and these MPs were monitored, characterizing them by three different techniques. Two parallel batch digesters were monitored. AD-Control (meaning Aerobic Digester) operated as a reference, with no external HDPE particles, whereas these polymeric fragments were introduced to the second aerobic digester (AD-HDPE) using ring pulls as microplastic support. FTIR, Raman spectroscopies and fluorescence analysis of these microparticles showed some relevant results that should be highlighted. Higher fluorescence appeared after 7 days in the digester. It coincided with an increase of active volatile suspended solids (AVSS) in the AD-HDPE, which means that an increase of the microbial activity took place. Despite the presence of HDPE particles in the sludge, the digester performance was not compromised. Besides, the HDPE particles did not affect the microbial diversity (Shannon index) of the bacterial community at the end of the experiment compared to the bacterial community of the aerobic digester control tank. Based on the analysis of the relative abundances of microbial taxa, it was concluded that HDPE had selective effects on sludge microbial community, increasing the relative abundance of Bacteroridota phylum.

Fracture Resistance and Failure Mode of Polyethylene Fiber-reinforced Resin-based Restorations in Structurally Compromised Premolars: an in Vitro Study.

OBJECTIVE: To evaluate the effect of polyethylene fiber-reinforcement on the fracture resistance and fracture mode of extensive resin-based composite (RBC) restorations in structurally compromised maxillary premolars. METHODS AND MATERIALS: Maxillary premolars (54) with specific dimensions and extracted for orthodontic reasons were used. Following mesio-occluso-distal (MOD) cavity preparation and endodontic access, teeth were randomly assigned to one of three restorative protocols (n=18): RBC applied incrementally (I) or reinforced with woven polyethylene fibers (Ribbond) placed horizontally (H) or U-shaped (U). Restored teeth were stored for 45 days in distilled water at 37°C and then loaded monotonically until fracture. Half of the specimens in each group received axial loading (A) and the other half was loaded paraxially (PA). Fracture load data was assessed using two-way analysis of variance and Tukey's post hoc test for multiple comparisons (α=0.05). The fracture initiation and propagation path were analyzed using stereomicroscopy and scanning-electron microscopy. RESULTS: No significant differences were observed for the fracture strength among loading configurations, except for groups IA (825 N) and HA (553 N). Fracture initiated and propagated mainly at and through the RBC restoration in the I group, whereas a shift to the interface was observed in both polyethylene fiber-reinforced groups. Blocking and bridging of cracks were identified around the fibers, especially in specimens of group U. CONCLUSIONS: Incorporation of woven polyethylene fibers to reinforce extensive MOD resin-based composite restorations on endodontically treated premolars reduced the occurrence of cohesive fractures in the restorative material but was unable to increase the fracture resistance of the affected teeth.

Behavioral and physiological responses of Girardia tigrina exposed to polyethylene microplastics.

Microplastic particles appear in great abundance and variety in freshwater ecosystems across the globe, spanning lakes and rivers, with increasingly frequent exposure of aquatic organisms. Studies on the mechanisms of any effects of plastic particles are still scarce, particularly in relation to the regenerative capacity of biota, for which there is no established model organism; however, planaria have shown sensitivity for assessing these risks to the aquatic environment. Thus, the present study aimed to investigate the behavioral and regeneration responses of the freshwater planaria Girardia tigrina exposed to polyethylene (PE) microplastics (MPs) incorporated into their food source. The greatest effect was observed on planarian regeneration, which was manifested at 10 µg/mg liver. Planaria reproduction and fertility were affected at 50 µg/mg liver; however, planaria locomotion was not affected at the concentrations evaluated. Mid-infrared absorption spectroscopy (FT-IR) was used to identify the constituent polymers, and ingestion of the polyethylene microplastic by the planaria was confirmed by infrared spectroscopy. The results highlight the potential adverse effects of exposure to polyethylene microplastic and show that the reproductive behavior and regeneration of a freshwater organism can be indicators of toxicity resulting from environmental pollution.

Immunotoxicity and oxidative damage in Litopenaeus vannamei induced by polyethylene microplastics and copper co-exposure.

This study examines the combined effects of polyethylene microplastics (PE-MP) and copper (Cu2+) on the immune and oxidative response of Litopenaeus vannamei. PE-MP adsorbed with Cu2+ at 2.3, 6.8, and 16.8 ng (g shrimp)-1) were injected into L. vannamei. Over 14 days, survival rates were monitored, and immune and oxidative stress parameters were assessed. The results showed that combined exposure to PE-MP and Cu2+ significantly reduced the survival rate and decreased total haemocyte count. Immune-related parameters (phagocytic rate, phenoloxidase and superoxide dismutase (SOD)) and antioxidant-related parameters (SOD, catalase and glutathione peroxidase mRNA and enzyme) also decreased, while respiratory burst activity significantly increased, indicating immune and antioxidant system disruption. Additionally, there was a significant increase in oxidative stress, as measured by malondialdehyde levels. Histopathological analysis revealed severe muscle, hepatopancreas, and gill damage. These results suggest that simultaneous exposure to PE-MP and Cu2+ poses greater health risks to white shrimp.

Plastic Quantification and Polyethylene Overestimation in Agricultural Soil Using Large-Volume Pyrolysis and TD-GC-MS/MS.

Quantification of microplastics in soil is needed to understand their impact and fate in agricultural areas. Often, low sample volume and removal of organic matter (OM) limit representative quantification. We present a method which allows simultaneous quantification of microplastics in homogenized, large environmental samples (>1 g) and tested polyethylene (PE), polyethylene terephthalate (PET), and polystyrene (PS) (200-400 µm) overestimation by fresh and diagenetically altered OM in agricultural soils using a new combination of large-volume pyrolysis adsorption with thermal desorption-gas chromatography-tandem mass spectrometry (TD-GC-MS/MS). Characteristic MS/MS profiles for PE, PET, and PS were derived from plastic pyrolysis and allowed for a new mass separation of PET. Volume-defined standard particles (125 × 125 × 20 µm3) were developed with the respective weight (PE: 0.48 ± 0.12, PET: 0.50 ± 0.10, PS: 0.31 ± 0.08 µg), which can be spiked into solid samples. Diagenetically altered OM contained compounds that could be incorrectly identified as PE and suggest a mathematical correction to account for OM contribution. With a standard addition method, we quantified PS, PET, and PEcorrected in two agricultural soils. This provides a base to simultaneously quantify a variety of microplastics in many environmental matrices and agricultural soil.

Selective recovery of pyrolyzates of biodegradable (PLA, PHBH) and common plastics (HDPE, PP, PS) during co-pyrolysis under slow heating.

Pyrolytic synergistic interactions, in which the production of pyrolyzates is enhanced or inhibited, commonly occur during the co-pyrolysis of different polymeric materials, such as plastics and biomass. Although these interactions can increase the yield of desired pyrolysis products under controlled degradation conditions, the desired compounds must be separated from complex pyrolyzates and further purified. To balance these dual effects, this study was aimed at examining pyrolytic synergistic interactions during slow heating co-pyrolysis of biodegradable plastics including polylactic acid (PLA) and poly(3-hydroxybutyrate-co-3-hydroxyhexaoate) (PHBH) and petroleum-based plastics including high-density polyethylene (HDPE), polypropylene (PP), and polystyrene (PS). Comprehensive investigations based on thermogravimetric analysis, pyrolysis-gas chromatography/mass spectrometry, and evolved gas analysis-mass spectrometry revealed that PLA and PHBH decompose at lower temperatures (273-378 °C) than HDPE, PP, and PS (386-499 °C), with each polymer undergoing independent decomposition without any pyrolytic interactions. Thus, the independent pyrolysis of biodegradable plastics, such as PLA and PHBH, with common plastics, such as HDPE, PP, and PS, can theoretically be realized through temperature control, enabling the selective recovery of their pyrolyzates in different temperature ranges. Thus, pyrolytic approaches can facilitate the treatment of mixed biodegradable and common plastics.

Effects of agricultural microplastics in multigenerational tests with insects; mealworms Tenebrio molitor.

Mulching films, widely used in agriculture, are a large source of microplastics (MPs) to soil. However, there is little knowledge on the long-term effects of agricultural MPs on soil invertebrates. We investigated the effects of MPs from conventional non-biodegradable, fossil-based, low-density polyethylene (PE) and biodegradable fossil-based poly(butylene adipate-coterephthalate) (starch-PBAT blend) mulching films on two generations of the mealworm Tenebrio molitor. No effects of MPs (0.005 %-5 %, w/w dry food) on mealworm development and survival were observed until the end of the experiments (12 weeks for the first generation, nine weeks for the second generation), but effects on their moulting and growth were observed. These were most evident for PE MPs (5 %, w/w), where a decrease in larval growth and moulting was noted in the first generation. On the contrary, PBAT MPs (5 %, w/w) significantly induced the growth of mealworms in the second generation. In addition, there was a non-significant trend towards increased growth at all other PBAT MP exposure concentrations. Increased growth is most likely due to the biodegradation of starch PBAT MPs by mealworms. Overall, these data suggest that PE and PBAT MPs do not induce significant effects on mealworms at environmentally relevant concentrations, but rather only at very high exposure concentrations (5 %).

The Impact of Virgin and Aged Microstructured Plastics on Proteins: The Case of Hemoglobin Adsorption and Oxygenation.

Plastic particles, particularly micro- and nanoparticles, are emerging pollutants due to the ever-growing amount of plastics produced across a wide variety of sectors. When plastic particles enter a biological medium, they become surrounded by a corona, giving them their biological identity and determining their interactions in the living environment and their biological effects. Here, we studied the interactions of microstructured plastics with hemoglobin (Hb). Virgin polyethylene microparticles (PEMPs) and polypropylene microparticles (PPMPs) as well as heat- or irradiation-aged microparticles (ag-PEMPs and ag-PPMPs) were used to quantify Hb adsorption. Polypropylene filters (PP-filters) were used to measure the oxygenation of adsorbed Hb. Microstructured plastics were characterized using optical microscopy, SAXS, ATR-FTIR, XPS, and Raman spectroscopy. Adsorption isotherms showed that the Hb corona thickness is larger on PPMPs than on PEMPs and Hb has a higher affinity for PPMPs than for PEMPs. Hb had a lower affinity for ag-PEMPs and ag-PPMPs, but they can be adsorbed in larger amounts. The presence of partial charges on the plastic surface and the oxidation rate of microplastics may explain these differences. Tonometry experiments using an original method, the diffuse reflection of light, showed that adsorbed Hb on PP-filters retains its cooperativity, but its affinity for O2 decreases significantly.

Development of innovative alkali activated paste reinforced with polyethylene fibers for concrete crack repair.

Concrete structures are susceptible to cracking, which can compromise their integrity and durability. Repairing them with ordinary Portland cement (OPC) paste causes shrinkage cracks to appear in the repaired surface. Alkali-activated binders offer a promising solution for repairing such cracks. This study aims to develop an alkali-activated paste (AAP) and investigate its effectiveness in repairing concrete cracks. AAPs, featuring varying percentages (0.5%, 0.75%, 1%, 1.25%, 1.5%, and 1.75%) of polyethylene (PE) fibers, are found to exhibit characteristics such as strain hardening, multiple plane cracking in tension and flexure tests, and stress-strain softening in compression tests. AAP without PE fibers experienced catastrophic failure in tension and flexure, preventing the determination of its stress-strain relationship. Notably, AAPs with 1.25% PE fibers demonstrated the highest tensile and flexural strength, exceeding that of 0.5% PE fiber reinforced AAP by 100% in tension and 70% in flexure. While 1% PE fibers resulted in the highest compressive strength, surpassing AAP without fibers by 17%. To evaluate the repair performance of AAP, OPC cubes were cast with pre-formed cracks. These cracks were induced by placing steel plates during casting and were designed to be full and half-length with widths of 1.5 mm and 3 mm. AAP both with and without PE fibers led to a substantial improvement in compressive strength, reducing the initial strength loss of 30%-50% before repair to a diminished range of 2%-20% post-repair. The impact of PE fiber content on the compressive strength of repaired OPC cube is marginal, providing more flexibility in using AAP with any fiber percentage while still achieving effective concrete crack repair. Considering economic and environmental factors, along with observed mechanical enhancements, AAPs show promising potential for widespread use in concrete repair and related applications, contributing valuable insights to the field of sustainable construction materials.

Dose equivalent consideration from neutron contamination in modified radiotherapy vault: a Monte Carlo study.

Laminated barriers incorporating metal sheets provide effective protection for space-restricted radiotherapy centers. This study aimed to assess photoneutron contamination in smaller vaults protected by different compositions of multilayer barriers during simulated pelvic radiotherapy with 18 MV photon beams. Monte Carlo Simulations of 18 MV LINAC (Varian 2100 C/D) and Medical Internal Radiation Dose (MIRD) phantom were used to assess photoneutron contamination within reconstructed vaults incorporating different combinations of metal sheet and borated polyethylene (BPE) during pelvic radiotherapy. The findings highlight a 3.27 and 2.91 times increase in ambient neutron doseHn*(10) along the maze of reconstructed vaults that use lead and steel sheets, respectively, compared to concrete. TheHn*(10) outside the treatment room increased after incorporating a metal sheet, but it remained within the permissible limit of 20µSv/week for uncontrolled areas adjacent to the LINAC bunker, even with a workload of 1000Gy/week. Neutron equivalent doses in the patient's organs ranged from 0.22 to 0.96 mSv Gy-1. There is no notable distinction in the organ's neutron equivalent dose, fatal cancer risk, secondary radiation-induced cancer risk, and cancer mortality for various laminated barrier compositions. Furthermore, the use of metal sheets for vault wall reconstruction keeps the variation in cancer risk induced by photoneutrons below 6%, while risks of fatal cancer and cancer mortality vary less than 11%. While the metal portion of the laminated barrier raises the neutron dose, the addition of a BPE plate reduces concerns of increased effective dose and secondary malignancy risk.

Antimicrobial Packaging for Plum Tomatoes Based on ZnO Modified Low-Density Polyethylene.

Food safety and quality are major concerns in the food industry. Despite numerous studies, polyethylene remains one of the most used materials for packaging due to industry reluctance to invest in new technologies and equipment. Therefore, modifications to the current materials are easier to implement than adopting whole new solutions. Antibacterial activity can be induced in low-density polyethylene films only by adding antimicrobial agents. ZnO nanoparticles are well known for their strong antimicrobial activity, coupled with low toxicity and UV shielding capability. These characteristics recommend ZnO for the food industry. By incorporating such safe and dependable antimicrobial agents in the polyethylene matrix, we have obtained composite films able to inhibit microorganisms' growth that can be used as packaging materials. Here we report the obtaining of highly homogenous composite films with up to 5% ZnO by a melt mixing process at 150 °C for 10 min. The composite films present good transparency in the visible domain, permitting consumers to visualize the food, but have good UV barrier properties. The composite films exhibit good antimicrobial and antibiofilm activity from the lowest ZnO composition (1%), against both Gram-positive and Gram-negative bacterial strains. The homogenous dispersion of ZnO nanoparticles into the polyethylene matrix was assessed by Fourier transform infrared microscopy and scanning electron microscopy. The optimal mechanical barrier properties were obtained for composition with 3% ZnO. The thermal analysis indicates that the addition of ZnO nanoparticles has increased thermal stability by more than 100 °C. The UV-Vis spectra indicate a low transmittance in the UV domain, lower than 5%, making the films suitable for blocking photo-oxidation processes. The obtained films proved to be efficient packaging films, successfully preserving plum (Rome) tomatoes for up to 14 days.

Long-Term Polyethylene (Bio)Degradation in Landfill: Environmental and Human Health Implications from Comprehensive Analysis.

This study investigates the process of long-term (bio)degradation of polyethylene (PE) in an old municipal waste landfill (MWL) and its implications for environmental and human health. Advanced techniques, such as ICP-ES/MS and IC-LC, were used to analyze heavy metals and anions/cations, demonstrating significant concentration deviations from control samples. The soil's chemical composition revealed numerous hazardous organic compounds, further indicating the migration of additives from PE to the soil. Toxicological assessments, including Phytotoxkit FTM, Microtox® bioassay, and Ostracodtoxkit®, demonstrated phytotoxicity, acute toxicity, and high mortality in living organisms (over 85% for Heterocypris Incongruens). An unusual concentration of contaminants in the MWL's middle layers, linked to Poland's economic changes during the 1980s and 1990s, suggests increased risks of pollutant migration, posing additional environmental and health threats. Moreover, the infiltration capability of microorganisms, including pathogens, into PE structures raises concerns about potential groundwater contamination through the landfill bottom. This research underscores the need for vigilant management and updated strategies to protect the environment and public health, particularly in older landfill sites.

Microplastics Biodegradation by Estuarine and Landfill Microbiomes.

Plastic pollution poses a worldwide environmental challenge, affecting wildlife and human health. Assessing the biodegradation capabilities of natural microbiomes in environments contaminated with microplastics is crucial for mitigating the effects of plastic pollution. In this work, we evaluated the potential of landfill leachate (LL) and estuarine sediments (ES) to biodegrade polyethylene (PE), polyethylene terephthalate (PET), and polycaprolactone (PCL), under aerobic, anaerobic, thermophilic, and mesophilic conditions. PCL underwent extensive aerobic biodegradation with LL (99 ± 7%) and ES (78 ± 3%) within 50-60 days. Under anaerobic conditions, LL degraded 87 ± 19% of PCL in 60 days, whereas ES showed minimal biodegradation (3 ± 0.3%). PE and PET showed no notable degradation. Metataxonomics results (16S rRNA sequencing) revealed the presence of highly abundant thermophilic microorganisms assigned to Coprothermobacter sp. (6.8% and 28% relative abundance in anaerobic and aerobic incubations, respectively). Coprothermobacter spp. contain genes encoding two enzymes, an esterase and a thermostable monoacylglycerol lipase, that can potentially catalyze PCL hydrolysis. These results suggest that Coprothermobacter sp. may be pivotal in landfill leachate microbiomes for thermophilic PCL biodegradation across varying conditions. The anaerobic microbial community was dominated by hydrogenotrophic methanogens assigned to Methanothermobacter sp. (21%), pointing at possible syntrophic interactions with Coprothermobacter sp. (a H2-producer) during PCL biodegradation. In the aerobic experiments, fungi dominated the eukaryotic microbial community (e.g., Exophiala (41%), Penicillium (17%), and Mucor (18%)), suggesting that aerobic PCL biodegradation by LL involves collaboration between fungi and bacteria. Our findings bring insights on the microbial communities and microbial interactions mediating plastic biodegradation, offering valuable perspectives for plastic pollution mitigation.

Insights into the Binding Interactions between Microplastics and Human α-Synuclein Protein by Multispectroscopic Investigations and Amyloidogenic Oligomer Formation.

Aggregation of human α-synuclein protein is regarded to be a key stage in the etiology of Parkinson's disease and numerous other neurodegenerative illnesses. Microplastics pollution can be a potential agent to promote various neurodegenerative disorders. In this study, we have employed various multispectroscopic analytical methods to investigate the binding interactions between polyethylene (PE-MPs), polyvinyl chloride (PVC-MPs), polystyrene (PS-MPs) microplastics, and human α-synuclein protein. Spectroscopic investigations using UV-vis absorption, circular dichroism, and Fourier transform infrared have indicated different alterations in α-synuclein protein's secondary structures induced by the formation of the α-synuclein protein-MP binding complex. This study suggests that PS-MPs are found to be the most effective microplastic that promote amyloidogenic oligomer emergence because of their tiny size (100 nm).

[Effect of Low-density Polyethylene Microplastics on Natural Attenuation of Oxygenated Polycyclic Aromatic Hydrocarbons in Soil].

The continuous accumulation of microplastics in agricultural soils may affect the natural attenuation of oxygen-containing polycyclic aromatic hydrocarbons (OPAHs). The effects of low-density polyethylene (LDPE) microplastics with the spiking proportion of 1 % and 0.01 % in soils on the natural attenuation of OPAHs were investigated via soil microcosm experiments. The relation between the response of bacterial communities and OPAHs dissipation was also explored. The initial content of OPAHs in the soil was 34.6 mg·kg-1. The dissipation of OPAHs in the soil on day 14 was inhibited by LDPE. The contents of OPAHs in LDPE groups were higher than that in the control by 0.9-1.6 mg·kg-1, and the inhibition degree increased with the proportion of LDPE. The contents of OPAHs were not significantly different among groups on day 28, indicating that the inhibitory effect of LDPE disappeared. LDPE did not change the composition of the dominant taxa in the OPAHs-contaminated soil community but influenced the relative abundances of some dominant taxa. LDPE increased the relative abundance of Proteobacteria and Actinobacteria at the phylum level and decreased that of Bacillus and increased those of Micromonospora, Sphingomonas, and Nitrospira (potential degrading bacteria of LDPE and endogenous substances) at the genus level, all four of which were the main genera dominating intergroup community differences. LDPE changed the α and ß diversity of bacterial communities, but the extents were not significant. LDPE affected the function of the bacterial community, reducing the total abundance of PAHs-degrading genes and some degrading enzymes, inhibiting the growth of PAHs-degrading bacteria and thus interfering with the natural decay of OPAHs.

[Effects of Polyethylene Microplastics on Soil Nutrients and Enzyme Activities].

The threat of microplastic pollution in soil ecosystems has caused widespread concern. In order to clarify the effect of polyethylene microplastics on soil properties, a 4-month soil incubation experiment was conducted in this study to investigate the effect of different mass fraction (1 %, 2.5 %, and 5 %) and particle sizes (30 mesh and 100 mesh) of polyethylene microplastics on soil chemical properties, nutrient contents, and enzyme activities. The results showed that:① When the particle size was 100 mesh, microplastics at the mass concentrations of the 2.5 % and 5 % treatments significantly reduced soil pH, and the exposure of polyethylene microplastics had no significant effect on soil conductivity. ② Compared to that in CK, the addition of microplastics reduced soil available potassium, available phosphorus, and nitrate nitrogen to varying degrees. The addition of 100 mesh microplastics significantly increased soil organic matter and ammonium nitrogen. ③ When the particle size was 100 mesh, compared to that in CK, treatments of all concentrations significantly increased soil catalase activity and alkaline phosphatase, showing an increasing but not significant trend, and the 5 % concentration treatment significantly decreased soil sucrase activity. ④ Changes in soil properties were influenced by the addition of microplastics of different concentrations and sizes, with higher concentrations and smaller particle sizes having more significant effects. In conclusion, the effects of microplastics on soil properties were not as pronounced as expected, and future research should focus on the mechanisms involved in the different effects.

Effects and molecular mechanisms of polyethylene microplastic oxidation on wheat grain quality.

Polyethylene microplastics (PE MPs) are the main MPs in agricultural soils and undergo oxidation upon environmental exposure. However, the influence of MP oxidation on phytotoxicity (especially for crop fruit) is still limited. This study aimed to explore the effect of PE MP oxidation on crop toxicity. Herein, a combination of plant phenotyping, metabolomic, and transcriptomic approaches was used to evaluate the effects of low-oxidation PE (LOPE) and high-oxidation PE (HOPE) on wheat growth, grain quality, and related molecular mechanisms using pot experiments. The results showed that HOPE induced a stronger inhibition of wheat growth and reduction in protein content and mineral elements than LOPE. This was accompanied by root ultrastructural damage and downregulation of carbohydrate metabolism, translation, nutrient reservoir activity, and metal ion binding gene expression. Compared with HOPE, LOPE activated a stronger plant defense response by reducing the starch content by 22.87 %, increasing soluble sugar content by 44.93 %, and upregulating antioxidant enzyme genes and crucial metabolic pathways (e.g., starch and sucrose, linoleic acid, and phenylalanine metabolism). The presence of PE MPs in the environment exacerbates crop growth inhibition and fruit quality deterioration, highlighting the need to consider the environmental and food safety implications of MPs in agricultural soils.

Plastic and terrestrial organic matter degradation by the humic lake microbiome continues throughout the seasons.

Boreal freshwaters go through four seasons, however, studies about the decomposition of terrestrial and plastic compounds often focus only on summer. We compared microbial decomposition of 13C-polyethylene, 13C-polystyrene, and 13C-plant litter (Typha latifolia) by determining the biochemical fate of the substrate carbon and identified the microbial decomposer taxa in humic lake waters in four seasons. For the first time, the annual decomposition rate including separated seasonal variation was calculated for microplastics and plant litter in the freshwater system. Polyethylene decomposition was not detected, whereas polystyrene and plant litter were degraded in all seasons. In winter, decomposition rates of polystyrene and plant litter were fivefold and fourfold slower than in summer, respectively. Carbon from each substrate was mainly respired in all seasons. Plant litter was utilized efficiently by various microbial groups, whereas polystyrene decomposition was limited to Alpha- and Gammaproteobacteria. The decomposition was not restricted only to the growth season, highlighting that the decomposition of both labile organic matter and extremely recalcitrant microplastics continues throughout the seasons.

Mechanochemical recycling of cellulose multilayer carton packages to produce micro and nanocellulose from the perspective of techno-economic and environmental analysis.

Despite being composed of recyclable materials, the main technological challenge of multilayer carton packs involves the efficient decompatibilization of the cellulosic, polymeric, and metallic phases. Here, a simple two-step mechanochemical process is described that uses only aqueous media and mechanical force to promote phase separation in order to fully recycle multi-layer carton packaging. The first step produces value-added micro- and nanocellulose, while in the second step, aluminum is extracted, forming precipitated aluminum and aluminum oxyhydroxides. Solid polyethylene (PE) remains with a degree of purity defined by the process efficiency. The results show that cellulose is efficiently extracted and converted into micro- and nanocellulose after 15 min of milling. In the second stage, approximately 90% of the aluminum is extracted from the PE after 15 min of milling. Due to the separation and drying medium conditions, the finely divided particles of extracted aluminum also have oxyhydroxides in their composition. It is believed that a passivation layer forms on the metallic aluminum particle. The techno-economic analysis revealed a positive net present value (NPV) of $17.5 million, with a minimum selling price of 1.62 USD/kg of cellulose. The environmental analysis concluded that most of the environmental impact of the process is associated with the entry of carton packages into the system, incorporating a small environmental load related to the industrial process. The results indicate a promising option toward a circular economy and carbon neutrality.