Polyethylene Terephthalate Particles Research Articles

Differential sensitivity of hemocyte subpopulations (Mytilus edulis) to aged polyethylene terephthalate micro- and nanoplastic particles

Bivalve hemocytes, particularly granulocytes and hyalinocytes, play a crucial role in cell-mediated immunity. However, their interactions with aged plastic particles, exhibiting altered properties that more closely resemble those in natural environments, remain largely underexplored. This study assesses the differential responses of hemocyte subpopulations (Mytilus edulis) to chemically aged polyethylene terephthalate (PET) microplastic (MPs) and nanoplastic (NPs) particles across multiple cellular effect endpoints. Particle characteristics were analyzed using Single Particle Extinction and Scattering, Raman Spectroscopy, Scanning Electron Microscopy, and Dynamic Light Scattering. In vitro experiments with aged PET MPs (1.9 µm) and NPs (0.68 µm) were conducted at three internally relevant concentrations: 10 (C1), 10³ (C2), and 10⁵ particles/mL (C3). Cellular responses were assessed by measuring lysosomal content stability, reactive oxygen species (ROS) production, cellular mortality, and morphological parameters using flow cytometry at 6, 12, 24, and 48 hours. Our findings provide mechanistic insights into the differential sensitivities of granulocytes and hyalinocytes to aged PET, influenced by particle size and concentration. Specifically, aged PET MPs and NPs induce distinct size and concentration-dependent patterns of lysosomal destabilization, coinciding with the loss of functional integrity. Elevated ROS levels were observed only in granulocytes and hyalinocytes exposed to high concentrations of aged PET NPs, underscoring the effects on oxidative stress. Both aged PET MPs and NPs induce significant increases in cellular mortality, particularly after 24 h of exposure at high concentrations. These findings reveal the complex cellular mechanisms underlying hemocyte functional impairment following exposure to aged PET particles under environmentally and biologically relevant conditions.

From microplastics to pixels: testing the robustness of two machine learning approaches for automated, Nile red-based marine microplastic identification.

Despite the urgent need for accurate and robust observations of microplastics in the marine environment to assess current and future environmental risks, existing procedures remain labour-intensive, especially for smaller-sized microplastics. In addition to this, microplastic analysis faces challenges due to environmental weathering, impacting the reliability of research relying on pristine plastics. This study addresses these knowledge gaps by testing the robustness of two automated analysis techniques which combine machine learning algorithms with fluorescent colouration of Nile red (NR)-stained particles. Heterogeneously shaped uncoloured microplastics of various polymers-polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP), polystyrene (PS), and polyvinyl chloride (PVC)-ranging from 100 to 1000µm in size and weathered under semi-controlled surface and deep-sea conditions, were stained with NR and imaged using fluorescence stereomicroscopy. This study assessed and compared the accuracy of decision tree (DT) and random forest (RF) models in detecting and identifying these weathered plastics. Additionally, their analysis time and model complexity were evaluated, as well as the lower size limit (2-4µm) and the interoperability of the approach. Decision tree and RF models were comparably accurate in detecting and identifying pristine plastic polymers (both > 90%). For the detection of weathered microplastics, both yielded sufficiently high accuracies (> 77%), although only RF models were reliable for polymer identification (> 70%), except for PET particles. The RF models showed an accuracy > 90% for particle predictions based on 12-30 pixels, which translated to microplastics sized < 10µm. Although the RF classifier did not produce consistent results across different labs, the inherent flexibility of the method allows for its swift adaptation and optimisation, ensuring the possibility to fine-tune the method to specific research goals through customised datasets, thereby strengthening its robustness. The developed method is particularly relevant due to its ability to accurately analyse microplasticsweathered under various marine conditions, as well as ecotoxicologically relevant microplastic sizes, making it highly applicable to real-world environmental samples.

Evaluating fresh and hardened properties of mortar composite with different types of modified polyethylene terephthalate (PET) materials as additives: Modification effects, surface properties, shape factors

Plastic disposal has become a challenge due to its challenging degradability, and plastics recycling is one of the ideal methods. The utilization of recycled plastic in building materials has been widely researched as a possible way to store plastics permanently. An investigation on the modification and incorporation of polyethylene terephthalates (PET) on fresh and hardened properties of mortar composites (MCs) is performed in the study. The work provides understanding of the synergistic effects of plastic modification methods with different types of PET additives on MC properties and to explain behavior of modified PET in mortar composites. Modification methods include microwave radiation, chemicals oxidation and alkaline hydrolysis. These methods are applied on three types of structural PET materials (hard particles, hard strips and soft yarns). The properties of 0.5%–3% PET added MCs include workability, compressive strength (CS), flexural strength (FS) and toughness are determined. At 28 days, 3% hydrolysis-treated PET yarns significantly increased FS by 69.6% and improved toughness by almost 15 times while CS with 3% PET particles modified by microwave radiation and chemicals oxidation were comparable to the control.

Unlocking a Key Residue in a Lipase for Efficient Polyethylene Terephthalate (PET) Hydrolysis and Influencing Depolymerization Product Profiles

Polyethylene terephthalate (PET) pollution is a global challenge. Advancing the bioprospecting of PET‐degrading enzymes through metagenomics and using computational and functional methods to identify key positions influencing the catalytic rate and selectivity are part of the solution. Here, we report PETase activity in the metagenomic lipase LipMRD9, which exhibits peak activity at 30 °C and pH 9.0 and has a denaturation temperature of 42 °C. In addition to acting on long‐chain triglycerides (up to 13 units (U)/mg, pH 8.0, 30 °C) and a wide range of 34 other esters (up to 228 U/g), LipMRD9 hydrolyses mono(2‐hydroxyethyl) terephthalate (57 U/g) and bis(2‐hydroxyethyl) terephthalate (131 U/g). It also efficiently deconstructs GoodFellow amorphous submicro‐ and nanosized PET particles (984/2238 µM degradation products at 30/40 °C, pH 7.0, 21.5 h) and films (112/198 µM degradation products at 30/40 °C, pH 7.0, 7 days). Through molecular modelling and experimental analysis, the active site of LipMRD9 was revealed, identifying a key residue contributing to its PETase activity compared with those of its closest homologues. This residue plays a crucial role in determining the distinct profiles of degradation products from PET hydrolysis and should be studied in other PETases for its influence on the catalytic process.

PET particles modify strain hardening cementitious composites: An approach to introduce defects to enhance deformation capacity

Enhancing deformation capabilities remains a critical direction in the research of Strain-Hardening Cementitious Composites (SHCC). This investigation introduces Polyethylene Terephthalate (PET) particles as a novel method to induce micro-defects within SHCC, aiming to reduce the material's initial crack strength and improve its deformability. Through the exploration of various PET particle volumetric substitutions for traditional aggregates, the development of PET particle-modified SHCC (PMSHCC) was achieved. The paper examines the impact and mechanisms of different PET volumetric substitution rates (0 %, 5 %, 10 %, 15 %, 20 %, and 25 %) on the workability, axial compression strength and tensile properties of PMSHCC. By employing Digital Image Correlation techniques, the progression of crack width and density in PMSHCC under tensile load was documented, facilitating an analysis of the influence mechanisms of varying PET volumetric substitution rates on the tensile strain-hardening behavior of PMSHCC. The findings indicate that the increased Interfacial Transition Zone (ITZ) thickness between PET particles and the cement matrix, combined with the lower elastic modulus of PET particles compared to the cement matrix and quartz sand, collectively contribute to a reduction in tensile initial crack strength and an enhancement in ultimate tensile strain of PMSHCC. Within the examined range, an increase in the PET volumetric substitution rate significantly improves the ultimate tensile strain of PMSHCC by up to 76.0 %, with a minimal reduction in tensile strength of only 3.99 %. Moreover, the study proposes a tensile linear strengthening elasto-plastic model for PMSHCC incorporating the PET substitution rate, enabling accurate prediction of the material's tensile stress-strain behavior. These findings not only offer a novel pathway for the utilization of waste plastics but also provide significant insights for enhancing the deformability of SHCC.

Investigation of the mechanical, microstructure, and durability properties of concrete with fine uniform and non-uniform polyethylene terephthalate (PET) aggregates

Concrete manufacturing is highly resource-intensive and is a major source of greenhouse gas emission. Accelerating depletion of natural resources such as sand, which is the primary material for aggregate in concrete manufacture is a growing problem. At the same time, the disposal of vast volumes of non-biodegradable plastic waste poses a global environmental challenge. The incorporation of aggregates derived from municipal plastic waste to substitute for sand has the potential to help address both issues, while at the same time mitigating greenhouse gas emission. This study examines the potential of municipal polyethylene terephthalate (PET) plastic waste as a fine aggregate in concrete manufacturing. The primary focus was on PET aggregates with non-uniform and uniform shapes ranging in size from 2.36 to 4.75 mm. In the concrete mixtures, 0 %, 30 %, and 50 % of the fine natural aggregate by volume were replaced with fine PET aggregate with a water to cement ratio of 0.40. The obtained results showed a reduction in compressive and splitting tensile strength when compared to control specimens. However, replacing 30 % of fine natural aggregate with PET (both uniform and non-uniform shapes) significantly improved chloride resistance by 13 % and 12 %, respectively, while also enhancing the bond between cement paste and PET particles. This study characterizes the material properties of PET concrete, which represents a promising method for reusing municipal plastic waste and mitigating environmental concerns in concrete production.

Assessing the impact of discarded plastic bottles on the resistance to rutting in hot mix asphalt

Undoubtedly, the damage to the upper layer of road pavement caused by the tremendous load of vehicles and climate factors is alarming and challenging to both the government and researchers in the respective field. Addressing these challenges requires innovative solutions to enhance pavement durability and sustainability. In this context, the authors seek to assess the impact of incorporating waste polyethylene terephthalate (PET) as a modifier on asphalt mixture properties. This study investigates the potential of PET, a commonly discarded plastic, to improve the performance of asphalt pavements. The authors conducted evaluations on the rutting performance of asphalt blends containing different PET percentages (0%, 0.2%, 0.6%, 0.8%, 1%) and diverse PET sizes (12 × 3 mm, 20 × 3 mm, and 30 × 4 mm). The experimental approach included dynamic creep tests and the use of a Hamburg wheel tracking device to simulate real-world traffic conditions and measure the mixtures' resistance to deformation. The findings revealed that incorporating PET into asphalt mixtures significantly enhances rutting resistance. Specifically, the addition of PET content improved the viscoelastic properties of the asphalt, making it more resistant to permanent deformation under load. However, the size of PET particles was found to play a crucial role in performance. Larger PET sizes were associated with a decrease in rutting resistance, suggesting an optimal particle size must be determined to maximize benefits. These results support the idea that the careful selection of PET content and size can significantly improve the performance and longevity of asphalt pavements. This approach not only addresses the issue of plastic waste but also contributes to the development of more sustainable infrastructure. By incorporating PET, the research highlights a viable method for enhancing road durability and supporting environmental sustainability, offering a promising solution for future road construction projects.

Polyethylene terephthalate (PET) micro- and nanoplastic particles affect the mitochondrial efficiency of human brain vascular pericytes without inducing oxidative stress

The objective of this investigation was to evaluate the influence of micro- and nanoplastic particles composed of polyethylene terephthalate (PET), a significant contributor to plastic pollution, on human brain vascular pericytes. Specifically, we delved into their impact on mitochondrial functionality, oxidative stress, and the expression of genes associated with oxidative stress, ferroptosis and mitochondrial functions. Our findings demonstrate that the exposure of a monoculture of human brain vascular pericytes to PET particles in vitro at a concentration of 50 μg/ml for a duration of 3, 6 and 10 days did not elicit oxidative stress. Notably, we observed a reduction in various aspects of mitochondrial respiration, including maximal respiration, spare respiratory capacity, and ATP production in pericytes subjected to PET particles for 3 days, with a mitochondrial function recovery at 6 and 10 days. Furthermore, there were no statistically significant alterations in mitochondrial DNA copy number, or in the expression of genes linked to oxidative stress and ferroptosis, but an increase of the expression of the gene mitochondrial transcription factor A (TFAM) was noted at 3 days exposure.These outcomes suggest that, at a concentration of 50 μg/ml, PET particles do not induce oxidative stress in human brain vascular pericytes. Instead, at 3 days exposure, PET exposure impairs mitochondrial functions, but this is recovered at 6-day exposure. This seems to indicate a potential mitochondrial hormesis response (mitohormesis) is incited, involving the gene TFAM. Further investigations are warranted to explore the stages of mitohormesis and the potential consequences of plastics on the integrity of the blood-brain barrier and intercellular interactions. This research contributes to our comprehension of the potential repercussions of nanoplastic pollution on human health and underscores the imperative need for ongoing examinations into the exposure to plastic particles.

Effects of microplastics on the structure and function of bacterial communities in sediments of a freshwater lake

As an emerging pollutant, microplastics (MPs) cause widespread concern around the world owing to the serious threat they pose to ecosystems. In particular, sediments are thought to be the long-term sink for the continual accumulation of MPs in freshwater ecosystems. Polyethylene (PE) and polyethylene terephthalate (PET) have been frequently detected with large concentration variations in freshwater sediments from the lower reaches of the Yangtze River, one of the most economically developed regions in China, characterized by accelerated urbanization and industrialization, high population density and high plastics consumption. However, the impact of PE and PET on the sedimental bacterial community composition and its function has not been well reported for this specific region. Herein, PE and PET particles were added to freshwater sediments to assess the effects of different MP types on the bacterial community and its function, using three concentrations (500, 1500 and 2500 items/kg) per MP and incubations of 35, 105 and 175 days, respectively. This study identified a total of 68 phyla, 211 classes, 518 orders, 853 families and 1745 genera. Specifically, Proteobacteria, Chloroflexi, Acidobacteriota, Actinobacteriota and Firmicutes were the top five phyla. A higher bacterial diversity was obtained in control sediments than in the MP-treated sediments. The presence of MPs, whether PET or PE, had significant impact on the bacterial diversity, community structure and community composition. PICRUSt2 and FAPOTAX predictions demonstrated that MPs could potentially affect the metabolic pathways and ecologically functional groups of bacteria in the sediment. Besides the MP-related factors, such as the type, concentration and incubation time, the physicochemical parameters had an effect on the structure and function of the bacterial community in the freshwater sediment. Taken together, this study provides useful information for further understanding how MPs affect bacterial communities in the freshwater sediment of the lower reaches of the Yangtze River, China.

Towards a reference material for microplastics’ number concentration—case study of PET in water using Raman microspectroscopy

Increasing demand for size-resolved identification and quantification of microplastic particles in drinking water and environmental samples requires the adequate validation of methods and techniques that can be used for this purpose. In turn, the feasibility of such validation depends on the existence of suitable certified reference materials (CRM). A new candidate reference material (RM), consisting of polyethylene terephthalate (PET) particles and a water matrix, has been developed. Here, we examine its suitability with respect to a homogeneous and stable microplastic particle number concentration across its individual units. A measurement series employing tailor-made software for automated counting and analysis of particles (TUM-ParticleTyper 2) coupled with Raman microspectroscopy showed evidence of the candidate RM homogeneity with a relative standard deviation of 12% of PET particle counts involving particle sizes >30 µm. Both the total particle count and the respective sums within distinct size classes were comparable in all selected candidate RM units. We demonstrate the feasibility of production of a reference material that is sufficiently homogeneous and stable with respect to the particle number concentration.Graphical

An Atomic-Level Perspective on the interactions between Organic Pollutants and PET particles: A Comprehensive Computational Investigation.

Microplastics (MPs) have recently attracted a lot of attention worldwide due to their abundance and potentially harmful effects on the environment and on human health. One of the factors of concern is their ability to adsorb and disperse other harmful organic pollutants in the environment. To properly assess the adsorption capacity of MP for organic pollutants in different environments, it is pivotal to understand the mechanisms of their interactions in detail at the atomic level. In this work, we studied interactions between polyethylene terephthalate (PET) MP and small organic pollutants containing different functional groups within the framework of density functional theory (DFT). Our computational outcomes show that organic pollutants mainly bind to the surface of a PET model via weak non-bonding interactions, mostly hydrogen bonds. The binding strength between pollutant molecules and PET particles strongly depends on the adsorption site while we have found that the particle size is of lesser importance. Specifically, carboxylic sites are able to form strong hydrogen bonds with pollutants containing hydrogen bond donor or acceptor groups. On the other hand, it is found that in such kind of systems π-π interactions play a minor role in adsorption on PET particles.

Understanding the microplastic pollution impact on Chironomus sancticaroli larvae development and emergence

Plastic materials are increasingly present in our lives. It is estimated that more than 360 million tonnes of plastics are produced annually worldwide. Particularly, single-use plastics represent an important segment in plastic production. In this context, plastic contamination, and consequently microplastic release, has become a growing concern for aquatic ecosystems. In this study, we investigated the effects of exposure to polyethylene terephthalate (PET) microplastics (&lt;32 μm) on Chironomus sancticaroli larvae. The larvae were exposed to different concentrations of PET particles (0 (control group), 500, and 5,000 particles.kg−1 of dry sediment) for 10 days. Our results demonstrated that C. sancticaroli larvae displayed PET microplastics in their digestive tracts, and the ingestion increased with increasing PET concentrations. Plastic particles in the digestive tract can reduce the energy obtained by larvae feeding and, consequently, impair their development. The adult emergence rate displayed a significant decrease observed at the highest PET concentration compared with the control group. These findings reinforce existing concerns that microplastics, at concentrations currently found in the natural freshwater environments, can impact the development of benthic macroinvertebrates and, consequently, result in an unbalance in the freshwater ecosystems.

The enhancement of waste PET particles enzymatic degradation with a rotating packed bed reactor

Polyethylene terephthalate (PET) is widely used, and biodegradation of waste PET results in a residue-free process, generating recyclable products, thereby contributing to the advancement of a more recyclable plastics lifecycle. Extensive research has been conducted on the modification and evolution of enzyme for PET degradation. As a solid-liquid heterogeneous reactions of PET degradation, the slow diffusion rate of the enzyme from liquid to solid PET surface leading to a slow reaction rate. Enhancement of mass transfer would accelerate PET degradation. Rotating packed bed (RPB) is a mass transfer enhancement reactor, but shear strength generated by the enzyme molecule knocking on rotator of RPB leads to enzyme denaturation. To address this issue, shear strength resistance agents were introduced in this study. With the protection of β-cyclodextrin combined with kieselguhr, PET particle degradation rate of 95% was achieved under the optimum conditions in 24 h, which was improved by 30% compared to that in stirred tank reactor. The results of this work demonstrated that the mass transfer greatly influenced the PET biodegradation process. RPB combined with the function of shear strength resistance agents could greatly improve the efficiency of the biodegradation process. This study provides a reference for the scaling up of PET degradation, and holds significant promise in the broader context of combatting plastic pollution challenges and advancing sustainable solutions for plastic waste.

Conversion of polyethylene terephthalate (PET) plastic particles in a microwave-assisted heating reactor

Abstract With the rapid economic development, PET (polyethylene terephthalate) plastic is widely used in various fields, i.e., clothing, food, housing and transportation. However, PET has a very strong chemical inertia, which makes it difficult to be degraded by microorganisms, thereby occupying a lot of space. Therefore, the recycling of waste PET has become one of the most important topics of environmental protection. Glycolysis requires the most mild and safe reaction environment among chemical recycling methods, and the ethylene glycol used in the reaction can be reused. Using glycolysis to recycle PET undoubtedly conforms to the green and sustainable concept, and glycolysis recycling is undoubtedly a low-cost, low-consumption and low-harm path for PET recycling. The heating and glycolysis characteristics of microwave-assisted PET glycolysis, and the energy analysis of glycolysis were studied. The aim was to produce BHET (bis(2-hydroxyethyl) terephthalate) as the target product from PET waste. In this study, the effects of reaction temperature, reaction time, and PET particle size on the performances of PET conversion rate, oligomeric BHET yield, and BHET yield were examined, and the energy efficiency and recovery efficiency also were presented. The results showed that the optimal conditions for microwave-assisted PET glycolysis were reaction temperature of 180 °C, reaction time of 30 min, and PET particle size of 75 μm, and the maximum PET conversion rate was 66.71 ± 9.71 wt%, the maximum yield of BHET was 48.08 ± 0.68 wt% and the maximum BHET yield was 19.83 ± 5.40 wt%. The energy efficiency and recovery efficiency were 11.88 % and 17.89 %, respectively.

Effective Use of Waste Plastic As Sand in Metakaolin/Brick-Powder Geopolymer Concrete

This study proposes recycling waste clay brick and waste polyethylene terephthalate (PET) bottles as substitution materials in geopolymer concrete. To accomplish this goal, the control mix of geopolymer concrete was prepared based on blended metakaolin and waste clay brick powder (CBP) at a 1:1 mixture by weight. To evaluate the use of shredded PET particles as fine aggregate, three mixtures were made by replacing sand with PET aggregate at volumetric percentages (10%, 15% and 20%). The specimens containing PET aggregate were tested and compared against the control mix (0% PET), with emphasis on the fresh and dry densities, mechanical performance, water absorption and microstructure characteristics. The results indicated the inclusion of PET aggregate to slightly reduce density and improve mechanical properties. When compared to the control mix, the compressive strength of the 20% PET replacement increased to 28.1 MPa after 28 days. Moreover, the concrete with 20% PET obtained the lowest water-absorption rate. The scanning electron microscopy images revealed that the inclusion of waste PET as sand had a significant effect on the microstructure of Mk-CBP geopolymer concrete. When compared to the control mix, the matrix containing 20% PET had a denser microstructure, as well as fewer holes and microcracks, in addition to the packing of paste at the interfacial transition zone. KEYWORDS: Brick powder, Fine aggregate, Geopolymer concrete, Metakaolin, Polyethylene terephthalate (PET).

Detection and quantification of microplastics in commercially bottled edible oil

The presence of microplastics in the food system has raised increasing public attention due to their potential risk to human health. However, knowledge regarding the presence and quantity of microplastics in daily consumed food products is very limited. The objective of this study is to quantify microplastics in polyethylene terephthalate (PET) bottled edible oil and determine the impact of oil on microplastics released from plastic packages in an accelerated storage experiment. For microplastic recovery, hexane was used to dilute the oil and facilitate the filtration process, and 62.73–118.00% of microplastics were recovered using standard polystyrene microplastics. Microplastics present in the oil were identified based on their Raman characteristics. The most frequent polymers identified were Poly(Ethylacrylate:St:Acrylamide) and Poly(Ethylene:Propylene) The result shows particles ranging from 1.34 × 105 to 5.80 × 105 per liter of oil were detected in 4 commercial edible oil (olive oil, canola oil, sunflower oil, and coconut oil). Over 80% of detected plastics were smaller than 10 µm. The accelerated experiment (40 °C, 10 days) did not lead to an increased number of particles (p > 0.05) nor the identification of any PET particles, suggesting that no PET microplastics were released from the bottles during the storage. Our results fill in the knowledge gap regarding the microplastics in edible oil and facilitate exposure analysis of microplastics through food.

Physical and mechanical properties of locally fabricated geopolymer-plastic ceiling boards

The 21st century has seen a rise in the demand for building materials, which is not unconnected to the rise in population. The high demand has led to an increase in the price of such commodities as well as a strain on environmental resources and the call for more sustainable, and cost-effective alternatives to replace the conventional materials. In this study, waste glass powder was alkali-activated to produce geopolymer, which was combined with both fine and coarse waste polyethylene terephthalate (PET) pulverized plastics (aggregates). The product was then cured to form the ceiling board. The impact of the employed glass, alkaline solution, aggregate size, and aggregate content in the boards were then investigated. Board J with 92.5% PET particles (Coarse and Fine) and 7.5% Glass Particles gave the best water absorption (16.561%), thickness swelling (3.332%) and density test (0.918 g/cm3) results. It was found that the geopolymer with equal proportions of fine and coarse PET aggregates reduced the material's ability to absorb water and increased its density and swelling thickness. The modulus of rupture and modulus of elasticity of the boards were both enhanced by adding more glass powder and fine PET aggregates. However, it was discovered that the board's mechanical qualities, unlike its physical properties, were not improved by the addition of the geopolymer during manufacture.

Microplastics effects on wettability, pore sizes and saturated hydraulic conductivity of a loess topsoil

Environmental contamination with microplastics (MP, 0.1 µm – 5 mm diameter) potentially threatens various soil functions and agricultural production. In this study we evaluated the effects of MP on physical soil parameters (saturated hydraulic conductivity, water retention and water repellency) at MP concentrations (0.5 to 2 % w/w) that have been reported for farmland soils. Polyethylene terephthalate (PET) and polystyrene (PS) of three sizes ranging between 0.5 and 3 mm diameter, were mixed with loess topsoil material from an agriculturally used Luvisol. Results show that increasing MP concentration decreased the saturated hydraulic conductivity (ksat) compared to the control soil (without MP), irrespective of MP type. The highest reduction of ksat was found for the highest concentration (2 %) and the largest size MP (approx. 3 mm diameter). Compared to the control, MP addition significantly decreased soil water retention with increasing concentration. In contrast, air capacity was increased with MP addition where strongest effect was found for largest PET particles at the highest concentration. Soil water repellency (measured as Wilhelmy Plate contact angles) was increased at a concentration of 2 % and for MP sizes > 1 mm, while no effect was observed for lower concentrations and smaller MP. In conclusion, MP type, size, and concentration did affect key soil physical parameters, likely to negatively influence plant growth in contaminated soils.

A plastics-derived organic anode material for practical and sustainable potassium-ion batteries

Organic electrode materials are of particular interest for storing large-size potassium ions. Herein, we demonstrate that polyethylene terephthalate (PET), a synthetic organic polymer with functional carbonyl groups, could deliver a two-electron redox mechanism for potassium storage. The PET particles, synthesized from PET plastic film by a simple solvent thermal method, achieve almost complete utilization of redox-active sites, providing a reversible capacity of 273 mAh/g. Over 800 cycles of cycling life are demonstrated by the PET, along with fast K+-transport kinetics and thus outstanding rate performance. Furthermore, a fabricated full cell composed of PET anode can provide a high operating voltage of 3.17 V with a high energy density of 245 Wh/kg. This study offers a new way to utilize PET plastic waste and guide the development of organic anode for low-cost potassium-ion batteries.

Life cycle assessment of eco-brick production using PET particle reinforced epoxy resin composites

The process of urbanisation contributes to the growth of waste generation and causes environmental pollution. One of the most common plastic waste is polyethylene terephthalate (PET). This plastic waste is often used as mixed material in construction. The use of life-cycle assessment (LCA) is a possible tool to assess the sustainability of a product in the long term. After analysing the latest literature, it was found that the study of PET waste in building materials is one of the sustainable alternatives for waste reduction. This research contributes to the improvement of sustainability in alternative building materials through LCA. A gate-to-gate approach is adopted in this research. LCA Calculations for the production of eco-bricks were carried out in accordance with ISO 14044. GaBi software was used to identify and quantify impacts within the system boundaries. The calculations were based on the EDIP 2003 method for assessing impacts. The results show that the use of epoxy resin and PET as raw materials for eco-tiles has an impact on ozone formation (OF) of 118 m2 UES*ppm*hours, which is due to the use of epoxy resin chemicals as adhesives in the production of eco-bricks. Eco-bricks made of PET and epoxy resin have better compressive strength than other materials. The addition of epoxy resin adhesive can increase the compressive strength of the eco-bricks by 50%. Despite the advantages of using epoxy resin and PET in eco-bricks, there are many uncertainties about their environmental impact. It can be concluded that the use of epoxy resin and PET particles in the production of eco-bricks does not pose excessive environmental risks and their use as alternative mixtures for the production of eco-bricks does not lead to a significant reduction in the environmental profile.