Accumulation Of Plastic Waste Research Articles

Cutting‐Edge Strategies and Advancements for Combating Synthetic Polymer Pollution in Various Environmental Samples: A Review

AbstractPlastic debris is unavoidably released into the ecosystems, and their physicochemical and mechanical qualities deteriorate when exposed to the environment. This, ultimately, leads to the generation of tiny fragments of plastic, which are known as nanoplastics (<1000 nm) and microplastics (<5 mm). Over the past few years, the pollution of synthetic polymers has been reported in almost all the compartments of the environment across the globe. It is regarded as a hazard to both human health and natural systems. In addition, synthetic polymers act as vectors for contaminants as they can adsorb and accumulate contaminants from seawater. The accumulation of plastic waste in the environment and its widespread presence have drawn the attention of policymakers and the public. This global issue has led to the creation of numerous remediation solutions by innovators in previous decades, either to clear up old waste or to stop plastic from entering the various matrices of the environment. This review focused on the extensive scientific research available on effective techniques for removing plastic debris to promote positive action and progress in this important area. Despite the various challenges, these techniques offer vital opportunities, from increasing awareness to enhancing environmental quality. Further, the article has been enriched by incorporating bibliometric data that illustrates the widely used methods for removing microplastics from various environmental matrices. According to the data analysis, numerous remediation techniques have been developed to date (2010 and 2024). These techniques encompass various approaches, among which the chemical‐based methods enjoy more success. This success can be attributed to the diverse advantages offered by chemical‐based methods over other remediation techniques. Much research is now focused on overcoming the disadvantages and developing more efficient and environmentally sound technologies.

Microbial consortia for multi-plastic waste biodegradation: selection and validation

The accumulation of plastic waste in the environment poses significant ecological and health risks. This study evaluates the effectiveness of microbial consortia in degrading various types of plastics, including low-density polyethylene (LDPE), low linear-density polyethylene (LLDPE), polyethylene terephthalate (PET) and polystyrene (PS). Qualitative enzyme assays for esterases and ligninases, which are related to plastic biodegradation, were conducted in five microbial strains. Four microbial consortia, combining bacterial and fungal strains, were assembled based on the enzyme profile of their components and evaluated for their ability to degrade both virgin and recycled plastics. The results showed that consortia C2 (Bacillus subtilis RBM2, Fusarium oxysporum RHM1, and Alternaria alternata RHM4) and C4 (Bacillus subtilis RBM2 and Pseudomonas alloputida REBP7) exhibited the highest biodegradation efficiency, particularly achieving significant weight loss in recycled LDPE, virgin LLDPE and recycled PET. The biodegradation was further confirmed by FTIR analysis, which revealed changes in the chemical composition and functional groups of the treated plastics, indicating microbial interaction and degradation. This study underscores the potential of microbial consortia in addressing plastic pollution, highlighting the importance of strategic consortia design based on enzymatic profiles and plastic colonization capabilities. These promising results suggest that further optimization of microbial consortia could offer a viable solution for large-scale plastic waste management.

Uranium and arsenic bioremediation potential of plastic associated multi-metal tolerant Bacillus sp. EIKU23

Plastic waste accumulation is a significant environmental concern as it promotes microbial growth and acts as a carrier for heavy metals. This study focuses on a Bacillus sp. strain isolated from the surface of a used plastic bottle, tolerant to various potential toxic elements (PTEs) such as chromium, nickel, cobalt, copper, zinc, arsenite [As(III)], but sensitive to uranium (U) and arsenate [As(V)] toxicity. The strain demonstrates growth under different abiotic stress conditions, with the optimal pH range of 5.0-8.0 and a temperature of 30 °C. It shows remarkable removal capabilities, removing >23.3% of U, >38% of As(III)), and >22.6% of As(V) from an initial dose of 100mgL−1 in an aqueous solution. The biosorption capacity for U, As(III), and As(V) is 3.12, 3.1, and 1.8mgg−1 of biomass, respectively. Kinetic modelling suggests that the biosorption of U and As(V) follows a pseudo-second-order mechanism, while As(III) biosorption follows a pseudo-first-order mechanism. Moreover, the strain has the ability to precipitate >38.1% and ~67% of U using bacterially released phosphate from inorganic and organic sources, respectively. These findings highlight the strain's potential for bioremediation of PTE-contaminated environments, providing valuable insights for optimizing metal removal and immobilization processes in future research.

A novel “reinforcing-foaming-recovering” strategy for achieving thermally insulating green foams with ultrafast degradation

Lightweight porous materials have garnered increasing attention in application domains of intelligent construction and flexible thermal insulation, owing to their customizable 3D porous structures and outstanding performances. Nonetheless, the severe environmental pollution resulting from the accumulation of non-degradable plastic waste in the ecosystem has sparked significant interest in developing bio-degradable thermal insulation foams. The preparation of biodegradable foam, however, typically requires operating specialized equipment for long periods under extreme conditions, which diminishes its environmental friendliness as claimed. Herein, we present a pioneering "Reinforcing-Foaming-Recovering" strategy to achieve ultralight and recyclable green foams with excellent thermal insulation properties. This innovative strategy, involving materials reinforcing and low-pressure foaming complemented by nitrogen-assisted gas recovering enables the preparation of low-density (0.08 g/cm3) biodegradable foams with restricted shrinkage ratio (<5%). Thanks to the easy-to-control foaming method, combined with the improved 3D network cellular structures caused by nitrogen-assisted gas exchange, the achieved green foams exhibit favorable thermal insulation (39.8 mW/m·K) and superior biodegradation efficiency (11.5%/2 months). The approach of energy-efficient nitrogen-assisted low-pressure foaming of degradable polymers offers a promising and practical solution for producing eco-friendly and multifunctional porous materials with economic advantages.

Hybrid Fiber Reinforcement in HDPE–Concrete: Predictive Analysis of Fresh and Hardened Properties Using Response Surface Methodology

Plastic waste accumulation has driven research into recycling solutions, such as using plastics as partial aggregate substitutes in concrete to meet construction needs, conserve resources, and reduce environmental impact. However, studies reveal that plastic aggregates weaken concrete strength, creating the need for reinforcement methods in plastic-containing concrete. This study used experimental data from 225 tested specimens to develop prediction models for the properties of concrete containing macro-synthetic fibers (MSFs), steel fibers (SFs), and high-density polyethylene (HDPE) plastic as a partial substitute for natural coarse aggregate (NCA) by volume utilizing response surface methodology (RSM). HDPE plastics were used as a partial substitute for NCA by volume at levels of 10%, 30%, and 50%. MSFs were added at levels of 0, 0.25%, 0.5%, and 1% by volume of concrete, while SFs were added at levels of 0, 0.5%, 1%, 1.5%, and 2% by volume of concrete. The input parameters for the models are the ratio of HDPE, the dose of MSF, and the dose of SF. The responses are the slump value, the compressive strength (CS), the splitting tensile strength (TS), and the flexural strength (FS) of concrete. The significance and suitability of the developed models were assessed and validated, and the parameters’ contribution was investigated using analysis of variance (ANOVA) and other statistical tests. Numerical optimization was used to determine the best HDPE, MSF, and SF ratios for optimizing the mechanical properties of concrete. The results demonstrated that replacing NCA with HDPE plastics increased the workability and decreased the strength of concrete. The results demonstrated the applicability of the developed models for predicting the properties of HDPE–concrete containing MSFs and SFs, which agreed well with the data from experiments. The created models have R2 values more than 0.92, adequate precision more than 4, and p-values less than 0.05, showing high correlation levels for prediction. The RSM modeling results indicate that the inclusion of MSFs and SFs improved the mechanical properties of HDPE–concrete. The optimum doses of MSFs and SFs were 0.73% and 0.74%, respectively, of volume of concrete, leading to improvement in the mechanical properties of HDPE–concrete. This approach reduces plastic waste and its detrimental environmental impact. Further development of models is needed to simulate the combined effects of different fiber types, shapes, and dosages on the performance and durability of plastic-containing concrete.

Microplastic contamination in the aquaculture icon Oreochromis mossambicus: Prevalence, characteristics, and comprehensive overview

The global production of plastics has surged to 368 million tonnes annually, leading to significant plastic waste accumulation, projected to reach 12,000 Mt by 2050, impacting aquatic ecosystems. Fish, crucial for their protein and nutrients, are particularly vulnerable to microplastic (MP) ingestion. As a major aquaculture producer and fish consumer, India faces rising plastic pollution in freshwater, which disrupts fish health and growth, posing a significant threat to the sustainability and productivity of aquaculture systems and potential health risks. This study focuses on Mozambique tilapia (Oreochromis mossambicus), valued for its widespread aquaculture use, rapid growth, and nutritional benefits. Our research reveals significant MP contamination (69.23 %) in Mozambique tilapia, with over 80 % from the Ulhas River and 60 % from the Bhima River contaminated and females showing higher susceptibility. These findings emphasise the need for further research on MP impacts on human health and the development of mitigation strategies.

Microbiological and Physicochemical Approach in the Feeding of Superworm (Zophobas morio) with Petroleum-Derived Polymer Diets

Plastics are very versatile materials that have contributed to the development of society since the 19th century; however, their mismanagement has led to an accumulation of plastic waste in almost every ecosystem, affecting the fauna of the planet. However, recently, some studies have shown that some insects might be able to adapt, consuming a wide range of hydrocarbon base polymers. In this work, the adaptive capacity of Zophobas morio larvae when feeding on different synthetic polymers derived from petroleum was studied. Four different thirty-day larval feeding treatments were carried out with synthetic polymers, including expanded polystyrene (PS), low-density polyethylene (LDPE), polyisoprene (PI), and butyl rubber (BR); in addition, a positive control of organic diet was included. Intestinal bacteria were isolated from the treatments and identified by Sanger sequencing. To analyze the chemical composition and physical form of the frass produced, Fourier transform infrared spectroscopy (FITR) was performed, and images of the feces’ surfaces were taken with scanning electron microscopy (SEM), respectively. Zophobas morio larvae were able to consume 54% of PS in 30 days, equivalent to 3.2 mg/d/larva. Nine culturable bacterial strains associated with the decomposition of synthetic polymers were identified in the intestine of the larvae. As for the physicochemical analysis of the feces, FTIR spectra showed the scission of bands corresponding to functional groups of the synthetic polymers in the comparison of the plastic diet treatments versus the feces of antibiotic-treated and plastic-fed larvae, while the comparison of spectra of the plastic and control treatments also identified differences in the absorption peaks. SEM imaging demonstrated that superworm feces differed in dependence on the substrate consumed. The findings demonstrated that Zophobas morio larvae possess a gut biological complex that allows them to feed and survive by consuming various petroleum-derived polymers.

Omic-driven strategies to unveil microbiome potential for biodegradation of plastics: a review.

Plastic waste accumulation has lately been identified as the leading and pervasive environmental concern, harming all living beings, natural habitats, and the global market. Given this issue, developing ecologically friendly solutions, such as biodegradation instead of standard disposal, is critical. To effectively address and develop better strategies, it is critical to understand the inter-relationship between microorganisms and plastic, the role of genes and enzymes involved in this process. However, the complex nature of microbial communities and the diverse mechanisms involved in plastic biodegradation have hindered the development of efficient plastic waste degradation strategies. Omics-driven approaches, encompassing genomics, transcriptomics and proteomics have revolutionized our understanding of microbial ecology and biotechnology. Therefore, this review explores the application of omics technologies in plastic degradation studies and discusses the key findings, challenges, and future prospects of omics-based approaches in identifying novel plastic-degrading microorganisms, enzymes, and metabolic pathways. The integration of omics technologies with advanced molecular technologies such as the recombinant DNA technology and synthetic biology would guide in the optimization of microbial consortia and engineering the microbial systems for enhanced plastic biodegradation under various environmental conditions.

Upcycling Plastic Waste into Valuable Carbon Nanomaterials

AbstractThe global issue of plastic waste accumulation is now widely acknowledged as a significant environmental challenge that affects all aspects of life, economies, and natural ecosystems worldwide. Hence, it is crucial to develop sustainable solutions to traditional disposal methods. One promising solution involves upcycling plastic waste into valuable carbon nanomaterials such as carbon nanotubes, graphene, and carbon nanofibers, among others. This critical review provides an overview of the problems associated with plastics, including their various types and properties, as well as their significant impact on the environment and the methods currently employed for waste management. Furthermore, it delves into recent advancements in upcycling plastic waste into carbon nanomaterials through four state‐of‐the‐art methods with the potential for scaling up and enabling industrial applications: thermal decomposition, flash joule heating (FJH), chemical vapor decomposition (CVD), and stepwise conversion. For each method, highly influential and seminal papers were selected, and their research approaches and observed results were thoroughly analysed. This upcycling approach transforms plastic waste into valuable resources, promoting a waste‐to‐value concept that reduces environmental impact and supports the circular economy. By creating new materials from discarded plastics, it addresses waste management challenges while generating economic value.

Bacterial Degradation of Low-Density Polyethylene Preferentially Targets the Amorphous Regions of the Polymer.

Low-density polyethylene (LDPE) is among the most abundant synthetic plastics in the world, contributing significantly to the plastic waste accumulation problem. A variety of microorganisms, such as Cupriavidus necator H16, Pseudomonas putida LS46, and Pseudomonas chlororaphis PA2361, can form biofilms on the surface of LDPE polymers and cause damage to the exterior structure. However, the damage is not extensive and complete degradation has not been achieved. The changes in polymer structure were analyzed using Time-domain Nuclear Magnetic Resonance (TD-NMR), High-Temperature Size-Exclusion Chromatography (HT-SEC), Differential Scanning Calorimetry (DSC), and Gas Chromatography with a Flame Ionization Detector (GC-FID). Limited degradation of the LDPE powder was seen in the first 30 days of incubation with the bacteria. Degradation can be seen in the LDPE weight loss percentage, LDPE degradation products in the supernatant, and the decrease in the percentage of amorphous regions (from >47% to 40%). The changes in weight-average molar mass (Mw), number-average molar mass (Mn), and the dispersity ratio (Đ) indicate that the low-molar mass fractions of the LDPE were preferentially degraded. The results here confirmed that LDPE degradation is heavily dependent on the presence of amorphous content and that only the amorphous content was degraded via bacterial enzymatic action.

Seaweed as a Valuable and Sustainable Resource for Food Packaging Materials.

Plastic food packaging causes massive pollution in the environment via resource extraction, gas emissions, and the enduring plastic waste accumulation. Hence, it is of crucial importance to discover sustainable alternatives in order to protect ecosystems and conserve precious resources. Recently, seaweed has been emerging as a promising sustainable solution to plastic pollution. Seaweed is a fast-growing marine plant that is abundant in tropical coastlines and requires minimal resources to cultivate. In addition, seaweed is rich in valuable polysaccharides such as alginate, fucoidan, carrageenan, agar, and ulva, which can be extracted and processed into biodegradable films, coatings, and wraps. This ability allows the creation of an alternative to plastic food packages that are completely biodegradable, made from renewable resources, and do not linger in landfills or oceans for centuries. In this context, this review discusses the main classification of seaweed, their production and abundance in the world, and provides a summary of seaweed-based materials developed in the last 2-5 years for potential usage in the food packaging sector.

Effect of particle size and replacement ratio on mechanical performance of cementitious mortar containing ground recycled acrylonitrile butadiene styrene (GRABS) waste plastics

While waste plastics have been used as a natural sand aggregate replacement in cementitious mortar as a sustainable option to mitigate global accumulation of plastic waste in landfills, fundamental mechanical properties like compressive, tensile, and shear must be known to advance design and practical application of these cement-concrete composites as suitable building construction materials. Experimental testing is conducted to reveal to what extent the cementitious composite properties are altered, thereby influencing their overall mechanical performance, when both ungraded and graded ground recycled acrylonitrile butadiene styrene (GRABS) plastic are employed as substitutes for natural aggregates. The novelty of this research lies in its pioneering investigation to quantify the effects of varying particle sizes and volume fractions of waste plastics acquired through mechanical recycling and their influences on the mechanical properties of mortars containing plastics as a composite material. The results from fresh and hardened material properties are compared to conventional mortar properties to examine the impact of various GRABS particle sizes and volume fractions on the overall material strength. While replacing sand with waste plastic generally reduced mechanical properties, the resulting mixes still met the minimum compressive strength (4060 psi [28 MPa]) as per ASTM C150 standards for Portland cement. Notably, graded plastic particles with sizes less than 0.024 in [0.6 mm] demonstrated an overall improvement in mechanical properties compared to ungraded particles. Failure mechanisms responsible for compressive, tensile, and shear damage development are discussed by analyzing the fracture surfaces, which provide insight into the intricate relationship between waste plastic size and distribution on the mechanical behavior of mortar. The findings indicate that GRABS waste plastics, when combined with sand at appropriate particle sizes and volume fractions, have the potential to create tailored mixes to meet minimum mix design standards for construction applications.

Conversion of polypropylene (PP) plastic waste to liquid oil through catalytic pyrolysis using Philippine natural zeolite

Abstract The accumulation of plastic waste compelled the need to develop energy recovery methods, such as pyrolysis, which could convert plastics into valuable energy sources. Pyrolysis requires high operating temperatures; thus, a catalyst is often utilized to speed up the process. In this study, the viability of Philippine Natural Zeolite (PNZ) as a catalyst was investigated through the conversion of polypropylene (PP) waste into liquid oil using catalytic pyrolysis. The PP waste feedstocks were pre-mixed with the PNZ in a 1:10 ratio. Pyrolysis was carried out in a heating mantle for three trials of non-catalytic and catalytic pyrolysis. SEM and XRD were conducted to characterize the PNZ, while FTIR was carried out for the pyrolysis oil. SEM analysis showed the voids formed from the pores of the catalyst that influenced the pyrolysis reaction. Results from the XRD pattern also revealed clinoptilolite, mordenite, and heulandite as the main minerals found in the PNZ. Non-catalytic pyrolysis of PP yielded an average of 75.03% liquid oil, 13.66% residue, and 11.31% uncondensed gas. Meanwhile, catalytic pyrolysis produced higher yields with 86.39% liquid oil, 12.49% residue, and 1.12% uncondensed gas. FTIR results exhibited clear peaks for both processes, with similar components but different intensities.

Consumer Perception And Willingness To Pay For Plastic Bags In Somalia's Traditional Markets: Evaluating The Ban's Effectiveness

The policy prohibiting the use of disposable plastic bags in Somalia represents a governmental effort to mitigate plastic waste accumulation. The policy's effectiveness remains uncertain, as it is implemented solely in modern retail stores, whereas the primary source of plastic bag waste originates from traditional markets. This study seeks to assess consumer perceptions of government policies concerning the ban on disposable plastic bags in traditional markets, as well as their willingness to pay for each plastic bag utilised. Data were collected through a survey questionnaire administered to consumers of traditional markets. The study's results indicated that most consumers concurred with the policy's implementation in traditional markets, albeit with a recommendation for gradual application. The implementation of paid plastic bags was also agreed upon. Their argument relies on the belief that the policy may enhance public awareness and concern regarding the reduction of disposable plastic bag usage. The average value of consumers' willingness to pay for a plastic bag is variable, indicating that consumers remain inclined to pay higher amounts. To decrease the utilisation of plastic bags within the community, it is essential to either increase the cost of plastic bags significantly or to explore alternatives, such as shopping baskets, reusable bags, or environmentally friendly plastic options

Microplastics in Urban Soils From Different Land Use Activities of Cyberjaya (Malaysia): Exploring Occurrence, Relationships, Sources and Pollution Level

ABSTRACTAs human activities continue to increase, the production and utilisation of plastics have become pervasive, leading to a surplus of plastic waste in the environment. This has turned the terrestrial ecosystem, encompassing soil, into a significant receptacle for the growing accumulation and discharge of plastic waste. Thus, the objective of this study is to investigate the occurrence, relationships, sources and pollution levels of microplastics in urban soils from different land use activities in Cyberjaya, Malaysia. Surface soil samples were collected from land uses (i.e., vacant areas, residential areas, commercial areas, construction areas and roadways). These surface soil samples were analysed for microplastic occurrence using density separation, microscopy and spectroscopy methods. The microplastics particles were analysed for size, colour and shape. Selected microplastics particles were also analysed for its plastics polymers using Fourier‐Transform Infrared Spectroscopy. Microplastics occurrence ranged from 0.3 to 1.5 particle/kg, with the highest average occurrence in the construction area (0.69 particle/kg) and lowest in the vacant area (0.33 particle/kg). Microplastics particle size was shortest in commercial areas (586.08 μm) and longest in vacant areas (793.78 μm). There were no similarities between microplastics occurrence and particle size across these different land use activities, suggesting that the microplastics occurrence in urban soils depends on external disturbances during each land use activity. Significant correlation between microplastic particle size and temperature (r 2 = 0.517) showed that each land use activity is influenced by external disturbances. The I geo values showed that the microplastics pollution level in urban soils is classified as uncontaminated to moderately contaminated. Microplastic particles in urban soils were found in various shapes (i.e., fragments, films and fibres) and colours (i.e., transparent, grey, blue, red, green, purple, black, white and yellow) along with plastic polymer types (i.e., ABS, PET, PP, PE and PS) due to traffic volume, tyre wear, mismanaged plastic waste and degradation rate. This study highlights the need for pollution management and waste disposal to avoid urban environmental problems and adverse health effects.

Optimization of PET depolymerization for enhanced terephthalic acid recovery from commercial PET and post consumer PET-bottles via low-temperature alkaline hydrolysis

The increasing demand for plastic has resulted in a surge in plastic waste production. Polyethylene terephthalate (PET), commonly used in beverage bottle manufacturing, is only partially recycled, with an estimated recycling rate of just 28.4% in 2019. This accumulation of plastic waste is harmful to the environment and living organisms, necessitating effective recycling methods for PET waste. One promising method is alkaline hydrolysis using NaOH, which can break down PET into its monomer components, terephthalic acid (TPA) and ethylene glycol (EG). This process not only recycles PET efficiently but also manages contaminants effectively, producing high-quality TPA, supporting the development of a circular economy. This study looks into PET depolymerization via alkaline hydrolysis at low temperature by investigating effects of various factors: pH levels, water to ethanol ratio, NaOH concentration, NaOH to PET ratio, reaction time, PET size, reusability of unreacted PET, air plasma pretreatment of PET, and different kinds of PET. Promisingly, PET conversion rates of over 90% and a TPA purity of 99.6% were achieved in this study highlighting the efficacy of alkaline hydrolysis in depolymerizing post-consumer PET waste. Ultimately, this research advances sustainable plastic waste management and supports the integration of PET into a circular economy framework.

Grave-to-cradle dry reforming of plastics via Joule heating

Both plastics and CO2 are waste carbon resources, and their accumulation in nature has led to severe environmental pollution. However, simultaneously converting plastic waste and CO2 into value-added chemicals remains a challenge. Here we demonstrate a catalytic reforming process that converts plastics and CO2 into syngas over an electrified FeCrAl heating wire. The temperature of the electrified heating wire can quickly exceed 800 °C, facilitating the decomposition of polyethylene into gaseous hydrocarbons. The high-temperature heating wire promote the CO2 deoxygenation, resulting in the generation of CO, as well as the dehydrogenation of gaseous hydrocarbons. Significantly, the additional O species from CO2 and the carbon species from hydrocarbons can react to form CO, maintaining the high catalytic activity of the electrified heating wire. This novel approach is of paramount to achieving a circular economy in addressing the ongoing environmental crisis caused by the accumulation of plastic waste and excessive CO2 emissions.

Effect of Graphite Nanoadditives on the Behavior of a Diesel Engine Fueled with Pyrolysis Fuel Recovered from Used Plastics.

Plastic waste accumulation is a significant threat to the environment and humans. Pyrolysis is a promising method for recycling plastic waste since all of the yields are useful, reducing the associated environmental risks of plastic waste. Energy recovery from used plastic waste can help restore ecosystems by utilizing waste as fuel while addressing the environmental problem of plastic disposal. This study experimentally investigates the application of oil obtained by the pyrolysis of waste high-density polyethylene (HDPE) as a viable energy source for diesel engines, offering a unique solution to the issues of plastic waste and energy sustainability. The catalytic pyrolysis method was employed to convert used HDPE plastics into a fuel called used polymer pyrolysis oil (UPO). The UPO was blended at 20% and 40% on a volume basis with mineral diesel. The graphite nanoadditives of 50 and 100 ppm were doped to enhance the properties of the UPO20 blend. The results showed that UPO20n100 blends exhibited a 2.79% increase in brake thermal efficiency and an 11.6% reduction in specific fuel consumption compared to diesel. Utilizing the UPO20n100 blend as a diesel engine fuel resulted in reductions of hydrocarbon, carbon monoxide, and smoke emissions by 8.9%, 9.9%, and 8.9%, respectively, compared with diesel operation. These findings provide a pathway for reducing plastic pollution and reliance on fossil fuels, with significant implications for the development of sustainable energy solutions. Additionally, this study presents a novel application of graphite nanoadditives in fuel blends prepared from used plastics, highlighting their significant impact on enhancing engine efficiency and reducing emissions.

Anodic Commodity Polymer Recycling: The Merger of Iron-Electrocatalysis with Scalable Hydrogen Evolution Reaction.

Plastics are omnipresent in our everyday life, and accumulation of post-consumer plastic waste in our environment represents a major societal challenge. Hence, methods for plastic waste recycling are in high demand for a future circular economy. Specifically, the degradation of post-consumer polymers towards value-added small molecules constitutes a sustainable strategy for a carbon circular economy. Despite of recent advances, chemical polymer degradation continues to be largely limited to chemical redox agents or low energy efficiency in photochemical processes. We herein report a powerful iron-catalyzed degradation of high molecular weight polystyrenes through electrochemistry to efficiently deliver monomeric benzoyl products. The robustness of the ferraelectrocatalysis was mirrored by the degradation of various real-life post-consumer plastics, also on gram scale. The cathodic half reaction was largely represented by the hydrogen evolution reaction (HER). The scalable electro-polymer degradation could be solely fueled by solar energy through a commercially available solar panel, indicating an outstanding potential for a decentralized green hydrogen economy.

Impact of weathered and virgin polyethylene terephthalate (PET) micro- and nanoplastics on growth dynamics and the production of extracellular polymeric substances (EPS) of microalgae

The ever-increasing plastic waste accumulation in the marine environment necessitates a deeper understanding of microalgae interactions with micro- and nanoplastics (MNP), and the role of extracellular polymeric substances (EPS). EPS, known for its adhesive properties and produced as an algal stress response, may facilitate aggregation of both algae and MNPs, thereby impacting ecological and hydrodynamic processes such as the trophic transfer or vertical transport of MNPs. Moreover, gaining a deeper understanding of the impact of weathering processes on the potential toxicological effects of plastic particles, and the comparative significance of plastic-specific effects relative to those of naturally occurring particles such as kaolin clay, is imperative. Therefore, this study investigated the impact of fragmented, polydisperse virgin polyethylene terephthalate (PET, Daverage = 910 nm) and weathered PET (Daverage = 1700 nm) on the growth and the production of EPS of Rhodomonas salina. Algae were exposed to a range of low MNP concentrations (10, 100 and 1000 and 10,000 MNPs ml-1) for 11 days. A natural particle control (kaolin, Daverage = 1600 nm) was deployed to differentiate particle effects from plastic effects. It was observed that exposure to both weathered PET and virgin PET resulted in initially increased growth rates (7.80 % and 7.28 % respectively), followed by significant decreases in algae cell density (−30.1 % and −11.2 % respectively). Furthermore, exposure to weathered PET caused a simultaneous elevation in cellular EPS production (76.51 %). The effects of plastics were significantly larger than the effect of kaolin. Also, the observed effects were amplified by the weathering of the plastics. These observations underscore the interactions between particle type, age and concentration, and their distinct impacts on algae density and growth inhibition. The observations indicate a role for EPS as an algal protection mechanism, potentially affecting the environmental fate of MNP – microalgae aggregates.