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Biodegradable green composites of poly(butylene succinate) (PBS) and poly(L-lactide) (PLA) fibers were initially melt-blended aiming to obtain balanced comprehensive properties. According to the morphological observations, the PLA fibers were uniformly embedded in the PBS matrix. Rheology measurements suggested that the incorporation of PLA fibers improved the viscoelasticity of PBS melt. The percolation network of PLA fibers was formed at content of 20 wt%. The presence of PLA fibers inhibited the crystallization and reduced the isothermal crystallization rate of PBS in the composites. Moreover, the reinforcing effect of PLA fibers on the PBS matrix was found to be very significant. The storage modulus and tensile modulus of the composite with 30 wt% PLA fibers were 74% and 94% higher than those of neat PBS, respectively. PBS/PLA fiber composites prepared by simple melt blending method displayed the combination of enhanced melt strength and modulus, while maintaining the biodegradability of PBS matrix, which is of great potential for the wider practical application of environmentally friendly polymers. [ABSTRACT FROM AUTHOR]

A method has been developed to quantify PET and PBT microplastics (MPs) based on depolymerization and detection of depolymerization products by gas chromatography-tandem mass spectrometry (GC–MS/MS) without a complex separation process from environmental samples. Under the optimal depolymerization conditions, PET and PBT were efficiently converted to ethylene glycol (78%) and 1,4-butanediol (87%), respectively. Subsequently, the linear curves were constructed between signal intensities of depolymerization products and polymer masses by GC–MS/MS, and the correlation coefficients of PET and PBT were 0.996 and 0.997, respectively. The spiking and recovery experiments of PET and PBT in the environmental samples showed that the recovery was stable in the range 89–100%, and the limit of detection was 4.95 μg and 1.39 μg of PET and PBT, respectively. The method has been proven to be capable of simultaneous identification and quantification of PBT and PET MPs in real environmental water samples without complex separation process, which provided a scheme for the determination of microplastics. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate the properties of biodegradable plantable pots made from biomaterials. Specifically, rapeseed straw and cow manure biomaterials were studied here because these biomaterials add nutrients to the soil during their biodegradation and are readily available agricultural by-products. Furthermore, the use of biomaterials helps in replacing the plastic materials which are currently used to make pots and decreases the environmental impact by producing a cleaner product. The physical and mechanical properties of biocomposites pots were investigated and optimized in the present work. The effect of mixing ratio (straw: cow manure) in the composite, straw particle size, and chemical pre-treatments of straw by 1% HCl or 2% NaOH on the physical and mechanical properties of biodegradable pots was investigated. Additionally, the Taguchi method and ANOVA statistical analyses were employed for parameters optimization. The results indicated the straw to cow manure ratio exhibited a significant effect on the compression strength (CS), penetration strength (PS), and water absorption (WA) of pots. While the CS and PS of pots decreased with increasing the ratio of straw from 2 to 10% and increasing the particle size of straw from 1.5 to 3.0 mm, these changes increased the water absorption of pots (126.52–141.21% for 1.5-mm untreated straw). Chemical pre-treatments of straw investigated here resulted in decreased CS and PS of pots. The straw ratio in the straw/manure mixture is the most significant factor affecting the characteristics of biodegradable pots. [ABSTRACT FROM AUTHOR]

Pt cocatalyst play bifunctions in the photoreforming of polyethylene terephthalate plastic waste by improving the charge transfer kinetics and regulating the adsorption-desorption of oxidation intermediates, thereby achieving efficient photocatalytic H 2 evolution rate and producing valuable commodities in the photoreforming reactions. [Display omitted] Upcycle polyethylene terephthalate (PET) waste by photoreforming (PR) is a sustainable and green approach to tackle environmental problems but with challenges to obtain valuable oxidation products and high purity hydrogen simultaneously. Noble metal cocatalysts are essential to enhance the overall PR reaction efficacy. In this work, TiO 2 nanotubes (TiO 2 NTs) decorated with single Pt atoms (Pt 1 /TiO 2) or Pt nanoparticles (Pt NPs /TiO 2) are used in the photoreforming reaction (in one batch), and the oxidation products from ethylene glycol (EG, hydrolysed product of PET) in liquid phase and hydrogen are detected. With Pt 1 /TiO 2 , EG is oxidized to glyoxal, glyoxylate or lactate, and hydrogen evolution rate (r H 2) reaches 51.8 μmol⋅h−1⋅g cat −1, that is 30 times higher than that of TiO 2. For Pt NPs /TiO 2 (size of Pt NPs: 1.97 nm), hydrogen evolution reaches 219.1 μmol⋅h−1⋅g cat −1, but with the oxidation product of acetate only. DFT calculation demonstrates that for Pt NPs, the reaction path for hydrogen evolution is preferred thermodynamically, due to the formation of Schottky junction. On the oxidation of EG, theoretical and spectroscopic analysis suggest that bidentate adsorption of EG at the interface is facile on Pt 1 /TiO 2 , compared to that on Pt NPs /TiO 2 (two Pt sites), but oxidation products, adsorb less strongly, compared to Pt NPs /TiO 2 , that eventually regulates the distribution of oxidation products. The results thus demonstrate the bifunctions of Pt in the PR reaction, i.e., electron transfer mediator for hydrogen evolution and reactive sites for molecules adsorption. The oxidation reaction is dominated by the adsorption-desorption behavior of molecules but the reduction reaction is controlled by the electron transfer. In addition, acidification of pretreated PET alkaline solution achieves separation of pure terephthalic acid (PTA), which further improves the reaction efficiency possibly by offering high density of active sites and acidic environment. Our work thus demonstrates that to upcycle PET plastics, an optimized process can be reached by atomic design of photocatalysts and proper treatment on the plastic wastes. [ABSTRACT FROM AUTHOR]

The urgent requirement for efficient recycling strategies in the wind energy industry prompted this study to explore the behavior of methanesulfonic acid (MSA) in the solvolysis of carbon fiber‐reinforced plastics (CFRP), as an alternative to standard solvents and acids. For the investigation, two layers of carbon fibers, infused with amine‐based epoxy through a vacuum‐assisted resin infusion process, were applied. The results showed that MSA was the most effective solvent for the solvolysis of CFRP, compared to other investigated common acids. The recycled products demonstrated satisfactory properties for both the matrix and fiber, which were comparable to those of the virgin materials. [ABSTRACT FROM AUTHOR]

The pervasive nature of plastic and the longevity of plastics leaves a legacy of microplastics (MPs) that contaminate our environment, including drinking water sources. Although MPs have been documented in every environmental setting, a paucity of research has focused on the transport and fate of MPs in groundwater. Previous field and laboratory studies have shown that MPs can migrate through aquifer material and are influenced by environmental factors. This study used controlled column experiments to investigate the influence of polymer type (polyamide, polyethylene, polypropylene, and polyester) and particle shape (fragment, fiber, and sphere) on MP retardation and retention. The results showed that all individual MP types investigated were retarded compared to the NaCl tracer, with a retardation factor ranging from 1.53 to 1.75. While hypothesized that presence of multiple types and shapes could change mobility, the results indicate that this hypothesis is not correct for the conditions tested. This study provides new insights into MP transport in groundwater systems based on the characteristics of MP particles. In addition, this study demonstrates the need for further research on types of MPs and under more conditions, especially in the presence of a mixture of types and shapes of MPs to gauge what is occurring in natural systems where many MPs are present together. Article impact statement: Microplastics are retarded approximately the same amount regardless of type or shape tested. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate (PET) is a major component of plastic waste. Enzymatic PET hydrolysis is the most ecofriendly recycling technology. The biorecycling of PET waste requires the complete depolymerization of PET to terephthalate and ethylene glycol. The history of enzymatic PET depolymerization has revealed two critical issues for the industrial depolymerization of PET: industrially available PET hydrolases and pretreatment of PET waste to make it susceptible to full enzymatic hydrolysis. As none of the wild-type enzymes can satisfy the requirements for industrialization, various mutational improvements have been performed, through classical technology to state-of-the-art computational/machine-learning technology. Recent engineering studies on PET hydrolases have brought a new insight that flexibility of the substrate-binding groove may improve the efficiency of PET hydrolysis while maintaining sufficient thermostability, although the previous studies focused only on enzymatic thermostability above the glass transition temperature of PET. Industrial biorecycling of PET waste is scheduled to be implemented, using micronized amorphous PET. Next stage must be the development of PET hydrolases that can efficiently degrade crystalline parts of PET and expansion of target PET materials, not only bottles but also textiles, packages, and microplastics. This review discusses the current status of PET hydrolases, their potential applications, and their profespectal goals. Key points: • PET hydrolases must be thermophilic, but their operation must be below 70 °C • Classical and state-of-the-art engineering approaches are useful for PET hydrolases • Enzyme activity on crystalline PET is most expected for future PET biorecycling [ABSTRACT FROM AUTHOR]

The effect of microplastics on the environment is currently one of the hotspots in environmental research. Biodegradable plastics will inevitably replace most of the traditional plastics. However, there are few reports on the effect of their natural degradation process on freshwater sediment. This study constructed a water column reactor indoors to simulate the environment of shallow freshwater lake, and investigated the effects of two commonly used biodegradable plastics, PLA and PBAT, on sediment at different time periods (90 and 365 days). The analysis of physicochemical parameters showed that the two degradable plastics significantly increased the total organic carbon (TOC) and total nitrogen (TN) concentrations of interstitial water in the short term (90 days) (P<0.05). PLA and PBAT significantly promoted the α diversity of bacterial communities over a long period of time (365 days) and increased the relative abundance of Proteobacteria. The number of denitrifying nirS genes in PLA and PBAT during the 90-day period was (2.33±0.33)x108 copies/g sediment and (2.16±0.09)x108 copies/g sediment respectively and the number of denitrifying nirK gene was (1.24±0.18)x107 copies/g sediment and (1.37±0.23)x107 copies/g sediment respectively, both of them were significantly higher than the control group (P<0.05). However, within 365 days, the number of nirS and nirK genes and anammox bacteria in degradable plastic groups were all significantly lower than the control group (P<0.05). Besides, the number these two kinds of bacteria in PBAT group was significantly lower than those of PLA group. Redundancy analysis revealed that the number of nirS and nirK genes was positively correlated with NH4+-N, TN, and TOC, and negatively correlated with total phosphorus. The correlation between anammox bacteria and environmental factors was completely opposite to that of denitrifying genes. This study preliminarily investigates the effects of different biodegradable plastics on sediment at different time periods, which may play an important role in further understanding the environmental effects and effect mechanisms of biodegradable plastics. [ABSTRACT FROM AUTHOR]

Background: Environmental concerns about petroleum-based plastic packaging materials and the growing demand for food have inspired researchers and the food industry to develop food packaging with better food preservation and biodegradability. Nanocomposites consisting of nanofillers, and synthetic/biopolymers can be applied to improve the physiochemical and antimicrobial properties and sustainability of food packaging. Scope and approach: This review summarized the recent advances in nanofiller and their applications in improved food packaging systems (e.g., nanoclay, carbon nanotubes), active food packaging (e.g., silver nanoparticles (Ag NPs), zinc oxide nanoparticles (ZnO NPs)), intelligent food packaging, and degradable packaging (e.g., titanium dioxide nanoparticles (e.g., TiO2 NPs)). Additionally, the migration processes and related assessment methods for nanofillers were considered, as well as the use of nanofillers to reduce migration. The potential cytotoxicity and ecotoxicity of nanofillers were also reviewed. Key findings: The incorporation of nanofillers may increase Young's modulus (YM) while decreasing the elongation at break (EAB) (y = −1.55x + 1.38, R2 = 0.128, r = −0.358, p = 0.018) and decreasing the water vapor (WVP) and oxygen permeability (OP) (y = 0.30x − 0.57, R2 = 0.039, r = 0.197, p = 0.065). Meanwhile, the addition of metal-based NPs could also extend the shelf-life of food products by lowering lipid oxidation by an average of approx. 350.74% and weight loss by approx. 28.39% during the longest storage period, and significantly increasing antibacterial efficacy against S. aureus compared to the neat polymer films (p = 0.034). Moreover, the migration process of nanofillers may be negligible but still requires further research. Additionally, the ecotoxicity of nanofillers is unclear, as the final distribution of nanocomposites in the environment is unknown. Conclusions: Nanotechnology helps to overcome the challenges associated with traditional packaging materials. Strong regulatory frameworks and safety standards are needed to ensure the appropriate use of nanocomposites. There is also a need to explore how to realize the economic and technical requirements for large-scale implementation of nanocomposite technologies. [ABSTRACT FROM AUTHOR]

Modifying starch allows for improvements in its properties to enable improved uses in food matrices, bioplastics, and encapsulating agents. In this research, four varieties of native potato starch were modified by acid treatment, enzymatic treatment, and ethanol precipitation, and their physicochemical, structural, thermal, and techno-functional characteristics were analyzed. According to FT-IR analysis, no influence of the modified starches on the chemical groups was observed, and by scanning electron microscopy (SEM), spherical and oval shapes were observed in the acid and enzymatic treatments, with particle sizes between 27 and 36 μm. In particular, the ethanolic precipitation treatment yielded a different morphology with a particle size between 10.9 and 476.3 nm, resulting in a significant decrease in gelatinization temperature (DSC) and more pronounced crystallites (XRD). On the other hand, the enzymatic treatment showed higher values for z-potential (ζ), and the acid treatment showed lower mass loss (TGA). Acid and ethanolic treatments affected the dough properties compared to native starches. The techno-functional properties showed a decrease in the water absorption index, an increase in the water solubility index, and varied swelling power behaviors. In conclusion, the modification of potato starches through acid, enzymatic, and ethanolic precipitation treatments alters their physicochemical properties, such as swelling capacity, viscosity, and thermal stability. This in turn affects their molecular structure, modifying morphology and the ability to form gels, which expands their applications in the food industry to improve textures, stabilize emulsions, and thicken products. Furthermore, these modifications also open new opportunities for the development of bioplastics by improving the biodegradability and mechanical properties of starch-based plastic materials. [ABSTRACT FROM AUTHOR]

In recent decades, synthetic plastics have posed a significant environmental threat due to their non-biodegradability. Research is being carried out to find alternative biodegradable sources similar to petroleum plastics but with a lower environmental impact than petroleum plastics. Solution casting was utilized to fabricate the blended films of poly(vinyl alcohol) (PVA)/cellulose acetate(CA)/starch with varying ratios with subsequent testing of their biodegradability using amylase and cellulase enzymes. Before and after enzymatic biodegradability testing, SEM, FTIR, tensile strength, elongation percentage, and swelling of (PVA/CA):(Starch) blended films were investigated. The optimized mechanical properties tensile strength appear at the ratio of (PVA/CA):(Starch) 1:1 was 37.17 ± 1.04 MPa. Using both amylase and cellulase enzymes at the same blend of the polymer best biodegradability that resulted in releasing 131.5 mg/dl of glucose units. The results suggest that (PVA/CA):(Starch) films blended in a ratio of 1:1 can replace petroleum-based plastics and become a green alternative. [ABSTRACT FROM AUTHOR]

Considerable interest in food packaging research has been prompted by the rising environmental impact of waste, customer awareness for readily accessible foods with extended shelf life, and ecological consciousness about the scarcity of natural resources. The utilization of plastic-based food packaging has resulted in a significant environmental concern due to the accumulation of substantial quantities of plastic in the surrounding areas. Research efforts are being motivated by ecological and health considerations in the pursuit of developing biodegradable films. Besides, poly(lactic acid) (PLA) has been suggested as a possible substitute for petroleum-based polymers because of its sustainability, simple accessibility, and biodegradability. PLA is a biodegradable plastic made from sugar beet or maize starch that may be fermented by bacteria to generate material with desirable qualities like transparency and rigidity. However, there is a need for further improvement in certain properties of PLA, such as flexibility, toughness, permeability, and thermal properties. One potential approach for enhancing these attributes involves the integration of nano-reinforcement. The utilisation of nanocellulose derived from biomass has garnered significant interest in recent times owing to its renewable nature, ability to biodegrade, impressive mechanical strength, low density, and considerable economic worth. In this study, we present a comprehensive overview of the most up-to-date methods for synthesising nanocellulose and its use as a filler material in the manufacture of PLA nanocomposites for food packaging. In addition, this study examines the emerging challenges and potential advantages associated with the utilization of PLA biocomposites incorporated with nanocellulose in the food packaging sector. [ABSTRACT FROM AUTHOR]

This work aims to present the results of evaluating the coloristic properties of polylactic acid (PLA) fibers. PLA is common nowadays in much research, as it is a biodegradable plastic from renewable sources. However, little research is devoted to PLA fibers, and even less to applied research of colored fibers. The prepared color masterbatches, created using inorganic pigments, such as titanium dioxide and carbon black, were subsequently used to prepare dyed PLA fibers in mass. The fibers were drawn to the maximum drawn ratio. The properties of the pure and dyed fibers were investigated before and after accelerated light aging using Q-SUN equipment. The changes were recorded by Fourier Transform Infrared (FTIR) spectroscopy and colorimetric properties were recorded using a device spectrometer from TECHKON SpectroDens. We also evaluated thermal properties from the first heating via differential scanning calorimetry (DSC). The measurements were taken before and after the aging of the PLA fibers, in order to see the effect of aging on the supermolecular structure, excluding the influence of the preparation process and the influence of the kind of PLA. Using inorganic pigments showed sufficient color stability even after accelerated light aging, which is beneficial for using colored fibers in practice. [ABSTRACT FROM AUTHOR]

Electrochemically converting CO2 into value-added chemicals is a promising approach to mitigate anthropogenic carbon emissions, yet largely limited to short-chained C1–C3 products. Herein, we demonstrate a tandem artificial synthesis of biodegradable polyhydroxybutyrate (PHB) plastic from CO2 building blocks. Batch synthesis of defects-enriched Bi catalyst is firstly demonstrated by plasma bombardment and following in situ electrochemical reduction, which delivers a HCOOH Faradaic efficiency above 80% at tunable concentration from 2 to 250 mM, an energy efficiency up to 41%, and a single-pass carbon conversion efficiency up to 60%. Annular dark field and second electron microscopic analysis, density functional theory (DFT) calcualtions, coupled with H-type and solid-state electrolyzer assessments, point out the vital role of defective and/or stepped Bi surface sites in promoting CO2-to-HCOOH conversion. Thereafter, as-synthesized high-purity HCOOH is used as the sole carbon source for C-chain growth within microbial fermentation reactor with Ralstonia eutropha, where activated formate dehydrogenase and increased metabolites related to Calvin–Benson–Bassham cycle are found to be responsible for the enhanced polyester accumulation. [ABSTRACT FROM AUTHOR]

Microplastics, an emerging contaminant, are widespread in oceans around the world, and rivers are the key conveyors of these pollutants into the oceans. There exists a dearth of available data pertaining to seasonal fluctuation, spatial distribution and risk assessment of microplastics in rivers extending from upper reaches to the lower reaches. The collection of such data is of utmost importance for the purpose of formulating beneficial management strategies for riverine microplastics. In order to bridge this research gap, an investigation was made in the Periyar River in Kerala, India, which is exposed to anthropogenic stress and is at risk of microplastic pollution. A total of eighteen sites (six sites each from downstream, midstream and upstream) along the 244 km of the river were investigated across three seasons in a year. The study revealed a discernible pattern in the spatial distribution of microplastic concentrations, wherein there was a rise in abundance from the upstream to midstream and then a sudden increase of abundance along the downstream regions towards the lower reaches. The highest mean microplastic abundance of 124.95 items/L was obtained during the monsoon season followed by post-monsoon season i.e. 123.21 items/L and pre-monsoon i.e. 120.50 items/L. The predominant forms of microplastics were found to be fibres, fragments and filaments. Most prevalent polymer types acquired were polyethylene (PE) and polypropylene (PP). Pollution hazard index (PHI) and pollution load index (PLI) were also evaluated to assess the water quality of this river. The findings of this study conclude that the Periyar River is polluted with microplastics throughout its course and offer significant insights into the detection of microplastic origins in river systems and lend support to the implementation of potential measures aimed at mitigating their impact. [ABSTRACT FROM AUTHOR]

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Over the last years, bio-based and biodegradable alternatives have gained considerable attention both of academic and of packaging industrial communities, driven by recent legislation and increasing awareness concerning environmental issues related to traditional plastic. However, it is often observed that packaging products made from bioplastics do not exhibit comparable performance to those produced using common non-biodegradable ones. The presence of long chain branching improves the processing behavior under elongational flow and, then, the filmability of low viscosity polymers such as polyesters. In this work it has been demonstrated that the presence of long chain branching in a bio-co-polyester, induced by the use of pentaerythritol in the synthesis a of poly(butylene adipate-co-butylene terephthalate), is able to dramatically change the rheological behavior of the linear chain polyester improving its filmability. The addition of branching lead to an increase of the elastic modulus and the tensile strength in branched polyester films if compared to the linear ones, while the elongation at break decreased. This is due to the answer of the branched polyester to the non-isothermal elongational flow that allows a better orientation of the macromolecules of the branched polyester. The film obtained with the branched polyester showed a decrease in clarity and a slight increase in haze if compared to linear one due to differences in the morphology of the two samples. [ABSTRACT FROM AUTHOR]

Biodegradable polymers for food applications have emerged as a sustainable alternative to reduce plastic waste. In this work, compostable films based on blends of poly(ε-caprolactone) (PCL) and thermoplastic gliadins (TPG) were developed for packaging applications. Firstly, gliadins were extracted from wheat gluten and plasticized with glycerol. Then, PCL/TPG films were prepared by cast-extrusion processing at pilot scale and samples were characterized in terms of their structural, morphological, thermal, mechanical, barrier and optical properties. The addition of TPG increased the glass transition temperature (Tg) of PCL, reduced the oxygen permeability at 0% and 50% relative humidity values, and improved the seal strength properties of the films, having a minimal effect on the thermal stability, transparency, and the high stretchability characteristic of PCL. On the other hand, the presence of gliadins led to more water sensitive materials, resulting in a slight increase in the water vapor permeability. Finally, the home-compostability assessment of the films revealed that the presence of gliadins accelerated the aerobic biodegradation and the disintegration with respect to pristine PCL film, thus, showing the potential interest of the developed materials for sustainable packaging applications. [ABSTRACT FROM AUTHOR]

In this study, the mechanical and morphological characteristics of poly(hydroxyalkanoate) (PHA)/poly(lactic acid) (PLA) blend matrix reinforced with spent coffee ground (SCG) were investigated across various weight ratios (100/0, 75/25, 50/50, 25/75, and 0/100) and SCG contents (10–40 wt%). SEM micrographs revealed a phase‐separated structure with cracks on the fracture surface, consistent with the lower flexural properties of biocomposites. The incorporation of SCG reduced mechanical properties, mainly due to its incompatibility with the PHA/PLA matrix. Biocomposites with high SCG content demonstrated lower energy absorption capabilities, likely due to SCG aggregates acting as stress concentrators and disrupting load‐transferring mechanisms. Moreover, increasing PHA content in the blends led to higher PLA crystallinity, as PHA acted as a nucleating agent for PLA. For biological treatment, biocomposites with PHA/PLA ratio (50/50) and SCG loading (20 wt%) were employed. The microscopic analysis highlighted well‐dispersed treated SCG within the matrix and improved interfacial contact. Biocomposites with treated SCG demonstrated remarkable enhancements of 52% and 113% in flexural strength and modulus, respectively. These findings proved the effectiveness of sustainable fungal treatment in enhancing interfacial adhesion and improving the mechanical performance of biocomposites. Highlights: Percentage of SCG in bioplastic blend as a significant effect on the flexural properties and impact strength.The ratio of the bioplastic blend has the strong influence on the flexural properties and impact properties.Biological treatment of SCG has improved the interfacial interaction between SCG and bioplastic blend.The treated SCG has rougher surface which facilitates the interfacial locking between bioplastic blend and treated SCG.The biological treatment of SCG has improved the mechanical properties of the composites. [ABSTRACT FROM AUTHOR]

The use of biodegradable polymers in the plastics industry has been increasing in recent years. The study of the chemical, physical, thermal, and mechanical properties of films based on biodegradable components is of interest to technologists because these properties determine their applicability for food packaging. In this work, films based on natural polymers such as linseed mucilage (LM) and chitosan (CH), as well as poly(acrylic acid) (PAA) were obtained through the casting method and using V‐50 as the initiator. The films were characterized through Fourier Transform Infrared spectroscopy, and thermogravimetric analysis, and their water absorption and swelling capacity, and thermal and mechanical properties were determined. Homogenous flexible, translucid, amber‐colored films, with low absorption and solubility in water were obtained. It was demonstrated through Fourier Transform Infrared analysis the chemical interaction between C–H, CO, and C–O chemical groups of LM, CH, and PAA. In addition, films showed high resistance to thermal decomposition between 125 and 425°C. The mechanical tests of tension allowed the composition of LM in the film, the behavior variates between a plastic and/or elastic material and with tensile strength (Rm) values between 10.8 and 16.4 MPa and elastic modulus (E) values between 56.2 and 169.2 GPa, we observed that at higher quantities of LM and thickness, both E and Rm tend to increase, while %EL decreases. This led us to conclude that the material transitioned from ductile and malleable to rigid and brittle. The films obtained with different ratios of LM/CH/PAA may exhibit a semi‐interpenetrating polymeric networking type morphology. Highlights: Thermal and mechanical properties are of interest in food packaging materials.Water absorption can impact the packaged food.Films can be processed on existing machines for conventional plastics.Some conventional plastics could be replaced by these biodegradable films.Biodegradable films are of great interest to the industry of food packaging. [ABSTRACT FROM AUTHOR]

Nano and micro plastics are harmful to the aqueous environment and the current treatment systems are either ineffective or expensive, which restricts their widespread use. In this research, reduced graphitic carbon oxide (rGO)‐Cu nanoparticles crosslinked with collagen support (rGO‐Cu/Coll) are employed as an efficient photocatalyst for the degradation of polystyrene (PS) nano plastics in water. It is shown that rGO‐Cu/Coll nanocomposite can degrade PS nano plastics when subjected to simulated visible light and direct sunlight. In the photocatalytic degradation of PS nano plastics, the reactive radical species (•OH and O2•−) produced on the surfaces of rGO‐Cu/Coll nanocomposite materials play major roles in de‐polymerization. The investigation of the FESEM, Raman, and UV–vis spectra of the irradiated and non‐irradiated samples reveal observable changes, including the distorted morphology and formation of a new band, with longer exposure times and greater degradation. Additionally, evidence for the photodegradation of PS chains is demonstrated by the observed increase in the intensities of the carboxylate, carbonyl, and hydroxyl absorption regions of the ATR‐FTIR spectra. The study provides a simple approach to the battle against plastic pollution in aquatic ecosystems using green photocatalysts under visible light including direct sunlight without consuming additional energy. [ABSTRACT FROM AUTHOR]

This review addresses the environmental challenges arising from the proliferation of plastic and electronic waste (E‐waste), driven by global economic and demographic expansion. Since the 1950s, the mass production of plastics has seriously threatened global sustainability, lacking effective post‐use management. E‐waste worsens the issue due to low recyclability and high toxicity. Resolving this requires improving biodegradability. The paper explores eco‐friendly biodegradable materials for a zero‐e‐waste society, focusing on multifunctional plastics in electronics, providing a comprehensive guide to material selection, and illustrating novel concepts through recent trials. The goal is fully biodegradable electronics, but transitioning from conventional material systems is complex. Notably, rendering engineering plastics in electronics biodegradable surpasses simply substituting conventional plastics. Thus, it is delved into various research initiatives focused on biodegradable materials for electronics, highlighting a systematic approach toward creating a fully integrated, biodegradable electronic system. This includes exploring the mechanisms of biodegradation and the integration of printed circuit boards (PCBs), a critical component in electronics. Achieving this represents a challenging but promising step toward a sustainable electronic future. [ABSTRACT FROM AUTHOR]

Microplastics pose significant challenges to ecosystems and organisms. They can be ingested by marine and terrestrial species, leading to potential health risks and ecological disruptions. This study aims to address the urgent need for effective remediation strategies by focusing on the biodegradation of microplastics, specifically polyvinyl chloride (PVC) derivatives, using the bacterial strain Bacillus albus. The study provides a comprehensive background on the accumulation of noxious substances in the environment and the importance of harnessing biodegradation as an eco-friendly method for pollutant elimination. The specific objective is to investigate the enzymatic capabilities of Bacillus albus, particularly the alpha/beta hydrolases (ABH), in degrading microplastics. To achieve this, in-silico studies were conducted, including analysis of the ABH protein sequence and its interaction with potential inhibitors targeting PVC derivatives. Docking scores of − 7.2 kcal/mol were obtained to evaluate the efficacy of the interactions. The study demonstrates the promising bioremediation prospects of Bacillus albus for microplastics, highlighting its potential as a key player in addressing microplastic pollution. The findings underscore the urgent need for further experimental validation and practical implementation of Bacillus albus in environmental remediation strategies. [ABSTRACT FROM AUTHOR]

The effective disposal of plastic waste has been a key global research issue. In this regard, the pyrolysis of plastic wastes seems to be an effective technique as this process is capable of producing fuel-grade oils. In the present work, the thermal decomposition of polyethylene (PE), polystyrene (PS), and their mixture (PS/PE) was investigated with an aim to enhance yields of liquid fractions with fuel-grade quality. The effect of operating parameters on the end products was studied. The obtained maximum liquid yields for polyethylene (PE) and polystyrene (PS) samples were 96.3 wt.% at 380 °C and 88.1 wt.% at 415 °C, respectively. For the PS/PE (50/50%) sample, the maximum conversion was 93.2 wt.% at 420 °C. Char yield was observed negligible (1–3 wt.%) at low reaction temperatures (350–420 °C). PE samples showcased a sharp initial decrease from 1.8 wt.% at 350 °C to 0.7 wt.% at 415 °C. PS also presented a similar trend; whereas, PS/PE sample was observed with 3.1 wt.% char at 350 °C that decreased to 1.4 wt.% at 420 °C. PE oil samples showed the presence of 1-alkenes and n-alkanes compounds in abundance, with carbon numbers in the range of C7 to C28. PS oil fractions comprised of toluene, ethylbenzene, and styrene in higher proportions of around 42%. On the other hand, PS/PE oil fractions mostly constituted the aliphatic hydrocarbons embracing both alkanes and alkenes with carbon numbers C12 to C22. Comparative assessment reveals that for PE oil fractions from the autoclave reactor are 44.4% and 90.2% higher than the same with fluidized bed and microwave-assisted reactors, whereas for PS oil fractions the values were marginally higher. [ABSTRACT FROM AUTHOR]

Agricultural solid waste (ASW) is a serious concern globally, specifically in agricultural countries like India, China, Japan, Indonesia, Malaysia, etc. A lot of agricultural waste like the remain of crop plants, peels, leaves, corn cob, decayed crops, etc., is produced directly or indirectly every year affecting the environment and is not appropriately managed. Therefore, to overcome this problem, there is a need to develop waste redemption techniques to transform solid waste into value-added products. The wastes are generally rich in carbohydrates, lipids, proteins, and many other organic and inorganic constituents. This composition allows us to produce numerous value-added products like livestock feed, bio-preservatives, biofuels, biofertilizers, single-cell proteins, nanoparticles, biodegradable plastic, chitosan, collagen, and antibodies. Additionally, various start-ups leading to new beneficial products from agricultural solid waste should be promoted. This review intends to explore the sources of agricultural solid waste generation and to provide a solution to manage the waste through modern technologies, saving the environment and boosting a country's economy. The outcome of our study will lead toward a sustainable approach to waste management as we have comprises the most innovative and successful working models in one place. This newly developed technique will help to achieve the greater goal of sustainable development. [ABSTRACT FROM AUTHOR]

Commercially pure green Al powder compacts were subjected to single-pass friction stir processing (FSP) with different tool rotational speeds. The effect of temperature and strain rate on the microstructural evolution during FSP was analyzed. The evolution of texture and different types of grain boundaries (GBs) (i.e., misorientation of GBs between 2° to 5°, 5° to 15°, 15° to 40° and 40° to 65°) were analyzed to find out the mechanism behind the microstructural evolution in the samples. At a lower strain rate, the restoration mechanism is mostly through extended recovery or continuous dynamic recrystallization. At a higher strain rate, with increased temperature, concomitant evolution of rotated cube component is noticed. Texture weakening with an increase in rotation speed and the presence of rotated cube component suggests the presence of other recrystallization mechanisms than continuous dynamic recrystallization. [ABSTRACT FROM AUTHOR]

European governments are addressing plastic pollution by implementing the Directive EU 2019/904 that bans single‐use items like cutlery, plates, straws, and beverage stirrers. One strategy proposed by several industries to continue their production is the conversion of single‐use items into multiuse items. Herein, the focus is on the production of polystyrene reusable plates and the suitability of this product for microwave and dishwasher use is assessed: in proper conditions, the structure is preserved without cuts or visible deformations, and the chemical stability is guaranteed. To get a full picture of the benefits and impacts of this new product, a life cycle assessment methodology is applied to compare the performances of one reusable plate with 20 single‐use plates. Results indicate that proper use is crucial: a reusable plate disposed after one use is more impactful than a single‐use plate. In contrast, the reuse of plates for 20 times allows to reduce carbon footprint and acidification potential. Eutrophication and ozone layer depletion, on the other hand, increase due to the washing phase. The solutions that can mitigate these issues and enhance the sustainability of the reusable plates include the improvement of the detergent compositions and the use of electricity from renewable sources. [ABSTRACT FROM AUTHOR]

Biosensors (biological sensors) are a promising alternative to standard analytical techniques for testing and monitoring in the environment, among others, heavy metals. Biological materials that detect heavy metals include enzymes, bacteria, fungi, and plant and animal cells. The paper aimed to evaluate the possibilities of biosensor usage in environmental analysis, considering an easy and environmentally friendly analysis of individual compounds (e.g., heavy metals) or their mixtures in various samples directly in the environment, as well as continuous monitoring of these compounds. The work considers biosensors' characteristics, classification, and operation principles. Attention is paid to the possibility of using bioluminescent bacteria as biological material in a biosensor. Examples of the study of heavy metals using various biological sensors were given. It also indicates the possibility of using biosensors to determine microplastics by applying specific hormones (estrogens) receptor use and peptides as a solution or incorporating them into living microbial cells. Additionally, support was given to the use of biosensors to monitor plastics' degradation in the water environment using recombinant whole-cell microbial biosensors as detectors for plastic monomers such as acrylic acid monomers. The application of the biosensors highlighted in the paper is to shorten the time of toxicity studies by using new indicators or acceptors. However, several challenges must be overcome, such as cell viability and activity. A continuous water-monitoring system that can handle a severely toxic sample has yet to be developed in toxicity monitoring [ABSTRACT FROM AUTHOR]

Abstract 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.

High levels of plastic pollutants threaten aquatic habitats as the plastic materials are ingested by aquatic organisms as food. This study assessed seasonal variations of microplastics and the water quality of Njoro River and Lake Nakuru. Selected water physico-chemical parameters were measured. Microplastic abundance in the surface water samples in the dry season was recorded as 47–649 MPs 300L−1 for sampling points in Njoro River and 54–508 microplastics (MPs) 300L−1 for Fisher’s Point in Lake Nakuru; an abundance during the rainy season was measured as 8–389 MPs 300L−1 and 28–259 MPs 300L−1 for Njoro River and Lake Nakuru, respectively. Our study observed a significant pattern of microplastics from polymers such as polyethylene (20%), polypropylene (25%), polyester (40%) and polyethylene terephthalate (10%). Salinity ranged between 0.085 to 2.59 ± 0.03 ppt; temperature 23.69–14.22 ± 0.07°C; pH 8.8–9.3; turbidity 13.95−36.03 ± 0.35 NTU; TN 5.9 to 8.57 ± 3.24 mg L−1; TP 7.49−.41 ± 1.84 mg L−1; EC 73.3−533.3 ± 0.64 μs cm−1; and TDS 46.67–243.33 ± 0.11ppm. These ranges were within the standards recommended by WHO and US EPA. Results indicate the possibility for the quantity and mass of plastic particles in Lake Nakuru to surpass that of Njoro River. [ABSTRACT FROM AUTHOR]

The joint impact of tadalafil (Cilais) as a pharmaceutical residue and microplastics on fish is not well comprehended. The current study examined haematological, biochemical, and antioxidant parameters, along with immunohistochemical and histological indications in tilapia (Oreochromis niloticus) after being exposed to tadalafil, polyethylene microplastics (PE-MPs), and their mixtures for 15 days. The fish were distributed into 1st group control group (The fish was maintained in untreated water without any supplements); 2nd group exposed to 10 mg/L PE-MPs;3rd group exposed to 20 mg/l tadalafil (Cilais); 4th group exposed to 20 mg/l tadalafil (Cilais) + 10 mg/LPE-MPs (in triplicate). The levels of creatinine, uric acid, glucose, AST, ALT, and albumin in fish treated with tadalafil alone or in combination with PE-MPs were significantly higher than those in the control group. Fish exposed to PE-MPs, tadalafil, and tadalafil plus PE-MPs showed significantly lower levels of RBCs, Hb, Ht, neutrophils, and lymphocytes compared to the control group. Serum levels of total antioxidant capacity and reduced glutathione (GSH) were notably lowered in fish groups subjected to PE-MPs, tadalafil, and tadalafil + PE-MPs combinations in comparison to the control group. Malondialdehyde (MDA) serum levels were notably elevated in fish groups subjected to PE-MPs, tadalafil, and tadalafil + PE-MPs combinations compared to the control group. The most severe impact was observed in the tadalafil + PE-MPs combination group. Interleukin-6 (IL-6) levels were significantly increased in liver tissues following exposure to both tadalafil and microplastics compared to tissues exposed to only one substance or the control group. Changes in the gills, liver, and renal tissues were seen following exposure to PE-MPs, tadalafil, and tadalafil + PE-MPs combination in comparison to the control group of fish. Ultimately, the mixture of tadalafil and PE-MPs resulted in the most detrimental outcomes. Tadalafil and PE-MPs exhibited showed greater adverse effects, likely due to tadalafil being absorbed onto PE-MPs. [ABSTRACT FROM AUTHOR]

Advanced recycling offers a unique opportunity for the circular economy, especially for mixed and contaminated plastics that are difficult to recycle mechanically. However, advanced recycling has barriers such as poor selectivity, contaminant sensitivity, and the need for expensive catalysts. Reported herein is a simple yet scalable methodology for converting mixed polyethylene (high-density and low-density polyethylene recycled polyethylene) into upcycled waxes with up to 94% yield. This high yield was possible by performing the reaction at a mild temperature and was enabled by using inexpensive and reusable table salt. Without table salt, in otherwise identical conditions, the plastic remained essentially undegraded. These upcycled waxes were used as prototypes for applications such as water- and oil-resistant paper, as well as rheology modifiers for plastics. Their performance is similar to that of commercial wax as well as rheology modifiers. A preliminary economic analysis shows that the upcycled waxes obtained by this table salt-catalyzed approach offer three times more revenue than those reported in the literature. This pioneering discovery opens the door for a circular economy of plastics in general and polyolefins in particular. [ABSTRACT FROM AUTHOR]

Background: Plastic is generating global pollution and the replacement such as bioplastic has been developed to mitigate the pollution. To this end, the fate, transformation and pathway of bioplastics need more research. For example, the fragmentation of bioplastic can release small debris that can be categorised as microplastics, which is tested herein by taking an example of a compostable plastic that is used as a bin bag on our kitchen table to collect the food residues. Results: First, we employ matrix-assisted laser desorption/ionisation mass spectrometry (MALDI-MS) to identify the main components of the bioplastic bag as polymer and starch. Next, we use Raman imaging to monitor the stability under laser illumination, in an oven at ~ 60 °C for ~ 2 weeks, or in the presence of tap water for half a year. Basically, the compostable plastic is stable under these conditions. Thirdly, however, once used as table-bin bag with involvement of food residues, within ~ 1 week, the bioplastic bag is broken and biodegraded to release debris. The derivate surface groups are effectively monitored and directly visualised via Raman imaging, and cross-checked with scanning electron microscope (SEM). The yielded small molecule such as formic acid is also identified, along with the released debris of microplastics, with the help of on-site extraction of the fragmented sample and imaging analysis algorithm of the hyper spectrum. Conclusions: After one week, the bag in the waste bin fragments, releasing a significant amount of debris. This could pose a functional issue if users intend to use the bag for at least a week, and could become a potential environmental problem if the waste is dispersed uncontrollably. In general, further research is needed to potentially distinguish the persistent conventional microplastics from the bioplastic fragments, to effectively mitigate the plastic pollution. [ABSTRACT FROM AUTHOR]

Plastics are extensively used in agriculture, but their weathering and degradation generates microplastics (MPs) that can be carried by runoff into water bodies where they can accumulate and impact wildlife. Due to its physicochemical properties, biochar has shown promise in mitigating contaminants in agricultural runoff. However, few studies have examined its effectiveness at removing MPs. In this study, we assessed MP pollution (>30 µm) in runoff from a farm in the Mississippi Delta and examined the effectiveness of biochar (pinewood and sugarcane) to remove MPs from aqueous solutions. Using micro-Fourier Transform Infrared spectroscopy (µ-FTIR), we observed an average of 237 MPs/L (range 27-609) in the runoff, with most particles identified as polyethylene, polyamide, polyvinyl chloride, polyurethane, acrylonitrile butadiene styrene, and polyarylamide. Biochar columns effectively removed MPs from runoff samples with reductions ranging from 86.6% to 92.6%. MPs of different sizes, shapes, and types were stained with Nile red dye (to facilitate observation by fluorescence) and quantified their downward progress with multiple column volumes of water and wet/dry cycles. Smaller MPs penetrated the columns further, but ≥90% of MPs were retained in the ~20 cm columns regardless of their shape, size, and type. We attribute these results to physical entrapment, hydrophobic behaviors, and electrostatic interactions. Overall, this proof-of-concept work suggests biochar may serve as a cost-effective approach to remove MPs from runoff, and that subsequent field studies are warranted. [ABSTRACT FROM AUTHOR]

This data paper presents microplastic (MP) concentration and composition data from four campaigns in a one-year period in the Seine River within the Greater Paris area. Detailed data on MP occurrence, physical water parameters, hydrological conditions, and potential sewer point sources are presented. Initial analysis of the data set shows that MP concentrations were significant (median: 600 particles m-3 and 100 mg m-3) and MP fluxes showed variations across sampling sites and campaigns. Three polymer types (polypropylene -- PP, polyethylene -- PE, polystyrene -- PS) account for 96% of the total number of MP. This dataset provides valuable insights for understanding river MP pollution under anthropogenic pressure. [ABSTRACT FROM AUTHOR]