Recycling Of Plastic Waste Research Articles (Page 1)

Traditional photoelectrochemical (PEC) systems struggle to simultaneously achieve high efficiency, high stability, and low cost. Replacing water oxidation with oxidation of organic molecules emerges as an attractive strategy to enhance the hydrogen production efficiency of PEC systems while generating value-added anodic products. Here, a PEC system utilizing a Mo, N co-doped BiVO4 photoanode and NaClO4 electrolyte for the glycerol oxidation reaction to approaching the theoretical limit of current doubling that enables a two-electron reaction to be driven by a single photon, is reported. While nitrogen doping optimizes the bulk charge separation/transport performance of Mo-doped BiVO4 photoanodes, NaClO4 as the supporting electrolyte further enhances the reaction kinetics and surface charge extraction efficiency. The optimized system reaches a record photocurrent density of 9.73mAcm-2 at 1.23V versus RHE and a maximum internal quantum efficiency of 182%. It predominantly produces C-C cleavage products, including glycolaldehyde and formaldehyde, and can maintain stable performance for over 500h. DFT calculations reveal that glycerol can undergo adjacent hydroxyl bidentate chelation adsorption on the BiVO4 surface. This system is applicable for the current doubling reaction of various polyhydroxy alcohols, providing a potential pathway for efficient valorization of platform molecules and effective recycling of waste plastics.

The transition toward a Circular Economy (CE) presents a transformative solution to global sustainability challenges by promoting resource efficiency, waste minimization, and material regeneration. This study explores the pivotal role of chemical engineering in advancing circular practices through innovative waste valorization and resource recovery strategies. Key technologies—including biomass conversion, plastic and electronic waste recycling, and food waste bioprocessing—are analyzed for their capacity to mitigate environmental impacts and close material loops. Chemical engineering principles such as catalysis, separation processes, and process intensification underpin these approaches, enhancing energy efficiency and resource utilization. Integration of digital tools, artificial intelligence (AI), and system optimization further enables real-time process control and sustainability assessment. However, widespread CE implementation faces barriers including technological limitations, high capital costs, and fragmented regulations. Overcoming these challenges requires interdisciplinary collaboration among industry, academia, and policymakers to develop scalable, cost-effective solutions. The study emphasizes the importance of next-generation catalysts, bio-based processing, and data-driven systems in achieving a resilient, low-waste industrial future. By bridging science, technology, and policy, chemical engineering can catalyze the global transition to a sustainable and circular economy.

Recycling waste plastics and biowaste into high-performance NiCo-MOF/activated carbon electrocatalyst for overall water splitting

Chemical recycling of refrigerator plastic waste by pyrolysis: Yields, product composition, and potential applications

Sustainable strategies for marine plastic waste remanufacturing systems under diverse carbon reduction policies.

Picture fuzzy geometric Heronian mean operator based novel ranking method for optimal plastic waste recycling technology selection

Abstract Geopolymer concrete has emerged as a sustainable alternative to traditional Portland cement concrete, addressing the need for environmentally friendly construction materials. This study explores the development of eco-friendly paver blocks using geopolymer concrete, where fly ash completely replaces cement, and recycled plastic waste is used as a partial substitute for fine aggregates at 5%, 10%, 15%, and 20% replacement levels. The investigation focuses on evaluating the mechanical and durability properties of the resulting paver blocks through tests such as flow table (workability), water absorption, ultrasonic pulse velocity, rebound hammer, compressive strength, and split tensile strength. Results indicate that incorporating plastic waste affects both the workability and strength of the mix. While higher plastic content reduces mechanical strength, it enhances sustainability by promoting waste utilization. An optimal replacement percentage was identified that maintains structural integrity while maximizing environmental benefits. The findings demonstrate that geopolymer paver blocks incorporating plastic waste offer a viable, sustainable alternative to conventional blocks. This approach significantly reduces cement usage and natural aggregate demand while contributing to effective plastic waste management, paving the way for greener infrastructure solutions.

ABSTRACTRecycled polyethylene (RPE) and recycled polypropylene (RPP) are the most abundant types of plastic waste. Developing novel base asphalt modifiers (additives used to enhance the properties of asphalt) by blending RPE and RPP in different ratios is of significant importance, as the composition directly influences both the properties of BM (blend modifiers of RPE/RPP) and the performance of BM‐modified asphalt (the asphalt obtained by adding modifiers (such as rubber, resin, and polymer) to improve its performance). This study investigated the performance of BM and BM‐modified asphalt prepared with different RPE/RPP ratios, as well as the underlying mechanisms. The results show that the notch impact strength and elongation at break of BM increase with a decrease in the RPE/RPP ratio, with a turning point observed at a 6:4 ratio. However, the influence of the ratio on tensile strength and flexural strength is relatively small. The findings are supported by infrared spectroscopy analysis. For BM‐modified asphalt, the penetration at 25°C, ductility at 25°C, and viscosity exhibit an increasing trend from an RPE/RPP ratio of 10:0 to 6:4, followed by a decrease as the ratio shifts from 6:4 to 0:10. Conversely, the softening point follows the opposite trend. Infrared spectroscopy analysis of the BM‐modified asphalt indicates that the ester group index reaches its maximum value of 0.812 at the 6:4 RPE/RPP ratio, suggesting that the interaction between RPE and RPP in BM significantly influences the properties of the modified asphalt. The physical blending between pure BM and the matrix asphalt has also been confirmed. Microstructural analysis of BM and BM‐modified asphalt demonstrates that when RPE/RPP = 6:4, the compatibility between BM and matrix asphalt is optimal. The conventional property changes of the BM‐modified asphalt are also validated, reinforcing the effectiveness of RPE and RPP. These findings suggest that selecting the optimal RPE/RPP ratio can significantly enhance the mechanical and rheological properties of BM‐modified asphalt, offering a promising approach for improving asphalt performance through recycled plastic waste utilization.

ABSTRACT Recycling of waste plastics is an important research direction for realizing resource recycling. Dyed waste plastics have huge reserves, so it is necessary to decolorize them before recycling to avoid poisoning of degradation catalysts or difficulties in the separation and purification of subsequent products. In the past, the decolorization of waste plastics was mostly done by organic solvents reacting at high temperatures, which was costly and put environmental pressure. This paper proposes that supercritical CO2 extraction can decolorize the dyed waste plastic pellets. With trace DMF as cosolvent, the reaction time is 3 hours at 90°C and 15 MPa, and the decolorization rate is as high as 87% and after the experiment, the solvent was recovered and reused. Based on the extraction kinetic curve, the solubility data of dyes in supercritical carbon dioxide were obtained and correlated with the density formula. The experimental results provide a possibility for green, efficient, and low-carbon decolorization of dyed waste plastics, and it is expected to realize large-scale production.

This study aimed to find the mechanical recycling of plastic waste to product plastic slices and cylindrical shape plastic materials as raw plastic with simple, low-cost, environmentally friendly processes with safe disposal of plastic waste, which is a practical approach to reduce their volume by 55%, and maintain the depletion of natural resources to reach the concept of sustainability, through the mechanical recycling of many plastic waste such as polyethylene terephthalate (PET), high-density and low-density polyethylene(PE). Plastic waste types were founded in different quantities as a result of the multiple uses of plastic materials, which included according to their chemical composition the main types of plastic, polyethylene terephthalate(PET), high-density and low-density polyethylene(PE), polyvinyl chloride (PVC), polypropylene(PP), polystyrene(PS) and other(O). These types of plastic were represented in different plastic materials in multi-uses for each type. The results showed that the productivity of plastic waste types per person each day in Al Hawija district affiliated to Kirkuk Governorate ranged from (0.41 kg), to (0.21kg), with an average of (0.24 kg/person/day), and that were due to the difference of families in terms of the economic, subsistence and cultural level which affected waste productivity, as well as the difference in the numbers of persons for each family. Among the different types of plastic materials, polyethylene tetravailate, low and high density polyethylene represented the large percentage of plastic waste productive with(16-40%) according to (0.225- 0.008 kg/ person/day), while other types of plastic materials were mostly found in close quantities.

Polymer-based product usage in modern society is increasing day by day. Following usage, these inert products and hydrophobic materials contribute to environmental pollution, often accumulating as litter in ecosystems and contaminating water bodies. The rapid socio-economic development in the Kingdom of Saudi Arabia (KSA) has resulted in a significant increase in waste generation. This study was conducted on the utilization of recycled plastic waste (RPW) polymer along with commercial polymer (CP) for the modification of the local binder. The hot environmental conditions and increased traffic loading are the major reasons for the permanent deformation and thermal cracks on the pavements, which require improved and modified road performance materials. The Ministry of Transport and Logistical Support (MOTLS) in Saudi Arabia, along with other related agencies, spends a substantial amount of money each year on importing modifiers, including chemicals, hydrocarbons, and polymers, for modification purposes. This research was conducted to investigate and utilize available local recycled plastic materials. Comprehensive laboratory experiments were designed and carried out to enhance recycled plastic waste, including low-density polyethylene (rLDPE), high-density polyethylene (rHDPE), and polypropylene (rPP), combined with varying percentages of commercially available polymers such as Styrene-Butadiene-Styrene (SBS) and Polybilt (PB). The results indicated that incorporating recycled plastic waste expanded the binder’s susceptible temperature range from 64 °C to 70 °C, 76 °C, and 82 °C. The resistance to rutting was shown to have significantly improved by the dynamic shear rheometer (DSR) examination. Achieving the objectives of this research, combined with the intangible environmental benefits of utilizing plastic waste, provides a sustainable pavement development option that is also environmentally beneficial.

This paper provides a systematic review of the current research status and application prospects of waste plastic modified asphalt (WPMA) technology. It begins by outlining the severity of global plastic pollution and the urgency of recycling waste plastics, emphasizing that its application in asphalt modification represents an effective pathway for high-value utilization. The article not only presents the current state of waste plastic recycling but also focuses on analyzing three preparation processes: wet process, dry process, and wet-dry composite process, along with a comparative evaluation of their advantages and disadvantages.

The transformation of plastic waste into valuable products remains a significant challenge for sustainable manufacturing. Fused deposition modeling (FDM), a melt extrusion-based additive manufacturing (AM) technique, has emerged as a promising solution for repurposing waste thermoplastics. However, multiple recycling cycles introduce substantial changes in material properties, limiting their mechanical performance and surface quality. Despite ongoing research efforts, FDM-printed components still lag behind conventionally manufactured parts in terms of mechanical integrity, microstructure, and overall durability. Additionally, while the use of recycled plastics in FDM has been explored, a structured literature review focusing on the development of functional and customized products from recycled waste is still lacking. To address this gap, the present study provides a comprehensive review of the utilization of recycled plastic waste in FDM-based 3D printing, emphasizing the role of reinforced materials in enhancing performance. It examines the effects of processing conditions on the properties of recycled FDM components and explores the incorporation of diverse additives to improve material quality. Furthermore, this review presents two case studies from the existing literature that demonstrate the successful integration of thermoplastic waste into FDM-based manufacturing. By identifying existing limitations and potential research directions, this study aims to contribute to the advancement of sustainable and circular manufacturing practices through FDM technology.

Functional materials derived from waste plastics: Applications, properties and challenges.

Peroxidase mimics through DEHP-rich plastic wastes upcycling for colorimetric sensing neonicotinoid insecticides.

Zeolite-based catalysis for plastic waste recycling: Sustainable solutions from laboratory testing to industrial applications

Introduction. Plastic decomposition is an exceptionally protracted process, requiring urgent measures to reduce environmental pollution, including that of water resources. Current solutions include increasing measures to sort and recycle plastic waste and developing biodegradable and environmentally friendly substitutes. Although plastic is recyclable, not all types are easily recycled. Therefore, most significant efforts are needed to find sustainable solutions. This highlights the importance of analysing the current situation regarding plastic waste and developing specific measures to reduce pollution. Aim and tasks. This study aims to analyse the concern of increasing plastic waste in Bulgaria and to develop strategies for its reduction. In particular, measures to reduce the consumption of plastic products, introduce separate waste collection, and recycle and reuse valuable raw materials are considered, emphasising the contribution of these actions to reducing water resource pollution. Results. This study analysed two main pollution control areas: limiting plastic use and introducing rapidly degradable materials. These approaches do not exclude but complement each other. This study confirms that using biodegradable polymers such as PLA, PHA, and PBS has significant environmental benefits despite their cost and the disadvantages of production technologies. Effective solutions to pollution problems have been shown to require legislative measures and innovations, raising public awareness, and developing a culture of separate waste collection. The research and analysis revealed ways to reduce the pollution of water bodies with plastic and polyethene waste. The effects of this waste on the development of humanity have been examined, and options for solving these problems on a global scale have been proposed. Conclusions. Plastic products and packaging have a significant negative impact on the environment, including reducing pollution of water and marine ecosystems. It is necessary to improve the efficiency of plastic waste management and recycling. Analysis of these data on the pollution of water bodies and adjacent territories showed the need to develop a system for monitoring and collecting information on pollution, including in hard-to-reach areas. To reduce this impact, it is important to combine limiting plastic consumption and using rapidly degradable bioplastics with the active implementation of recycling and reuse programs.

Abstract With the worsening of plastic pollution and increasing attention being paid to sustainable development, the upgrading and recycling of waste plastics have become important tasks. In this study, organic ligand‐modified PdPr nanosheets (PdPr O‐NSs) with the lanthanide contraction effect are constructed and used as high‐performance electrocatalysts for the value‐added transformation of polyethylene terephthalate. PdPr O‐NSs only require a potential of 0.75 V to supply current densities of 200 mA cm −2 . The Faraday efficiency and selectivity for the primary product glycolic acid reached 97.5% and 94.6% at 0.675 V, respectively. Density functional theory calculations confirm that the existence of Pr and n ‐octanoic acid adjusts the electronic structure and coordination environment, improving the electron transfer efficiency and catalytic performance. This work not only provides a new strategy for constructing novel and efficient lanthanide‐doped nanomaterial electrocatalysts but also paves the way for recycling waste plastics.

The economic recovery of anodes in lithium-ion batteries remains challenging due to their low value. Here, the study presents a cross-sector battery-plastic co-upcycling strategy that transforms spent graphite anodes into bifunctional photothermal catalysts for efficient Polyethylene terephthalate (PET)depolymerization. Upon reaction with ethylene glycol (EG), lithiated graphite spontaneously enables copper foil detachment, graphite regeneration, and in situ formation of organolithium species (C2H4O2Li2-xHx). The resulting catalyst system achieves 95% PET conversion and 64.6% BHET yield within 15 minutes under 0.71W/cm2 sunlight. Mechanistically, a synergistic effect between solid electrolyte interphase (SEI)-derived Li2CO3/Li2O and organolithium intermediates significantly accelerates glycolysis. Techno-economic modeling for a 90000 ton/year facility reveals a minimum selling price of $0.956/kg for BHET and annual energy savings of 5.039 × 1011kJ. This work highlights a scalable, low-cost approach to integrate battery and plastic waste recycling, offering a new paradigm for sustainable urban mining and circular polymer economy.

Abstract Researchers are increasingly exploring non-crystalline alkali-aluminosilicate geopolymers to utilize byproduct waste from geopolymer concrete (GPC) and reduce carbon dioxide emissions. However, the material’s quasi-brittle nature limits its application. Recent studies on incorporating various fibers aim to improve this limitation. This research reviews the mechanical properties of modified metakaolin fiber-reinforced geopolymer concrete, including the use of waste aggregate. At a 5% by weight ratio, calcium oxide and silica fume were added to metakaolin (MK). MK, coarse aggregate, fine aggregate, superplasticizer, and additional water were reacted with a mixture of sodium hydroxide and sodium silicate solution at 372, 910, 603, 8, 56, 83, and 192 kg/m³, respectively. This research investigates an eco-friendly approach by partially replacing 10% of the natural coarse aggregate in geopolymer concrete with recycled plastic waste or tire crumb rubber. It also examines the mechanical properties of fiber-reinforced geopolymer concrete with 0, 0.15, and 0.2% carbon fiber additions. The study evaluates the impact of these carbon fibers on the mechanical properties, including compressive strength, tensile strength, and modulus of elasticity, particularly in the context of utilizing recycled aggregates. The study found that incorporating fibers, particularly carbon fibers, significantly improved the properties of GPC mixes. The addition of 0.2% carbon fiber resulted in notable increases in tensile characteristics, modulus of elasticity, and compressive strength. Crumbed rubber showed a 10% improvement, while splitting tensile strength and static modulus of elasticity increased by 59% and 25%, respectively. Microstructural analysis of the mixtures with and without carbon fiber supported these findings.