Waste PET Bottles Research Articles

Waste PET Bottle Derived, Hierarchical Core–Shell Activated Charcoal Reinforced PET Nanofiber: A Sustainable and Scalable Closed Carbon Loop Solution for Formaldehyde Sensing

Waste PET Bottle Derived, Hierarchical Core–Shell Activated Charcoal Reinforced PET Nanofiber: A Sustainable and Scalable Closed Carbon Loop Solution for Formaldehyde Sensing

Generating 3D Models for UAV-Based Detection of Riparian PET Plastic Bottle Waste: Integrating Local Social Media and InstantMesh

In recent years, waste pollution has become a severe threat to riparian environments worldwide. Along with the advancement of deep learning (DL) algorithms (i.e., object detection models), related techniques have become useful for practical applications. This work attempts to develop a data generation approach to generate datasets for small target recognition, especially for recognition in remote sensing images. A relevant point is that similarity between data used for model training and data used for testing is crucially important for object detection model performance. Therefore, obtaining training data with high similarity to the monitored objects is a key objective of this study. Currently, Artificial Intelligence Generated Content (AIGC), such as single target objects generated by Luma AI, is a promising data source for DL-based object detection models. However, most of the training data supporting the generated results are not from Japan. Consequently, the generated data are less similar to monitored objects in Japan, having, for example, different label colors, shapes, and designs. For this study, the authors developed a data generation approach by combining social media (Clean-Up Okayama) and single-image-based 3D model generation algorithms (e.g., InstantMesh) to provide a reliable reference for future generations of localized data. The trained YOLOv8 model in this research, obtained from the S2PS (Similar to Practical Situation) AIGC dataset, produced encouraging results (high F1 scores, approximately 0.9) in scenario-controlled UAV-based riparian PET bottle waste identification tasks. The results of this study show the potential of AIGC to supplement or replace real-world data collection and reduce the on-site work load.

Crystallization of Bis(2-hydroxyethylene) Terephthalate as a Part of a Bottle-to-Bottle Recycling Concept for Poly(ethylene terephthalate).

The chemical recycling of poly(ethylene terephthalate) (PET) is very attractive as PET bottle waste provides an abundant clean material with low levels of additives. One of the most promising processes is glycolysis, which depolymerizes PET in the presence of ethylene glycol. For this process, it is necessary to think through the whole concept, from the waste material to the newly polymerized virgin polymer. Most research ends with determining the yield of bis(2-hydroxyethyl)terephthalate (BHET) after glycolysis. Some research includes antisolvent crystallization with water to separate BHET from ethylene glycol. However, the subsequent separation of water and ethylene glycol is an energy-intensive process. Therefore, this work aims to directly crystallize BHET from ethylene glycol. For this reason, the crystallization of BHET was investigated experimentally. Crystallization was simulated using gPROMS Formulated Products with the aim of estimating kinetic parameters and using these to optimize an industrial process. Kinetic parameters were determined by model validation, including primary and secondary nucleation and crystal growth. The best-fitting set of kinetic parameters was used to optimize BHET crystallization in batch and continuous modes by minimizing equipment costs. Impeller parameters were found to have a great influence on crystallization performance. Ultimately, the continuous and batch processes gave comparable results in terms of equipment cost, with the batch process giving larger crystals and higher yields but the continuous process requiring a smaller crystallizer.

Waste plastics to prepare eutectogel: Wearable, highly deformable, transparent flexible ionic conductors

The emergence of flexible conductor wearable electronics will revolutionize motion detection and smart healthcare. Eutectogel (E-GEL) is more economical, resistance to extreme temperatures, green and environmentally friendly compared to ionic gels and hydrogels. PET is generally recycled as a conventional polymer. This paper presents a new process for the production of flexible ionic conductor from PET. Here, we using waste PET bottles as raw material, and the green, ternary low-eutectic solvent (DES) ChCl/EG/Zn(Ac)2 as a catalyst, synthesized waterborne polyurethane by the one-pot method. By modulating the types and densities of multiple hydrogen bonds and supramolecular interactions of binary DES (ChCl/EG), using WPU, P(AAm-AA) and ChCl/EG, responsive E-GELs with excellent mechanical (stress of 8.87 MPa, strain of 680 %), excellent ionic conductivity. In addition, the E-GEL can be loaded-unloaded continuously for 1000 cycles at 25 % strain, that demonstrates excellent fatigue resistance. DES give eutectogel the ability to resist both −50 ℃ to 80 ℃ temperatures. As a demonstration of the device performance, wearable strain sensors assembled using E-GEL can monitor and recognize complex human movements in a fast, real-time manner.

Experimental Evaluation of Waste PET Bottles as a Sustainable Building Material

Experimental Evaluation of Waste PET Bottles as a Sustainable Building Material

Effect of Recycled Waste PET Bottle Fibers on Mechanical Properties of Geopolymer Mixtures Containing Crushed Waste Glass Sands

This research focused on evaluating geopolymer mixture made of ASTM class F fly ash (FFA), ground granulated blast furnace slag (GGBFS), plastic fibers obtained from recycled waste pet bottles, and crushed waste glass bottle sand (WGS) from household waste. A total of 9 mixtures were designed: 3 mixtures with long fibers (5% of aggregate weight) and without WGS, 3 mixtures with shorter non-twisted fibers (2% of aggregate weight) and WGS, and 3 mixtures with shorter twisted fibers (2% of aggregate weight) and WGS. All geopolymer mixtures contained GGBFS, FFA, WGS, plastic fibers, and 10 M of alkali-activated solution. Mechanical properties of geopolymer mixtures were evaluated at 7, 14, and 28 days. Test results indicated that PET fiber-reinforced geopolymer mixtures have lower compressive strength than non-reinforced ones. The increased length of PET fiber and extended air-curing time also decrease compressive strength. Increasing WGS content generally tends to decrease the compressive strength, but 15% replacement shows improvement compared to the reference mixture. Adding PET fibers to the geopolymer mixtures significantly increases flexural strength due to better crack resistance and good strain-hardening effect. Non-twisted fibers concrete’s flexural strength was noticeably higher than that of twisted one, while the length of fibers did not have an impact. The introduction of fibers does not increase ultimate tensile strength. However, the strain coefficient was substantially increased. Non-twisted fibers geopolymer mixtures performed better than twisted ones in terms of tension resistance. The geopolymer mixture with 30% WGS showed the highest results.

Circular closed-loop supply chain network design considering 3D printing and PET bottle waste

AbstractOne of the most critical pillars of Industry 4.0 (I4.0) is Additive Manufacturing (AM) or 3D Printing technology. This transformative technology has garnered substantial attention due to its capacity to streamline processes, save time, and enhance product quality. Simultaneously, environmental concerns are mounting, with the growing accumulation of plastic bottle waste, offering a potential source of recycled material for 3D printing. To thoroughly harness the potential of AM and address the challenge of plastic bottle waste, a robust supply chain network is essential. Such a network not only facilitates the reintegration of plastic bottle waste and 3D printing byproducts into the value chain but also delivers significant environmental, social, and economic benefits, aligning with the tenets of sustainable development and circular economy. To tackle this complex challenge, a Mixed-Integer Linear Programming (MILP) mathematical model is offered to configure a Closed-Loop Supply Chain (CLSC) network with a strong emphasis on circularity. Environmental considerations are integral, and the primary objective is to minimize the overall cost of the network. Three well-known metaheuristics of Simulated Annealing (SA), Genetic Algorithm (GA), and Particle Swarm Optimization (PSO) are employed to treat the problem which are also efficiently adjusted by the Taguchi design technique. The efficacy of our solution methods is appraised across various problem instances. The findings reveal that the developed model, in conjunction with the fine-tuned metaheuristics, successfully optimizes the configuration of the desired circular CLSC network. In conclusion, this research represents a significant step toward the establishment of a circular supply chain that combines the strengths of 3D printing technology and the repurposing of plastic bottle waste. This innovative approach holds promise for not only reducing waste and enhancing sustainability but also fostering economic and social well-being.

From PET bottle waste to enzyme support for removal of estrogens from wastewaters

Recycling poly(ethylene terephthalate) disposables into electrospun functional membranes creates new opportunities for pollution reduction. In this study, two types of electrospun membranes made of poly(ethylene terephthalate) (PET) recycled from bottles and PET recycled from recycled bottles (rPET) were utilized in order to produce four types of biosystems with immobilized laccase for the removal of synthetic hormones micropollutants from wastewater. The enzyme was adsorbed onto the fibers directly or after a prior 24 h treatment with 10% glutaraldehyde. Obtained removal efficiency of 17α-ethynylestradiol from aqueous systems was in a range of 71% to 85%, depending on the type of PET utilized for the fabrication of the membranes and the way of laccase immobilization. Moreover, fabricated biosystems showed highly improved storage stability of 72% to 85% compared to only 55% activity exhibited by free laccase after 20 days of storage. Immobilization of the laccase on the PET-based fibrous substrates also increased their thermal stability after 2 h at 50 °C with preserved activity in a range of 27% to 55%, compared to only 5% registered for the free enzyme. Produced biosystems exhibited high reusability and the activity of the enzyme remains over 60% after seven catalytic cycles for all tested samples, with 79% activity after eight cycles obtained for the enzyme immobilized on PET membranes modified with glutaraldehyde prior to immobilization of laccase. The presented approach has been proven to have great potential as a sustainable tool for the enzymatic removal of synthetic hormones from wastewaters showing superior properties compared to the utilization of the enzyme in its basic form.

Harnessing waste PET bottles for sustainable Ca-MOF synthesis: a high-efficiency adsorbent for uranium and thorium

The contamination of water sources by radioactive elements like uranium and thorium presents significant environmental and health challenges. To resolve this issue waste derived calcium MOF has been developed using waste PET bottle and marble slurry.

Synthesis of an efficient MOF catalyst for the degradation of OPDs using TPA derived from PET waste bottles

In this study, a method for degrading PET-waste plastic bottles using ZnCl2:Urea as a catalyst was developed, resulting in high conversion (87%). The terephthalic acid obtained from the degradation of Waste PET Bottles (WPTs) was combined with copper and zinc salts to synthesize bimetallic metal–organic frameworks (MOF). The effectiveness of a bimetallic Cu-Zn(BDC)-MOF in catalyzing the reduction reaction of organic pollutant dyes (OPDs) was investigated, and the degradation efficiency of individual dyes was optimized, achieving over 95% degradation within 6–12 min under optimal conditions. Various techniques, including FT-IR, XRD, FE-SEM, EDS, and TEM were used to characterize the synthesized MOF. Results showed that the catalytic activity of Cu-Zn-MOF in reduction reaction of OPDs was enhanced by increasing the copper content. The reaction kinetics were investigated following pseudo-first-order kinetics with rate constants of 0.581, 0.43, 0.37, and 0.30 min−1 for Methylene Blue (MB), Methyl Orange (MO), 4-Nitrophenol (4-NP), and 4-Nitroaniline (4-NA), respectively. The investigations revealed that the produced catalyst exhibited excellent stability and recoverability, while its activity remained well-preserved even after undergoing three reuse cycles.

Production and characterisation of solid waste-derived fuel briquettes from mixed wood wastes and waste pet bottles

Wood waste and waste Polyethylene Terephthalate (PET) bottles are two of the solid wastes posing severe challenges to waste management facilities and constituting nuisance to humans and the environment in Nigeria due to poor management. These wastes could be utilized to produce solid biofuels for various energy applications to reduce CO2 emissions. This study, therefore, aims to investigate the potential of converting these wastes locally into solid waste-derived fuels (SWDF) briquettes in a bid to present an alternative approach to managing them. Four types of SWDF briquettes were produced from mixed wood waste and waste PET bottles in blend ratios of 100:0, 60:40, 50:50, and 40:60 using a screw press briquetting machine with single extrusion die. The effect of PET plastic amount on different properties, such as net calorific value, ash content, durability, and density, of the produced briquettes was investigated. In addition, obtained results were compared with the quality standards of densified fuels specified by the European Pellet Council. to ascertain the quality of the produced SWDF briquettes. The results revealed that the SWDF briquettes made only from mixed wood waste exhibited the lowest calorific value (17.15 MJ/kg) and highest ash content (2.74 %), while the SWDFs made from blends of mixed wood waste and PET bottles had higher calorific values (17.85–20.77 MJ/kg) and lower ash contents (1.05–1.37 %). Moreover, except for density and chlorine content (<750 kg/m3 and <0.03 wt% respectively), all the produced SWDFs complied with the quality standards of densified fuels specified by the European Pellet Council. These results suggest that these blends could yield SWDFs with improved quality and combustion properties, and could present a new way of managing these solid wastes.

Upcycling spent coffee grounds and waste PET bottles into electrospun composite nanofiber mats for oil structuring applications

Spent coffee grounds (SCG) and post-consumer PET bottles (PETbot) are major waste materials from the food industry. In this work, their use to obtain electrospun composite nanofibers is explored aiming to develop a new route for their upcycling into high added-value oil-based products. Raising the proportion of PETbot increased the average fiber diameter (from 0.36 to 0.89 μm) and enhanced the tensile properties of the mats. Young's modulus and strain-at-break increased from 5.1 to 32.8 MPa and from 13.8 to 39.4 %, respectively, as the SGC:PETbot weight ratio decreased. Dispersions of the mats in castor oil exhibited shear-thinning and gel-like viscoelastic properties which can be tuned through the SCG:PETbot ratio. Friction coefficient values of resulting oleogels tested in a tribological contact ranged from 0.165 to 0.092. SCG and PETbot can be used to obtain electrospun nanofibers with oil structuring capabilities while resulting oleogels are proposed as environmentally-friendly alternatives to semisolid lubricants.

Comparative study of different metal-organic framework electrodes synthesized using waste PET bottles for supercapacitor applications

The conversion of plastic waste into high-value metal-organic framework (MOF) materials has currently grabbed the attention as an important research area for mitigating environmental and economic issues. Due to their large surface area and high porosity, MOFs have a significant advantage as supercapacitor electrode material. In this study, MOFs (Cu-MOF, Zr-MOF, and Ti-MOF) were produced from plastic wastes (PET bottles) using hydrothermal approach. These MOFs were tested electrochemically in 1 M H2SO4 electrolyte using three-electrode setup. Among them, Cu-MOF (104.8 F/g at 0.5 A/g) showed higher capacitance and increased diffusion contribution (78.4 %) than its counterparts Zr-MOF (70.5 F/g at 0.5 A/g; 70.4 %) and Ti-MOF (55.5 F/g at 0.5 A/g; 67.5 %). Further, solid-state symmetrical supercapacitor devices have been assembled using all the plastic wastes derived MOFs viz. Cu-MOF//Cu-MOF, Zr-MOF//Zr-MOF, and Ti-MOF//Ti-MOF. Among them, Cu-MOF//Cu-MOF symmetric supercapacitor device performed better than the others by rendering energy density of 18.2 Wh/kg at 825 W/kg power density along with a cyclic stability of 87 % after 10,000 charge-discharge cycles. These studies open new avenues to utilize waste PET bottles to synthesize high functional MOFs for next generation supercapacitors.

An Integrated Framework for Environmental and Social Life Cycle Assessments in PET Bottle Waste Management: A Case Study in Brazil

The improper disposal of PET bottle waste in Brazil jeopardizes the sustainability goals, impacting the social, economic, and environmental aspects. In order to tackle this issue, this study introduces a framework that was developed using a combination of environmental and social life cycle assessments (LCAs), along with a modified Analytic Hierarchy Process (AHP) methodology. Nine disposal scenarios were evaluated in Bauru, Brazil, including various combinations of landfills, sorting cooperatives, and incineration. Environmental (Env-LCA) and social (S-LCA) assessments followed the ISO 14040 standards, with the S-LCA incorporating the UNEP/SETAC guidelines. Scenario 9 was identified as the most sustainable option from the evaluated scenarios, with 100% of the waste sent to sorting cooperatives, with modified collection schemes. Conversely, Scenario 1, with a high landfill percentage, proved to be the least sustainable.

Development of Recycled Air-filled PET Bottle Blocks for Cavity Wall Construction

This study examines the prospect of using PET bottles in mortar block for cavity wall construction in respect of compressive strength and cost. 500-mL air-filled waste plastic bottles encased by mortar plaster worked as the voids in the masonry units. Three different type of blocks B1, B2, B3 were prepared with the cement sand proportion 1:3, 1:3.5 and 1:4 respectively. Result shows that the strength decreased with the reduction of the proportion of cement. The maximum compressive strength found in B1which was 5.21 MPa after 7 days and 9.29 after 28 days of curing. B2 and B3 also shows 74% and 71% increase in strength as they reach the curing age of 28 days. The comparison of cost for wall construction with both bottle block and hollow concrete block shows, for external wall, the material cost can be reduced by 27% in the case of bottle block. So it can be used as a sustainable alternative of hollow concrete blocks in terms of strength and cost for cavity wall construction and have a great effect on plastic waste management. Key Words: Waste PET Bottles, Hollow Block, Compressive strength, Cost analysis.

Mechanically strong and heat-resistant waste poly (ethylene terephthalate) derived by carbon dioxide treatment at ambient temperature

Due to the ever-increasing consumption of poly (ethylene terephthalate) (PET) for the industries of packaging and electronics, the waste non-degradable PET has brought serious ecological pollution. However, the current recovery rate of waste PET is still limited, and the mechanical and heat-resistant properties are too poor to meet the requirements of practical applications. The recycling of waste PET is of practical significance to material/energy saving and environmental protection, contributing to the sustainable development of economy and society. In this work, an innovative method was proposed to fabricate strong and heat-resistant materials by using waste PET bottle flakes via carbon dioxide (CO2) treatment at ambient temperature. The results show that the crystallinity of the PET samples treated by CO2 at 800 psi is increased by 30.6%, the tensile strength and Young's modulus are increased by 21.9% and 20.6%, respectively, compared with untreated samples. Moreover, the dynamic mechanical analysis indicates that the heat-resistant performance of CO2-treated samples is significantly improved, whose storage modulus increased 33.5% and glass transition temperature increased 17.7 °C. Furthermore, aiming to investigate how the CO2-treatment improved the mechanical performance of the waste PET, the sorption-desorption experiments were conducted to examine the sorption kinetics of CO2 in the matrix, combined with the Avrami model employed to analyze the crystallization kinetics of PET under high-pressure CO2. It demonstrates that the enhancement of the tensile strength is ascribed to the transition of crystals from two-dimensional structures to three-dimensional structures with an increment in the CO2 pressure.

Ionothermal synthesis of activated carbon from waste pet bottles for dye waste water treatment

The production and use of poly-ethylene terephthalate (PET) bottles in packaging have increased significantly. Thus, PET bottles have become a significant plastic waste with environmental problems. Currently, the conventional methods for producing activated carbons (ACs) from waste PET are unsustainable, complex, and unfeasible. As a result, ionothermal synthesis (IS) of waste PET bottles impregnated with choline chloride-urea (CU) deep eutectic solvent (DES) was carried out in order to prepare ACs. The obtained ACs were characterized using XRD, CHNS Elemental analysis and FTIR. The as-prepared ACs were effective as adsorbents for dye adsorption from dye waste water. Specifically, the AC obtained from pristine waste PET bottles (956 mgg−1 at 100 ppm) displayed higher adsorptive capacity compared to the ACs obtained from CU-DES impregnated PET flakes (550mgg−1 at 100ppm). Even though it was expected that the use of CU-DES required no post-synthesis washing or higher temperature treatments might be required to improve the adsorptive capacity of the ACs obtained from IS.This research work established that the synthesis of AC from abundant waste PET bottles using a sustainable and facile method could facilitate its commercial application. Also, this work represents the first attempt to produce activated carbons from PET using low temperature annealing in the presence of limited air, instead of the usual pyrolysis.

From PET Bottles Waste to N-Doped Graphene as Sustainable Electrocatalyst Support for Direct Liquid Fuel Cells

Direct liquid fuel cells represent one of the most rapidly emerging energy conversion devices. The main challenge in developing fuel cell devices is finding low-cost and highly active catalysts. In this work, PET bottle waste was transformed into nitrogen-doped graphene (NG) as valuable catalyst support. NG was prepared by a one-pot thermal decomposition process of mineral water waste bottles with urea at 800 °C. Then, NG/Pt electrocatalysts with Pt loadings as low as 0.9 wt.% and 1.8 wt.% were prepared via a simple reduction method in aqueous solution at room temperature. The physical and electrochemical properties of the NG/Pt electrocatalysts are characterized and evaluated for application in direct borohydride peroxide fuel cells (DBPFCs). The results show that NG/Pt catalysts display catalytic activity for borohydride oxidation reaction, particularly the NG/Pt_1, with a number of exchanged electrons of 2.7. Using NG/Pt composite in fuel cells is anticipated to lower prices and boost the usage of electrochemical energy devices. A DBPFC fuel cell using NG/Pt_1 catalyst (1.8 wt.% Pt) in the anode achieved a power density of 75 mW cm−2 at 45 °C. The exceptional performance and economic viability become even more evident when expressed as mass-specific power density, reaching a value as high as 15.8 W mgPt−1.

Development of Eco-friendly Self-compacting Concrete Using Fly Ash and Waste Polyethylene Terephthalate Bottle Fiber

This study aims to utilize fly ash and waste PET bottles for producing more sustainable self-compacting concrete (SCC) with better mechanical strength. Fly ash is utilized as a supplementary cement material and waste PET bottles as fiber reinforcement to improve its flexural strength and achieve the targeted compressive strength. The experimental works were conducted on eight variations using 80 specimens, divided into two main groups of partial cement replacement using 0% and 15% fly ash by weight. The two variants are added with PET fiber based on the volume fractions of 0%, 0.25%, 0.50%, and 0.75%. Fresh concrete was tested using the slump flow method (T50) and the Visual Stability Index (VSI) based on ASTM 1611. The hardened concrete tests are conducted after 56 days and include testing the concrete's compressive strength, flexural strength, and ultrasonic pulse velocity. Test results showed that the presence of PET fiber in the SCC mix decreased its flowability. However, when added up to 0.75%, the mixes still meet the flowability requirements of fresh-state SCC. PET fiber addition tends to reduce the compressive strength, whereas the reduction in compressive strength of SCC with PET fiber without fly ash is insignificant. However, in SCC that uses fly ash, the addition of PET fiber causes a significant decrease in its compressive strength. Adding PET fiber into SCC mixes can increase flexural strength, both for the two variants: SCC without fly ash and SCC with fly ash. It can be concluded that PET waste fiber with an aspect ratio of 40 can be added up to 0.5% for SCC without fly ash and up to 0.25% by volume fraction for SCC with fly ash addition. The ultrasonic pulse velocity test results have an excellent tendency to predict the concrete's compressive and flexural strengths. Therefore, the UPV test can be applied for the non-destructive test evaluation of PET fiber-reinforced SCC. Doi: 10.28991/CEJ-2023-09-02-014 Full Text: PDF

Preparation of Carbon Dots from PET Waste by One-step Hydrothermal Method and its Application in Light Blocking Films and LEDs.

An environmentally friendly PET-based Carbon Dots (PET-CDs) with excellent fluorescence properties were prepared with waste PET bottle, pyromellitic acid and ammonia water as raw materials by one-step hydrothermal method. The preparation mechanism of PET-CDs was as follows: PET first underwent ammonolysis reaction to produce terephthalic acid diamide and ethylene glycol, and then dehydrated and carbonized with pyromellitic acid to form PET-CDs. The as-prepared PET-CDs exhibit excitation-independent emission properties in the range from 340 to 440nm, and the fluorescence quantum yield is as high as 87.36%. In terms of structure, PET-CDs is a spherical structure with an average particle size of 2.0nm, and its surface contains carboxyl and amino groups. The PET-CDs were dispersed in a PVA matrix to obtain an light blocking films(LBFs) for 250-450nm light with excellent properties, and its transparency for 450-700nm light is good. In addition, PET-CDs was used in the fields of LED, and it was found that the color coordinate for the LED assembled with PET-CDs and 395nm LED chips is (0.55, 0.44) and the correlated color temperature is 2018K.