Waste PET Bottles Research Articles

Facile synthesis of Sn(II)-MOF using waste PET bottles as an organic precursor and its derivative SnO2 NPs: Role of surface charge reversal in adsorption of toxic ions

A new Sn(II)-based metal-organic framework (MOF) has been solvothermally synthesized using post-consumer waste PET bottles as an organic linker source. The potential of the Sn(II)-MOF as an adsorbent material in the removal of arsenate (AsO43−) and phosphate (PO43−) from the aqueous medium was examined. The adsorption kinetics of the target anions followed the pseudo-second-order kinetic model, and the Langmuir isotherm best describes the adsorption profile. The adsorbent displayed a significant adsorption capacity of 90.90 mg g−1 and 126.58 mg g−1 for AsO43− and PO43−, respectively. The synthesized Sn(II)-MOF demonstrated promising anti-interference activity in the presence of co-existing anions, mainly F−, Cl−, NO3−, and SO42−. Besides, the synthesized Sn(II)-MOF exhibited remarkable removal efficiency (~ 99%) of AsO43− from actual water samples viz. tap water and lake water. Further, the work elucidates the role of surface charge regulation where the positively charged Sn(II)-MOF is converted to negatively charged tin oxide nanoparticles (SnO2 NPs) via a simple thermal decomposition route. The MOF derived highly crystalline SnO2 NPs (~ 25 nm) were explored in the adsorptive removal of toxic manganese (Mn2+) ions. The synthesized SnO2 NPs displayed excellent Mn2+ adsorption capacity (qm) of 52.63 mg g−1, which is in good agreement with the experimental value (qexp) of 56.96 mg g−1. Moreover, the SnO2 NPs displayed remarkable selectivity in Mn2+ adsorption despite the presence of other cations/anions. Notably, the present work can prove to be an economically viable method of recycling waste PET bottles into value-added adsorbent material for the decontamination of water.

Environmentally benign synthesis of fluorescent carbon nanodots using waste PET bottles: highly selective and sensitive detection of Pb2+ions in aqueous medium

Green fluorescent carbon nanodots (size ∼6 nm) as a turn-off fluorescent optical nano-sensor for selective and sensitive detection of Pb2+ions from aqueous medium.

Development and characterization of PET flakes reinforced polyester resin composites

The need for transforming waste Poly(ethylene terephthalate)(PET) bottles to usable products is of primary concern due to high ratio of use of PET bottles to recycling, around the world. One of the methods of recycling waste PET bottles is by developing composites which can find application in the construction industry. PET flakes are used as reinforcing material to resin cast PET reinforced polymer composite. In this study PET flakes of different weight percentages (5%, 10%, 15% and 20%) are reinforced in polyester resin matrix and mechanical properties evaluated. The surface hardness (ASTM D2240 and DIN 53505), compressive (ASTM D695-15) and tensile strength (ASTM D3039) of the developed composites are evaluated experimentally. The morphological features of the fractured samples were studied using scanning electron microscopy. The hardness of the developed composites was found to increase with increase in percentage of PET flakes up to and including 15%. The composite with 10% PET flakes exhibited maximum tensile strength and the composite with 5% PET flakes exhibited maximum compressive strength. The tensile and compressive strength follow similar trends in comparison.

The environmental impact of various forms of waste PET bottle management

ABSTRACT The paper analyses the environmental impact of three forms of waste PET bottle management, i.e. through recycling, energy recovery and as a result of its disposal. The analysis was carried out using the Life Cycle Assessment (LCA) technique enabling comprehensive assessment covering both direct and indirect environmental impacts. The research carried out included changes resulting from technological progress and the development of environmental protection technologies, which may have a significant impact on the obtained results. An attempt has been made to take into account these changes and assess the environmental benefits of various forms of PET bottle management. The study confirmed the results of research carried out by Chinese and British scientists indicating that the most environmentally friendly form of waste PET bottle management is recycling (1.38 mPt). Energy recovery (2.73 mPt) shows a higher environmental burden, while disposal is the most unfavourable form of waste PET bottles management (7.31 mPt). As a result, despite differences in environmental technologies used a decade ago and today, as well as legal differences in force in the compared regions of the world, the main conclusions of the study remain valid. For this reason, it is important adopt environmentally friendly waste PET bottles management and to include them in the global material balance for the implementation of circular economy solutions that correspond directly with the Sustainable Development Goals of the 2030 Agenda of Sustainable Development.

Polyurethane adhesive based on polyol monomers BHET and BHETA depolymerised from PET waste

During the development of the polyurethane (PU) industry, one of its biggest challenges has been synthesis and formulation-related due to a lack of renewable resources and thus an over-reliant dependence on fossil reserves which has led to considerable research effort focused on alternative renewable sources of supply. In this study, PET bottle waste and castor oil have been considered as alternative sources for the synthesis of a PU adhesive. A cheap and environmentally friendly synthesis pathway for polyols is provided using depolymerization reactions of recyclable materials. The structures of the polyols have been demonstrated using Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) spectroscopy. Different NCO/OH ratios with calculated amounts of MDI were used to prepare polyols which were then employed during PU preparation and their effects on the resultant PUs were investigated. Solvent-free polyurethane adhesives were synthesized. Changes in the properties of PU synthesized by the addition of castor oil and boron species to the structure were also determined. The thermal behaviour of PU samples were characterized by DSC-TG; and functional group detection and covalent bonding formation were investigated via FTIR analysis.

Life cycle comparative assessment of pet bottle waste management options: A case study for the city of Bauru, Brazil

This study analyzed the environmental impacts of nine scenarios for Polyethylene Terephthalate (PET) bottle waste disposal, in the city of Bauru, Brazil. Nine scenarios were considered in this study: (1) current (base) scenario (96.4% of PET waste is sent to landfill, 3.6% is sent to sorting cooperatives); (2) 50% to sorting cooperatives, 50% to landfill; (3) 50% to sorting cooperatives, 50% to incineration; (4) 50% to landfill, 50% to incineration; (5) 100% to sorting cooperatives (keeping the current collection distribution); (6) 100% to landfill; (7) 100% to incineration; (8) and (9) 100% sent to sorting cooperatives, with changes in the collection scheme. Life cycle assessment was implemented to compute the impacts for each scenario and compare their environmental performances. The results have shown that recycling is a better option than incineration across all impact categories analyzed. Landfilling had lower net impacts than incineration in all categories, except for ozone depletion and freshwater eutrophication. All recycling scenarios proposed outperformed the current scenario in all impact categories. Even though recycling presents itself as an environmentally-promising alternative, much work still needs to be done for its successful implementation, such as promoting source-separation at home and improving the management strategies of recycling cooperatives, including additional funding and training to support an increased sorting capacity.

Exploring shredded waste PET bottles as a biofilter media for improved on-site sanitation

This study explores an improved alternative on-site treatment for unsewered urban Bhutan. The system combines up-flow anaerobic sludge blanket for blackwater treatment and anaerobic biofilter for a mixture of up-flow anaerobic sludge blanket effluent and greywater. Shredded waste plastic bottles are used as novel biofilter media that provides a large surface area for attached growth while addressing waste plastic problems. A bench-scale up-flow anaerobic sludge blanket (operated at hydraulic retention time or HRT of 1–10 days) and anaerobic biofilter (HRT of 0.25–3 days) study were conducted for 188 days. At 2-d HRT, up-flow anaerobic sludge blanket removed 70–80 % of chemical oxygen demand (COD) while anaerobic biofilter achieved 90–98 % COD removal at eight-hour HRT. Combined up-flow anaerobic sludge blanket and anaerobic biofilter achieved final effluent with COD less than 50 mg/L and turbidity of less than 3 NTU that meets the discharge standard of Bhutan. The study shows that shredded waste plastic bottles can be an effective biofilter support medium for low-cost on-site treatment while helping address waste plastic problems.

Stabilization of Black Cotton Soil using Waste Beverage Cans and Pet Bottles

Stabilization of Black Cotton Soil using Waste Beverage Cans and Pet Bottles

Material efficiency to measure the environmental performance of waste management systems: A case study on PET bottle recycling in Austria, Germany and Serbia

Material efficiency measures, such as recycling rates, are often used to set circular economy targets to achieve higher resource efficiency and lower environmental impact. The aim of this study was to identify material efficiency indicators suitable to reflect the environmental performance of waste and recycling systems using PET bottle waste management in three European countries with diverse waste management structures and recycling performance levels. Material flow analysis and life cycle assessment were performed to assess the material efficiency and environmental impacts of each system as a basis to analyze the relation between these two dimensions. PET bottle waste generation was 5.4 kg/person and year (pa) in Austria in 2013, 6.0 kg/pa in Germany in 2017 and 6.9 kg/pa in Serbia in 2015. Out of this waste flow 41%, 91%, and 11% were directed into PET recyclate in Austria, Germany and Serbia, respectively. For all systems, higher material efficiency translated into lower environmental impact and vice versa. However, linear regression analysis between different material efficiency indicators and environmental impacts showed that indicators targeted at actual recycling, specifically at closed loop, were better suited to reflect environmental performance than input-based indicators. Therefore, whenever data are available, output-based quality-related indicators should be used to measure the material efficiency of waste and resource systems because they correlate best with the goals of increasing resource efficiency and decreasing environmental impacts.

Environmental performance analysis on resource multiple-life-cycle recycling system: Evidence from waste pet bottles in China

Resource multiple-life-cycle (MLC) recycling process is a complex system with closed-loop and open-loop recycling interwoven with each other, which has recieved vast attention in recent years. Resource MLC recycling has a cascading effect, one recycling process will have an impact on the next cycle, and ultimately affect the overall environmental performance of the social system. Policies will affect the flow of resource MLC recycling. How to maximize the emission reduction effect of resource MLC recycling through policy design is still under exploration. Employing MLC recycling of China's waste PET bottles as an example, this paper constructs an environmental performance accounting method based on MLCA, and simulates the overall impact of various policies such as implementing deposit system, promoting recycled materials, strenghtening environmental regulation and enhancing regeneration technology on the recycling system of PET bottles. The combined policy scenario is constructed by selecting advantageous strategies that can effectively give full play to the strengths of each policy scenario. From 2020 to 2040, the environmental performance loss value of the combined policy scenario will be 52.52% of the baseline scenario without policy support, and the cumulative emission reductions of wastewater, waste gas and solid waste will be 0.98, 3.61 and 341.39 million tonnes respectively, which can help China to achieve emission reduction targets set out in each five-year plan. In order to realize the combined policy scenario, it is suggested that the life cycle assessment (LCA) should be replaced by multiple life cycle assessment (MLCA), the effect of resource saving and environmental emission reduction in the recycling process should be accounted as accurately as possible, a top-level management organization of natural resources across multiple departments should be established as soon as possible, with the goal of maximizing the comprehensive environmental and economic benefits of MLC processes.

Biosynthesis of silver nanoparticles as catalyst by spent coffee ground/recycled poly(ethylene terephthalate) composites

Spent coffee ground (SCG) and poly(ethylene terephthalate) (PET) bottles are common wastes in the beverage industries. In this study, SCG and PET sheets from waste PET bottles were utilized to prepare PET/SCG composites. Those composites were embedded with silver nanoparticles (AgNPs) prepared from AgNO3 solutions (0–100 mM) without addition of catalyst or reducing agent, to be AgNPs@PET/SCG sheets. The generation of AgNPs was confirmed by field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). According to inductively coupled plasma (ICP) analysis, the loaded amount of AgNPs on PET/SCGs was in the range of 0.9–7.3 μg/cm2. The catalytic performance and kinetics of AgNPs@PET/SCGs for the reduction of 4-nitrophenol with NaBH4 was studied, where 100% conversion can be reached in 20 min. The prepared AgNPs@PET/SCGs sheets allow easy separation from the reaction media, and can be reused for at least seven cycles while maintaining >90% conversion rate. The durable and reusable AgNPs@PET/SCGs made from waste materials may provide a promising alternative for further industrial applications.

Life-cycle environmental implications of China’s ban on post-consumer plastics import

China used to receive more than 50% of the global post-consumer plastics export, the largest share of which was PET bottles. However, China recently banned the import of foreign wastes including waste plastics. The original intention of this ban was to protect China’s ecosystem quality and human health, while its environmental implications have yet to be examined. This study analyzes the life-cycle environmental impacts of this ban on post-consumer PET under a number of post-ban scenarios. Our analysis shows that the ban may substantially exacerbate environmental impacts both in China and globally, if China, in the absence of imported recyclates, increases its virgin PET fiber production using carbon-intensive coal as the feedstock. Recycling waste PET bottles within the countries that generate them to replace China’s virgin PET fiber production, however, is shown to significantly reduce life-cycle environmental impacts both in China and globally. Our study highlights the potential unintended environmental consequences of the ban and the need to consider marginal technologies and their consequences in policy decisions. Our results call for cost-effective recycling infrastructure among the waste-producing countries and the mechanism to coordinate plastics recycling on a global scale.

Composite sulfur cathode for Li-S batteries comprising hierarchical carbon obtained from waste PET bottles

Waste PET bottles have been processed towards carbonaceous material through pyrolysis at 500 °C in nitrogen atmosphere followed by chemical activation with K2CO3. The obtained carbon was found to feature hierarchical pore structure, as evidenced by nitrogen sorption isotherm analysis. Composite sulfur-carbon electrode has been prepared using this carbon by means of simple dry-mixing technique and subjected to electrochemical testing in model Li-S cells with electrolyte being 0.5 M lithium trifluoromethanesulfonate (LiTf) and 0.5 M lithium nitrate (LiNO3) in mixture of 1,2dimethoxyethane (DME) and 1,3-dioxolane (DOL). The Li-S cells assembled with obtained composite sulfur-carbon cathode demonstrated a large initial specific discharge capacity of about 829 mA h g−1 at 0.05 C current rate and delivered ca. 712 mA h g−1 after subsequent 50 charge and discharge cycles, which corresponds to 86% capacity retention. Generally, the investigated Li-S cells have exhibited good cycling stability and excellent reversibility. Thus, the obtained waste-derived activated porous carbon can be considered as a promising component for the composite cathode material of Li–S batteries.

Hardened properties of binary cement concrete with recycled PET bottle fiber: An experimental study

The mechanical and fracture properties of binary cement concrete containing recycled waste PET bottle fiber (RWPBF) are studied as part of this experimental research work. The mix was designed to produce a concrete of grade M50. The binder for the first series of mix was Ordinary Portland Cement (OPC) and the second series of mix contained binary cementetious blends of 10% metakaolin (MK) and 90% OPC, with varied percentages of RWPBF. RWPBF was added at five designated percentages of 0%, 0.2%, 0.4%, 0.6% and 0.8%. The 28 days test results show an increased compressive strength of 5% in addition of MK and further increase of up to 10.67% on inclusion of RWPBF. Moreover, the use of RWPBF significantly improved the tensile, elastic and flexural strength of concrete specimens. The optimum level of addition of RWPBF was found to be 0.4%, beyond which the strength decreased and was lower than control specimens.

Preparation of a one-component epoxy adhesive using PET bottle waste derived terephthalic dihydrazide as latent curing agent

The present work discusses the effect of PET bottle waste derived terephthalic dihydrazide (TDH) as a latent curing agent in diglycidyl ether of bis-phenol A (DGEBA) based epoxy resin. Differential scanning calorimetric studies were conducted to examine the latent character of TDH and its curing pattern in DGEBA and FTIR spectroscopy was used to confirm the completion of curing. A latent accelerator (Ajicure PN-40) was used to reduce the extremely high cure temperature of DGEBA-TDH system to a feasible range. Cure characteristics, barrier and aluminium to aluminium (Al/Al) adhesive properties of the synthesized adhesive with varied TDH content were studied to optimize the dosage of TDH. Pot life of the synthesized adhesive was determined through brookfield viscosity measurements. Ageing studies of the bonded Al/Al samples were carried out to study the practical utility of the newly synthesized adhesive. The properties of TDH cured one-component epoxy adhesive were compared with a commercial dicyandiamide (DICY) cured one-component epoxy adhesive. TDH cured adhesive displayed comparable properties to the DICY cured adhesive.

Preparation, characterization, and evaluation of polymeric resin (BHMET) from the reaction of malic anhydride with recycled PET as a corrosion inhibitor for Csteel in HCl

Introduction: The plastic soft drink bottle from polyethylene terephthalate (PET) was introduced to consumers in 1970s. Because PET have ester group its chemical recycling is preferred. To control and reducethe environmental pollution recycling and reusing of PET has turned into an imperative procedure from the ecological perspective and it has given business opportunity because of far reaching use and accessibilityof PET polymer. Also another source of pollution to the environment was the corrosion of materials. Corrosion is the deterioration and loss of a material and its critical properties due to chemical, electrochemical and other reactions of the exposed material surface with the surrounding environment. Understanding corrosion mechanisms allow to use corrosion-resistant materials and altering designs. Organic inhibitors are very efficient to protect the metals from corrosion in all chemicals (acidic, basic and salt) media. There were many types of corrosion inhibitors and the organic inhibitor are being applied widely to protect metals from corrosion in many aggressive media. The aim of this study is to utilize waste PET-bottles will be depolarized by 2,2-dithioethanol to produce (Bis(2-((2-hydroxyethyl) thio) ethyl) terephthalate (BHTE), then by reacting of (BHTE) with maleic anhydride to produce Bis (2-((6-Mono malic acid –hydroxyethyl ester) sulfanyl) ethyl terephthalate(BHMET). The prepared (BHMET) will be used as corrosion inhibitor andits efficiency to protect the carbon steel in acidic will be assessed. Materials and Methods: Depolymerization of PET waste done with 2,2-dithioethanol. The weight proportion of PET to 2,2-dithioethanol 1:8 (wt%) and zinc acetate (0.5 wt% based on PET) was added as catalyst. Temperature of the reaction mixture was between 160-180 oC for 12 h, then the reaction mixture was kept at 140 oC for 3 h, then allowed to cool to room temperature. With vigorous agitation distilled water in excess to the reaction mixture to allow the black liquid viscous compound oligomer of Bis(2-((2-hydroxyethyl) thio) ethyl terephthalate (BHET) to precipitate. In a three neck round bottom (250 ml) attached with mechanical stirrer and thermometer (5.7gm) of (BHET) compound was added and heated for (15 min.) at (60 OC). Then (2.5gm) of malic anhydride and (1%) sulfuric acid was added. By the mechanical stirrer the mixture was mixed for (50 min.) at temperature (80OC). After the reaction the mixture was washed with distilled water to avoid the acid residue. Scheme (1) shows the mechanism for the prepared (BHMET) corrosion inhibitor.

ZnO@ porous graphite nanocomposite from waste for superior photocatalytic activity.

In this work, a new type of advanced 3D mesoporous carbon nanocomposites derived from Zn dust/PET bottle mixed waste with a high surface area is created. Interestingly, simultaneous transformation of Zn metal into ZnO nanoparticles and PET bottle waste to porous carbon materials occurred upon thermal treatment at 700°C. The effect of the amount of Zn metal on the prepared materials has been studied. The carbon material-based waste presented very large surface area (up to 684.5m2/g) with pore size distribution (18.47-16.88nm). The SEM and TEM analysis revealed that the produced carbon materials have 3D porous dense layers with a gradient pore structure. The created waste-based nanocomposite exhibited an enhanced photocatalytic performance for the degradation of organic dyes (methylene blue and malachite green). It is believed that the presented work not only provides a sustainable approach to the creation of new nanocomposites of ZnO-mesoporous carbon materials for the application in photocatalysis but also introduces a new way of upcycling of mixed waste materials.

Development of Ultrafiltration Membrane from Polyethylene Terephthalate (Pet) Bottle Waste

Polyethylene Terephthalate (PET) bottle is used as beverage packaging, which is very convenient as one time use packaging. However, the huge amount of PET bottle waste has been becoming a serious problem for the environment. The utilization of PET bottle waste is very important to reduce the environmental problem. In this work, PET bottle waste was used a raw material to develop an ultrafiltration (UF) membrane. The membrane was prepared by using a phase inversion technique. The effect of the type of solvent, additive, and non-solvent on the microstructure and ultrafiltration performance of the membrane was studied. Different type of solvent, phenol, m-cresol, and DMSO were used to dissolve PET bottle as the source of membrane polymer. Two different additives, Polyethylene Glycol (PEG) and Polyvinyl Pyrrolidone (PVP) were used. Membrane 3 with the composition of PET, phenol as solvent, and PEG as additive was prepared successfully. The variation of aqueous alcohol solutions as non-solvent resulted in different microstructures of the membranes as shown by the scanning electron microscopy (SEM). The permeation experiment result using pure water as the feed showed that membrane 3 using aqueous butanol as non-solvent (membrane 3-ButOH) exhibited the highest permeate flux compared to that of membrane 3 using aqueous propanol (membrane 3-PrOH) or ethanol as non-solvent (membrane 3-EtOH). The ultrafiltration experiment was carried out using a feed solution of water containing polyethylene glycol (PEG) 20,000. The membrane 3-EtOH showed the lowest permeate flux of 3.24 kg/m h, but the highest rejection of PEG 20,000 of 65.87%. The membrane 3-PrOH had a permeate flux of 11.57 kg/m h and a rejection of 64.73%. Whereas the membrane 3-ButOH showed the highest permeate flux of 27.78 kg/m h, but the lowest rejection 16.93%. This result was obtained due to the different membrane microstructures which were strongly affected by the type of non-solvent.

Environment and economic impacts assessment of PET waste recycling with conventional and renewable sources of energy

The use of large amount of plastic has created environment threats and thus it needs to be recycled. The recycling of plastic waste requires energy but the energy production with conventional sources depletes the natural resources and creates environmental degradation. This study aims to assess and compare the environmental and economic impacts from the recycling of PET plastic bottle waste with conventional and renewable sources of electricity in India. An experiment is conducted wherein the PET bottle waste is used to make filament for 3-D printing by using three different scenarios. Scenario A uses the virgin PET granules with conventional Indian electricity mix, scenario B uses PET bottle waste recycling with conventional Indian electricity mix, and scenario C uses PET bottle waste recycling with solar electricity. The ISO 14040 guidelines are followed to conduct cradle-to-grave LCA for scenario A; and grave to grave LCAs for scenarios B & C. The impact categories considered for the endpoint assessment are ecosystem quality, human health and resources. Climate change, fossil depletion, human toxicity, ozone depletion, terrestrial acidification, and water depletion are considered for midpoint assessment. The results of the study show that scenario B has high environmental impacts followed by scenarios C & A. The findings of this experimental study suggest the use of renewable energy (solar electricity) for recycling of PET bottle waste for filament production. The limitation of the study is that it’s a region specific experiment for environmental and economic impacts.

Fundamental investigation of solid waste generation and disposal behaviour in higher education institute in the Kingdom of Saudi Arabia

Waste characterization is a fundamental step for the development of solid waste management plan. In this regard, understanding the waste generation and disposal patterns plays a crucial role in developing realistic waste reduction strategies. Presently, there exists no solid waste management plan for higher education institutes in the Kingdom of Saudi Arabia. Hence, this article details the fundamental study related to the waste generation and disposal behaviour. The study also dwells into the existing practices of solid waste management and sheds light on the new polices that can be adopted for waste reduction, along with highlighting barriers to optimization of solid waste management. Through investigation, it was found that by adopting E-learning system for examination and replacing paper towels with air dryers in washroom and by revising policy related to printing, considerable reduction in paper waste could be achieved. Furthermore, the adoption of the proposed sustainable drinking water solution led to 90% reduction in plastic pet bottle waste. The recommendations made by the presented investigation can be employed by other similar sized institutes in developing countries for the development of sustainable green campuses.