Plastic Solid Waste Research Articles

Raman technology application for plastic waste management aligned with FAIR principle to support the forthcoming plastic and environment initiatives

Plastic production and worldwide use of plastic materials have continued to rise due to their convenience and excellent marketing advantages. This is generating an environmental crisis and global scale pollution which is one of the greatest threats to our planet. One of the best responses could be accomplished by improving recycling and waste management strategies. In this paper we conducted Raman analyses of representative stock of plastics aged in terrestrial or aquatic environments spanning in age up to 15 years. We aimed to establish any potential influence of the aging conditions on the Raman signature of specific plastics. This information is further used to build up a Raman logic gate for automatic sorting of plastic waste recovered from environment. Pigments and aging introduced indeed small changes in the Raman signature of the respective plastics. However, we were able to identify unique spectral ranges characteristic for the main plastic types and intensity threshold of fingerprint bands sufficiently strong for building robust Raman barcodes for sorting. Waste plastics Raman data handling and the proposed methodology for sorting complies with the FAIR (Findability, Accessibility, Interoperability and Reusability) principles of scientific data, being useful for researchers, policymakers and stakeholders. Our spectral characterization of solid plastic waste comes in support of improved waste plastic management and could have economic and environmental positive impact.

Utilizing solid plastic wastes in subgrade pavement layers to reduce plastic environmental pollution

The present study investigated the utilization of plastic wastes as reinforcement to improve the strength and swelling behavior of weak subgrade expansive soils and reduce plastic pollution. Expansive soils are known for their volume change during different seasons, while plastic waste is the most hazardous waste pollutant material that causes damage to the environment and organisms. Utilizing plastic wastes in subgrade construction reduces the quantity of waste and improves the problematic behavior of expansive soils. The studied soil is categorized as expansive clay soil according to the AASHTO soil classification system. Various geotechnical laboratory tests were conducted by varying the plastic strip sizes with treatment percentages of 0%, 0.25%, 0.5%, 1%, 1.5% and 2%. The study found that swelling percentages and compaction parameters were decreased with an increase in plastic waste strips. As percentages of plastic strips increase, CBR values increase while unconfined compressive strength increases up to 0.5% addition of plastic strips and then slightly decreasing. The cohesion of the soil increases up to 1.5% of plastic strips addition. The study recommends that the utilization of plastic waste in subgrade road construction is the best alternative to improve the strength of expansive soils and reduce environmental pollution.

High-yield H2 production from polypropylene through pyrolysis-catalytic reforming over activated carbon based nickel catalyst

With the aggravation of energy crisis and environmental pollution, green and renewable new alternative energy has become the focus of global attention. Hydrogen energy has become an important part of the global energy pattern in the future. Conversion of solid waste plastics into hydrogen energy by pyrolysis/gasification is a promising solution. This study aims to explore a method of high-yield in hydrogen by breaking down polypropylene, a cheap and efficient nickel catalyst is prepared and applied to the experimental study of hydrogen production by pyrolysis-catalytic reforming. The effects of catalytic temperature, Ni loading (%) and catalyst addition amount on hydrogen production of catalyst were investigated, the hydrogen production was increased by introducing water vapor. Under the optimized reaction parameters (catalytic temperature 900 °C, PP to catalyst ratio 1:0.75, Ni loading 15 wt%), the hydrogen yield is up to 40.24 mmol/gPP without water and 134.91 mmol/gPP with water, the addition of water significantly increased hydrogen production. this results have obvious advantages in hydrogen production compared with similar studies. Furthermore, the existence of various forms (snake-like, straight carbon nanotubes and carbon nanospheres) of carbon deposition found in this paper can provide new ideas for researchers working on graphite carbon. This study provides an effective new approaches for enhancing hydrogen production by pyrolysis/gasification of waste plastics.

ATR-FTIR Spectroscopy Combined with Chemometric Methods for the Classification of Polyethylene Residues Containing Different Contaminants

Low density polyethylene (LDPE) and high density polyethylene (HDPE) are the principal plastics present in solid plastic waste and are found out as the main components of microplastics in marine and terrestrial environments. Currently, efforts have been made to develop new and effective methods to ensure the identification and separation of plastics in waste, ensuring the necessary purity to obtain quality and economically competitive recycled products. In this contribution, we investigated the usage of Fourier-Transform Infrared Spectroscopy in Attenuated Total Reflection mode (ATR-FTIR) combined with Principal Component Analysis (PCA), Linear Partial Least Squares Regression by Intervals (iPLS-R) and Competitive Adaptive Weighted Sampling (CARS/PLS-R) as chemometric methods to classify and determine the compositional fraction of the pristine and recycled mixtures of HDPE and LDPE from plastic waste in São Paulo, Brazil. Here, the 3D PCA plots were not effective in classifying the different polyethylenes and their polymer blends using the three main Principal Components (PC), but 2D PCA diagrams using PC1 and PC3 presented promising performance for this purpose. The iPLS-R presents the best predictive ability than CARS/PLS-R to determine the LDPE content in HDPE/LDPE recycled blends. However, the presence of different contaminants (in 5 wt%), such as silicon dioxide (SiO2), calcium carbonate (CaCO3), recycled polypropylene (PP), and recycled poly(ethylene terephthalate) (PET), reduces the potential usage of the iPLS-R models as identification tools for LDPE and HDPE sorting in industrial recycling processes.

In-situ construction of particle-accumulated hydrophobic packing layer from rigid polyurethane wastes for gas pre-dehydration

HypothesisRigid polyurethane, a common insulation material, is difficult to degrade naturally and poses significant health and environmental risk. Consequently, the cost-effective and efficient reuse of these solid wastes is a great challenge. ExperimentsHerein, we report an in-situ construction of hexadecyltrimethoxysilane (HDTMS) hydrophobic films on rigid polyurethane waste particle (RPUWP) as an accumulated packing layer in the gas-liquid pre-separator for gas pre-dehydration. FindingsThe RPUWP grafted with HDTMS (P-HDTMS) packing layer exhibits excellent hydrophobicity in the air, acid (pH = 1), alkali (pH = 14), and high-temperature (over 95 ℃) resistance. Also, the gas pre-dehydration performance of the accumulated P-HDTMS packing layer in the gas-liquid pre-separator was evaluated by the water dew point depression (ΔTd). It is worth mentioning that the accumulated packing layer can stabilize and greatly reduce the ΔTd by 17.8 ℃ in over 48-hour uninterrupted operation through the coalescence separation mechanism. Therefore, the low-cost accumulated P-HDTMS packing layer is expected to be an ideal candidate material for gas pre-dehydration in large-scale practical applications. This work not only provides a novel method for the resource utilization of plastic solid wastes but also provides a hitherto unexplored perspective for gas dehydration in industrial production.

Distillation of Pyrolysis Results from Mixed Used Plastic and Palm Oil in The Fractionation Column to Produce the Gasoline Fraction, with RON Analysis: Experiments and Modeling

Reprocessing plastic waste to become fuel oil is a good process. Plastics were originally obtained from the polymerization of petroleum products. According to SIPSN data from the Ministry of Environment in 2020, plastic waste in Indonesia has reached 17.314 million tons/year. In addition to using recycling, reduction can be made using hydrothermal pyrolysis cracking to convert solid plastic waste into liquid gasoline fractions with the help of co-reactants. However, with the pyrolysis process, the final result of the process allows the presence of impurities that are still contained in it. In this research, the distillation of the pyrolysis results for gasoline fraction plastic waste was carried out using a fractionated distillation column. The distillation process enhances the performance of petroleum oil with an average of RON 98 and a caloric value of 10,609,7 cal/gr. Modeling and simulation using excel of the distillation results of pyrolysis were carried out, it was found that the increase in the reflux ratio led to an increase in the purity of the distillation product and the effect of residence time caused the longer the process to run, the lower the distillation product. Therefore, the separation should not be done too long, which can cause the purity to decrease every time. The higher the reflux ratio, the smaller the kinematic viscosities get proven by experimental and modeling, but the value is a striking difference due to deviation from the model.

Transformation of solid plastic waste to activated carbon fibres for wastewater treatment

In this study, the solid waste plastic was converted into activated carbon fibres through carbonization and chemical activation process. The morphological structure, composition, thermal stability and pore structure of the produced activated carbon materials were characterized. The results revealed that the activation process substantially increases the specific surface area of carbon materials via forming large micropores and mesopores (0.01–0.85 cm3g-1) within average nano size range of 50–100 nm. This study provides an effective means to remove the thymol blue dye via adsorption over activated carbon (ACs) as adsorbent. Batch adsorption of thymol blue was conducted to verify the effect of variety of pH, dye concentrations, contact time, adsorbent dose and temperature. The highest dye removal efficiency (approximately 98.05%) of ACs generated from waste plastic polybags, cups and bottles was observed at 10 ppm of thymol blue dye. The results also exhibited that the dye adsorption was favourable at basic pH (9.0) and increasing amount of adsorbent dosage promotes the dye removal efficiency. The excellent dye removal performance was primarily due to the presence of higher available surface area on the surface of developed carbon fibres. In addition, the current results have given the large overview and useful information of dye removal properties by adsorption isotherm and kinetic measurements. The adsorption kinetics and thermodynamic prospective of formed ACs explored the physical, spontaneous and endothermic adsorption process. The as prepared ACs provided easy regeneration of adsorbents with fast response which further suggests the efficiency of nanoparticles to promote their usage up to 5 consecutive cycles. The current work illustrated that better means to transform solid waste plastic into carbon fibres for providing effective and cheap viable option for the fast removal of thymol blue dye from waste water samples.

Microbial degradation of low-density polyethylene by Neopestalotiopsis phangngaensis.

Low-density polyethylene (LDPE) has been commercially used and accumulated as plastic solid waste. LDPE has also been found to be a non-degradable waste for decades and found as a pollution source in the environment. In this study, 65 fungi were screened for their biodegradation of LDPE. The fungi Neopestalotiopsis phangngaensis, Alternaria burnsii, Alternaria pseudoeichhorniae, and Arthrinium sacchari showed significant potential in LDPE biodegradation. These fungi were individually cultured with an LDPE sheet as a carbon source for 90 days. A maximum weight loss of the LDPE sheet was detected by the fungus N. phangngaensis (54.34%). This fungus also revealed the highest reduction rate of tensile strength of the LDPE sheet (0.33 MPa). The morphological surface of LDPE culturing with N. phangngaensis was crack, pit, and rough analyzed by scanning electron microscopy. The biodegradation of the LDPE sheet by N. phangngaensis was also confirmed by the Sturm test and analysis of enzymatic activities. The Sturm test showed the highest decomposition of the LDPE sheet by N. phangngaensis into CO2 with 2.14 g/L after incubation. Enzymatic activities of laccase, manganese peroxidase, and lignin peroxidase enzymes were found by N. phangngaensis during the LDPE degradation. The volatile organic compounds in culture supernatant of N. phangngaensis were also investigated. The major compounds were 3Z-diethyl acetal hexenal, 2E,4E-decadienol, and 2Z-diethyl acetal hexenal. This study reveals the utilization of the fungus N. phangngaensis as the carbon source at a considerable biodegradation rate without any prior treatment. Therefore, the fungus N. phangngaensis may be applied as an alternative degrader for LDPE degradation in the environment.

Pyrolysis of plastic waste for a better environmental system

Owing to the rapid utilization of fossil fuels, the world is in need of a sustainable and renewable energy source. Surplus resources of municipal solid waste and plastic waste will act as a better biomass fuel for generating electricity and liquid fuels, which can be extracted using Pyrolysis process. The present work addresses the pyrolysis process of mixed plastic wastes. This leads to fuel oil production, which is capable to reduce the problems associated with plastic waste disposal.Plastic wastes along with municipal solid waste getting generated day to day in diversified house hold and industrial wastes are addressed to be a threat and among the major sources of environmental pollution. On other hand it’s to be noticed that theses carbonaceous plastics wastes and municipal solid waste having rich carbon content. This Biomass wastes are highly capable not only to provide a renewable source of fuel but also these technologies will act as a gate way of recycling the multidisciplinary waste getting generated in the society.

A waste to energy approach for the effective conversion of solid waste plastics into graphene nanosheets using different catalysts for high performance supercapacitors: a comparative study

Conversion of plastic waste into graphene nanosheets and its application in supercapacitor.

Talking Trash: The Rhetoric of Waste Bins

There is no mythical “land of away.” We have a trash problem, and plastic is a major contributor. In 2015, we generated 34.5 million tons of municipal solid plastic waste (EPA, “National Overview”), and it is only a part of our waste. Ironically, plastic containers, from household cans to plastic liners to the large green curbside bins, held that solid waste at one time—and were soon to be their own contribution to the 3.4 million tons. The banality, opacity, and capacity of our waste bins facilitate consumer culture. Reflective design, however, can help us query our trash practices by defamiliarizing the trashcan through making its attributes and properties visible and explorable. “Talking Trash” is an act of reflective design in which I wove a waste bin from the environmental articles of various magazines. Next, I set up a Twitter account, @Talking_Trash_, to tweet about items I was placing in the bin. Then, I considered the pedagogical value of Talking Trash and similar reflective design projects in environment humanities classes. Ultimately, I argue that our trashcans engage in a rhetoric of the everyday that encourages consumer practice and waste-world-making. Talking Trash provides insight into the public and private natures of waste, the revealing and concealing our bins promote, and the affordances of materiality present in our waste bins. Talking Trash is an intervention of hope.

Co-processing of plastic waste in a cement kiln: a better option.

This paper deals with the techniques to use plastic waste for co-processing in cement kiln for energy recovery. Plastics, a versatile material and friend to the common man, have now become one of the most serious environmental issues when it is discarded into the environment. The focus of this study is on eco-friendly disposal of plastic waste. Plastic is user-friendly, but because of its incomplete lifecycle, it has become a global issue. It is commonly disposed of by land filling or incinerating the waste, which adds to the pollution load at later stages. The authors' focus is on innovative techniques to use waste plastics in different proportions for the co-processing in cement kiln in order to highlight the energy recovery of the entire plant. It is a good solution to the waste disposal problems that arise due to plastic waste as well as municipal solid waste. The use of plastic waste as an alternative fuel for cement plants is suggested in this paper. The authors also promote this approach and suggest encouraging its calorific value utilization in the cement manufacturing plant. A systematic approach has been presented in this work to mitigate the energy consumption in the cement industries as well as environmental hazards due to plastic and municipal solid waste.

Production and utilization of pyrolysis oil from solidplastic wastes: A review on pyrolysis process and influence of reactors design

This paper reviews the new progress, challenges and barriers on production of pyrolysis oil from the plastic waste. Among the different processes thermal and catalytic are the potential methods to produce oil. Since the global plastic production increased over years the accumulation of plastic waste increases. Thus, converting the waste plastics into useful energy is very essential to avoid the environmental concerns. Initially the thermal pyrolysis process and its advantage on production of pyrolysis oil were discussed. During the thermal decomposition the waste plastic had been converted into the products such as gas, crude oil and solid residues. Secondly, the catalytic process and its recent trends were discussed. In addition, the factors affecting the catalytic pyrolysis process had been evaluated. Furthermore, the optimized concentration of catalyst subjected to the higher yield of fuel with low hydrocarbon content was found. The pyrolysis oil produced from the catalytic process has higher heating values, lower density and lower viscosity compared to thermal process. In addition, the application of pyrolysis oil on the diesel engines had been discussed. The effects of pyrolysis oil on combustion and emission characteristics were observed. This review summarizes the potential advantages and barriers of both thermal and catalytic process. Further, the optimized solutions and applications of pyrolysis oil are suggested for sustainability of the process. Besides the introduction of the pyrolysis oil were viable without making major modification to the existing engine design.

Polyolefins and Polyethylene Terephthalate Package Wastes: Recycling and Use in Composites

Plastics are versatile materials used in a variety of sectors that have seen a rapid increase in their global production. Millions of tonnes of plastic wastes are generated each year, which puts pressure on plastic waste management methods to prevent their accumulation within the environment. Recycling is an attractive disposal method and aids the initiative of a circular plastic economy, but recycling still has challenges to overcome. This review starts with an overview of the current European recycling strategies for solid plastic waste and the challenges faced. Emphasis lies on the recycling of polyolefins (POs) and polyethylene terephthalate (PET) which are found in plastic packaging, as packaging contributes a signification proportion to solid plastic wastes. Both sections, the recycling of POs and PET, discuss the sources of wastes, chemical and mechanical recycling, effects of recycling on the material properties, strategies to improve the performance of recycled POs and PET, and finally the applications of recycled POs and PET. The review concludes with a discussion of the future potential and opportunities of recycled POs and PET.

The relative importance of COVID-19 pandemic impacts on biodiversity conservation globally.

The COVID‐19 pandemic has had an enormous impact on almost all aspects of human society and endeavor; the natural world and its conservation have not been spared. Through a process of expert consultation, we identified and categorized, into 19 themes and 70 subthemes, the ways in which biodiversity and its conservation have been or could be affected by the pandemic globally. Nearly 60% of the effects have been broadly negative. Subsequently, we created a compendium of all themes and subthemes, each with explanatory text, and in August 2020 a diverse group of experienced conservationists with expertise from across sectors and geographies assessed each subtheme for its likely impact on biodiversity conservation globally. The 9 subthemes ranked highest all have a negative impact. These were, in rank order, governments sidelining the environment during their economic recovery, reduced wildlife‐based tourism income, increased habitat destruction, reduced government funding, increased plastic and other solid waste pollution, weakening of nature‐friendly regulations and their enforcement, increased illegal harvest of wild animals, reduced philanthropy, and threats to survival of conservation organizations. In combination, these impacts present a worrying future of increased threats to biodiversity conservation but reduced capacity to counter them. The highest ranking positive impact, at 10, was the beneficial impact of wildlife‐trade restrictions. More optimistically, among impacts ranked 11‐20, 6 were positive and 4 were negative. We hope our assessment will draw attention to the impacts of the pandemic and, thus, improve the conservation community's ability to respond to such threats in the future.

Understanding choice behavior towards plastic consumption: An emerging market investigation

Globally, plastic production and consumption have led to a large amount of plastic waste. Plastic solid waste poses a serious menace to the environmental wellbeing. Plastic pollution is a matter of great concern for planetary creatures as plastic consumption is detrimental to human and animal welfare. The present research investigates the empirical relationships among environmental concern, perceived consumer effectiveness, connectedness to nature, love for nature, and choice behavior for plastic consumption. The hypothesized relationships are conversant with the norm activation model (NAM), and the theoretical framework is based on the Biophilia Hypothesis. The research tested the hypotheses employing a covariance-based structural equation modeling. The cross-sectional data was collected via an online survey with 745 respondents from across the country, viz., India. The findings propose that environmental concern and perceived consumer effectiveness drive connectedness to nature and love for nature, with perceived consumer effectiveness being the critical construct in both conditions. Environmental concerns do not directly influence choice behavior, but perceived consumer effectiveness directly affects choice behavior. In comparison, perceived consumer effectiveness have the strongest effect on connectedness to nature and love for nature. In addition, connectedness to nature and love for nature partially mediate the relationship of environmental concern and perceived consumer effectiveness with choice behavior for plastic consumption in an emerging economy.

Combustion and emission characteristics of diesel engine fueled with nanocatalyst and pyrolysis oil produced from the solid plastic waste using screw reactor

In recent years, the concerns of non-biodegradable mixed plastic waste have been growing and resulting in strengthening of technologies devoted to convert waste into energy. This study examined the technique to extract plastic oil from mixed plastic, non-biodegradable waste. Further, the mechanical characteristics of plastic pyrolysis oil were done. Pyrolysis method was used to extract the oil from plastic waste with screw reactor and the chemical compounds and the characterization of this oil was analyzed. The Fe2O3 doped Al2O3 was dispersed to enhance the quality of Waste pyrolysis oil (PO) by ultrasonication. The performance and emission characteristics of various fuels at different load conditions were analyzed by conducting a series of tests in single cylinder 4 stroke water cooled diesel engine. The benefit of the addition of 25 ppm of Fe2O3 doped Al2O3 in PO was represented graphically. A series of tests was conducted for various brake mean effective pressure of 1.3 bar, 2.6 bar, 3.9 bar and 5.2 bar for the test blends, PO (neat pyrolysis oil) and P25A (25% PO+ 75% diesel with 25 ppm of Al2O3). From the procured results, the addition of the novel nanoparticles increases the production of brake power by 35% with reduced emission of 45% and 60% of HC and CO2 respectively. On the other hand, the NOx emission was reduced by 15% and 9 % than the neat plastic oil and diesel fuel. Further, the usage of the pyrolysis oil at 25% generated the positive effects on both combustion and emission compared to neat PO.

Recent Progress in Low-Cost Catalysts for Pyrolysis of Plastic Waste to Fuels

The catalytic and thermal decomposition of plastic waste to fuels over low-cost catalysts like zeolite, clay, and bimetallic material is highlighted. In this paper, several relevant studies are examined, specifically the effects of each type of catalyst used on the characteristics and product distribution of the produced products. The type of catalyst plays an important role in the decomposition of plastic waste and the characteristics of the oil yields and quality. In addition, the quality and yield of the oil products depend on several factors such as (i) the operating temperature, (ii) the ratio of plastic waste and catalyst, and (iii) the type of reactor. The development of low-cost catalysts is revisited for designing better and effective materials for plastic solid waste (PSW) conversion to oil/bio-oil products.

Influence of Pet Fiber Geometry on Properties of Concrete Using Partial Replacement of Fine Aggregate with Copper Slag

In the last few years with the growth of population, development of industry and technology there has been rapid increment in the waste materials and by-products production. The basic strategy to decrease solid waste and plastic waste bottle disposal problems have been focused at the reduction of waste production and retrieval of usable materials from waste as raw materials . In present study, the PET fibers were achieved by manually hand cutting from Kinley polyethylene terephthalate (PET) plastic drinking water bottles. Three different geometrical shape Straight shape fiber, Flattened shape fiber and ‘O’ shape polyethylene terephthalate (PET) fibers 0.5% by weight of cement were used. Fine aggregate were partially replaced with copper slag at percentages of 0%, 20%, 40% and 60%. Effect of different geometry of PET fiber and copper slag on fresh and hardened properties of concrete was investigated. Test result revealed that geometry of fiber and copper slag has good effect on fresh properties of concrete. Without use of super plasticizer workability was increasing. The combination of O shape fiber with 60% copper slag demonstrate enhancement in compressive strength, split tensile strength and flexural strength up to 25.85%,26.39% and 28.09% respectively compared to standard mix M 25 grade concrete. With the Increment of copper slag enhancement in strength was observed it was due to the friction developed between copper slag and PET fiber surface. Development of friction was due to the angularity of copper slag particles and bridging action of PET fiber. From water absorption test result it was concluded that water absorption is less in O shape fiber. It is due to the less water absorption properties of PET fiber and copper slag and also the O shape fiber provide good interlocking property in concrete matrices compare to other two geometrical shape fiber.

A STATE OF ART AND PROSPECTS OF PLASTIC SOLID WASTE MANAGEMENT

Basic data on the volume and structure of solid waste in the world and Ukraine are presented. The need to improve the ways of handling plastic solid waste as one of the most dangerous for the environment and promising from the point of view of using their properties is shown. A detailed classification of methods for handling plastic solid waste is proposed and a critical analysis of each of them is given. Particular attention is paid to the methods of disposal of plastic solid waste, in particular, recycling, which makes it possible to effectively use secondary plastic raw materials directly for their intended purpose. The features of physical, chemical, biological and combined processing methods are also considered, in particular combustion, gasification, pyrolysis, plasma decomposition of plastic solid waste, as well as their decomposition under the influence of sunlight and microorganisms. The main ways of solving the problem of plastic solid waste in Ukraine are proposed. Bibl. 83, Fig. 3, Tab. 3.