How to enhance agricultural plastic waste management in China?Insights from public participation

Agricultural plastics play a pivotal role in agricultural production.However,due to expensive costs,agricultural plastic waste management(APWM)encounters a vast funding gap.As one of the crucial stakeholders,the public deserves to make appropriate efforts for APWM.Accordingly,identifying whether the public is willing to pay for APWM and clarifying the decisions’driving pathways to explore initiatives for promoting their payment intentions are essential to address the dilemma confronting APWM.To this end,by applying the extended theory of planned behavior(TPB),the study conducted an empirical analysis based on 1,288 residents from four provinces(autonomous regions)of northern China.Results illustrate that:1)respondents hold generally positive and relatively strong payment willingness towards APWM;2)respondents’attitude(AT),subjective norm(SN),and perceived behavioral control(PBC)are positively correlated with their payment intentions(INT);3)environmental cognition(EC)and environmental emotion(EE)positively moderate the relationships between AT and INT,and between SN and INT,posing significant indirect impacts on INT.The study’s implications extend to informing government policies,suggesting that multi-entity cooperation,specifically public payment for APWM,can enhance agricultural non-point waste management.

Photocatalytic Degradation of Plastic Waste: Recent Progress and Future Perspectives

Microplastics are persistent anthropogenic pollutants that have become a global concern due to their widespread distribution and unfamiliar threat to the environment and living organisms. Conventional technologies are unable to fully decompose and mineralize plastic waste. Therefore, there is a need to develop an environmentally friendly, innovative and sustainable photocatalytic process that can destroy these wastes with much less energy and chemical consumption. In photocatalysis, various nanomaterials based on wide energy band gap semiconductors such as TiO2 and ZnO are used for the conversion of plastic contaminants into environmentally friendly compounds. In this work, the removal of plastic fragments by photocatalytic reactions using newly developed photocatalytic composites and the mechanism of photocatalytic degradation of microplastics are systematically investigated. In these degradation processes, sunlight or an artificial light source is used to activate the photocatalyst in the presence of oxygen.

Impact of Plastic Waste on the Human Health in Low-Income Countries: A Systematic Review

Background: Plastic pollution is the accumulation of waste composed of plastic and its derivatives all over the environment. Whether in the form of visible garbage or microparticles, as it slowly degrades, plastic pollution poses significant threats to terrestrial and aquatic habitats and the wildlife that call them home, whether through ingestion, entanglement or exposure to the chemicals contained in the material. Unfortunately, there is a lack of documentation on the impact of plastic waste on human health in low- and middle-income countries (LMICs). Methods: We searched five electronic databases (PubMed, Embase, Global Health, CINAHL and Web of Science) and gray literature, following the preferred reporting elements for systematic reviews and meta-analyses (PRISMA), for the impact of plastic waste on human health in developing countries. We included quantitative and qualitative studies written in English and French. We assessed the quality of the included articles using the Mixed Methods Appraisal tool (MMAT). Results: A total of 3779 articles were initially identified by searching electronic databases. After eliminating duplicates, 3167 articles were reviewed based on title and abstract, and 26 were selected for full-text review. Only three articles were retained. The three articles dealt with practices likely to lead to oral exposure to plastic chemicals in human health, as well as the level of awareness of participants concerning the possible impact of plastic on human health, namely, the use of plastic baby bottles, the use of microwaves to cook food and reheat precooked food, the use of plastic bottles to store water in the refrigerator, water purifier containers with plastic bodies and plastic lunch boxes, the reuse of plastic bags and the inadequacy of treatment facilities. Conclusion: Plastic waste poses different risks to human health at every stage of its life cycle. Hence, strategies must be adopted to raise public awareness of the dangers of plastic waste to their health. Trial registration: The review protocol is registered in the PROSPERO international prospective register of systematic reviews (ID = CRD42023409087).

Evaluation of the Influence of Plastic Waste in Improving the Mechanical Characteristics of Asphalt Mixes (Senegal, West Africa)

The recovery of plastic waste has a positive impact on two fronts: The environment, through waste reduction, and the economy, through its use in road construction. This work involves recycling plastic variants such as Polypropylene (PP) 50% and LDPE (Low Density Polyethylene) 50% in proportions of 2% to 8%, incorporated into a 0/14 BBSG. The results of the Marshall test gave stability values ranging from 826 to 1523 kg and creep values from 5.5 to 2.45 mm. The Duriez test gave r/R values ranging from 0.769 to 0.786, with water absorption percentages from 2.24% to 0.69%. The PCG test at 80 gyrations gave void percentages ranging from 11.9% to 5.23%. The rutting test gives a rutting depth percentage that drops at 30,000 cycles from 11.5% to 1.3%. This study shows a considerable increase in the mechanical characteristics of asphalt mixes by adding plastic waste.

Effect of Polyethylene Terephthalate Plastic Waste on the Physico-Mechanical and Thermal Characteristics of Stabilized Laterite Bricks

The present work investigated the effect of polyethylene terephthalate (PET) plastic waste on the physico-mechanical and thermal properties of cement-stabilized laterite bricks to see the durability of the modified bricks (CSLB). Samples were formulated by mixing laterite, cement, and different percentages of PET (0%, 3%, 5%, and 7%) by volume. The bricks were produced using the M7MI Hydraform standard interlocking block and kept in the shade for a curing period of 28 days. The addition of 3% to 5% PET to the laterite stabilized with 10% cement results in a decrease in both dry and wet compressive strength, which is determined using the Controlab compression machine. However, the obtained results are in concordance with the standards. The thermal conductivity of CSLB, determined using the box method with the EI700 measurement cell, decreases as the PET content of the mixture increases. A decrease in bulk density from 1.67 to 1.58 g/cm3 was observed.

Synthesis of Activated Carbon from Polyethylene Terephthalate(PET)Plastic Waste and Its Application for Removal of Organic Dyes from Water

Synthetic plastics are often considered to be materials that cannot be broken down by natural processes.One such plastic,polyethylene terephthalate(PET),is commonly used in everyday items but when these products are discarded,they can cause serious harm to the environment and human health.In this study,PET plastic waste was used to create activated carbon using a physical activation process that involved using CO2 gas.The researchers investigated the effects of different temperatures,carbonization,and activation times on the resulting activated carbon’s surface area.The activated carbon was then analyzed using scanning electron microscopy(SEM),X-ray diffraction(XRD),FTIR,and BET.The activated carbon created from PET plastic waste showed excellent absorption properties for methylene blue in aqueous solutions across a wide range of pH levels.By creating activated carbon from plastic waste,not only are environmental issues addressed,but high-value activated carbon is produced for environmental remediation purposes.

Estimation and prediction of plastic waste annual input into the sea from China

Marine plastic debris has been a pervasive issue since the last century, and research on its sources and fates plays a vital role in the establishment of mitigation measures. However, data on the quantity of plastic waste that enters the sea on a certain timescale remain largely unavailable in China. Here, we established a model using material flow analysis method based on life cycle assessment to follow plastic product from primary plastic to plastic waste with statistical data and monitoring data from accurate sources. This model can be used to estimate and forecast the annual input of plastic waste into the sea from China until 2020. In 2011, 0.547 3-0.751 5 million tons of plastic waste entered the seas in China, with a growth rate of 4.55% per year until 2017. And the amount will decrease to 0.257 1 to 0.353 1 million tons in 2020 under the influence of governmental management. The amount of plastic waste discharged from coastal areas calculated in this study was much larger than that from river, thus it is suggested to strengthen the governance and control of plastic waste in coastal fishery activities in China in order to reduce the amount of marine plastic waste input.

Looking for a Chinese solution to global problems:The situation and countermeasures of marine plastic waste and microplastics pollution governance system in China

As one of the top ten environmental problems to be solved in the world,marine plastic waste and microplastic pollution seriously affect the health of marine ecosystems and the sustainable development of Marine economies.It is necessary to promote the establishment of a scientific and systematic Marine plastic waste and microplastic pollution control system and take strong measures to fundamentally curb and reverse the trend of marine pollution intensification in China.This paper first explains the practical significance of marine plastic waste and microplastic pollution control from three aspects:the sustainable development of the blue economy,the structural upgrading of the pan-plastic industry,and the improvement of public health awareness.Secondly,the particularity of marine plastic waste and microplastic pollution control system is summarized from three aspects of formation mechanism,migration path and damage performance.Then,it identifies domestic and international governance strategies and action plans from the perspectives of mechanism,subject,object,and measures,summarizes existing problems in the existing marine plastic waste and microplastic pollution control system,and gives directions for future improvement.Finally,some countermeasures and suggestions are put forward to accelerate the construction of China’s marine plastic waste and microplastic pollution control system,including the formation of a cross sectoral integrated land and sea control system,a full life cycle waste management process,a multi-participation model for marine ecological and environmental governance,and a global marine pollution prevention and control system.

Advances in study of dehalogenation of plastic waste by pyrolysis

Several methods ofdehalogenation by pyrolysis were summarized in this paper. Some crucial academic problems have been brought forward after analyzing and comparing the technical character as well as dehalogenation efficiency of these methods, which should be emphasized in the future research.

Dechlorination Behavior of Mixed Plastic Waste by Employing Hydrothermal Process and Limestone Additive

The usage of plastic-impregnated waste derived solid fuel in conventional combustor is hindered by many technical factors, especially its organic chlorine content. In this paper, experimental study of hydrothermal treatment on mixed plastic waste using the mixture of polypropylene, polystyrene, polyethylene and polyvinyl chloride （PVC） has been performed to observe the dechlorination effect of hydrothermal treatment on the waste. The system was generally applying saturated steam at around 2.4 MPa in a stirring reactor for about 90 minutes. After undergoing the process, the organic chlorine in treated plastic waste was reduced to 1,700 ppm level while the inorganic chlorine content was increased, suggesting an organic chlorine conversion phenomenon to inorganic chlorine, accompanied with low pH due to dehydrochlorination process. Additional limestone （Ca（OH）2） in subsequent experiment showed that the similar phenomenon was occurred but with higher pH and lower chlorine content in the condensed water, suggesting the production of inorganic salt rather than hydrochloric acid. Laboratory scale experiment was also performed to confirm the dechlorination phenomena especially for PVC, and the result showed that the main parameter which affected the dechlorination phenomena was the amount of water in hydrothermal process rather than limestone addition. It is suggested that a combination ofhydrothermal process and alkali addition would produce a low-chlorine solid product from plastic waste, promoting its usage as alternative solid fuel.

An Experience from Japan:The Challenge to Establish a Plastic Waste Recycling-Based Society in Vietnam

As a result of expanding economies and a growing pattern of mass production,mass consumption,and mass disposal,these last decades have seen an increase in the discharge of domestic waste on a global basis.Used plastic products are frequently pathogen-contaminated,and ought to be handled as hazardous waste.We have learned that companies and policy makers in Vietnam want to transform plastic waste to value and to create its first zero plastic waste cities,but they struggle to make connections,especially across industries,material types and districts.This paper gives a prospective outlook on plastic waste management practices in Vietnam.Based on Japanese plastic waste recycling basic laws systematically,we also discuss and propose the future tasks to apply them in Vietnam.The initiative is expected to help governments,enterprises,and social organizations develop knowledge,capacity,policy planning and plans of action to reduce plastic waste pollution.

Influencing Factors of Plastic Waste Pollution Reduction in Kinshasa

Plastic products, e.g., plastic bags, plastic bottles, and other plastic materials are widely used in people’s daily life and industrial production worldwide since they are cheap, easy to get, and convenient for all-purpose of transportation or movement. The wide application of plastic products also brings a lot of problems. The significant adverse consequences include plastic waste pollution and waste of resources, which pose a high threat to social development and environmental protection. In this research, a social survey involving 267 people was conducted to examine how certain factors reduce plastic waste pollution in Kinshasa. Statistical Product and Service Solutions were employed to analyze the data gathered from the survey. The results indicate that all the factors or strategies for reducing plastic waste pollution have a significant positive impact on plastic waste pollution reduction. The environmental factors have the highest contribution to the control of plastic waste pollution with an impact of 88.8%, followed by Government policy with an impact of 42.3%. Economic factors have the least impact contribution, with an impact of 36.0%. This finding and conclusion could be used as a framework for implementing plastic waste pollution management strategies or developing waste management systems.

Adsorption of Indigo Carmine Dye by Composite Activated Carbons Prepared from Plastic Waste (PET) and Banana Pseudo Stem

This study is on the adsorption of indigo carmine dye by composite activated carbons prepared from banana pseudo stems and plastic waste. The activated carbons named TB1P1, TB1P1h and TB2P1 were obtained by pyrolysis at 700°C under steam of raw materials at different ratios (1:1 and 2:1). They were characterized by different techniques such as SEM/EDX, Raman Spectroscopy, FTIR, XRD, TGA/DTA and BET/BJH. Analyses indicate amorphous structures with specific surface areas of 424.37;385.45 and 338.84 m2/g for TB1P1, TB1P1h and TB2P1 respectively. The study of the adsorption of indigo carmine dye by these adsorbents was carried out by varying parameters such as contact time, mass of adsorbent and initial concentration of the dye. The maximum retention is 94.71%, 86.18% and 84.17% for TB1P1, TB1P1h and TB2P1 respectively after 60 min of stirring, for a pH = 4.6 using 0.6 g of adsorbents. The adsorption of indigo carmine follows well, the Langmuir model, with the most suitable kinetics as pseudo second order.

The Environmental Impact of Plastic Waste

The pollution caused by disposable plastic products is becoming moreand more serious, and “plastic limit” has become a global consensus. Thisarticle mainly discusses the pollution problem from the following aspects:Integrate all relevant important indicators to establish a multiple regressionmodel of the maximum amount of disposable plastic waste to estimatethe maximum amount of disposable waste in the future without causingfurther damage to the environment;Establish an environmental safety levelevaluation model and analyze the impact of plastic waste on environmentalsafety;Try to set the lowest level target that can be achieved by globalwaste at this stage, and conduct correlation analysis on the impact ofhumans, enterprises, and the environment;Select several countries basedon their comprehensive strengths, conduct a comparative analysis of theirplastic production, economic strength, and environment, and try to exploretheir responsibilities.

Chemical Plant Design for the Conversion of Plastic Waste to Liquid Fuel

This paper presents the plant design for fuel production from plastic waste. The types of plastics to be used for the fuel production include polyethylene, polypropylene and polystyrene. All these materials are to be sourced from Kpone landfill site in Accra, Ghana, where the plant is to be situated. The major fuels produced are gasoline, diesel and kerosene with a plant capacity of approximately 1000 tons of plastic waste per day and its attainment is 95%. The production process involves sorting the municipal solid waste to obtain suitable plastics. The plastics are extruded and cracked thermally in a Pyrolyzer and the gases from it are reformed over Zeolite-ZSM 5 as the catalyst in a reactor. Resulting vapours are fractionated in a column to obtain the various fuel components. The plant operates 24 hours/day and 347 days/year with 3 shifts per day of 8 hours per shift. Total capital required to build and start up the plant amounts to approximately 17 Million US Dollars. The plant life is 25 years with an annual rate of return of 34% and a payback period of 2.9 years for this project, after setting up. Annually, the plant would generate gross and net profits of approximately 9 Million US Dollars and 6.7 Million US Dollars respectively.

Re-Use of Hospital Plastic Waste in Asphalt Mixes as Partial Replacement of Coarse Aggregate

About 1.3 billion tons of waste is being generated in the world annually. This waste is a cause of various diseases. Open dumping of waste also destroys valuable agricultural land. Various researchers have beneficially used plastic waste in cement concrete and asphalt concrete in the past. This study aims at the use of aggregates, made from different types of plastic waste, as partial replacement of coarse aggregates in asphalt mixes. For this purpose waste is collected from different hospitals of the city. Sorted plastic from the waste consists of 64% low density polyethene, 32% high density polyethene and 4% of polypropylene. Plastic waste is shredded, heated and after cooling, pulverizes manually and mechanically. Specific gravity of plastic aggregates is 0.96. Water absorption and soundness values are 4.68% and 7.68% respectively. Impact, crushing and Loss Angeles values of plastic aggregates are 0.7%, 0.5%, and 1.1% respectively. Replacement of natural aggregates by plastic aggregates in asphalt mixes is done up to 25% with 5% incremental increase. Density of asphalt mixes decreases to 2060 kg/m3. Consequently flow increases to 5.73 mm. Maximum stability is at 20% replacement i.e. 34.57 KN. Cost analysis of the study indicates that 205% increase in stability are observed with 219% increase in cost.

Green Product of Liquid Fuel from Plastic Waste by Pyrolysis at 900 ℃

Alternative treatments to convert plastic waste into fuel currently receive great attention from researchers worldwide. The objective of the research is to obtain liquid fuel from pyrolysis of waste plastics that is safe for humans as well as environment, with a heating value and fuel quality meet the standardized compliant. The method used for the research is plastic waste pyrolysis heated at 900 ℃, and the resulting vapor is condensed through a crossflow condenser. The method resulted in a liquid fuel with a calorific value of 46,848 J/g, which is greater than that of plastic waste processing at a temperature of 425 ℃ that is only 41,870 J/g. In addition, the nature of current method for treating plastic waste is considered more secure than that of plastic waste processing at the temperature of 425 ℃. The reason for this is the fact that the percentage of compounds that could potentially be carcinogenic （boric acid and cyclopentanone） is reduced.

Studying the Utilization of Plastic Waste by Chemical Recycling Method

The rapid increase in the use of plastic materials in the recent years led to the accumulation of excessive amounts of plastic waste. The so-called thermoplastics such as PE, PP, PS, PVC and PET as well as materials that are derived from these are the type of plastic that is most used and consequently creates most of the waste. In this study, the original and waste forms of PE and PP plastic types have been chosen for thermal and catalytic degradation. As process parameter, 410oC - 450oC temperature interval and 600 mL/min constant flow rate nitrogen gas have been chosen as the carrier gas and the reaction time was considered to be 90 minutes for all experiments. Liquid products collected in experiments were separated by means of fractioned distillation process. For purposes of determining product distribution, the fractions, which were separated by distillation, were diluted in an appropriate solution for analysis of GC/MS. In the study conducted, it has been observed that the liquid product distribution obtained mainly consists of a mixture of saturated and unsaturated (heptane, heptane, octane, nonane, dodecane, etc.) hydrocarbons.

The effect of the concentration of plastic waste on the formation of reaction products of the Ti-PET system

The paper presents research results of the synthesis,phase composition,and structure of products obtained by highly exothermic reactions between Ti and C10H8O4mixture components,depending on the plastic waste concentration and Ti powder dispersiveness,density of initial samples,and synthesis medium.The dependence of the phase composition and structure of the synthesis products on the concentration of the polymer(plastic)component in the initial Ti-PET(C10H8O4)system was found.When the plastic waste content is 20 wt%to 25 wt%,synthesis products contain TiC0.5O0.5-TiC0.6-0.75particle agglomerates.Further growth in the polyethylene terephthalate content from 30 wt%to 45 wt%leads to the formation of synthesis products consisting of titanium carbide(TiC0.6-1.0).The gaseous byproduct composition of the exothermic reaction is investigated for the Ti--C10H8O4mixture composition.It is found that the gaseous by-product mostly contains hydrogen and carbon monoxide as well as impurities of different hydrocarbons(methane,acetylene,ethane,ethene)and carbon dioxide.The maximum adiabatic temperature of the gas combustion temperature is 2080℃,which demonstrates the possibility of using gas as a fuel for energy generation devices.Based on the data obtained,it is possible to create a basis for a new plastic waste technology to fabricate carbide-containing materials.

Electrocatalysis-driven sustainable plastic waste upcycling

With large quantities and natural resistance to degradation,plastic waste raises growing environmental concerns in the world.To achieve the upcycling of plastic waste into value-added products,the electrocatalytic-driven process is emerging as an attractive option due to the mild opera-tionconditions,highreactionselectivity,andlowcarbonemission.Herein,this review provides a comprehensive overview of the upgrading of plastic waste via electrocatalysis.Specifically,key electrooxidation processes including the target products,intermediates and reaction pathways in the plastic electro-reforming process are discussed.Subsequently,advanced electrochemical systems,including the integration of anodic plastic monomer oxidation and value-added cathodic reduction and photo-involved electrolysis processes,are summarized.The design strategies of electrocatalysts with enhanced activity are highlighted and catalytic mechanisms in the electrocatalytic oxidation of plastic waste are eluci-dated.To promote the electrochemistry-driven sustainable upcycling of plastic waste,challenges and opportunities are further put forward.