Challenges of plastic waste generation and management in sub-Saharan Africa: A review

An overview of waste management practices of street vendors in sub-saharan africa: A meta-analysis

Many low-income developing countries struggle with waste collection and the development of disposal facilities, leading to issues such as illegal dumping and poor enforcement of waste management regulations. The pollution caused by street vendors' waste is particularly evident in the central business districts of cities in developing nations. The informal economy, which includes activities such as street vending has become prevalent in developing countries, particularly in Sub-Saharan African (SSA) nations. This study aims to conduct a systematic review and meta-analysis of existing literature on street vendors' waste management practices in the region, with a focus on understanding the factors influencing waste mismanagement and identifying integrated strategies employed across SSA. In most SSA areas, research is conducted to evaluate food vendor hygienic practices (33%), however the waste management component, which is crucial to hygiene, makes up just 15%, which is twice as small as the research that focused on hygienic practices. As a result, street vendors in the majority of sub-Saharan nations have little interest in waste management procedures. Many street vendors in the region resort to informal waste disposal methods because of no access to formal waste management infrastructure since they are not recognised as formal businesses. The study acknowledges the street vendors' contribution to food security in developing Sub Saharan Africa, as well as the significance of comprehending their waste management practices. Despite their prevalence in urban areas, these informal businesses still face a lack of recognition and inclusion from governing bodies. Therefore, the study emphasises the necessity of incorporating street vendors into formal municipal waste management systems and providing them with enhanced infrastructure and services. Given that the lack of recognition subsequently make it challenging to integrate vendors into formal waste management systems. Subsequently this has a negative cumulative impact on developing and enforcing clear regulations that specify the responsibilities of street vendors in waste management. Thus, leading to the absence of comprehensive by laws regulations governing waste management for street vendors within Sub-Saharan Africa.

The role of Geographic Information Systems in mitigating plastics pollution in the Global South-A spatial analysis of recycling facilities in Costa Rica

Costa Rica is at the forefront of environmental conservation in Central America, with its focus on sustainability and green practices. Building on this foundation, the country joins a cohort of middle-income developing countries that have set forth ambitious goals to eliminate plastic pollution and become plastics-free. Recycling remains one of the most effective ways of removing plastic waste from the environment. Although GIS has been utilized in environmental research, its use is still expanding in developing countries of the Global South. These countries are experiencing unprecedented adverse climate and ecological impacts while also pursuing fundamental socioeconomic growth. The application of more cost-effective and strategic technological solutions, as well as data-driven decision-making, could fast-track the achievement of their urgent environmental goals. Using Geographic Information Systems (GIS) analysis, this study applies hot spot, location-allocation, and time-distance measures to examine Costa Rica's capacity to recycle plastic waste. Focusing specifically on availability and the public's access to recycling facilities, this article offers insights into the resource constraints and evolution of plastics governance in developing countries with environmentally-focused priorities. The findings of this study suggest that while Costa Rica is implementing progressive plastics regulatory policies, the ability to achieve plastics-free status is hampered by shortfalls in the number and distribution of recycling facilities and the public's access to recycling services. Expanding recycling infrastructure, including transportation, and adopting a less canton-centric waste administration system could contribute to resolving these challenges. This study contributes to discourses on global plastics governance and environmental change management in the Global South.

Meta-analysis of impacts of microplastics on plant heavy metal(loid) accumulation

The co-occurrence of microplastics (MPs) and heavy metal(loid)s (HMs) has attracted growing scientific interest because of their wide distribution and environmental toxicity. Nevertheless, the interactions between MPs and HMs in soil-plant systems remain unclear. We conducted a meta-analysis with 3226 observations from 87 independent studies to quantify the impact of MPs addition on the plant biomass and HMS accumulation. Co-occurrence of MPs and HMs (except for As) induced synergistic toxicity to plant growth. MPs promoted their uptake in the shoot by 11.0% for Cd, 30.0% for Pb, and 47.1% for Cu, respectively. In contrast, MPs caused a significant decrease (22.6%, 17.9-26.9%) in the shoot As accumulation. The type and dose of MPs were correlated with the accumulation of HMs. MPs increased available concentrations of Cd, Pb, and Cu, but decreased available As concentration in soils. Meanwhile, MPs addition significantly lowered soil pH. These findings may provide explanations for MPs-mediated effects on influencing the accumulation of HMs in plants. Using a machine learning approach, we revealed that soil pH and total HMs concentration are the major contributors affecting their accumulation in shoot. Overall, our study indicated that MPs may increase the environmental risks of HMs in agroecosystems, especially metal cations.

Recycling and reusing potential of disposable low-density polyethylene plastic waste for flexible paver tile construction for outdoor application

Plastic waste disposal has escalated into a serious global concern due to the non-biodegradable nature of plastics, which are composed of high-molecular-mass organic polymers along with other ingredients. Therefore, this study focuses on reusing and recycling LDPE plastic waste as a binding agent in paver tile production. This aligns with global sustainability goals by promoting resource efficiency and reducing waste generation. The investigation aims to address the environmental impact of plastic waste by finding sustainable solutions for its management. This includes exploring the feasibility and viability of using LDPE plastic waste in paver tile production as a means of recycling and reusing locally collected waste. The LDPE waste plastic collection, identification, milling, and melting at 170 °C. Subsequently, the sampled sand, sieved to a size of ≤0.75 mm, was blended with molten plastic in a specified proportion and then molded to create paving tiles using a hydraulic press machine. The researchers utilized response surface methodology (RSM) combined with Box-Benken designs (BBD) to optimize three key experimental parameters (plastic-to-sand ratio: 10 %, 25 %, 40 %; time: 2, 5, 8 min, pressure: 1, 3, 5 MPa) influencing mechanical properties of paver tiles, including water absorption (WA), flexural strength (FS), and compressive strength (CS). The result revealed that the optimal combination of 25 % waste plastic, 5 min, and 3 MPa of pressure resulted in a maximum flexural strength (FS) of 3.689 MPa and compressive strength (CS) of 4.141 MPa, with an average water absorption (WA) of 0.322 %. Therefore, the mechanical properties of the developed tiles met the desired standard. In conclusion, the mechanical qualities of the tiles were promising, indicating that reusing waste LDPE plastic to create paver tiles presents an appealing option for plastic waste disposal. The composite paver tiles exhibited promising attributes for outdoor applications, such as park pavement and outdoor public spaces, owing to their favorable mechanical properties and low water absorption.

Estimating plastic waste generation using supervised time-series learning techniques in Johannesburg, South Africa

In recent times, many investigators have delved into plastic waste (PW) research, both locally and internationally. Many of these studies have focused on problems related to land-based and marine-based PW management with its attendant impact on public health and the ecosystem. Hitherto, there have been little or no studies on forecasting PW quantities in developing countries (DCs). The key objective of this study is to provide a forecast on PW generation in the city of Johannesburg (CoJ), South Africa over the next three decades. The data used for the forecasting were historical data obtained from Statistics South Africa (StatsSA). For effective prediction and comparison, three-time series models were employed in this study. They include exponential smoothing (ETS), Artificial Neural Network (ANN), and the Gaussian Process Regression (GPR). The exponential kernel GPR model performed best on the overall plastic prediction with a determination coefficient (R2) of 0.96, however, on individual PW estimation, ANN was better with an overall R2 of 0.93. From the result, it is predicted that between 2021 and 2050, the total PW generated in CoJ is forecasted to be around 6.7 megatonnes with an average of 0.22 megatonnes/year. In addition, the estimated plastic composition is 17,910 tonnes PS per year; 13,433 tonnes PP per year; 59,440 tonnes HDPE per year; 4478 tonnes PVC per year; 85,074 tonnes PET per year; 34,590 tonnes LDPE per year and 8955 tonnes other PWs per year.

Plastic Venture Builder (PVB): An empirically derived assessment tool to support plastic waste management ventures in low- and middle-income countries

Plastic waste management is a complicated challenge that in recent years has gained attention as a global policy priority. In low- and middle-income countries (LMIC), waste management is heterogeneous and context-specific and many organizations provide needed waste management services, including entrepreneurs. Sustainable entrepreneurs are uniquely positioned to provide these services; however, they face challenges such as limited support system and lack of capacity. The goal of this paper is to understand critical characteristics of successful plastic waste management ventures in LMIC and operationalize those insights into a strategic tool. A wide variety of successful ventures from diverse LMIC contexts are systematically analyzed to identify which factors contribute to their business viability and ability to deliver services. The identified success factors were built into a tool, the Plastic Venture Builder (PVB), based on the multi-criteria analysis methodology. This is validated using empirical cases, tested on projects currently in development and discussed with experts in the field. The results show that political, economic, financial, technological, operational, social, team and legal factors contribute to success; however pathways to success are diverse. We identify a strong team as the most critical factor, whereas financial, political and social factors have the least impact. The PVB can be used by entrepreneurs who want to set up or improve plastic waste management ventures by identifying weak spots or avenues for improvement. The assessment framework can also be used by policy makers, development agencies and financing organizations who want to support or assess waste management initiatives by prioritizing their resources to match the identified critical factors.

Municipal solid waste management instruments that influence the use of the refuse as fuel in developing countries: A critical review

Landfills are the destination of most of the refuse generated whereas composting, material recycling, and Waste-to-Energy (WtE) technologies are not commonly employed in developing countries. However, the destination for energy purposes could be supplied with this refuse, improving the viability of energy use. Thus, this article raises some questions to identify aspects that could encourage its use as refuse-derived fuel (RDF) in these countries. Among them, does environmental education affect the municipal solid waste (MSW) source separation with emphasis on a destination? Can selective collection and extended producer responsibility (EPR) affect the MSW for energy recovery? Is there competition between the recycling market and the energy market for RDF? A systematic review of the literature was conducted to gather data and provide answers to such questions. This enabled to observe that EPR, selective collect expansion and source separation influence the quantity and quality of waste sent for energy use. Both internal and external factors impact on source separation. Additionally, there is evidence to support that despite several studies showing their technical, economic, environmental and social viability, the methods of energy usage of the refuse still need to improve their deployment in developing countries. In addition to identifying the main research gaps to be filled in future studies, the article also identified the instruments of MSW management that are to be applied in developing countries to divert recyclable and organic waste from landfill.

Evaluating the impact of China's MSW sorting pilot policy on urban sustainable development: Empirical evidence from 95 cities

The escalating challenge of municipal solid waste (MSW) critically tests the sustainable development capacities of urban centers. In response, China initiated pilot policies in 2017 aimed at bolstering MSW management. The effectiveness of these initiatives, however, necessitates empirical scrutiny. This study leverages panel data spanning 95 cities at the prefectural level or higher, covering the period from 2006 to 2020, to assess the impact of the MSW sorting pilot policy on urban sustainable development using a difference-in-differences approach. The research found that the MSW sorting pilot policy has significantly increased the processing volume of MSW, thereby enhancing the sustainable development capabilities of cities. Further, the study identifies augmented fixed asset investments as a key mechanism through which pilot cities have enhanced their MSW management capabilities. Notably, the policy's stimulative effects are more pronounced in less densely populated and economically lagging regions. These findings provide critical insights for developing nations in shaping MSW sorting strategies and advancing urban sustainability.

Designing a circular carbon and plastics economy for a sustainable future

The linear production and consumption of plastics today is unsustainable. It creates large amounts of unnecessary and mismanaged waste, pollution and carbon dioxide emissions, undermining global climate targets and the Sustainable Development Goals. This Perspective provides an integrated technological, economic and legal view on how to deliver a circular carbon and plastics economy that minimizes carbon dioxide emissions. Different pathways that maximize recirculation of carbon (dioxide) between plastics waste and feedstocks are outlined, including mechanical, chemical and biological recycling, and those involving the use of biomass and carbon dioxide. Four future scenarios are described, only one of which achieves sufficient greenhouse gas savings in line with global climate targets. Such a bold system change requires 50% reduction in future plastic demand, complete phase-out of fossil-derived plastics, 95% recycling rates of retrievable plastics and use of renewable energy. It is hard to overstate the challenge of achieving this goal. We therefore present a roadmap outlining the scale and timing of the economic and legal interventions that could possibly support this. Assessing the service lifespan and recoverability of plastic products, along with considerations of sufficiency and smart design, can moreover provide design principles to guide future manufacturing, use and disposal of plastics.

Enduring pathogenicity of African strains of Salmonella on plastics and glass in simulated peri-urban environmental waste piles

In low- and middle-income countries, plastic has become a major constituent of landfills and urban dump sites. Environmental plastic pollution can also provide a novel surface for the formation of microbial biofilm, which often includes pathogenic bacteria and viruses. Here, under conditions simulating a peri-urban waste pile typical of an African informal settlement, we aimed to determine if pathogenic Salmonella spp. can retain their virulence following a prolonged period of desiccation on the surfaces of environmental plastic and glass. We show that clinically (and environmentally) relevant strains of Salmonella including S. Enteritidis, S. Typhimurium and S. Typhi can persist on plastic and glass for at least 28-days and that temperature (which increases with the depth of an urban waste pile) is a key determinant of this survival. All three strains of Salmonella retained their pathogenicity (determined by using a Galleria mellonella model of infection) following their recovery from the plastisphere indicating that plastics in the environment can act as reservoirs for human pathogens and could facilitate their persistence for extended periods of time. Pathogens colonising environmental plastic waste therefore pose a heightened public health risk, particularly in areas where people are frequently exposed to plastic pollution.

Toxigenic Vibrio cholerae can cycle between environmental plastic waste and floodwater: Implications for environmental management of cholera

Globally, there has been a significant rise in cholera cases and deaths, with an increase in the number of low- and middle-income countries (LMICs) reporting outbreaks. In parallel, plastic pollution in LMICs is increasing, and has become a major constituent of urban dump sites. The surfaces of environmental plastic pollution can provide a habitat for complex microbial biofilm communities; this so-called 'plastisphere' can also include human pathogens. Under conditions simulating a peri-urban environmental waste pile, we determine whether toxigenic Vibrio cholerae (O1 classical; O1 El Tor; O139) can colonise and persist on plastic following a simulated flooding event. Toxigenic V. cholerae colonized and persisted on plastic and organic waste for at least 14 days before subsequent transfer to either fresh or brackish floodwater, where they can further persist at concentrations sufficient to cause human infection. Taken together, this study suggests that plastics in the environment can act as significant reservoirs for V. cholerae, whilst subsequent transfer to floodwaters demonstrates the potential for the wider dissemination of cholera. Further understanding of how diseases interact with plastic waste will be central for combating infection, educating communities, and diminishing the public health risk of plastics in the environment.

Synergistic and additive effects of microplastic, nickel and pyrene on survival, reproduction, and egestion of a tropical copepod

Coastal tropical ecosystems provide livelihood for millions of people but are at the same time exposed to an increasing intensity of diverse anthropogenic stressors, including pollution. Nevertheless, the combined effects of pollutants on marine ecosystems are poorly understood, particularly regarding lower trophic levels (plankton) and tropical ocean. We exposed the tropical copepod Centropages velificatus to 4-5 concentrations of a heavy metal (nickel), an oil compound (pyrene) and microplastic (PET), either alone or in combination, and measured their egestion, reproduction, and mortality rates. Microplastic alone did not have any effect on pellet or egg production of copepods, whereas nickel reduced egg production rate at concentrations ≥1 µg L-1 and pyrene reduced both egg and pellet production rates at concentrations ≥1 nM. The addition of nickel and pyrene to PET - microplastic resulted in a reduction similar to one caused by nickel or pyrene alone, suggesting an additive effect. In contrast, a combination of nickel and pyrene had a synergistic effect, with a strong reduction in survival, egg and pellet production. Our results suggest that combinations of contaminants that are commonly found in tropical coastal waters have detrimental effects on copepods-the crucial link in the pelagic food web-at lower concentrations than suggested by single stressor studies. This can have an influence on the food web productivity - the basis of fisheries that local communities rely on.

Transdisciplinary pragmatic melioration for the plastic life cycle: Why the social, natural, and technical sciences should prioritize reducing harm

Plastics underpin modern society but also threaten to choke it. Only 9 % of all plastic waste is recycled, usually with loss of quality ("downcycling"); the rest is landfilled or dumped (79 %) or incinerated (12 %). Put bluntly, the "plastic age" needs a "sustainable plastic culture." Consequently, we urgently need to develop a global and transdisciplinary approach not only to fully recycle plastics but also to manage the harms across their life cycle. The past decade has witnessed an explosion in research on new technologies and interventions that purport to help solve the plastic waste challenge; however, this work has, in most cases, been carried forward within single disciplines (for example, researching novel chemical and bio-based technologies for plastic degradation, engineering processing equipment innovations, and mapping recycling behaviours). In particular, although there has been vast progress within individual scientific fields, such work does not address the complexities of various plastic types and waste management systems. Meanwhile, research on the social contexts (and constraints) of plastic use and disposal is rarely in conversation with the sciences to drive innovation. In short, research on plastics typically lacks a transdisciplinary perspective. In this review, we urge the adoption of a transdisciplinary approach that focuses on pragmatic melioration; such an approach combines the natural and technical sciences with the social sciences to focus on the mitigation of harms across the plastic life cycle. To illustrate our case, we review the status of plastic recycling from these three scientific perspectives. Based on this, we advocate 1) foundational studies to identify sources of harm and 2) global/local interventions aimed at those plastics and aspects of the plastic life cycle that cause maximal harm, both in terms of planetary welfare and social justice. We believe this approach to plastic stewardship can be a showcase for tackling other environmental challenges.

Plastics and Micro/Nano-Plastics (MNPs) in the Environment: Occurrence, Impact, and Toxicity

Plastics, due to their varied properties, find use in different sectors such as agriculture, packaging, pharmaceuticals, textiles, and construction, to mention a few. Excessive use of plastics results in a lot of plastic waste buildup. Poorly managed plastic waste (as shown by heaps of plastic waste on dumpsites, in free spaces, along roads, and in marine systems) and the plastic in landfills, are just a fraction of the plastic waste in the environment. A complete picture should include the micro and nano-plastics (MNPs) in the hydrosphere, biosphere, lithosphere, and atmosphere, as the current extreme weather conditions (which are effects of climate change), wear and tear, and other factors promote MNP formation. MNPs pose a threat to the environment more than their pristine counterparts. This review highlights the entry and occurrence of primary and secondary MNPs in the soil, water and air, together with their aging. Furthermore, the uptake and internalization, by plants, animals, and humans are discussed, together with their toxicity effects. Finally, the future perspective and conclusion are given. The material utilized in this work was acquired from published articles and the internet using keywords such as plastic waste, degradation, microplastic, aging, internalization, and toxicity.

Assessing the economic and ecological viability of generating electricity from oil derived from pyrolysis of plastic waste in China

The increased plastic waste generation worldwide poses ponderous issues for public health and the environment. China is the highest generator of plastic waste around the world. The current treatment process (incineration) of the increased plastic waste causes dangerous environmental consequences. Pyrolysis has recently surfaced as an ecologically friendly technique for energy and material recovery from plastic waste. The present study assesses the financial and ecological viability of power production from oil derived from the pyrolysis of mixed plastic wastes in China from 2009 to 2028. The prominent findings show that the amount of plastic waste collected in 2020 (24.16 Mt) increased by 53.19% in 2028.The pyrolysis of mixed plastic wastes during the project period yielded 359.29 Mt oil, which has a power potential of 1,060.86 GWh. The economic analysis indicated the project is viable and profitable with a positive net present value (US$8.80 million) and profitability index (1.26) greater than 1. The project has 10.6 y payback period, US$0.0752/kWh levelized cost of energy, 22.5% return on investment, and 13.0% internal rate of return. The life cycle assessment results show that conversion of mixed plastic waste to pyrolysis oil for electricity generation during the project period has a total global warming potential (GWP) of 1,311.4 kt CO2eq. The GWP is mainly from conversion of pyrolysis oil to electricity (73.42%), pyrolysis oil production (15.01%) and upgrading of pyrolysis oil (11.38%). The consumption of power from the project could avoid the combustion of 2,659.0 t coal, minimizing global warming by 11,278.8 kt CO2eq. Sensitivity analysis, which examines the influence of variation in sensitive factors on the success of the project, is presented. This paper provides scientific strategies for optimal investment and decision-making on the environmental sustainability of plastic waste-to-energy pyrolysis projects.

Selection of the final solid waste disposal site in the Bolgatanga municipality of Ghana using analytical hierarchy process (AHP) and multi-criteria evaluation (MCE)

The various components of Municipal Solid Waste (MSW) such as collection, sorting, transportation, and disposal have their peculiarities and challenges. However, final disposal sites, generally referred to as landfill sites, present a complex difficulty. The aggregation of the problems of other components has consequences on the microenvironment, public health, and groundwater. Final disposal of MSW, site selection, and management presents an enormous burden for most Metropolitan, Municipal, and District Assembly (s) in Ghana. The case of Bolgatanga Municipality is similar to many others in the Upper East region in particular and Ghana as a whole. The existing landfill site is improperly sited and poses a great danger to adjoining communities. In this work, we used the Analytical Hierarchy Process (AHP) in a G.I.S. suite and Multi-Criteria Evaluation to assess the current location and select a possible new site within the municipality. The criteria used are generally environmental and socio-economic parameters, including; distance from major roads, rivers, settlements, and the selection of an appropriate slope and soil type that suits the guidelines for the siting of a landfill. The outcome of this multi-criteria assessment is the selection of a new site far from the current disposal site indicating the inappropriate location of the current site. A combination of all weighted criteria through a model builder process produced a suitability index map for candidate landfill sites. The selected site at Sherigu is about 16 km by road from the proposed site, which is much bigger than the threshold of 500 sq. meters. The separation distance and size between the current and the proposed site are indications of how economically and environmentally inappropriate the Sherigu site is and the need for a better site that is better situated for socio-economic and environmental considerations.

Microbial Enzyme Biotechnology to Reach Plastic Waste Circularity: Current Status, Problems and Perspectives

The accumulation of synthetic plastic waste in the environment has become a global concern. Microbial enzymes (purified or as whole-cell biocatalysts) represent emerging biotechnological tools for waste circularity; they can depolymerize materials into reusable building blocks, but their contribution must be considered within the context of present waste management practices. This review reports on the prospective of biotechnological tools for plastic bio-recycling within the framework of plastic waste management in Europe. Available biotechnology tools can support polyethylene terephthalate (PET) recycling. However, PET represents only ≈7% of unrecycled plastic waste. Polyurethanes, the principal unrecycled waste fraction, together with other thermosets and more recalcitrant thermoplastics (e.g., polyolefins) are the next plausible target for enzyme-based depolymerization, even if this process is currently effective only on ideal polyester-based polymers. To extend the contribution of biotechnology to plastic circularity, optimization of collection and sorting systems should be considered to feed chemoenzymatic technologies for the treatment of more recalcitrant and mixed polymers. In addition, new bio-based technologies with a lower environmental impact in comparison with the present approaches should be developed to depolymerize (available or new) plastic materials, that should be designed for the required durability and for being susceptible to the action of enzymes.

Plastic Waste: Challenges and Opportunities to Mitigate Pollution and Effective Management

The present world is now facing the challenge of proper management and resource recovery of the enormous amount of plastic waste. Lack of technical skills for managing hazardous waste, insufficient infrastructure development for recycling and recovery, and above all, lack of awareness of the rules and regulations are the key factors behind this massive pile of plastic waste. The severity of plastic pollution exerts an adverse effect on the environment and total ecosystem. In this study, a comprehensive analysis of plastic waste generation, as well as its effect on the human being and ecological system, is discussed in terms of source identification with respect to developed and developing countries. A detailed review of the existing waste to energy and product conversion strategies is presented in this study. Moreover, this study sheds light on sustainable waste management procedures and identifies the key challenges to adopting effective measures to minimise the negative impact of plastic waste.

Particulate plastics in drinking water and potential human health effects: Current knowledge for management of freshwater plastic materials in Africa

Plastic materials have contributed to the release of environmentally relevant particulate plastics which can be found almost everywhere and may be present in drinking water. Human exposure to these materials is diverse and our understanding of their internalization in the human body is incipient. This review discusses the state of knowledge of particulate plastics exposure in drinking water and the potential risks of adverse health in the human body. Particulate plastics have problematized water systems worldwide, and about 4,000,000 fine plastics may be ingested from drinking water annually by an individual. Testing methods for these materials in environmental media are presently inconsistent and standard protocols do not exist. Their potential ecotoxicological consequences are recognised to be linked to their physicochemical diversity, biological transpositions, and cytological tolerance in living organisms. It is observed that toxicological endpoints are varied and lack properly defined modes of action. In particular, fine particulate plastics have been observed to translocate into body tissues and cells where they are capable of provoking endocrine disruption, genetic mutations, and cancer responses. We propose a reclassification of particulate plastics to cater for their biological deposition and attributable risks of adverse health. Environmental management of particulate plastics in many developing countries is weak and their potential releases into drinking water have received limited research. Given that large populations are exposed to fresh surface water and plastic packaged drinking water worldwide, and that the risk assessment pathways are unvalidated at the moment, we argue for developing countries to increase their capacity for the environmental monitoring and circular management of plastic materials. Large-scale epidemiological cohort studies and surrogate assessment pathways are also recommended to provide a better understanding of the hazard characterization of particulate plastics exposure.

Consumer Perceptions of the Use of Nondegradable Plastic Packaging and Environmental Pollution: A Review of Theories and Empirical Literature

Studying people’s perceptions of their attitudes and behaviour toward the use and inappropriate disposal of plastics is necessary because it helps explain the meaning of sustainable environmental behaviour in the context of African countries. Formulating appropriate behavioural change interventions may lead to a shift in people’s behaviour in terms of plastic consumption if they become aware of the environmental risk of plastics. Using a qualitative review of literature, relevant materials for this paper were identified using a search strategy that involved keywords and databases. Previous empirical studies employed several theoretical frameworks. However, inconsistences in the use and definition of variables, make comparing the results of these studies difficult. Although the literature is growing, more empirical evidence is still needed to understand the drivers of people’s perceptions toward unsustainable environmental behaviour in the context of African countries and to formulate appropriate behavioural change interventions. A review of the literature determined four broad drivers of people’s perceptions toward unsustainable environmental behaviour. These include policy or institutional variables, product and market attributes, community variables, and individual characteristics. Additionally, we offer a consolidated conceptual framework for analysing consumer perception in relation to the use of nondegradable plastics and environmental pollution and identify the drivers of people’s perceptions. Policy implications for developing countries as well as future research directions are flagged.

Plastic waste management: A road map to achieve circular economy and recent innovations in pyrolysis

The contemporary world is challenged by mounting of plastic waste on the environment due to increase in economy and population. Over 90% of virgin plastics are produced from fossil fuels, hence, recycling is the best solution to reduce extracting and exploiting fossil fuels, and grow towards a circular economy. The type of waste and its hierarchy offers a route to pick up proper waste recycling policies which get the most out of the available resources and its protection. Pyrolysis process offers more valuable ways to turn the plastic waste to useful products for fueling and raw materials for making new plastics, and acts as an environmentally sound alternative to incineration and inefficient landfilling. This study provides a basic insight into plastic pyrolysis technology with recent trends and innovations in various countries, and their path towards the achievement of a circular economy. Plastic manufacturers, waste managers and the public plays a vital role in the development of the recycling sector. Recycling will stay underdeveloped and borderline without specific regulations to increase its effectiveness. Sustainable development in managing the plastic would be possible only through significant policies to instruct the individual and social challenges. The current article also targets the readers without scientific knowledge to get a basic idea of pyrolysis and general awareness of proper plastic waste management in a closed loop system.

Mapping the environmental impacts and policy effectiveness of takeaway food industry in China

The takeaway food industry, involving more than 0.4 billion consumers in China, has brought mass of packaging waste and salient environmental burden. Here we mapped the distribution of takeaway food industry across China including the industry scale, diet structure and order time based on the analysis of more than 35 million takeaway food orders. The real use situation of various packaging materials in the takeaway food industry market has been clarified. The life cycle assessment of "a piece of takeaway food delivery order" has been carried out in different regions. Results show that in addition to plastic waste generation, takeaway food industry causes more types of environmental impacts. In terms of the national resource consumption, greenhouse gases emission, water pollution and health damage risk, the top 5 ranked provinces in each accounted for 44%, 48%, 43% and 49%, respectively. Under the latest Chinese plastic pollution control policy, the industry needs to reduce 1.12 million tons of non-degradable plastic packaging by the end of 2025, and 65% of the pressure is clustered in the metropolis and provincial capitals. However, without targeted and regionally differentiated plastic pollution control policies, the environmental impact control of takeaway food industry is still ineffective. It is urgent to explore the control measures applicable to different regions. Overall, packaging reduction is more effective than material substitution.

Macro problems from microplastics: Toward a sustainable policy framework for managing microplastic waste in Africa

Microplastic pollution is a ubiquitous and emerging environmental and public health concern in Africa due to increased plastic production, product and waste importation, and usage. While studies on the environmental monitoring and characterization of microplastics demonstrated the urgent need for a drastic reduction in plastic waste generation, the effectiveness of the various regulatory and policy interventions implemented or proposed in Africa countries remains poorly understood. We critically examined policies, legislations, and regulations enacted to control microplastic pollution in Africa to develop a sustainable, harmonized framework for the coordinated reduction of plastic waste generation across Africa. Analysis of the interventions revealed most African countries employed traditional perspective (i.e., command-and-control) approaches, whereby state instruments such as plastic ban, production and importation levies, and consumer taxes were enacted. However, the continued increase in microplastic waste generation suggests traditional perspective approaches might not be effective in Africa. Although rarely used in Africa, market-oriented approaches such as private-public waste management are often effective in controlling plastic pollution. Hence, we proposed a bottom-up hybrid regulatory approach for managing microplastics pollution in Africa, involving price-based, right-base, legislation and behavioral frameworks based on best practices in microplastic waste management.

Separation of virgin plastic polymers and post-consumer mixed plastic waste by sinking-flotation technique

The main objective of this research is to separate virgin polymers (PA, PC, PP, HDPE; PS, and ABS) and post-consumer plastic waste from municipal solid waste (MSW) using the sinking-flotation technique. Separation was carried out on a pilot scale in an 800-l useful volume container with 160 rpm agitation for one hour. Tap water, ethanol solutions, and sodium chloride at different concentrations were used as densification medium. Virgin polymers were separated into two groups: low-density (HDPE and PP) and high-density polymers groups (PS, ABS, PA, and PC). Polymers whose density was less than that of the medium solution floated to the surface, while those whose density was greater than those of the medium solution sank to the bottom. The experimental results showed that complete separation of HDPE from PP achieved 23% ethanol v/v, whereas high-density polymers separated up to 40% w/v sodium chloride. Polymer recovery ranged from 70 to 99.70%. In post-consumer recycled plastic waste, fractions of 29.6% polyolefins, 37.54% PS, 11% ABS, 8% PA, 12% PC PET, and PVC were obtained. Finally, cast plates were made of the post-consumer waste to properly identify the polymer type present in the separated fractions.

Conversion of Plastic Waste into Supports for Nanostructured Heterogeneous Catalysts: Application in Environmental Remediation

Plastics are ubiquitous in our society and are used in many industries, such as packaging, electronics, the automotive industry, and medical and health sectors, and plastic waste is among the types of waste of higher environmental concern. The increase in the amount of plastic waste produced daily has increased environmental problems, such as pollution by micro-plastics, contamination of the food chain, biodiversity degradation and economic losses. The selective and efficient conversion of plastic waste for applications in environmental remediation, such as by obtaining composites, is a strategy of the scientific community for the recovery of plastic waste. The development of polymeric supports for efficient, sustainable, and low-cost heterogeneous catalysts for the treatment of organic/inorganic contaminants is highly desirable yet still a great challenge; this will be the main focus of this work. Common commercial polymers, like polystyrene, polypropylene, polyethylene therephthalate, polyethylene and polyvinyl chloride, are addressed herein, as are their main physicochemical properties, such as molecular mass, degree of crystallinity and others. Additionally, we discuss the environmental and health risks of plastic debris and the main recycling technologies as well as their issues and environmental impact. The use of nanomaterials raises concerns about toxicity and reinforces the need to apply supports; this means that the recycling of plastics in this way may tackle two issues. Finally, we dissert about the advances in turning plastic waste into support for nanocatalysts for environmental remediation, mainly metal and metal oxide nanoparticles.

Plastic Pollution, Waste Management Issues, and Circular Economy Opportunities in Rural Communities

Rural areas are exposed to severe environmental pollution issues fed by industrial and agricultural activities combined with poor waste and sanitation management practices, struggling to achieve the United Nations’ Sustainable Development Goals (SDGs) in line with Agenda 2030. Rural communities are examined through a “dual approach” as both contributors and receivers of plastic pollution leakage into the natural environment (through the air–water–soil–biota nexus). Despite the emerging trend of plastic pollution research, in this paper, we identify few studies investigating rural communities. Therefore, proxy analysis of peer-reviewed literature is required to outline the significant gaps related to plastic pollution and plastic waste management issues in rural regions. This work focuses on key stages such as (i) plastic pollution effects on rural communities, (ii) plastic pollution generated by rural communities, (iii) the development of a rural waste management sector in low- and middle-income countries in line with the SDGs, and (iv) circular economy opportunities to reduce plastic pollution in rural areas. We conclude that rural communities must be involved in both future plastic pollution and circular economy research to help decision makers reduce environmental and public health threats, and to catalyze circular initiatives in rural areas around the world, including less developed communities.

Blockchain Technology for Governance of Plastic Waste Management: Where Are We?

Blockchain technology is emerging as a plausible disruptor of waste management practices that influence the governance of plastics. The interest among the waste management community in the potential and fundamental changes to complex resource management associated with blockchain adoption parallels recent research in other sectors, such as finance, health, public administration, etc. During any comparable period characterized by a step-change in positive coverage of an early-stage technology, it can be challenging for actors to access a grounded, evidence-based oversight of the current state of practice and make informed decisions about whether or how to adopt blockchain technology. The current absence of such a systematic overview of recent experiences with blockchain initiatives disrupting waste practices not only limits the visibility of these experimental efforts, but also limits the learning that can be shared across waste plastics researcher and practitioner communities. This paper contributes with a current overview of blockchain technology adoption in the waste management sector, giving particular attention to implications for the governance of plastics. Our study draws on both primary interview data and secondary documentation data to map the landscape of current blockchain initiatives in the global waste sector. We identify four areas of blockchain use that are beginning to change waste management practices (payment, recycling and reuse rewards, monitoring and tracking of waste, and smart contracts). We conclude by outlining five areas of significant blockchain uses, implications, and influences of relevance to the development of circular plastic waste governance in both research and practice.

Cost benefit analysis of a municipal solid waste recycling facility in Soweto, South Africa

Rapid population and economic growth, changes in consumption pattern etc. have become major contributing factors to severe municipal solid waste generation globally. Thus, various methods are being employed to manage the incessant municipal solid waste generation for a sustainable solid waste management and one of the viable approaches is the recycling option. The main objective of this paper is to determine the cost benefit analysis of setting up a recycling facility for the processing of various wastes for use as raw materials by industries. The cost benefit analysis was carried out based on historic data obtained from the municipality and some recent waste composition data. The overall analysis was done using Excel software. From the Excel software analysis, Internal Rate of Return on investment was 42%, Internal Rate of Return on equity was 98% and Net Present Value was R 63, 420,000 (USD$ 4646225.33). In ascertaining the result obtained from the Microsoft Excel, three data analysis and technical computing software (MATLAB, Python, and R-Studio) were employed. This was necessary to compare and validate the cost-benefit indicators (Net Present Value and Internal Rate of Return). Besides, evaluating the performance of each software with regards to the cost-benefit evaluation is ideal for a recycling plant like this to establish the feasibility of the project. Moreover, sensitivity analysis was conducted, and a breakeven point of 211 tons of waste was obtained. In addition, the total benefit of recycling was valued and was given as R 486,008,582.85 (USD$ 35605572.16). From the overall analysis, it was observed that the IRR and Net Present Value were alike, about 677 potential jobs could be created on the project and the Net Present Value > 0. Based on the overall analysis, it was concluded that the project is viable.

Durability Assessment and Microstructure of High-Strength Performance Bricks Produced from PET Waste and Foundry Sand

Fired clay brickwork in buildings is prone to cracks and deterioration upon exposure to long-time acidic contamination and water absorption, hence decreasing the bearing capacity of masonry walls. As its contribution toward resolving this challenge, this study assessed the durability and morphological characteristics of high-strength performance bricks produced from a mixture of PET waste (PW) and foundry sand (FS). The PET waste bricks (PWBs) were produced through different proportioning (PW: FS) of 20%, 30%, and 40% of the dry mass of FS. The PWBs produced were tested for durability and compressive and tensile strengths and compared to fired clay bricks to evaluate their load-bearing capacity under compression and tension. Furthermore, scanning electron microscopy (SEM) tests were employed to analyze the morphological structure of the bricks. The test results revealed that the PWBs recorded an appreciable strength of 1.5–2 times that of fired clay bricks, and lower water absorption whilst retaining their ultimate strengths after complete immersion in water and acidic concentrations. The morphology of PWB possessed greater intercluster bonds on the surface compared to clay bricks. The findings demonstrate a reasonable methodological approach toward the production of masonry bricks using a mixture of PET waste and spent foundry sands.

Reverse logistics models for the collection of plastic waste: A literature review

To support the understanding of recycling models applied to plastics, the main objective of this work is to offer a literature review of the different reverse logistics (RL) models for collecting plastic waste (PW). The methodology used for processing the scientific literature was content analysis, using the google scholar search engine. The main keywords used were RL and PW. This article is divided into two parts: the first part discusses the development of circular economy models and RL networks and raises the conceptual framework of the research, and the second part presents mathematical models and exploratory studies, proposed as a solution for RL problems of PW. Articles published between years 2014 and 2019 were reviewed. In total, 102 references were used, 70 of them are part of the literature review. According to our findings, we can state that the most widely used solution method for mathematical modeling is mixed-integer linear programming, and for exploratory studies, it was evaluations. About 93% of studies evaluated raw materials related to PW; only 13% of studies had models with stochastic processes; and 88% of the investigations used continuous variables, being the multiobjective functions one of the most used to provide solutions to RL problems. Regarding the mathematical models, 49% were evaluations, 9% corresponded to multicriteria analysis, 29% to linear and nonlinear programming, and 4% to another type of evaluation or model.

The Management of Polymer and Biodegradable Composite Waste in Relation to Petroleum-Based Thermoplastic Polymer Waste—In Terms of Energy Consumption and Processability

The article presents a comparative analysis of the flow and utilisation of biodegradable polymer waste in relation to the waste of petroleum-based thermoplastic polymers. It compares energy expenditures and the costs of the reutilisation of both types of plastics in industrial applications. The performed studies and an analysis of the yielded results enabled the acquisition of real data involving the subject of managing petroleum-based plastic waste after the end of its life cycle, as well as biodegradable plastic waste, over the recent years, which is the main purpose of the study. So far, this subject has not been analysed very frequently, and, considering climate change, the predatory economy and the growing population of our planet, it is becoming an important topic, within the scope of which it is necessary to develop a new approach and new solutions regarding legal regulations and social awareness, as well as the technological possibilities of their implementation. The authors’ own research will indicate factual results related to managing various types of waste, based on the example of data acquired from a company involved in the retreatment of plastics and give answers to bothering questions such as: Is there an impact of retreatment on technological indicators defined by means of the mass flow rate? Is the retreatment of biodegradable plastics justified in terms of economy, energy and ecology? Is the retreatment of biodegradable plastics efficient?

Lab-Scale Study of Temperature and Duration Effects on Carbonized Solid Fuels Properties Produced from Municipal Solid Waste Components

In work, data from carbonization of the eight main municipal solid waste components (carton, fabric, kitchen waste, paper, plastic, rubber, paper/aluminum/polyethylene (PAP/AL/PE) composite packaging pack, wood) carbonized at 300–500 °C for 20–60 min were used to build regression models to predict the biochar properties (proximate and ultimate analysis) for particular components. These models were then combined in general models that predict the properties of char made from mixed waste components depending on pyrolysis temperature, residence time, and share of municipal solid waste components. Next, the general models were compared with experimental data (two mixtures made from the above-mentioned components carbonized at the same conditions). The comparison showed that most of the proposed general models had a determination coefficient (R²) over 0.6, and the best prediction was found for the prediction of biochar mass yield (R² = 0.9). All models were implemented into a spreadsheet to provide a simple tool to determine the potential of carbonization of municipal solid waste/refuse solid fuel based on a local mix of major components.

Plastic credit: A consortium blockchain-based plastic recyclability system

By the end of 2015, approximately 6300 million tons (Mt) of plastic waste had been generated globally, but less than 10% of plastics was recycled. Since different types of plastics have various degrees of recyclability, consumer information about plastic product recyclability is paramount in order to increase the levels of plastic recycled. Against this context, the objective of this work is to define a plastic credit system to increase the amount of recyclable plastics. The plastic credit system assigns credit information to each plastic product and its corresponding company based on the percentage recyclability value of the plastic type and its composition. The methodology proposed is based on a unified and transparent credit system established by a double-chain system, which comprises a public blockchain CreditChain and a consortium blockchain M-InfoChain. The results show through the overall system performance analysis that the designed plastic credit system is capable of promoting a demand shift towards plastic products with higher plastic recyclability and achieving a lightweight operation for resource requirements and system maintenance.

Improving urban household solid waste management in developing countries based on the German experience

Countries worldwide strive to improve their urban household solid waste management (UHSWM) practices. While developed countries like Germany have achieved good results with different UHSWM initiatives, developing countries still struggle to be effective with their waste management (WM) policies. With an interest in learning from the German experience, this paper provides a cross-case analysis between a German and a Brazilian city that can be of practical relevance to improving UHSWM in developing countries. The paper uses "process flow diagram" (PFD) and "wasteaware benchmark indicators" for integrated sustainable waste management (ISWM). Both methods confirmed the German city as a benchmark and attested the inefficiency of the Brazilian UHSWM. The total maximum score weightage percentage of the matrix quantification difference was significant, 98% against 50%. Findings highlight viable solutions based on the three pillars of the German solid WM system: clear laws, regular public campaigns, and fee methodology. The formalization and improvement of Brazilian UHSWM require better governance to obtain additional investments. Herein, the application of the Green Dot methodology, sponsored by industry and consumers in Germany, would enable an increase of up to 318% of the values received by a typical Brazilian cooperative. This additional investment can empower a sustainable solution where the population could opt to work with recycling, either as a formal employee or as a formal entrepreneur, shedding more light on the social pillar of the triple bottom line. Moreover, it can enable improvements in technologies, and on regular public campaigns to increase education in important sustainable matters.

Environmental impacts characterization of packaging waste generated by urban food delivery services. A big-data analysis in Jing-Jin-Ji region (China)

Controversies on food delivery services environmental impacts have been sparked due to the growth of this economic sector. This study focuses on the environmental impacts generated by packaging waste related to urban food delivery services. In particular, the Python based web-crawling and sample survey methods are used for big data mining, and LCA-based environmental impacts evaluation and Kernel density analysis methods are combined to determine the positioning trend of food delivery service providers and expansion direction of environmental pollution load in Jing-Jin-Ji region (North China). Results indicate that (1) food delivery service packages presently account for a very small proportion (<0.1%) of municipal solid waste (MSW). However, this study also evidences that food packaging accounts for 15.7% of the total MSW generated in this region. Even if this growing market sector might have a relatively low impact, households' lifestyle might affect the results. (2) In terms of consumption quantity, plastic bags are the most used packages, accounting for 35.08%; wooden chopsticks account for 32.21% and plastic boxes account for 27.43%. Among all environmental impact categories resulting from the process of production of packages, greenhouse effect is the most distinct one. Paper boxes generate the most serious environmental pollution. (3) The distribution of environmental pollution loads resulting from food delivery service packages positively correlates with the distribution of food delivery service providers in Jing-Jin-Ji. Shijiazhuang has the highest degree of pollution resulting from food delivery service packages with the interrupt value ratio of 80%, followed by Baoding City and Chengde City, which have the interrupt value ratios of 65.1% and 48.6%, respectively. Finally, as bridges between food delivery service providers and consumers, food delivery service platforms should improve their environmental protection mechanisms. Meanwhile, the government should define a standard concerning food delivery service packages to consolidate the concept of environmental protection in the society to change the ways people consume, in order to achieve a harmonious co-existence between resource utilization and environmental protection.