Abstract

Low-carbon (LC) cities are the cities that people long for today. LC environmental protection plays a very important role in people’s health. The construction of a city in LC is a great cause that contributes to the present and benefits the future. In this study, we propose a development and sustainability evaluation system for building low-carbon cities based on the Internet of Things (IoT). The study is novel in that it considers key areas such as urban planning, environmental issues and solutions, and how the Internet of Things can optimize low-carbon logistics and smart grids, with the aim of promoting the formation of low-carbon city models. This comprehensive approach not only presents problems and solutions in low-carbon urban planning but also focuses on how the Internet of Things can be used as a key technology to promote low-carbon urban development. The urban development of LC was constructed with a sustainable evaluation system, so that people could experience the life of LC. Through the investigation of the degree of atmospheric pollution of LC cities using the Internet of Things, this article found that the highest degree of atmospheric pollution was 30. The highest degree of atmospheric pollution in cities in LC without IoT was 53. The severity of water pollution in cities in LC using IoT technology ranged from 10 to 25, while those without IoT ranged from 30 to 60. The degree of soil pollution in LC cities using IoT technology was concentrated in 10–30, while those without using IoT were concentrated in 30–50. Through these experimental data, it could be seen that IoT technology could reduce environmental pollution, thus achieving the effect of LC cities. This shows that the use of IoT technology in LC cities was highly feasible.

Introduction

LC cities are currently a prominent topic of discussion and delight the imaginations of people around the world. The concept of LC cities, short for “Low-Carbon” cities, has gradually gained traction among the populace. People harbor a deep yearning for the LC lifestyle, envisioning medium-sized cities that are environmentally friendly and pristine, capable of fostering both health and happiness. Consequently, there is an ongoing surge in scholarly endeavors aimed at comprehensively understanding LC cities.

As public interest in LC cities continues to increase, so does the volume of research dedicated to unraveling their intricacies. Liu C, for instance, espoused the view that LC policies are not merely geared towards fostering economic development, but also towards mitigating the impacts of climate change. He posited that LC policies foster a symbiotic relationship between economic industrial structures and foreign investments, thus achieving mutually beneficial growth. Despite the promotion of regional innovation by LC policies, Liu cautioned that innovation might not produce immediate results [1]. Similarly, Xin L stated that the promotion of green and LC development has become a global consensus, but lamented the dearth of studies exploring the scientific nuances and repercussions of LC development [2]. Chen L, on the other hand, emphasized that the primary environmental challenge lies in carbon emissions arising from urbanization. He advocated for stringent measures to curb the growth of urban carbon emissions as part of experimental policies aimed at achieving carbon neutrality [3]. Colenbrander S shed light on the prevalent misconception that LC development is inherently more expensive than high-carbon development, a belief that often hampers opportunities for sustainable growth, especially in resource-constrained environments [4]. It is posited that integrating LC city construction with the Internet of Things (IoT) could potentially catalyze more comprehensive LC development, thereby fostering cities’ transformation towards greater sustainability.

Conclusions

With the increasing severity of pollution, people gradually began to pay attention to the development of LC, which can reduce environmental pollution and bring health to people. As a new technology, the IoT can play a very good role in the construction of LC cities. Cities become intelligent and can reduce many unnecessary pollutants, thus achieving the effect of reducing pollution. This paper studied the development of LC cities based on IoT, in hopes of improving the construction of LC cities through IoT technology. This paper tested the air pollution level, water pollution level, and soil pollution level of LC cities using the IoT technology and without the IoT technology. From the experimental data, it could be seen that the level of air pollution level, water pollution level, and soil pollution level after using IoT technology were lower than those without using IoT technology, which proved that the IoT technology was suitable for the LC development of cities and could reduce pollution. Due to the length of this paper, the experiments and discussions on LC cities were still insufficient and would be improved in the future. Finally, it was hoped that the LC of the city could develop better and better and that people could lead a life that was environmentally friendly and LC.

Abstract

Microplastics pose a severe threat to marine ecosystems; however, relevant mathematical modeling and analysis are lacking. This paper formulates two stoichiometric producer-grazer models to investigate the interactive effects of microplastics, nutrients, and light on population dynamics under different settings. One model incorporates optimal microplastic uptake and foraging behavior based on nutrient availability for natural settings, while the other model does not include foraging in laboratory settings. We establish the well-posedness of the models and examine their long-term behaviors. Our results reveal that in natural environments, producers and grazers exhibit higher sensitivity to microplastics, and the system may demonstrate bistability or tristability. Moreover, the influences of microplastics, nutrients, and light intensity are highly intertwined. The presence of microplastics amplifies the constraints on grazer growth related to food quality and quantity imposed by extreme light intensities, while elevated phosphorus input enhances the system’s resistance to intense light conditions. Furthermore, higher environmental microplastic levels do not always imply elevated microplastic body burdens in organisms, as organisms are also influenced by nutrients and light. We also find that grazers are more vulnerable to microplastics, compared to producers. If producers can utilize microplastics for growth, the system displays significantly greater resilience to microplastics.

Introduction

Plastic pollution has steadily increased due to widespread plastic use, insufficient disposal practices, and limited waste management capacity over decades. Plastic wastes discharged into terrestrial and aquatic habitats are considered a serious threat to biodiversity, due to their resistance to decomposition (Gall and Thompson, 2015, Carbery et al., 2018). The small plastic particles, ranging from 0.1 to 5 mm in size, are called microplastics (EFSA Panel on Contaminants in the Food Chain (CONTAM), 2016). Microplastics are observed almost in all aquatic habitats (Eerkes-Medrano et al., 2015, Peeken et al., 2018). Chronic exposure to microplastics presents several challenges for aquatic organisms (Cui et al., 2017, Duis and Coors, 2016, Nolte et al., 2017, Zhang et al., 2017, Khoironi et al., 2019, Sjollema et al., 2016, Besseling et al., 2014).

Studies have shown that microplastics can be absorbed, concentrated, and transported into various organisms, such as algae. This process significantly hampers algal growth, chlorophyll levels, and photosynthetic activity (Cao et al., 2022, Liu et al., 2019, Chae et al., 2019, Wu et al., 2021, Jiao et al., 2022, Gray and Weinstein, 2017, Zhang et al., 2017, Sjollema et al., 2016, Yang et al., 2020, Ferguson, 2011, Wang et al., 2020, Khoironi et al., 2019, Rodrigues et al., 2019, Salman et al., 2016). This inhibition may occur due to physical factors, such as the blockage of light and airflow (Bhattacharya et al., 2010, Wang et al., 2020, Salman et al., 2016, Bhattacharya et al., 2010), or interactions between microplastics and algae, including adsorption, aggregation (Zhang et al., 2017), and the destruction of algal cell walls through surface absorption (Liu et al., 2019). However, it is worth noting that some laboratory studies suggest that certain algae species may increase in the presence of smaller-sized microplastics, possibly because microplastic particles can be utilized as substrates for the growth of algae (Yokota et al., 2017, Mao et al., 2018, Jiao et al., 2022, Canniff and Hoang, 2018).

Discussion

Microplastics can be mistakenly ingested or adhere to the surfaces of marine organisms, resulting in significant adverse effects (Zhang et al., 2017, Liu et al., 2019, Sazli et al., 2023, Gregory, 1996, Derraik, 2002, Blarer and Burkhardt-Holm, 2016, Alomar et al., 2017). This paper presents two stoichiometric models to investigate population dynamics in the presence of microplastics in both field and laboratory settings. The interactive effects of light, nutrients, and microplastics on population dynamics have been rigorously studied.

For natural ecosystems, the OMUF model reveals complex dynamics. When the microplastic concentration is relatively low, the behavior of the system is strongly influenced by the initial conditions and can exhibit bistability or tristability. Conversely, when microplastics in the environment become excessively abundant, the only outcome is the extinction of grazers. Furthermore, the tolerance to microplastics of the producer-grazer system described in OMUF model (3.5) is significantly lower, compared to that of the system defined in NM model (2.11). This discrepancy potentially arises from the fact that in the natural ecosystem, grazers have to face more challenges and pay significant feeding costs, such as food scarcity, nutrient deficiencies, predation risk, multiple toxins, and human impact, making them more susceptible to microplastics.

Extreme light condition, either too low or too high, restricts the growth of grazers. When light intensity is excessively low, producers can only survive at low densities due to weakened photosynthesis, and grazers go extinct because of insufficient food. When light intensity is excessively high, the P:C ratio in producers becomes very low, and grazers go extinct due to nutrient deficiency. However, when light intensity falls within a moderate range, coexistence of both species may occur, and the system demonstrates a greater ability to withstand microplastics.

Abstract

     Globally, to ensure food security bio-based fertilizers must replace a percentage of chemical fertilizers. Such replacement must be deemed sustainable from agronomic and greenhouse gas (GHG) emission perspectives. For agronomic performance several controlled protocols are in place but not for testing GHG emissions. Herein, a pre-screening tool is presented to examine GHG emissions from bio-waste as fertilizers. The various treatments examined are as follows: soil with added mineral nitrogen (N, 140 kg N ha−1) fertilizer (MF), the same amount of MF combined with dairy processing sludge (DS), sludge-derived biochar produced at 450 °C (BC450) and 700 °C (BC700) and untreated control (CK). These treatments were combined with Danish (sandy loam) or Irish (clay loam) soils, with carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) emissions and soil inorganic-N contents measured on selected days. During the incubation, biochar mitigated N2O emissions by regulating denitrification. BC450 reduced N2O emissions from Danish soil by 95.5% and BC700 by 97.7% compared to emissions with the sludge application, and for Irish soil, the N2O reductions were 93.6% and 32.3%, respectively. For both soils, biochar reduced CO2 emissions by 50% as compared to the sludge. The lower N2O reduction potential of BC700 for Irish soil could be due to the high soil organic carbon and clay content and pyrolysis temperature. For the same reasons emissions of N2O and CO2 from Irish soil were significantly higher than from Danish soil. The temporal variation in N2O emissions was correlated with soil inorganic-N contents. The CH4 emissions across treatments were not significantly different. This study developed a simple and cost-effective pre-screening method to evaluate the GHG emission potential of new bio-waste before its field application and guide the development of national emission inventories, towards achieving the goals of circular economy and the European Green Deal.

Introduction

     Agricultural sources of greenhouse gas (GHG) emissions crucially influence climate change. During the period from 2007 to 2016, GHG emissions from agriculture, forestry and land use contributed about 23% of total net anthropogenic emissions, and emissions of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) from agriculture accounted for 13%, 44% and 81% of the anthropogenic emissions, respectively (IPCC et al., 2019). In November 2016 the legally binding international treaty on climate change called the Paris Agreement was adopted by 195 Parties. The key messages of the Paris Agreement include 1) limiting global warming to well below 2 °C, preferably to 1.5 °C, compared to pre-industrial levels; 2) establishing climate resilience and mitigating GHG emissions without threatening food production; and 3) aligning financial flows with pathways for low GHG emissions and climate-resilient development (UNFCCC, 2015). Therefore, the reduction of GHG emissions from agricultural soils with new effective mitigation strategies within the framework of the Paris Agreement becomes vital for the achievement of global warming reduction goals.

Conclusions

     Addition of biochar from pyrolysis of dairy sludge (DS) to soils together with mineral N fertilizer instead of directly adding DS, substantially reduced emissions of N2O to a level near that of untreated soil. Biochar pyrolyzed at 450 °C (BC450) reduced emissions of N2O by 95.5% and CO2 by 59.4% when applied to a Danish sandy loam soil (DA), and from an Irish clay loam soil (IR), emissions were reduced by 93.6% and 57.1%, respectively. Biochar from 700 °C pyrolysis (BC700) suppressed 97.7% and 49.7% of N2O and CO2 emissions from DA soil, and 32.3% and 62.4% from IR soil. Biochar shows no effect on CH4 emissions. Pyrolysis conditions and soil properties significantly affect the suppression of N2O emissions by biochar. This study provides a simple and cost-effective tool to examine the GHG emission potential of bio-waste before applying it in agricultural lands and helps in developing national emission inventories.

Abstract

     This work suggests an optimal strategy to sort and recycle plastic waste as a renewable energy resource with maximizing economic feasibility and mitigating environmental pollution. To derive the optimal sorting and recycling strategies of plastic waste, a novel optimization model is developed; it calculates the overall profit by subtracting the profit of recycling plastic from the total annualized cost. Then the model is used to identify the optimal strategy to sort and recycle plastic waste as a renewable energy resource in mixed-integer nonlinear programming that maximizes the overall profit. In the derived optimal sorting and recycling strategy, high-density polyethylene is recycled to produce downgrade plastic; low-density polyethylene, polypropylene, and polystyrene are recycled as pyrolysis oil; and polyethylene terephthalate is recycled to produce refuse plastic fuel. The derived optimal case can significantly increase the overall profit by about 3,137% (i.e., 35 US$/1 kg of recycled plastic), and 492% (i.e., 29 US$/1 kg of recycled plastic) compared to conventional case in South Korea and Japan respectively.

Introduction

     The demand for plastics has rapidly increased in many industries because of their versatility, and easy production. Consequently, plastic waste is discharged in massive quantities; estimates of plastic waste discharged into rivers, lakes, and seas is 9–23 million t per year globally (Borrelle et al., 2020; Masuda et al., 2001). Thus, the importance of plastic waste recycling is increasing (Shah et al., 2015; Zhang et al., 2020). Plastic waste is a mixture of different types, so it must be sorted into before it is recycled (Gundupalli et al., 2017; Hearn and Ballard, 2005; Lim and Cho, 2003). Economically-viable sorting and recycling of plastic will yield a cheap and abundant source of valuable chemicals and renewable energy (Gadaleta et al., 2020). However, current systems to sort and recycle plastic waste are not optimized, so their costs are high. Thus, only 27.2 wt% of plastic waste is recycled, whereas 36.4 wt% is landfilled, and 36.4 wt% is incinerated (Vieira et al., 2022). Therefore, the soil and air pollution according to the landfilled plastic and the significant amount of SOx, NOx, and CO2 emitted in the incineration of waste plastic is serious. The types of recycled plastic have different uses depending on the product (e.g., downgrade plastic, pyrolysis oil, and refuse plastic fuel) that is produced (Kim et al., 2020; Krauklis et al., 2021; Shaha et al., 2020; Yaqoob et al., 2021). Methods to recycle plastic waste are classified into material, chemical, and thermal types (Zhuo and Levendis, 2014). They have very different capital and operating costs according to the throughput of the plastic waste of each method (Huang et al., 2002). Therefore, to improve plastic waste recycling, it is crucial to derive optimal sorting and recycling strategy for plastic waste that indicate which plastics will be sorted to be recycled and how the plastic will be recycled according to each recycling method considering economic feasibility.

Conclusion

     This study found an optimal strategy to sort and recycle plastic waste as a renewable energy resource for maximizing economic feasibility and mitigation of environmental pollution caused by landfilled plastic and air pollutants according to incineration of plastic. This study makes two major contributions to the literature. First, to the best of the author’s knowledge, it is the first attempt to optimize the plastic waste sorting and recycling system by deriving an optimal sorting and recycling strategy to improve the recycling of for plastic waste as a renewable energy resource maximizing economic feasibility and mitigating of environmental pollution. Also, the results allow us to increase the recycling of plastic waste by maximizing the overall profit of the plastic waste sorting and recycling system. In the derived optimal sorting and recycling strategy, HDPE is recycled to produce downgrade plastic; LDPE, PP and PS are recycled as pyrolysis oil; and PET is recycled to produce refuse plastic fuel. The derived optimal case can increase overall profit by ∼ 3,137% compared to CCS, and 492% compared to CCJ, and also emission of air pollutants. Thus, this study provides valuable insight into the many recycling industries of waste plastics to achieve clean production, cost-effectiveness, and environmental protection. In many literatures, strategies such as operating condition optimization were proposed to reduce the cost of each sorting method. Thus, in further study, it is crucial to consider the detailed proposed strategies in deriving the optimal solution to maximize economic feasibility.

Abstract

     While supporting the values and goals of sustainable development at the international level, states might employ very different strategies at the national level. The goal of this Forward and of special issue is twofold. First, it aims to advance our understanding of different strategies, paying special attention to China and Russia at global, national, and sub-national levels. Thus, analysis of their strategies across different levels presents a more rounded picture. The second goal is to identify at least a few of the most pressing challenges of sustainable development across Eurasia (e.g. nuclear supply chain, emissions, environmental conflict management) and to attempt to understand their triggers, outcomes, and potential solutions. This Forward aspires to develop a better dialogue across different sets of literature in area studies, environmental politics, and international relations to improve our understanding of obstacles to sustainable development in Eurasia.

Introduction

     Studies on democratisation and regime transition in Eurasia have flourished over the last two decades.1 The literature has looked into a wide range of causal explanations of the consolidation of a variety of political regimes in Eurasia and in the European Union’s (EU) neighbourhood, such as historical legacies of Communism, the impact of the EU, and (associated with it) the diffusion of democratic values and principles even beyond its enlargement, at national and sub-national levels.2 Membership in international organisations (IOs) has usually been associated with promotion of human rights, democratisation, marketisation, and economic development.3 Only recently have scholars made the next step to ask a question regarding the possibility of the opposite impact of regional IOs led by autocracies on the consolidation of non-democratic regimes across Eurasia.4 Yet, this rich and fast-growing body of literature on the variety of political regimes emerged in Eurasia, their causes, and their consequences, has somehow been detached from studies looking into the problems, challenges, and strategies of sustainable development in Eurasia.5 In economics, however, a few studies have emerged connecting political regimes to outcomes of environmental policies, among other issues (e.g. Fredriksson & Neumayer, 2013; Fredriksson & Wollscheid, 2007; Nazarov & Obydenkova, 2021b). Despite this, there seems to be space for further, more interdisciplinary analysis of specific case studies and actors in Eurasia. While two sets of studies have been developing fast, they seemed to exist in two parallel worlds without much engagement with each other. Yet, both bodies of literature exhibit some similarities and unique insights, and can certainly benefit from establishing a deeper dialogue with each other. This special issue aspires to build on both somewhat separate sets of studies (on political regimes and on sustainable development in Eurasia) and to develop further the dialogue between them.

Conclusion

     This volume contributes to multiple sets of literature and has raised a number of issues that are likely to stay on the research agenda. The collection of articles advances studies on the diffusion of values and practices, on the role of history, and importance of external influences for sustainable development (e.g. historical legacies of nuclear chain and emissions; external impact on environmental movements; environmental rhetoric). These concluding remarks outline some of these findings presented in this volume and place them within broader cross-disciplinary literature.

      First, the special issue contributes to diffusion literature and studies of regionalism. It focuses on the international and national strategies of state actors and on environmental challenges. An important question is whether and how membership of states in different IOs (e.g. global climate clubs or the EU) matters in the fight against climate change (dealing with nuclear chain or emissions). As the study by Tosun and Shyrokykh (2021) argues, membership in climate clubs is associated with learning across states at the global level and allows direct access to the latest information, practices, and innovations. These activities, contacts, and formal and informal meetings within climate clubs (as well as within other IOs) are strongly associated with the diffusion of values and principles. Diffusion takes place at both cross-national and cross sub-national levels (Lankina et al., 2016a). On the other hand, the environmental commitments of China, Russia, and Kazakhstan can be analysed within the literature in terms of formal goals versus real motivations (see also, Libman & Obydenkova, 2018a, 2018b; Poberezhskaya & Bychkova, 2021). While formally proclaiming support for sustainable development, these nondemocracies also seek to augment their international image as global, environmentally friendly actors (Kochtcheeva, 2021; Tosun & Rinscheid, 2021).

Highlights

Abstract

Graphical abstract

Keywords

1. Introduction

2. Materials and methods

3. Results and discussions

4. Conclusion

Author contribution

Declaration of competing interest

Acknowledgement

Appendix A. Supplementary data

References

Abstract

During the Covid-19 pandemic, personal protection equipment (PPE) was widely used to control the virus further spared. In this study, the presence of PPE wastes along the coastline of Bushehr port, the Persian Gulf from nine stations was investigated (4 times during 40 days), and their potential for microplastics (MPs) creation was preliminarily assessed. In total, more than 2380 PPE were collected in the study area. No significant differences were found between various beaches regarding their types and common activities. In addition, the estimated disposal rate of PPE per day and year is 350 and 127,750 items, respectively. More than 10% of the collected PPE from Bushehr’s coastal areas on each sampling day were damaged. Based on the microscopic analysis, the left surgical masks and torn plastic gloves in the coastal regions are emerging sources of secondary microfibers and MP particles (mostly fragments and films) in the marine environments, respectively.

1. Introduction

During the last year, human beings have faced deadly infectious disease, and since March 2020, Covid-19 was declared as a pandemic by the World Health Organization (WHO) (Ducharme, 2020). Then, different measures have been used in different parts of the world, such as staying at home (lockdown), travel restriction, social distancing, washing of hands, surface disinfection, and isolation (Aragaw, 2020; Fadare and Okoffo, 2020; Rhee, 2020). Moreover, various personal protective equipment (PPE-i.e., face masks, gloves, face shields, alcohol spray) was used in different countries in order to control the virus further spared (De-la-Torre and Aragaw, 2021; Nowakowski et al., 2020). It is estimated that more than 129 billion face masks and 65 billion gloves have been used monthly all around the world (Prata et al., 2020). Discarded only 1% of these PPE exceeds ten million items (Celis et al., 2021) and can cause an environmental crisis.

Single-use face masks, N95 masks, gloves, and face shields are mainly produced from plastic polymers such as polypropylene, polystyrene, polyacrylonitrile, polyester, and polyurethane (Aragaw, 2020; Ardusso et al., 2021; Potluri and Needham, 2005; Sangkham, 2020). Most of the surgical masks have three layers: 1) an inner layer with soft fibers, 2) a middle layer with melt-gusted filter, and 3) an outer layer with nonwoven fibers which are usually colored and water-resistant (Aragaw, 2020; Fadare and Okoffo, 2020). Approximately the weight of polypropylene (PP) in a single N95 mask and surgical mask is 11 and 4.5 g, respectively (Abbasi et al., 2020; Liebsch, 2020). In addition, the most commonly single-use gloves are made of polyethylene (PE), latex, and nitrile (Nowakowski et al., 2020). Although these types of plastics can easily be recycled, they are usually mixed with other wastes or left in the environment (i.e., parks, beaches, forests) (Nowakowski et al., 2020).

Abstract

Keywords

1. Introduction

2. Framework and model formation

3. Computational experiments

3.1. Experimental data design

3.2. Results and discussion

4. Conclusion

Declaration of Competing Interest

Acknowledgements

References

Abstract

Generally, the activities of post-disaster waste management usually produce high carbon emissions, which can cause damage to the environment. However, the issue of carbon emissions in the post-disaster waste supply chain is neglected. Hence, this paper aims to propose a mixed-integer linear programming model to address the post-disaster waste processing supply chain network design problem with the consideration of a carbon tax policy. The proposed model is developed based on the concept of a mixed strategy of waste separation to reduce carbon emissions. Not only the carbon emission perspective but also the financial perspective for post-disaster waste supply chain management is determined in the objective function. The proposed model was verified and validated by employing a numerical example based on realistic data. Based on the numerical example, the results show that the implementation of a carbon tax policy with the mixed strategy for waste separation can reduce carbon emissions in the post-disaster waste supply chain efficiently.

1. Introduction

In a large-scale disaster, thousands of tonnes of mixed wastes are generated. The mixed waste is usually composed of building rubble, household materials, electrical appliances, a small amount of concrete, wood chips, plastics, glass, soil, sand, and so on [1]. The mixed waste is removed and disposed of after the disaster. Normally, the activities of mixed waste management involve waste collection, transfer, recycling, and disposal, all of which can produce CO2, causing damage to the environment, and can threaten the health of the disaster victims and workers in the affected area [2], [3]. According to Ritchie and Roser [4], the average annual growth rate of CO2 emissions was 30.36 billion tonnes from 1950 to 2017. In 2017, the world emitted 36.15 billion tonnes of CO2, while in 2000 the figure was 11.59 billion tonnes. Due to the issue of carbon emissions, CO2 emissions reduction has become an effective way to reduce the pressure on many countries [5]. Nowadays, several policies have been proposed to reduce CO2 emissions, such as carbon taxes, carbon caps, cap and trade, and so on [6], [7]. The Energy Information Administration stated that “the real constraint lies not in our ability to develop the necessary technologies but in our political will to deploy them” [8]. Nowadays, low-carbon supply chains are becoming more and more popular in many organizations. Many organizations usually apply carbon tax policies because this policy has been successful in many countries. However, consideration of a carbon tax policy in the post-disaster waste supply chain is still neglected. Most policymakers pay attention to the cost or time only [2], [9].

To reduce carbon emissions, the carbon tax policy in the post-disaster waste supply chain should be determined. Therefore, this paper aims to propose a mathematical model for post-disaster waste management with consideration of a carbon tax policy. The proposed mathematical model is developed based on the concept of a mixed strategy of waste separation (on-site and off-site separation) to reduce carbon emissions. Not only the carbon emissions but also the total cost for the post-disaster waste supply chain management is determined in the proposed model.

Highlights

Abstract

Graphical abstract

Keywords

1. Introduction

2. Methods used to conduct the mini-review

3. Composition of healthcare waste

4. Persistence rate of COVID-19 virus and its possible transmission through healthcare solid waste

5. Waste management strategies during the COVID-19 pandemic

6. Challenges

7. Potential for healthcare solid waste management strategies

8. Conclusions

Funding

Ethical approval

CRediT authorship contribution statement

Declaration of competing interest

Acknowledgments

References

Abstract

Healthcare waste comprises the waste generated by healthcare facilities, medical laboratories and biomedical research facilities. Improper treatment of this waste poses serious risks of disease transmission to waste pickers, waste workers, health workers, patients, and the community in general through exposure to infectious agents. Poor management of the waste emits harmful and deleterious contaminants into society. However, contamination of highly contagious agents such as the COVID-19 virus has created enormous instability in healthcare waste handling and subsequent recycling because of the volume of the waste generated and its contagious nature. Several countries have adopted safety measures to combat this contamination and manage healthcare waste; however, these measures are insufficient and vary depending on the context of the country. In addition, the WHO has set out guidelines for management of healthcare waste. These guidelines are helping to manage the highly contagious healthcare waste resulting from the current pandemic. Proper healthcare waste management may add value by reducing the spread of the COVID-19 virus and increasing the recyclability of materials instead of sending them to landfill. Disinfecting and sorting out healthcare waste facilitates sustainable management and allows their utilization for valuable purposes. This review discusses the different healthcare solid waste management strategies practiced in different countries, the challenges faced during this management, and the possible solutions for overcoming these challenges. It also provides useful insights into healthcare solid waste management scenarios during the COVID-19 pandemic and a possible way forward.

1. Introduction

After radiation waste, healthcare waste is considered the second most hazardous waste globally. It includes various forms of waste, both hazardous and non-hazardous, such as sharps, human body parts, blood, chemical waste, pharmaceutical waste, and medical devices (Rodriguez-Morales, 2013). All of this waste is produced mainly by hospitals, primary care facilities, laboratories, mortuaries, autopsy centers, laboratories, blood banks, nursing homes, and other medical locations (Pepin et al., 2014). It is generated during diagnosis, treatment, immunization of humans or animals, research, or the production or testing of biologicals. If not properly handled, it can have devastating effects on human health (Johannessen et al., 2000). During any infectious disease outbreak, the waste generated from healthcare facilities increases exponentially; as a result, special care must be taken by management in order to avoid troubling impacts (Ramteke and Sahu, 2020).

The outbreak of coronavirus disease 2019 (COVID-19) has arisen from the SARS-CoV-2 virus, which causes an acute respiratory disease (Mol and Caldas, 2020; WHO, 2019; WHO, 2020b); it was first reported in Wuhan, China (Wang et al., 2020) in December 2019. It has been acknowledged as a Public Health Emergency of International Concern (PHEIC) (Wilder-Smith and Osman, 2020), and the virus has spread to almost all countries across the globe. The pandemic continues to be a significant public health threat worldwide. The rapid increase in the number of COVID-19 infected patients and the highly transmissible nature of the disease have led to a high number of hospitalizations.

1- Introduction

2- Conceptual framework

3- Methods and material of the literature review

4- Synthesis of study results

5- Discussion and conclusions

References

Abstract

Consumers play an important role in the market penetration of environmentally-friendly food packaging because it is they who decide whether or not to buy a particular product. The objective of this paper is to analyse the state of the art regarding consumers’ response to environmentally-friendly food packaging in order to identify existing barriers to purchase and potential measures to overcome these barriers. The paper is based on a systematic synthesis of 46 scientific journal articles on consumer studies related to environmentally-friendly packaging. The literature review applies a conceptual framework regarding the ways consumers respond to product stimuli and the psychological processes involved. Three important barriers to purchasing environmentally-friendly packaging are identified. First, consumers need guidance in recognizing environmentally-friendly packaging; for while consumers primarily consider the packaging material itself and any eco-labels, they also consider other packaging design elements such as colours and pictures of ‘nature’ that can be misleading. Second, it became obvious that consumers lack knowledge, in particular about new packaging materials like bio-based packaging. Third, many of the studies reviewed provide evidence that other product attributes such as price and product quality are more important to consumers than environmentally-friendly packaging. Nevertheless, some studies recorded a significantly higher willingness on the part of consumers to buy and pay for environmentally-friendly packaging and products with reduced packaging compared to products with standard packaging, signalling an overall positive attitude. The literature review revealed many research gaps. For example, it became obvious that consumers’ response to environmentally-friendly food packaging is not yet well understood, in particular with regards to purchasing behaviour (in the real world as opposed to in a survey setting) and measures for overcoming existing barriers.

Introduction

Human activities are causing irreversible environmental effects, such as climate change and loss of biodiversity (Rockström et al. 2009). A large part of each individual’s ecological footprint stems from their consumption of products. The production and consumption of more environmentally-friendly products is an important step towards achieving more sustainable lifestyles. At present, however, environmentally-friendly or ‘green’ products are still a niche market. Gleim et al. (2013) estimate the global market share for green products at less than 4%. According to FTSE Russell (2018), the green economy accounts for 6% of the market capitalization of globally listed companies. A serious side effect of product consumption is the generation of packaging waste. The global packaging market was estimated at 4,300 billion packaging units in 2015, of which 73% were for food and drinks (ALL4PACK 2016). In the European Union, 1,130 billion packages were used for food and drinks in 2018 (Fuhr et al. 2019). Since 2010, waste production has grown at an annual rate of 4.2% and is expected to continue at the same rate to 2024. Rigid and flexible plastic is the packaging material with the largest market share, at 47% in 2015 (ALL4PACK 2016). One way to tackle the waste problem is to introduce environmentally-friendly food packaging (Geueke et al. 2018).

1- Introduction

2- Unfolding China’s pollutant emissions trading practices

3- Regional comparison of PETSs

4- Discussion

5- Conclusion

References

Abstract

Over the past few decades, the pollutant emissions trading policies in China have undergone significant innovation and exploration. It is considered as a market-based approach that became integrated with command-and-control mechanisms such as total emissions control or pollution permits. This study is the first to provide systematic, reflective thinking that tracks the regional initiatives of pollutant emissions trading systems in China. In this article, we divided China’s emissions trading practices into three stages and conducted a comparative qualitative analysis of the country’s eleven provincial emissions trading pilots. We found that provincial pilots are highly diverse and complex regarding the pollutants that can be traded, the industrial sectors involved, the design of trading administration and processes, and the implementation of trading practices such as allowance, pricing and platforms. We also identified four main challenges: legislation setup, monitoring and verification, administrative interference, and the technical quantification of pollutant hotspots. We conclude the article by providing policy implications so that emissions trading policies can be integrated with the newly developed pollution permitting system.

Introduction

The economic incentive approach enables more flexibility and efficiency in environmental management. Emissions trading has been recognized as one of the most effective environmental policies in Western countries (Stavins, 1995; FØRSUND and NÆVDAL, 1997). In the United States, for example, the report on emissions trading policies issued by the Regan Government summarized the practices of banking, bubbles, offsets, and tradable credit (Schwarze and Zapfel, 2000). These practices were integrated into an emissions trading system at the state level, which formalized the market mechanisms to monitor and reduce pollution. The EU Emission Trading System (EU-EST) covers approximately 11 000 power stations and manufacturing plants in the 28 EU Member States, as well as aviation activities in these countries (Boemare and Quirion, 2002). In total, roughly 45% of total EU greenhouse gas emissions are regulated by the EU-ETS.1 China has been piloting pollutant emissions trading systems (PETSs) since the 1980s. Despite the complexities and ambiguities of policy design and implementation, PETS initiatives keep evolving with ongoing challenges of environmental pollution and have become one of the fundamental environmental policies in China for point-source environmental management (Jiang et al., 2016; Guo, 2018). Thus, such initiatives are significantly different from carbon (CO2) emissions trading systems in China (Jotzo and Loschel, € 2014; B. Zhang et al., 2014) since the latter are usually not considered part of China’s fundamental climate mitigation strategies. Most previous studies about PETSs in China apply environmental economics analyses (Cao and Ikeda, 2005; Zhang et al., 2010) to reveal the efficiency of a single emissions trading scheme at the enterprise level, regardless of the regulatory nature of a single pollutant, i.e., CO2 is not considered ak “pollutant” in China at central or local levels. This is probably why the outcomes of PETSs are diverse (Ji et al., 2017; Dickson and Mackenzie, 2018; Xian et al., 2019). Researchers have also pointed out that the maneuverability of the current emissions trading policy, conflicts between different environmental policies, and administrative interference are considered as the main barriers to the success of the SO2 emissions trading programs in China (Wang et al., 2002; Dudek et al. 2004, 2007).