Pollution Crisis Research Articles

Enzymatic polyethylene biorecycling: Confronting challenges and shaping the future

Polyethylene (PE) is a widely used plastic known for its resistance to biodegradation, posing a significant environmental challenge. Recent advances have shed light on microorganisms and insects capable of breaking down PE and identified potential PE-degrading enzymes (PEases), hinting at the possibility of PE biorecycling. Research on enzymatic PE degradation is still in its early stages, especially compared to the progress made with polyethylene terephthalate (PET). While PET hydrolases have been extensively studied and engineered for improved performance, even the products of PEases remain mostly undefined. This Perspective analyzes the current state of enzymatic PE degradation research, highlighting obstacles in the search for bona fide PEases and suggesting areas for future exploration. A critical challenge impeding progress in this field stems from the inert nature of the C-C and C-H bonds of PE. Furthermore, breaking down PE into small molecules using only one monofunctional enzyme is theoretically impossible. Overcoming these obstacles requires identifying enzymatic pathways, which can be facilitated using emerging technologies like omics, structure-based design, and computer-assisted engineering of enzymes. Understanding the mechanisms underlying PE enzymatic biodegradation is crucial for research progress and for identifying potential solutions to the global plastic pollution crisis.

Green Plants as a Sustainable Solution to Air Pollution

In today’s global context, the escalation of air pollution stands out as an immensely critical environmental challenge that has attained a worldwide magnitude. This pressing issue not only impacts every living organism on our planet but is also intricately linked to the phenomenon of climate change. The significant increase in vehicular traffic, rapid urbanization, and infrastructure development have indirectly contributed to a higher concentration of harmful gaseous and particulate pollutants in the atmosphere, posing serious risks to human health. Extensive research has thoroughly documented the adverse effects of these air pollutants, with mortality and morbidity rates varying depending on the type of pollutant and the duration of exposure. However, amidst this crisis, green plants emerge as a cost-effective and promising solution to combat environmental pollution, presenting several additional benefits. Specifically, pollutiontolerant plant species are crucial in reducing ambient air pollution and the urban heat island effect. To assess a plant’s tolerance towards air pollution, experts use the air pollution tolerance index (APTI), which calculates crucial factors such as ascorbic acid, total chlorophyll, pH, and relative water content in the plant. This determination provides a reliable method for categorizing plants into either tolerant or sensitive types in the face of air pollution. Moreover, the morphological characteristics of leaves, such as stomata distribution and density, cuticle thickness, and trichome density, play an essential role in adsorbing and absorbing particulate matter from the air. These inherent qualities further enhance plants’ potential to combat air pollution in a sustainable manner, making them valuable assets for the future. In light of this, the present review highlights the impressive capacity of plants to remediate air pollutants and explores the various strategies employed in this crucial endeavor. By leveraging the remarkable capabilities of green plants, we have the opportunity to address the air pollution crisis and embrace a sustainable path for the times to come. These remarkable organisms could be the sustainable saviors we need to protect our environment and secure a healthier future for all.

Human Rights and the Global Plastics Treaty to Protect Health, Ocean Ecosystems and Our Climate

Abstract The global plastics pollution crisis has multiple visible and invisible effects on marine, land and air environments. Fossil fuel-based plastics production is projected to triple by 2060, driving a plastics lifecycle that exacerbates climate change, contaminates ecosystems and poses risks to human rights, especially the human right to health. Existing governance measures help tackle plastics waste pollution but cannot effectively address its systemic nature. Drafting a Global Plastics Treaty, due for adoption in 2025, is an opportunity to design ambitious international plastics governance. This article argues for a human rights-based approach to the proposed treaty’s framing and substance by integrating, in particular, the human right to health, supplemented by the human right to a healthy environment. Embedding human rights considerations through a precautionary and preventative approach, shifting responsibility to polluters and showing concern for intergenerational equity would combat plastics pollution, accelerate climate action, protect ocean ecosystems and safeguard human rights.

City-scale model to assess rooftops performance on air pollution mitigation; validation for Tehran

Cities have a significant role in the current climate change and air pollution crisis; hence, it is urgent to mitigate the negative effects of pollution in urban settlements. This situation requires developing agile plans to simultaneously investigate the efficiency of green infrastructures and feedback from their targets. A crucial consideration for these plans is the potential rooftops have – broadly abundant and underused in urban areas – to harbour sustainable, effective, and viable alternatives. This study aims to develop a new model to optimize the utilization of feasible pollutant reducers, investigate the ability rooftops present to reduce air pollution and recommend the most suitable city-scale solutions. The proposed model combines mathematical patterns, GIS, and sensitivity analysis. This systematic and adaptable approach was first applied to heavily air-polluted Tehran city, which has vastly unused rooftops. This leading application identified: i) two appropriate pollutant reducing alternatives – photovoltaic and green roofs –; ii) optimized total performance alternative when simultaneous mitigation of PM and CO2 is required – compound alternative –; iii) three significant indicators for target building groups – land use, building height, and surface scale –; and iv) the most suitable group – residential medium height in medium surface scale buildings. Applying a compound alternative with a 3:1 ratio (photovoltaic:green roof) to all potential target buildings enables a 9% decrease in the total city level for PM and CO2 emissions.

Optimizing coupling effect of confined FeNi nanoalloys within graphitic carbon nanofibers to improve photothermal energy conversion efficiency for solar water purification

Sustainable and energy-efficient water purification by harnessing solar energy is critical to tackling the challenges of water scarcity and the on-going water pollution crisis. Nevertheless, the biggest challenge to the practical deployment of solar-driven water purification, however, continues to be the poor solar evaporation efficiency of materials. Herein, FeNi nanoalloys encapsulated in graphitic carbon nanofibers (FeNi3/CNF) using Prussian blue analogue (PBAs) derivatives were fabricated using electrospinning and carbonization. The PBAs metal precursors play a critical role in encapsulating and safeguarding the FeNi alloy nanostructures from oxidation and agglomeration challenges. Furthermore, the synergistic effects between the non-noble hybrid plasmonic nanoalloys and graphitic CNFs can be constructed and optimized from the mass loading of PBAs precursor. Benefiting from the broad solar absorption band, high specific surface area, abundant micro-mesopores, and well-organized interlayer channel, the resultant 2D FeNi3/CNF solar evaporator demonstrates an efficient water evaporation rate of 1.51 kg m-2h−1 with an outstanding solar evaporation efficiency of 93.3 % under one sun irradiation, among the best values reported thus far. Impressively, the resultant 2D FeNi3/CNF solar evaporator can be constructed using only 0.02 kg m−2 loading of photothermal materials without compromising evaporation performance, which highlights its cost-efficiency in the practical application. Furthermore, the desalinated water meets the drinking standards of the World Health Organization (WHO) with an efficient 99 % separation of multiple organic industrial dye pollutants. Hence, this work demonstrates an efficient cost-effective approach to novel non-noble plasmonic alloy-based metal–carbon composites for enhanced solar-driven interfacial evaporation and wastewater purification.

China’s environmental pollution crisis: A comparative analysis of newspaper coverage of the Songhua River Spill

This article scrutinizes global media coverage of the 2005 Chinese Songhua River Spill, a significant transboundary water pollution crisis. It compares media narratives in China’s Party press, liberal press, and U.S. newspapers, revealing divergences in the symbolic communication of environmental risk. China’s Party press altered its reporting in response to criticisms and new events. U.S. newspapers consistently targeted Chinese government institutions and officials. Meanwhile, China’s liberal newspapers provided nuanced, topic-specific accounts, navigating between journalistic professionalism and political restrictions.

Making the most of what we already have: Activating UNCLOS to combat marine plastic pollution

Adequately responding to the crisis of marine plastic pollution will require parallel actions, by a variety of actors, on multiple fronts. The ocean governance regime, which has generally failed at shaping state behavior around land-based pollution, offers important legal and conceptual resources that can and should be utilized in these efforts. This article reviews three areas where the United Nations Convention on the Law of the Sea (UNCLOS) could be activated or applied to the problem of marine plastic pollution: the common heritage of mankind principle, the dispute settlement system, and reform through implementing agreements. Utilizing these elements of the ocean governance regime would be complementary to on-going efforts to negotiate a new plastics treaty. Working through UNCLOS offers several advantages, including important in-roads for non-state actors, norm-strengthening through an already well-subscribed regime, and expanding the avenues and obligations for scientific data collection on the patterns and impacts of marine plastics.

An Up-to-Date Review on the Remediation of Dyes and Phenolic Compounds from Wastewaters Using Enzymes Immobilized on Emerging and Nanostructured Materials: Promises and Challenges.

Addressing the critical issue of water pollution, this review article emphasizes the need to remove hazardous dyes and phenolic compounds from wastewater. These pollutants pose severe risks due to their toxic, mutagenic, and carcinogenic properties. The study explores various techniques for the remediation of organic contaminants from wastewater, including an enzymatic approach. A significant challenge in enzymatic wastewater treatment is the loss of enzyme activity and difficulty in recovery post-treatment. To mitigate these issues, this review examines the strategy of immobilizing enzymes on newly developed nanostructured materials like graphene, carbon nanotubes (CNTs), and metal-organic frameworks (MOFs). These materials offer high surface areas, excellent porosity, and ample anchoring sites for effective enzyme immobilization. The review evaluates recent research on enzyme immobilization on these supports and their applications in biocatalytic nanoparticles. It also analyzes the impact of operational factors (e.g., time, pH, and temperature) on dye and phenolic compound removal from wastewater using these enzymes. Despite promising outcomes, this review acknowledges the challenges for large-scale implementation and offers recommendations for future research to tackle these obstacles. This review concludes by suggesting that enzyme immobilization on these emerging materials could present a sustainable, environmentally friendly solution to the escalating water pollution crisis.

Will Mismatched New Infrastructure Investment Cause Air Pollution Crisis? Environmental Impact Analysis Based on the Coupling Degree of Digital Economy and new Infrastructure Investment

Will Mismatched New Infrastructure Investment Cause Air Pollution Crisis? Environmental Impact Analysis Based on the Coupling Degree of Digital Economy and new Infrastructure Investment

ETMS: Efficient Traffic Management System for Congestion Detection and Alert using HAAR Cascade

Rapid social development has resulted in the emergence of a new major societal issue: urban traffic congestion, which many cities must address. In addition to making it more difficult for people to get around town, traffic jams are a major source of the city's pollution crisis. In order to address the problems of automobile exhaust pollution and congestion, this paper uses the system dynamics approach to develop a model to study the urban traffic congestion system from the perspectives of trucks,private cars, bikes and public transportation. This project proposes a system for detecting vehicles and sending alerts when traffic levels rise to dangerous levels using Haar Cascade and Fuzzy Cognitive Maps (FCP). The proposed system uses Haar Cascade to detect moving vehicles, which are then classified using FCP. The system can make decisions based on partial or ambiguous information by utilising FCP, a soft computing technique, which allows it to learn from past actions. An algorithm for estimating traffic density is also used by the system to pinpoint active areas. In congested areas, the system will alert the driver if it anticipates a collision with another vehicle and also Experiments show that the proposed system is able to accurately detect vehicles and provide timely alerts to the driver, drastically lowering the probability of accidents occurring in heavily travelled areas.
 The importance of introducing such a system cannot be overstated in today's transportation system. It's a big deal for the future of intelligent urban planning and traffic control. Congestion relief, cleaner air, and increased security are just some of the long-term benefits that justify the high initial investment. To add, this system is adaptable to suburban and rural areas, which can also experience traffic congestion issues.

Defect-anchored single-atom-layer Pt clusters on TiO2−x/Ti for efficient hydrogen evolution via photothermal reforming plastics

Hydrogen generation from plastics waste is a promising strategy to solve the plastic pollution crisis. Making full use of infrared energy of solar spectrum is an important subject for efficient solar photocatalysis. Herein, single-atom-layer Pt (SAL-Pt) clusters anchored on TiO2−x/Ti was used as photothermal catalyst to generate hydrogen from plastic in liquid conditions. The confinement effect of laser-regulated oxygen vacancies in TiO2−x/Ti plays an important role in anchoring SAL-Pt under mildly temperature and pressure condition. The obtained Pt/TiO2−x/Ti possesses excellent photothermal catalytic hydrogen evolution performance from reforming plastic waste under infrared light (273.12 μmol cm−2 h−1). The enhanced photothermal activity of Pt/TiO2−x/Ti is due to enhanced infrared light absorption via plasmonic effect and hot electron aggregation on SAL-Pt from TiO2−x/Ti. The practical applicability is further verified by photothermal catalytic reforming plastics to H2 under ambient sunlight irradiation, which possesses high performance (25.5 μmol cm−2 h−1) and stability (in consecutive week).

Unveiling Bharalu River's Pollution Crisis through a Choice Experiment

In recent years, there has been a growing global concern regarding environmental degradation, pollution, and climate change, which significantly impact the development of both developing and developed nations. This growing concern has piqued the interest of economists in the field of environmental economics, which focuses on understanding how economic activities of producers and consumers affect our environment. Environmental economists aim to explain policies and initiatives that can improve the quality of life for present and future generations. Environmental issues hold particular significance for developing countries, where widespread poverty exists and there is an urgent need for accelerated economic growth. One crucial aspect of environmental degradation is declining water quality, which can have various impacts on the economy. These impacts can be observed in the health sector, where labor productivity can be affected, as well as in agriculture, where both the quality and quantity of food production may decrease. Furthermore, sectors such as tourism, real estate, aquaculture/fisheries, and others that rely on environmental quality and ecosystem services can also suffer negative consequences. The Bharalu River in Guwahati, Assam, is a prime example of an essential water resource that has undergone gradual degradation over the years, transforming into an urban municipal drain. Once a river flowing with pristine water and teeming with biodiversity, it has now experienced heavy industrialization and urbanization along its course, resulting in alarming pollution levels. This study aims to analyse the economic impact of Bharalu River's pollution from the perspective of consumers. It employs a discrete choice experiment to determine people's willingness to support the ecological restoration of the river and discusses the associated issues and challenges involved in the restoration efforts.

Assessing benefits and risks of incorporating plastic waste in construction materials

Plastic pollution and climate change are serious and interconnected threats to public and planetary health, as well as major drivers of global social injustice. Prolific use of plastics in the construction industry is likely a key contributor, resulting in burgeoning efforts to promote the recycling or downcycling of used plastics. Businesses, materials scientists, institutions, and other interested stakeholders are currently exploring the incorporation of plastic waste into building materials and infrastructure at an accelerated rate. Examples include composite asphalt-plastic roads, plastic adhesives, plastic-concrete, plastic/crumb rubber turf, plastic lumber, plastic acoustic/thermal insulation, plastic-fiber rammed earth, and plastic soil reinforcement/stabilizers. While some believe this to be a reasonable end-of-life scenario for plastic waste, research shows such efforts may cause further problems. These uses of plastic waste represent an ongoing effort at “greenwashing,” which both delays and distracts from finding real solutions to the plastic pollution crisis. Hypothesized effects of incorporating plastic waste in construction materials, including economic, environmental, human health, performance, and social impacts, are evaluated in this mini review. We compare known impacts of these treatments for plastic waste and provide recommendations for future research. Evidence shows that such practices exacerbate the negative ecological, health, and social impacts of plastic waste and increase demand for continued production of new (virgin) plastics by creating new markets for plastic wastes. We urge caution—and more research—before widely adopting these practices.

Life cycle assessment studies to evaluate the sustainability of various facemasks used during COVID-19: A UAE case study

The major hurdle in recovering from the COVID-19 pandemic would be the safe management of plastic waste generated from personal protective equipment and mitigating a plastic pollution crisis. Facemasks were adopted worldwide as the first line of defense against the COVID-19 pandemic, and their demand increased exponentially during the last few years. Through a life cycle assessment, this study aims to evaluate the environmental impacts of various facemasks available in the UAE market. SimaPro software was used to conduct a cradle-to-grave LCA, with a functional unit of "The number of face masks required by a person in UAE over a month (30 days)". Results show that the GWP (in kg CO2 eq) of 1 FU of surgical FM is 0.867, activated carbon FM is 1.11, N95 FM is 1.55, cloth FM is 0.642, and PLA FM is 0.946. Packaging increases the GWP by 36–178%. Long-distance transportation from China to UAE was identified to be a significant hotspot under GWP and FRS. Other hotspots include polypropylene material in filtration layers, aluminum in nosepieces, electricity usage in cloth masks, and disposal scenarios. Multiple supply chain optimizations are suggested, such as the substitution of recycled aluminum in nose pieces, the use of sustainable transportation, and limiting the use of packaging material to a bare minimum to improve the sustainability of the face mask industry.

Overcoming Plastic Pollution: Challenges Faced by Brazilian Policies and Perspectives for Stakeholder Engagement and Global Governance Opportunities

This policy position paper begins with a historical overview of the invention and uses of various plastic types, particularly polyethylene, which has become the most widely used plastic commercially. It highlights the rapid growth of our dependence on plastics and the subsequent mismanagement, which has led to their omnipresent and pervasive presence as pollutants, threatening biodiversity, climate change, ocean health, economic sustainability, and human health. The paper also provides an overview of plastic draft laws proposed by lawmakers at the Brazilian Houses of Representatives, emphasizing the importance of delivering effective policies, setting targets and priorities, and aligning with global trends to address the plastic pollution crisis and transition towards a circular economy. The section on governance opportunities examines a practical recommendation specific to Brazil, and subsequently presents ambitious pathways for global standardization and implementation of Environment and Social Governance (ESG). Additionally, a policy roadmap is suggested to incorporate existing approaches, promising strategies, UN Ocean Decade targets, and address concerns identified during the negotiations among UN Member States for a binding legal agreement by 2024 (Plastic Pollution INC1). In the last section, I present practices for adapting ocean literacy and scientific knowledge for different audiences, such as lawmakers and waste pickers, to support informed decision-making processes. Additionally, I present an overview of the benefits that transitioning to a new plastic economy can bring, ranging from global to local social justice associated with the triple planetary crisis: pollution, climate change, and biodiversity loss. Science diplomacy and stakeholder involvement are strongly recommended to find solutions to the plastic pollution problem and towards transforming the circular plastics economy.

Thermal management analysis of new liquid cooling of a battery system based on phase change material and thermoelectric cooler

The crisis of global warming and environmental pollution has led to the development of electric cars in recent decades. Meanwhile, designing a suitable cooling system for the battery is one of the ways to improve the performance of the electric vehicles. The present work experimentally introduces and examines a new type of liquid cooling system based on the combination of phase change materials (PCM) and thermoelectric cooler (TEC). The battery simulator pack is cooled by water and the heat of water is absorbed by the TEC. In this work, unlike previous works, PCM is used as a passive method to control the temperature of the hot side of the TEC. The effect of fluid flow rate, number and electric power of the TEC as well as the types of the PCM (RT35&RT50) on the system performance have been investigated. In a certain electric power, by changing the number of modules, the voltage is regulated in such a way that the input electric power remains constant. Results showed that increasing flow rate, TECs number and input electrical power decreases the battery pack temperature. However, improvement of the coefficient of performance have a direct relationship with the water flow rate and the TECs number and it is inversely related to the input power. It was also observed that in the same conditions, RT35 keeps the battery pack at a lower temperature than RT50 due to its lower phase change temperature. However, RT35 has higher COPw but lower COPc than RT50. Because the temperature of the battery pack and COP both play a decisive role in designing a cooling system, with the simultaneous application of two limits of TBPS<40℃ and COPw>2, 3TEC/P2 mode exhibits the best performance in the present work with COPc = 6.7, COPw = 2.14 and TBPS = 34.7 ℃.

Air pollution crisis in Southeast Asia and its impact on international travellers.

Air pollution levels in Southeast Asia have increased, affecting the health of tourists. While short-term effects are reversible, prolonged exposure poses significant risks, particularly for those with pre-existing conditions. Effective communication and awareness are crucial to minimize harm, and urgent action is needed for traveller well-being and global health.

Insights into substitution strategy towards thermodynamic and property regulation of chemically recyclable polymers

The development of chemically recyclable polymers serves as an attractive approach to address the global plastic pollution crisis. Monomer design principle is the key to achieving chemical recycling to monomer. Herein, we provide a systematic investigation to evaluate a range of substitution effects and structure−property relationships in the ɛ-caprolactone (CL) system. Thermodynamic and recyclability studies reveal that the substituent size and position could regulate their ceiling temperatures (Tc). Impressively, M4 equipped with a tert-butyl group displays a Tc of 241 °C. A series of spirocyclic acetal-functionalized CLs prepared by a facile two-step reaction undergo efficient ring-opening polymerization and subsequent depolymerization. The resulting polymers demonstrate various thermal properties and a transformation of the mechanical performance from brittleness to ductility. Notably, the toughness and ductility of P(M13) is comparable to the commodity plastic isotactic polypropylene. This comprehensive study is aimed to provide a guideline to the future monomer design towards chemically recyclable polymers.

Charting success for the Plastics Treaty

Charting success for the Plastics Treaty

From source to disposal: Cracking the code for sustainable polymers

The development of synthetic polymers with high stability has transformed modern life, but it has also led to a pollution crisis. Because of the useful nature of these materials, fossil fuel resources are being depleted rapidly to meet the exponentially growing demand. This increase in demand often relates to disposable items that are discarded quickly, leading to rapid accumulation of plastics in landfills and the environment. Here, we present multidisciplinary approaches that will all be needed to improve polymer sustainability, in terms of both the source of the materials and the end of life, while maintaining our quality of life. From biomass sources for the production of new plastics to the recycling and upcycling of currently produced plastics, the vast diversity of commercial plastics with different properties will need multi-pronged strategies for improvements. We hope these discussions will encourage the community to avoid a one-size-fits-all approach to polymer pollution and instead meet a complicated problem with our entire toolbox. The development of synthetic polymers with high stability has transformed modern life, but it has also led to a pollution crisis. Because of the useful nature of these materials, fossil fuel resources are being depleted rapidly to meet the exponentially growing demand. This increase in demand often relates to disposable items that are discarded quickly, leading to rapid accumulation of plastics in landfills and the environment. Here, we present multidisciplinary approaches that will all be needed to improve polymer sustainability, in terms of both the source of the materials and the end of life, while maintaining our quality of life. From biomass sources for the production of new plastics to the recycling and upcycling of currently produced plastics, the vast diversity of commercial plastics with different properties will need multi-pronged strategies for improvements. We hope these discussions will encourage the community to avoid a one-size-fits-all approach to polymer pollution and instead meet a complicated problem with our entire toolbox.