ABSTRACT
The rapid expansion of plastic manufacturing industries in last several decades has brought serious concerns over the environmental impacts of plastic wastes. Recent outbreak of Covid-19 drastically increased production, use, and disposal of plastic products. Current management strategies for wasted plastics still rely on landfill and incineration that continue to exacerbate plastic pollution and carbon emissions. Many countries have put forward multifaceted administrative efforts to reduce plastic wastes, but the annual global generation of plastic wastes is still increasing. In techno-society, researchers have been exploring more effective plastic wastes treatment technologies to alleviate environmental impacts of plastic wastes. Such efforts entailed several technical options that can potentially contribute to establishing a circular economy for plastics. Thermochemical process is a prominent example of such techniques. This review presents an overview of the issue of plastic pollution, covering topics including global plastic production, environmental impacts, and toxicity. In addition, the global administrative efforts aimed at reducing plastic pollution are discussed, as well as detection and treatment strategies to establish a circular economy in plastic management. © 2023 Elsevier B.V.
ABSTRACT
The low degradability of waste plastics will continue to pollute the environment, and the spread of the COVID-19 has exacerbated the use and accumulation of plastics, and thus the efficient treatment of waste plastic resources has become an urgent technical problem to be solved. By analyzing several mainstream waste plastics treatment technologies, it was clear that resourceful and high value-added utilization technology was the most competitive and environmentally friendly waste plastics treatment route in the market. The research progress of high value-added utilization technology of waste plastics at home and abroad in recent years were reviewed. The development and variation of conventional thermal cracking technology were discussed. Through this route, the highest yield of waste plastics into fuel products can reach 97%—98%. It was pointed out that the conversion of waste plastics into jet fuel, high value-added chemicals and functional materials for special applications through chemical, catalytic and biological technologies was the mainstream research direction and development trend in this field. Among them, the yield of conversion to high value-added monomer could reach more than 97%, so as to realize the upgrading of plastic waste from the primary treatment stage of "waste clearance” to "turning waste into use” and "turning waste into treasure”, and help China achieve the goal of "double carbon”。. © 2023 Chemical Industry Press. All rights reserved.
ABSTRACT
The COVID-19 pandemic has resulted in an alarming accumulation of plastic waste. Herein, an integrated hydropyrolysis and hydrocracking process was performed to upcycle disposable masks into fuel-range iso-alkanes over carbon supported ruthenium (Ru/C). Experimental results indicated that catalyst type significantly affected product distribution during the hydropyrolysis and vapor-phase hydrocracking of disposable masks. Compared with zeolites-induced catalytic cascade process where up to ∼25.9 wt% yield of aromatic hydrocarbons such as toluene and xylenes were generated, a ∼82.7 wt% yield of desirable iso-alkanes with a high C5–C12 gasoline selectivity of 95.5% was obtained over Ru/C under 550 °C hydropyrolysis temperature and 300 °C hydrocracking temperature at 0.2 MPa H2. The cascade hydropyrolysis and hydrocracking process also exhibited high adaptability and flexibility in upcycling single-use syringes, food packaging, and plastic bags, generating 79.1, 81.6, and 80.3 wt% yields of fuel range iso/n-alkanes, respectively. This catalytic cascade hydrotreating process provides an efficient and effective approach to convert pandemic-derived plastic waste into gasoline-range fuel products. © 2022 Elsevier Ltd
ABSTRACT
This paper aims to critically review the production of alternative fuels through medical plastic waste. In the recent past, medical plastic waste has been disposed of and incinerated in the dumping yards, which is the main cause of the threat of infection and environmental hazards. Adopting proper waste management and the appropriate technology like the 5R's (refuse, reduce, reuse, repurpose, and recycle) may significantly improve the ecosystem. Moreover, the 5R's is a comprehensive approach that can be applied, either awareness of stakeholders or enforcement mandate and regulation by the government. The current review suggested the possible route for converting medical-plastic waste into drop-in fuel and value-added products to minimize the waste through suitable technology. In this, the pyrolysis technique plays an important role which is more ecologically friendly, effective and produces minimal pollutants. It has been observed that using COVID medical waste management (CMWM) technology, 70–80 % plastic pyrolysis oil (PPO), 10–15% bio-char, and gaseous fuel can be extracted. As per the ASTM, the extracted PPO is a potential feedstock for the CI engine fuel. This review work provides a suitable solution for CMWM and improves the quality of medical infrastructure for sanitation in a sustainable mode. © 2022 Elsevier Ltd
ABSTRACT
Since the end of 2019, the world has faced a major crisis because of the outbreak of COVID-19 disease which has created a severe threat to humanity. To control this pandemic, the World Health Organization gave some guidelines like wearing PPE (personal protective equipment) (e.g., face masks, overshoes, gloves), social distancing, hand hygiene and shutting down all modes of public transport services. During this pandemic, plastic products (e.g., household plastics, PPE and sanitizer bottles) have substantially prevented the spread of this virus. Since the outbreak, approximately 1.6 million tons of plastic waste have been generated daily. However, single-use PPE like face masks (N95), surgical masks and hand gloves contain many non-biodegradable plastics materials. These abandoned products have created a huge number of plastic debris which ended up as microplastics (MPs) followed by nanoplastics (NPs) in nature that are hazardous to the eco-system. These MPs and NPs also act as vectors for the various pathogenic contaminants. The goal of this review is to offer an extensive discussion on the formation of NPs and MPs from all of these abandoned plastics and their long-term impact on the environment as well as human health. This review paper also attempts to assess the present global scenario and the main challenge of waste management to reduce the potential NP/MPs pollution to improve the eco-systems.
ABSTRACT
Due to the recent and ongoing pandemic - COVID-19 - there was an urgency to determine a method to delay the continuously rapid development of the new virus. As a result, Ultraviolet-C (UVC) light, also known as Ultraviolet Germicidal Irradiation (UVGI), has been in higher demand because of its known ability to disinfect quickly and effectively. However, because of its short wavelength/higher energy, either 222nm or 254nm, material degradation is usually much more accelerated than Ultraviolet-A (UVA) or Ultraviolet-B (UVB). At this moment, this study only observed color change when exposing polystyrene to UVC light, and it is believed that this is one of the first studies, if not the first, conducted with this material. Polystyrene was selected because of its availability, abundance of relevant research (ie. UVA/UVB exposure results), and its use in weathering standards. Additionally, since there are no standards specifically about UVC exposure, this preliminary research may provide some direction. © 2022 Society of Plastics Engineers. All rights reserved.
ABSTRACT
In response to international trends regarding the reduction in plastic waste (or plastic pollution), this work used the official statistics that were recently released, focusing on regulatory actions restricting the use of plastic products and/or the increase in recycling in Taiwan. In addition, the impacts of the COVID-19 pandemic on plastic waste generation and plastic products' recycling were also addressed in the present study. The results showed that the plastic compositions in the garbage slightly increased in recent years, suggesting that the effect of restrictions on the use of plastic products in Taiwan was not significant, even though the regulatory measures have been implemented since 2002. However, chlorine contents in the garbage were significantly increased in 2020. The increase could be attributed to the fact that kitchen waste (containing salt), household waste containing disinfectant (e.g., chlorine dioxide, sodium hypochlorite) or PVC-made products were generated more during the COVID-19 pandemic. Furthermore, the data also indicated that the monthly quantities of recycled plastic containers and other plastic products had no significant change since January 2020, especially in the outbreak period from May 2021 to July 2021.
ABSTRACT
To reveal the spatiotemporal distribution and risks of plastic additives in Taihu Lake during the COVID-19 pandemic, the occurrences of typical bisphenols, phthalate esters, and benzotriazoles in the surface water of Taihu Lake were investigated. The plastic additives in 19 sites in Taihu Lake were monitored in four seasons, and their potential ecological risks were evaluated. Diethylphthalate (DEP), dimethoxyethyl phthalate (DMEP), benzyl butyl phthalate (BBP), bisphenol A (BPA), and 2-(2H-benzotriazol-2-yl)-4, 6-di-tert-pentylphenol (UV-328) were detected, with detection rates of 100%, 97%, 58%, 98%, and 7%, respectively. During the COVID-19 pandemic, the sharply increasing usage of plastic products did not result in a significant increase in the plastic additives pollution in Taihu Lake. Conversely, the pollution of plastic additives showed a decreasing trend due to reduced human activities. There were significant seasonal differences in the concentrations of plastic additives in Taihu Lake. The average concentrations of plastic additives in spring and summer were 104.7 and 100.3 ng•L-1, respectively, which were higher than those in autumn (30.7 ng•L-1) and winter (29.9 ng•L-1). The plastic additive pollution also showed some differences in spatial distribution. The concentrations of plastic additives near the southwest coast of Taihu Lake were higher than those in other monitoring sites. The presence of plastic additives in Taihu Lake showed low risks to algae with the proportion of 30%. The risks in autumn and winter were higher than those in spring and summer. BPA and UV-328 may have been the main risk factors, which should be of concern. © 2022, Science Press. All right reserved.