CATALYTIC PYROLYSIS OF DISCARDED COVID-19 MASKS OVER SEPIOLITE

This research aims to develop a new strategy to valorize wasted COVID-19 masks based on pyrolysis to convert them into useful products. First, surgical and FFP2 masks were thermally pyrolyzed at temperatures of 450–550 ºC with the purpose of determining gas, liquid (oil) and solid (char) yields. At low temperatures, solid yield was high, while at high temperatures the gas product was enhanced. The highest yield of liquid was found at an operating temperature of 500 ºC in both surgical and FPP2 masks pyrolysis. The liquid product yields were 59.08% and 58.86%, respectively. Then, the volatiles generated during thermal pyrolysis of residual masks were cracked over sepiolite as catalyst at a temperature of 500 ºC. The catalytic pyrolysis increased the yield of gas product (43.89% against 39.52% for surgical masks and 50.53% against 39.41% for FFP2 masks) and decreased the viscosity of the liquid product. Finally, the effect of sepiolite regeneration and reuse in consecutive pyrolysis tests was examined. Results showed that, with the higher regeneration-reuse of sepiolite, the catalyst was degraded obtaining a liquid product with higher molecular mass. This effect was hardly noticeable in the case of FFP2 masks. © 2022 International Multidisciplinary Scientific Geoconference. All rights reserved.

Strategic use of thermo-chemical processes for plastic waste valorization

Plastic is one of the most widely used materials in industries including packaging, building, and construction due to its lightweight, low cost, durability, and versatility. However, the mass production of plastics has exacerbated plastic pollution. Globally, plastic waste is predominantly incinerated, landfilled, or released into the environment;only 5-6% is recycled in the United States. Although conventional management protocols such as incineration and landfilling are evidently effective for plastic waste disposal, they are associated with significant environmental and societal challenges. In addition, most recycled plastic is downcycled, and thus does not provide sufficient incentive to use recycled materials instead of virgin materials. This review discusses thermo-chemical upcycling processes such as (catalytic) pyrolysis and heterogeneous catalysis. Furthermore, we present the recent progress in the thermo-chemical upgrading of single-type plastic waste, heterogeneous plastic mixtures, and post-consumer plastic waste obtained from different locations and, finally, suggest future research directions.

Demographic characteristics with compliance on the implementation of health protocol on ship passengers.

Objectives: To analyse the relationship of demographic characteristics with coronavirus disease-2019 protocol compliance among ship passengers. Method: The descriptive, correlational, cross-sectional study was conducted in May 2022 at the harbour in East Java, Indonesia, after approval from the ethics review committee of Universitas Airlangga, Indonesia, and comprised individuals of either gender aged 18-65 years who had a passenger ship departure ticket and were able to communicate well in the Indonesian language. Data related to demographic characteristics and coronavirus disease-2019 standard protocol compliance. Data was analysed using SPSS 25. RESULTS: Of the 157 subjects, 71(45.2%) were males, 86(54.8%) were females, 68(43.3%) were aged 26-45 years, 79(50.2%) had studied up to the bachelor's level,106(66.2%) were employees, 89(56.7%) had earnings below the provincial standard, and 116(73.9%) were married. Health protocol compliance at the harbour had a significant correlation with gender, age, education, occupation and income (p<0.05). CONCLUSIONS: The factors related to the compliance of the coronavirus disease-2019 protocol at the harbour were gender, age, education, occupation and income.

Pandemic diplomacy and patron–client relations in Sino-Serbian cooperation

Since the outbreak of the COVID-19 pandemic, the authorities of Serbia have undertaken a concerted effort to secure China's support in containing the coronavirus. This asymmetrical cooperation, apart from aspects concerning health security, has allowed both sides to obtain considerable political and economic benefits. This article examines how China and Serbia utilize pandemic cooperation to pursue and realize their wider foreign and internal policy goals through patron–client ties, as well as highlighting the pitfalls of this kind of relationship. Although the outbreak of the pandemic and the medical cooperation that followed do not constitute a turning point in the well-established relations between the two countries, the article argues that pandemic cooperation has considerably strengthened relations. In many ways, the pattern observed by the authors resembles China's pandemic exchanges with other countries, especially smaller states with authoritarian inclinations. © The Author(s) 2023.

Research on Mask Wearing Recognition Based on Deep Learning

Since the outbreak of COVID-19 epidemic, research results have shown that the COVID-19 transmitted by droplets, and the most effective means of epidemic prevention is to wear masks. In public places where crowds gather, it is particularly important to use technical means to detect the situation of wearing masks, and remind people to wear masks in time to prevent cross-infection. This paper mainly starts with the target detection and tracking technology in the field of computer vision, and takes the recognition of whether to wear a mask as the entry point. Using python as the development tool, based on the convolutional neural network, the YOLOv2 algorithm is used as the core algorithm, and the ResNet50 network structure is built. Compared with other existing system test experiments, we can see that the system we built has better detection performance. © 2022 Association for Computing Machinery.

Medical Assistance Robot with capabilities of Mask Detection with Automatic Sanitization and Social Distancing Detection/ Awareness

Healthcare sectors such as hospitals, nursing homes, medical offices, and hospice homes encountered several obstacles due to the outbreak of Covid-19. Wearing a mask, social distancing and sanitization are some of the most effective methods that have been proven to be essential to minimize the virus spread. Lately, medical executives have been appointed to monitor the virus spread and encourage the individuals to follow cautious instructions that have been provided to them. To solve the aforementioned challenges, this research study proposes an autonomous medical assistance robot. The proposed autonomous robot is completely service-based, which helps to monitor whether or not people are wearing a mask while entering any health care facility and sanitizes the people after sending a warning to wear a mask by using the image processing and computer vision technique. The robot not only monitors but also promotes social distancing by giving precautionary warnings to the people in healthcare facilities. The robot can assist the health care officials carrying the necessities of the patent while following them for maintaining a touchless environment. With thorough simulative testing and experiments, results have been finally validated. © 2022 IEEE.

Access Control Through Mask Detection and Estimation of People Capacity in Covered Premises

The health emergency due to the COVID-19 pandemic requires the search for technological and intelligent solutions that facilitate the control of biosecurity measures such as social distancing, to use of a mask, and capacity in covered spaces. This work aims to develop a prototype based on artificial vision algorithms, capable of performing the automatic mask detection and people counting who go to covered premises such as bars, restaurants, gyms, cinemas, and micro-market among others. The prototype implements SSD-MobileNet object detection and SORT tracking algorithms that work on the electronic device NVIDIA Jetson Nano, equipped with two video cameras to perform mask detection and people counting respectively, as well as speakers, for emission of audible alert messages about the use of mask and the capacity estimation within the premise and an external web server too in which people counter information is displayed. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

Property assessment of an eco-friendly mortar reinforced with recycled mask fiber derived from COVID-19 single-use face masks

Wearing a face mask is strongly advised to prevent the spread of the virus causing the COVID-19 pandemic, though masks have produced a tremendous amount of waste. As masks contain polypropylene and other plastics products, total degradation is not achievable, and masks may remain in the form of microplastics for several years in the environment. Therefore, this urgent issue ought to be addressed by properly handling waste face masks to limit their environmental impact. In relation to this goal, a novel application of recycled mask fiber (MF) derived from COVID-19 single-use surgical face masks (i.e., shredded mask fiber-SMF and cut mask fiber-CMF) has been undertaken. Eighteen mortar mixes (9 for water and 9 for 10% CO2 concentration curing) were fabricated at 0%, 0.5%, 1.0%, 1.5%, and 2.0% of both SMF and CMF by volume of ordinary Portland cement-based mortar. The compressive strength, flexural strength, ultrasonic pulse velocity, shrinkage, carbonation degree, permeable voids, and water absorption capabilities were assessed. The outcomes reveal that the compressive strength decreased with an increased percentage of MFs due to increased voids of the mixes with MFs as compared to a control mix. In contrast, significantly higher flexural strength was noted for the mortar with MFs, which is augmented with an increased percentage of MFs. Furthermore, the inclusion of MFs decreased the shrinkage of the mortar compared to the control mix. It was also found that MFs dramatically diminished the water absorption rate compared to the control mix, which reveals that MFs can enhance the durability of the mortar. © 2023 Elsevier Ltd

Property assessment of an eco-friendly mortar reinforced with recycled mask fiber derived from COVID-19 single-use face masks

Wearing a face mask is strongly advised to prevent the spread of the virus causing the COVID-19 pandemic, though masks have produced a tremendous amount of waste. As masks contain polypropylene and other plastics products, total degradation is not achievable, and masks may remain in the form of microplastics for several years in the environment. Therefore, this urgent issue ought to be addressed by properly handling waste face masks to limit their environmental impact. In relation to this goal, a novel application of recycled mask fiber (MF) derived from COVID-19 single-use surgical face masks (i.e., shredded mask fiber-SMF and cut mask fiber-CMF) has been undertaken. Eighteen mortar mixes (9 for water and 9 for 10% CO2 concentration curing) were fabricated at 0%, 0.5%, 1.0%, 1.5%, and 2.0% of both SMF and CMF by volume of ordinary Portland cement-based mortar. The compressive strength, flexural strength, ultrasonic pulse velocity, shrinkage, carbonation degree, permeable voids, and water absorption capabilities were assessed. The outcomes reveal that the compressive strength decreased with an increased percentage of MFs due to increased voids of the mixes with MFs as compared to a control mix. In contrast, significantly higher flexural strength was noted for the mortar with MFs, which is augmented with an increased percentage of MFs. Furthermore, the inclusion of MFs decreased the shrinkage of the mortar compared to the control mix. It was also found that MFs dramatically diminished the water absorption rate compared to the control mix, which reveals that MFs can enhance the durability of the mortar.

Hydrogen-rich gas production from disposable COVID-19 mask by steam gasification.

Globally, the demand for masks has increased due to the COVID-19 pandemic, resulting in 490,201 tons of waste masks disposed of per month. Since masks are used in places with a high risk of virus infection, waste masks retain the risk of virus contamination. In this study, a 1 kg/h lab-scale (diameter: 0.114 m, height: 1 m) bubbling fluidized bed gasifier was used for steam gasification (temperature: 800 °C, steam/carbon (S/C) ratio: 1.5) of waste masks. The use of a downstream reactor with activated carbon (AC) for tar cracking and the enhancement of hydrogen production was examined. Steam gasification with AC produces syngas with H2, CO, CH4, and CO2 content of 38.89, 6.40, 21.69, and 7.34 vol%, respectively. The lower heating value of the product gas was 29.66 MJ/Nm3 and the cold gas efficiency was 74.55 %. This study showed that steam gasification can be used for the utilization of waste masks and the production of hydrogen-rich gas for further applications.

The life of COVID-19 mask memes: A diachronic study of the pandemic memescape

Taking as its point of departure a fine-tuned definition of an Internet meme (vis-a-vis a memetic construct), this paper reports the findings of the first diachronic study of memes, the focus being on mask memes on the vast COVID-19 mask memescape evolving in the wake of the pandemic, relative to the changing socio-political situation. The study capitalises on a diachronic corpus of user-tagged COVID-19 mask memes (posted online from January 2020 to January 2021) collected from Google through a Python script. Based on a grounded-theory approach, ten memetic categories (clustered into four groups) are extracted and examined through a multimodal discourse analytic lens. The diachronic quantitative analysis shows that the memetic constructs, inspired by the current socio-political situation/events and facilitated by the socio-political context (e.g. going into lockdown), seem to persist, albeit with varied intensity, for the best part of the year, with many individual memes going viral. Memes' and memetic constructs' long lifespan is indicative of users' primary goal, which is to share interesting and/or humorous (not always newly minted or relevant) items for the sake of fun, regardless of the memes' nature (i.e. autotelic humour for its own sake or users' commentaries on the surrounding reality).

A new strategy for butanol extraction from COVID-19 mask using catalytic pyrolysis process over ZSM-5 zeolite catalyst and its kinetic behaviour

This research aims to develop a new thermochemical strategy to extract butane from the billions of wasted Covid-19 masks that are generated every month. The experiments were conducted with 3-ply face masks (3PFM) over ZSM-5 zeolite with different ratios of ZSM-5 to 3PFM (w/w: 6, 12, 25, and 50 wt.%) using thermogravimetry (TGA) at different heating conditions. Also, the effect of ZSM-5 concentration and heating rates was examined using TG-FTIR and GC-MS measurements. Besides, the kinetics behaviour of the developed strategy was modelled using linear and nonlinear isoconversional modelling techniques, thus calculating the activation energy (Ea) for each conversion region. Finally, all required parameters to fit TGA and differential scanning calorimetry (DTG) experimental curves were estimated using the distributed activation energy (DAEM) and the independent parallel reactions (IPR) techniques, respectively. The results showed that the decomposed samples are very rich in aromatic and aliphatic (-C-H) compounds. Meanwhile, and based on GC-MS results, butanol compound was the basic component in the generated compounds with abundance of 31% at 25 wt.% of ZSM-5 at lowest heating rate (5 ˚C/min), whereas the average Ea at 25% of ZSM-5 (sample enriched with butanol) was estimated in the ranges 158-187 kJ mol−1 (linear methods with R2 > 0.96) and 167-169 kJ/mol (nonlinear methods with R2 > 0.98). Finally, DAEM and IPR succeeded to simulate TGA and DTG curves of ZSM-5/3PFM samples with very small deviation. Based on that, the catalytic pyrolysis strategy over ZSM-5 zeolite can be used effectively to dispose of Covid-19 masks and to convert them into butanol compound that can be used as a liquid fuel and lubricant.

Pyrolysis of COVID-19 disposable masks and catalytic cracking of the volatiles.

The disposable masks generated in the battle against COVID-19 has attracted wide attention in the world. Pyrolysis can convert the masks into useful chemicals and fuels. In this work, the masks are pyrolyzed at temperatures of 400-580 °C and the volatiles generated are cracked without or with catalysts at 440-580 °C. The catalysts used include metal oxides (Al2O3, kaolin, Fe2O3, CeO2, TiO2) and molecular sieves (HZSM5, HY, ß(25H), ß(60H)). The yields and composition of gas and liquid products are studied in detail where the tetrahydrofuran (THF) soluble compounds are defined as the liquid product and the n-hexane soluble compounds are defined as the oil. The liquid product and the oil were identified by GC-MS and quantified by GC. Results indicate that 440 °C is sufficient for the masks' pyrolysis and the yields of gas, liquid product and oil are 23.4, 74.7 and 42.1 wt%, respectively. About 30% of the liquid product are C6-C35 hydrocarbons while about 70% are C36-C70 hydrocarbons trapped in the GC column (termed as column residue). The gas products are mainly C5, propylene and butene, accounting for 54.8%, 22.8% and 14.5% of the total gas product, respectively. Cracking of volatiles over various catalysts converts the liquid product mainly to propylene, butene and smaller organic gases. TiO2, HY and ß(60H) are good catalysts, especially ß(60H), which increases the yield of gas product to 86.5 wt% with 73.0% being ethylene, propylene and butene at 580 °C.

Valorization of hazardous COVID-19 mask waste while minimizing hazardous byproducts using catalytic gasification.

This study proposes a method to valorize hazardous waste such as used COVID-19 face mask via catalytic gasification over Ni-loaded ZSM-5 type zeolites. The 25% Ni was found as an optimal loading on ZSM-5 in terms of H2 production. Among different zeolites (ZSM-5(30), ZSM-5(80), ZSM-5(280), mesoporous (m)-ZSM-5(30), and HY(30)), 25% Ni/m-ZSM-5(30) led to the highest H2 selectivity (45.04 vol%), most likely because of the highest Ni dispersion on the m-ZSM-5(30) surface, high porosity, and acid site density of the m-ZSM-5(30). The content of N-containing species (e.g., caprolactum and nitriles) in the gasification product was also reduced, when steam was used as gasifying agent, which is the source of potentially hazardous air pollutants (e.g., NOx). The increase in the SiO2/Al2O3 ratio resulted in lower tar conversion and lower H2 generation. At comparable conditions, steam gasification of the mask led to ~15 vol% higher H2 selectivity than air gasification. Overall, the Ni-loaded zeolite catalyst can not only suppress the formation of hazardous substances but also enhance the production of hydrogen from the hazardous waste material such as COVID-19 mask waste.

A simple HEPA filtering facepiece.

Shortages of efficient filtering facepiece respirators leave the public vulnerable to transmission of infectious diseases in small particle aerosols. This study demonstrates that a high-filtration-efficiency facepiece capable of filtering out >95% of 0.05µm particles while being worn can be simply produced with available materials.