Notwithstanding the end of 2009 H1N1 pandemic,the threat for its revisit still persists and WHO has warned to remain vigilant.During that lime the situation was more panicky than fatal.In this article,a suggestion to ...Notwithstanding the end of 2009 H1N1 pandemic,the threat for its revisit still persists and WHO has warned to remain vigilant.During that lime the situation was more panicky than fatal.In this article,a suggestion to minimize the panic is provided by the usage of colour-coded masks and is proposed hereby as a "population segregation" approach in case of the revisit of HlNl or similar threatening respiratory viral infections.展开更多
With extensive attention being paid to the potential environmental hazards of discarded face masks,catalytic pyrolysis technologies have been proposed to realize the valorization of wastes.However,recent catalyst sele...With extensive attention being paid to the potential environmental hazards of discarded face masks,catalytic pyrolysis technologies have been proposed to realize the valorization of wastes.However,recent catalyst selection and system design have focused solely on conversion efficiency,ignoring economic cost and potential life-cycle environmental damage.Here,we propose an economic-environmental hybrid pre-assessment method to help identify catalysts and reactors with less environmental impact and high economic returns among various routes to convert discarded face masks into carbon nanotubes(CNTs)and hydrogen.In catalyst selection,it was found that a widely known Fe-Ni catalyst exhibits higher catalytic activity than a cheaper Fe catalyst,potentially increasing the economic viability of the catalytic pyrolysis system by 38%-55%.The use of this catalyst also results in a carbon reduction of 4.12-10.20kilogram CO_(2) equivalent for 1 kilogram of discarded face masks,compared with the cheaper Fe catalyst.When the price of CNTs exceeds 1.49×10^(4) USD·t^(-1),microwave-assisted pyrolysis is the optimal choice due to its superior environmental performance(in terms of its life-cycle greenhouse gas reduction potential,eutrophication potential,and human toxicity)and economic benefits.In contrast,conventional heating pyrolysis may be a more economical option due to its good stability over 43 reaction regeneration cycles,as compared with a microwave-assisted pyrolysis catalyst with a higher conversion efficiency.This study connects foundational science with ecological economics to guide emerging technologies in their research stage toward technical efficiency,economic benefits,and environmental sustainability.展开更多
Over 950 billion(about 3.8 million tons)masks have been consumed in the last four years around the world to protect human beings from COVID-19 and air pollution.However,very few of these used masks are being recycled,...Over 950 billion(about 3.8 million tons)masks have been consumed in the last four years around the world to protect human beings from COVID-19 and air pollution.However,very few of these used masks are being recycled,with the majority of them being landfilled or incinerated.To address this issue,we propose a repurposing upcycling strategy by converting these polypropylene(PP)-based waste masks to highperformance thermally conductive nanocomposites(PP@G,where G refers to graphene)with exceptional electromagnetic interference shielding property.The PP@G is fabricated by loading tannic acid onto PP fibers via electrostatic self-assembling,followed by mixing with graphene nanoplatelets(GNPs).Because this strategy enables the GNPs to form efficient thermal and electrical conduction pathways along the PP fiber surface,the PP@G shows a high thermal conductivity of 87 W m^(-1)K^(-1)and exhibits an electromagnetic interference shielding effectiveness of 88 dB(1100 dB cm^(−1)),making it potentially applicable for heat dissipation and electromagnetic shielding in advanced electronic devices.Life cycle assessment and techno-economic assessment results show that our repurposing strategy has significant advantages over existing methods in reducing environmental impacts and economic benefits.This strategy offers a facile and promising approach to upcycling/repurposing of fibrous waste plastics.展开更多
In the context of global COVID-19 epidemic preparedness,the extensive use of disposable surgical masks(DSM)may lead to its emergence as a main new source of microplastics in the environment.Nowadays,DSMs have become a...In the context of global COVID-19 epidemic preparedness,the extensive use of disposable surgical masks(DSM)may lead to its emergence as a main new source of microplastics in the environment.Nowadays,DSMs have become a non-negligible source of plastic waste in aquatic environment,however,less research has been done on DSM after biofilm colonization in freshwater environment.The study investigated the microbial community of DSM-associated biofilms by 16S rRNA gene sequencing.Analysis of the microbial community in the middle and inner/outer layers of the DSM showed that the middle layer was different from the remaining two layers and that potential pathogens were enriched only in the middle layer of the DSM.Herein,we focused on the middle layer and explored the characterization properties and extracellular polymeric substances(EPS)components changes during biofilm formation.The results showed that the EPS components varied with the biofilm incubation time.As the formation of biofilm,the protein(PN)and polysaccharide(PS)in EPS showed an overall increasing trend,and the growth of PS was well synchronized with PN.Three fluorescent components of EPS were determined by the three-dimensional excitation emission matrix(3D-EEM),including humic acid-like,fulvic acid-like,and aromatic protein-like components.The percentage of fluorescent components varied with increasing biofilm development time and then stabilized.Fourier transform infrared spectroscopy(FTIR)characterization results elucidated the emergence of oxygen-containing functional groups during biofilm formation.Moreover,the hydrophilicity increased with biofilm development.In conclusion,the environmental behavior and ecological risks of DSM in aquatic environment deserve urgent attention in future studies.展开更多
The outbreak of coronavirus has led to an increase in the demand for facemasks globally. Unavailability of appropriate polypropylene non-woven fabrics face masks as a result of inadequate supply to satisfy the growing...The outbreak of coronavirus has led to an increase in the demand for facemasks globally. Unavailability of appropriate polypropylene non-woven fabrics face masks as a result of inadequate supply to satisfy the growing population has brought about the manufacturing of locally fabrics masks to augment or substitute standard medical class facemasks. The study aims at analyzing airflow of these locally manufactured fabrics to determine possible means of transmitting the virus as well as establish comfort of the user of these masks. Standard polypropylene non-woven, woven and knitted fabrics were considered for the study. Air permeability test was conducted on these fabrics using Frazier Air permeability tester. Depending on the property significant variation in the textile fabrics, polypropylene non-woven is widely accepted for facial masks. Nevertheless, this study illustrates that woven and knitted fabrics have more open structures, which allow a high rate of air penetration and so may require two or three layers to prevent antimicrobial or antiviral potential.展开更多
By using two PM2.5 automatic monitors,the protective effects of five common masks against PM2.5 were synchronously tested under actual ambient air conditions for a whole day. The results showed that not all masks had ...By using two PM2.5 automatic monitors,the protective effects of five common masks against PM2.5 were synchronously tested under actual ambient air conditions for a whole day. The results showed that not all masks had protective effects on PM2.5,and the protective effects of masks N95 and N90,which were designed specially for dust-proof,were superior among the five tested masks.展开更多
The exact risk association of coronavirus disease 2019(COVID-19)for surgeons is not quantified which may be affected by their risk of exposure and individual factors.The objective of this review is to quantify the ris...The exact risk association of coronavirus disease 2019(COVID-19)for surgeons is not quantified which may be affected by their risk of exposure and individual factors.The objective of this review is to quantify the risk of COVID-19 among surgeons,and explore whether facemask can minimise the risk of COVID-19 among surgeons.A systematised review was carried out by searching MEDLINE to locate items on severe acute respiratory syndrome coronavirus 2 or COVID-19 in relation to health care workers(HCWs)especially those work in surgical specialities including surgical nurses and intensivists.Additionally,systematic reviews that assessed the effectiveness of facemask against viral respiratory infections,including COVID-19,among HCWs were identified.Data from identified articles were abstracted,synthesised and summarised.Fourteen primary studies that provided data on severe acute respiratory syndrome coronavirus 2 infection or experience among surgeons and 11 systematic reviews that provided evidence of the effectiveness of facemask(and other personal protective equipment)were summarised.Although the risk of COVID-19 could not be quantified precisely among surgeons,about 14%of HCWs including surgeons had COVID-19,there could be variations depending on settings.Facemask was found to be somewhat protective against COVID-19,but the HCWs’compliance was highly variable ranging from zero to 100%.Echoing surgical societies’guidelines we continue to recommend facemask use among surgeons to prevent COVID-19.展开更多
文摘Notwithstanding the end of 2009 H1N1 pandemic,the threat for its revisit still persists and WHO has warned to remain vigilant.During that lime the situation was more panicky than fatal.In this article,a suggestion to minimize the panic is provided by the usage of colour-coded masks and is proposed hereby as a "population segregation" approach in case of the revisit of HlNl or similar threatening respiratory viral infections.
基金supported by the National Natural Science Foundation of China(52076099,52306257,and 72293601)。
文摘With extensive attention being paid to the potential environmental hazards of discarded face masks,catalytic pyrolysis technologies have been proposed to realize the valorization of wastes.However,recent catalyst selection and system design have focused solely on conversion efficiency,ignoring economic cost and potential life-cycle environmental damage.Here,we propose an economic-environmental hybrid pre-assessment method to help identify catalysts and reactors with less environmental impact and high economic returns among various routes to convert discarded face masks into carbon nanotubes(CNTs)and hydrogen.In catalyst selection,it was found that a widely known Fe-Ni catalyst exhibits higher catalytic activity than a cheaper Fe catalyst,potentially increasing the economic viability of the catalytic pyrolysis system by 38%-55%.The use of this catalyst also results in a carbon reduction of 4.12-10.20kilogram CO_(2) equivalent for 1 kilogram of discarded face masks,compared with the cheaper Fe catalyst.When the price of CNTs exceeds 1.49×10^(4) USD·t^(-1),microwave-assisted pyrolysis is the optimal choice due to its superior environmental performance(in terms of its life-cycle greenhouse gas reduction potential,eutrophication potential,and human toxicity)and economic benefits.In contrast,conventional heating pyrolysis may be a more economical option due to its good stability over 43 reaction regeneration cycles,as compared with a microwave-assisted pyrolysis catalyst with a higher conversion efficiency.This study connects foundational science with ecological economics to guide emerging technologies in their research stage toward technical efficiency,economic benefits,and environmental sustainability.
基金the National Key Research and Development Program of China(2023YFD2201404)the National Natural Science Foundation of China Youth Fund(No.52103072)+2 种基金Beijing Natural Science Foundation(No.2222068)5·5 Engineering Research&Innovation Team Project of Beijing Forestry University(No:BLRC2023A02)the Regional Research Collaboration(RRC)Program-“Sustainable Industry Manufacturing Planning for Long‑term Ecosystems(SIMPLE)Hub”.
文摘Over 950 billion(about 3.8 million tons)masks have been consumed in the last four years around the world to protect human beings from COVID-19 and air pollution.However,very few of these used masks are being recycled,with the majority of them being landfilled or incinerated.To address this issue,we propose a repurposing upcycling strategy by converting these polypropylene(PP)-based waste masks to highperformance thermally conductive nanocomposites(PP@G,where G refers to graphene)with exceptional electromagnetic interference shielding property.The PP@G is fabricated by loading tannic acid onto PP fibers via electrostatic self-assembling,followed by mixing with graphene nanoplatelets(GNPs).Because this strategy enables the GNPs to form efficient thermal and electrical conduction pathways along the PP fiber surface,the PP@G shows a high thermal conductivity of 87 W m^(-1)K^(-1)and exhibits an electromagnetic interference shielding effectiveness of 88 dB(1100 dB cm^(−1)),making it potentially applicable for heat dissipation and electromagnetic shielding in advanced electronic devices.Life cycle assessment and techno-economic assessment results show that our repurposing strategy has significant advantages over existing methods in reducing environmental impacts and economic benefits.This strategy offers a facile and promising approach to upcycling/repurposing of fibrous waste plastics.
基金Supported by the Natural Science Foundation of Shandong Province(Nos.ZR2022MD115,ZR202111160067)。
文摘In the context of global COVID-19 epidemic preparedness,the extensive use of disposable surgical masks(DSM)may lead to its emergence as a main new source of microplastics in the environment.Nowadays,DSMs have become a non-negligible source of plastic waste in aquatic environment,however,less research has been done on DSM after biofilm colonization in freshwater environment.The study investigated the microbial community of DSM-associated biofilms by 16S rRNA gene sequencing.Analysis of the microbial community in the middle and inner/outer layers of the DSM showed that the middle layer was different from the remaining two layers and that potential pathogens were enriched only in the middle layer of the DSM.Herein,we focused on the middle layer and explored the characterization properties and extracellular polymeric substances(EPS)components changes during biofilm formation.The results showed that the EPS components varied with the biofilm incubation time.As the formation of biofilm,the protein(PN)and polysaccharide(PS)in EPS showed an overall increasing trend,and the growth of PS was well synchronized with PN.Three fluorescent components of EPS were determined by the three-dimensional excitation emission matrix(3D-EEM),including humic acid-like,fulvic acid-like,and aromatic protein-like components.The percentage of fluorescent components varied with increasing biofilm development time and then stabilized.Fourier transform infrared spectroscopy(FTIR)characterization results elucidated the emergence of oxygen-containing functional groups during biofilm formation.Moreover,the hydrophilicity increased with biofilm development.In conclusion,the environmental behavior and ecological risks of DSM in aquatic environment deserve urgent attention in future studies.
文摘The outbreak of coronavirus has led to an increase in the demand for facemasks globally. Unavailability of appropriate polypropylene non-woven fabrics face masks as a result of inadequate supply to satisfy the growing population has brought about the manufacturing of locally fabrics masks to augment or substitute standard medical class facemasks. The study aims at analyzing airflow of these locally manufactured fabrics to determine possible means of transmitting the virus as well as establish comfort of the user of these masks. Standard polypropylene non-woven, woven and knitted fabrics were considered for the study. Air permeability test was conducted on these fabrics using Frazier Air permeability tester. Depending on the property significant variation in the textile fabrics, polypropylene non-woven is widely accepted for facial masks. Nevertheless, this study illustrates that woven and knitted fabrics have more open structures, which allow a high rate of air penetration and so may require two or three layers to prevent antimicrobial or antiviral potential.
基金Supported by the Monitoring Scientific Research Foundation of Jiangsu Province,China in 2013(1321)
文摘By using two PM2.5 automatic monitors,the protective effects of five common masks against PM2.5 were synchronously tested under actual ambient air conditions for a whole day. The results showed that not all masks had protective effects on PM2.5,and the protective effects of masks N95 and N90,which were designed specially for dust-proof,were superior among the five tested masks.
文摘The exact risk association of coronavirus disease 2019(COVID-19)for surgeons is not quantified which may be affected by their risk of exposure and individual factors.The objective of this review is to quantify the risk of COVID-19 among surgeons,and explore whether facemask can minimise the risk of COVID-19 among surgeons.A systematised review was carried out by searching MEDLINE to locate items on severe acute respiratory syndrome coronavirus 2 or COVID-19 in relation to health care workers(HCWs)especially those work in surgical specialities including surgical nurses and intensivists.Additionally,systematic reviews that assessed the effectiveness of facemask against viral respiratory infections,including COVID-19,among HCWs were identified.Data from identified articles were abstracted,synthesised and summarised.Fourteen primary studies that provided data on severe acute respiratory syndrome coronavirus 2 infection or experience among surgeons and 11 systematic reviews that provided evidence of the effectiveness of facemask(and other personal protective equipment)were summarised.Although the risk of COVID-19 could not be quantified precisely among surgeons,about 14%of HCWs including surgeons had COVID-19,there could be variations depending on settings.Facemask was found to be somewhat protective against COVID-19,but the HCWs’compliance was highly variable ranging from zero to 100%.Echoing surgical societies’guidelines we continue to recommend facemask use among surgeons to prevent COVID-19.
