Pyrolysis: An effective technique for degradation of COVID-19 medical wastes

A review on emergency disposal and management of medical waste during the COVID-19 pandemic in China

The surge of medical waste (MW) generated during the COVID-19 pandemic has exceeded the disposal capacity of existing facilities. The timely, safe, and efficient emergency disposal of MW is critical to prevent the epidemic spread. Therefore, this review presents the current status of MW generation and disposal in China and analyzes the characteristics and applicability of emergency disposal technologies. The results show that movable disposal facilities can dispose of infectious MW on site, even though most of their disposal capacity is at a low level (<5 t/day). Co-disposal facilities need to be reformed completely for emergency MW disposal, in which separate feeding systems should be taken seriously. Specifically, municipal solid waste (MSW) incineration facilities have great potential to improve emergency MW disposal capacities. For hazardous waste incineration facilities, compatibility of the wastes must be matched to the composition and calorific value of the waste. As for cement kiln, MW can only be used as an alternative fuel instead of a raw material for cement. Based on the environmental risk and technical adaptability, the six emergency MW disposal technologies are recommended to be prioritized as follows: movable microwave sterilization, movable steam sterilization, movable incineration, co-incineration with hazardous waste, co-incineration with MSW and co-disposal in cement kilns. Infectious MW, especially COVID-19 MW, should be prioritized for disposal by centralized and movable disposal facilities, while non-infectious MW can be disposed of using co-disposal facilities. All stakeholders should strengthen the delicacy management of the end-of-life stage of MW, including collection, classification, packaging identification, transportation, and disposal. Currently, it is necessary for centralized disposal enterprises to follow the emergency disposal operation flowchart. From a long-term strategic perspective, making full use of regional movable and co-disposal facilities in the megacities can effectively enhance the emergency MW disposal capacity.

Waste surgical masks to fuels via thermochemical co-processing with waste motor oil and biomass

In this work, the co-processing of waste surgical masks, waste motor oil, and biomass was investigated to reduce the environmental impacts of the increasing medical-derived plastic pollution as well as to elucidate its effect on the production of chemicals . The results showed high yields towards an oily product with an interesting hydrocarbon content in the diesel range. Furthermore, although the initial waste motor oil had a high sulfur content, the oily products showed a low sulfur content, that was logically distributed in the solid and gas phases. In addition, all oily products presented HHVs ​​higher than 44 MJ/Kg, with cetane indices, densities, and viscosities lower than those of petroleum-derived diesel. This work could impact on the management of waste surgical masks and the joint recovery of everyday waste towards high value-added products.

Systematic Literature Review and Bibliometric Study of Waste Management in Indonesia in the COVID-19 Pandemic Era

It is globally known that the COVID-19 pandemic affected all aspects of society, including issues pertaining to health, economic, social, and environmental issues. The pandemic has already continued for two years and counting, and we are now advised to live coexisting with COVID-19 in the new normal era. During this new normal era, especially in Indonesia, many medical wastes (face masks, gloves, goggles, etc.) and other type of wastes are being generated due to COVID-19. However, the waste profile (waste management or waste handling) and the specific waste distribution in Indonesia during COVID-19 is not clearly understood. Therefore, in this study we perform a systematic literature review and bibliometric analysis of studies published during COVID-19 to describe the aforementioned issues regarding waste management in Indonesia by extracting data from Scopus as a leading indexing service for peer-reviewed publications. From more than 230,000 titles in Scopus regarding COVID-19, there are only 24 titles related to waste management in Indonesia during COVID-19. From the bibliometric analysis of the extracted data from Scopus, it can be observed that there are four clusters of interest, namely (1) medical waste and its processing, (2) COVID-19-related issues, (3) Indonesia and waste management, and (4) solid waste. The study of these issues is essential to obtain not only a clean environment, but also a sustainable future for an Indonesia that is free from COVID-19 and other related diseases in the future. Moreover, the bibliometric analysis also uncovers the research and publication gap for the topic of waste management in Indonesia in the COVID-19 pandemic era.

COVID-19 and industrial waste mitigation via thermochemical technologies towards a circular economy: A state-of-the-art review

The increasing awareness of waste circular economy has motivated valorization strategies for minimizing resource consumption and waste production in the private sector. With the rise of various industrial wastes and with the emergence of COVID-19 wastes, a sustainable approach is needed to mitigate the growing concern about wastes. Thermochemical treatment technologies in the form of direct combustion, torrefaction, pyrolysis, and gasification have been identified to have vital roles in the value-creation of various waste streams. Moreover, the alignment of thermochemical processes for waste mitigation concerning the circular economy framework needs to be established. Accordingly, a comprehensive review of the different thermochemical treatment options for industrial and the novel COVID-19 medical wastes streams is conducted in this study. This review focuses on highlighting the instrumental role of thermochemical conversion platforms in achieving a circular economy in the industrial sector. Various strategies in waste mitigation through various thermochemical processes such as management, recovery, reduction, and treatment are discussed. The results show that thermochemical technologies are beneficial in addressing the sustainability concerns on mitigating wastes from the industrial sector and wastes brought by the COVID-19 pandemic. This also includes the current issues faced as well as future perspectives of the thermochemical conversion technologies.

Challenges Faced in Large-Scale Nucleic Acid Testing during the Sudden Outbreak of the B.1.617.2 (Delta)

The Delta variant (B.1.617.2) has dominated in many countries over the world. Its sudden outbreak in China has led the government to quickly carry out large-scale nucleic acid testing to curb its spread. This qualitative study aims to find the challenges based on empirical evidence from the perspectives of the different groups of people involved in the testing, and further explore possible strategies to improve the efficiency of large-scale nucleic acid testing. Using a phenomenological approach, we selected 35 participants (seven managers, eight health professionals, six community volunteers and 14 residents) by purposive sampling. The interviews were conducted by in-depth semi-structured interviews and the data were analyzed by Colaizzi’s seven-step method. Qualitative analysis revealed three main themes: unreasonable and unsafe testing points layout settings, human and medical resources challenges, and potential infection risk. From the different angles, participants all experienced challenges during large-scale nucleic acid testing, making positive planning and adequate preparation important parts of the smooth development of testing. Large-scale nucleic acid testing relies on the cooperation and efforts of all to support containment of the spread of the virus. Local governments should improve their ability to respond to and deal with public health emergencies.

Waste Face Surgical Mask Transformation into Crude Oil and Nanostructured Electrocatalysts for Fuel Cells and Electrolyzers

A novel route for the valorization of waste into valuable products was developed. Surgical masks commonly used for COVID 19 protection by stopping aerosol and droplets have been widely used, and their disposal is critical and often not properly pursued. This work intended to transform surgical masks into platinum group metal-free electrocatalysts for oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER) as well as into crude oil. Surgical masks were subjected to controlled-temperature and -atmosphere pyrolysis, and the produced char was then converted into electrocatalysts by functionalizing it with metal phthalocyanine of interest. The electrocatalytic performance characterization towards ORR and HER was carried out highlighting promising activity. At different temperatures, condensable oil fractions were acquired and thoroughly analyzed. Transformation of waste surgical masks into electrocatalysts and crude oil can open new routes for the conversion of waste into valuable products within the core of the circular economy.

Resource Resurgence from COVID-19 Waste via Pyrolysis: a Circular Economy Approach

Since the end of 2019, COVID-19 pandemic has affected 220 countries and currently majority of the world is facing the wrath of the second wave. One of the outcomes of the ongoing pandemic is the generation of huge amount of solid polymeric "COVID-waste" comprising medical waste, personal protective equipment (PPE) waste, packaging waste, and other household waste with potential infectious components residing on it. Thermochemical route is the preferred treatment and effective way of disposal of such infectious polymeric waste. Typically, incineration is employed to ensure complete destruction of the pathogens which is not a resource-efficient method. Pyrolysis is a sustainable alternative which can handle the present COVID-waste stream in short-term and long-term yielding valuable fuel and material products. Recently published literature in this avenue have clearly shown the versatility of this technology in efficiently handling both mono and mixed stream of polymers. Based on facts, we propose a resource resurgence framework that utilizes pyrolysis as the core conversion route for effectively handling COVID-waste streams. Our framework suggests how these plants can be operational and helpful in generation of revenue in post-pandemic times as well. We expect that the conscientious adoption of pyrolysis will certainly lead us towards a circular economy paradigm.

Estimation of COVID-19 generated medical waste in the Kingdom of Bahrain

Coronavirus disease 2019 (COVID-19) is not only a great matter of concern from a medical and health perspective, but it is a serious threat to the environment in terms of waste generated during the prevention and cure of COVID-19. The world has so far compromised more than 3 million human lives, and millions are being infected. Environmental threat is most serious because it can cause secondary complications. As per our knowledge, the amount of waste generated during the pandemic and its estimated quantity has not been assessed, thereby keeping the scientific community, Government authorities and public ignorant of its adverse effects. In this context, we have evaluated the waste generated by the Kingdom of Bahrain, estimated to be 35.480 kg/day (face masks), 1894 kg/day (PPEs) by the selected health facilities, 16,633.505 kg (vaccination-related) and 53,551.240 kg (related to tests conducted so far) in the Kingdom of Bahrain.

Co-pyrolysis performances, synergistic mechanisms, and products of textile dyeing sludge and medical plastic wastes

This study aimed to quantify the co-pyrolysis of textile dyeing sludge (TDS) and the two medical plastic wastes of syringes (SY) and medical bottles (MB) in terms of their performances, synergistic mechanisms, and products. The pyrolysis of polyolefin plastics with its high calorific value and low ash content can offset the poor mono-pyrolytic performance of TDS. The synergistic mechanisms occurred mainly in the range of 400-550 °C. The addition of 10% SY or MB achieved the best co-pyrolysis performance with the lowest activation energy. The co-pyrolysis increased the contents of CH₄ and CH but reduced CO₂ emission. The co-pyrolysis released more fatty hydrocarbons, alcohols, and cyclic hydrocarbon during but reduced the yields of ethers and furans, through the synergistic mechanisms. The addition of the polyolefin plastics made the micro surface particles of chars smaller and looser. Our results can benefit energy utilization, pollution control, and optimal operational conditions for the industrial thermochemical conversions of hazardous wastes.

Medical Waste Treatment Technologies for Energy, Fuels, and Materials Production: A Review

The importance of medical waste management has grown during the COVID-19 pandemic because of the increase in medical waste quantity and the significant dangers of these highly infected wastes for human health and the environment. This innovative review focuses on the possibility of materials, gas/liquid/solid fuels, thermal energy, and electric power production from medical waste fractions. Appropriate and promising treatment/disposal technologies, such as (i) acid hydrolysis, (ii) acid/enzymatic hydrolysis, (iii) anaerobic digestion, (vi) autoclaving, (v) enzymatic oxidation, (vi) hydrothermal carbonization/treatment, (vii) incineration/steam heat recovery system, (viii) pyrolysis/Rankine cycle, (ix) rotary kiln treatment, (x) microwave/steam sterilization, (xi) plasma gasification/melting, (xii) sulfonation, (xiii) batch reactor thermal cracking, and (xiv) torrefaction, were investigated. The medical waste generation data were collected according to numerous researchers from various countries, and divided into gross medical waste and hazardous medical waste. Moreover, the medical wastes were separated into categories and types according to the international literature and the medical waste fractions’ percentages were estimated. The capability of the examined medical waste treatment technologies to produce energy, fuels, and materials, and eliminate the medical waste management problem, was very promising with regard to the near future.

Recent Trends in the Pyrolysis of Non-Degradable Waste Plastics

Waste plastics are non-degradable constituents that can stay in the environment for centuries. Their large land space consumption is unsafe to humans and animals. Concomitantly, the continuous engineering of plastics, which causes depletion of petroleum, poses another problem since they are petroleum-based materials. Therefore, energy recovering trough pyrolysis is an innovative and sustainable solution since it can be practiced without liberating toxic gases into the atmosphere. The most commonly used plastics, such as HDPE, LDPE (high- and low-density polyethylene), PP (polypropylene), PS (polystyrene), and, to some extent, PC (polycarbonate), PVC (polyvinyl chloride), and PET (polyethylene terephthalate), are used for fuel oil recovery through this process. The oils which are generated from the wastes showed caloric values almost comparable with conventional fuels. The main aim of the present review is to highlight and summarize the trends of thermal and catalytic pyrolysis of waste plastic into valuable fuel products through manipulating the operational parameters that influence the quality or quantity of the recovered results. The properties and product distribution of the pyrolytic fuels and the depolymerization reaction mechanisms of each plastic and their byproduct composition are also discussed.

Estimation of COVID-19 waste generation and composition in Vietnam for pandemic management

Despite its initial success in COVID-19 pandemic control, Vietnam faces a growing risk of outbreaks as new infection waves driven by the highly contagious Delta variant surge in the region. In the context of preparedness through waste management, this study estimated the rate and quantity of generation and the composition of COVID-19 waste in Vietnam from the supply of resources and equipment. Over a year under COVID, 1486 t of COVID-19 waste was produced from the treatment of isolated COVID-19 patients (4.64 kg bed^-1 day^-1), quarantine in medical facilities (3.86 kg bed^-1 day^-1), centralised quarantine (46.43 g bed^-1 day^-1), testing (50 g test^-1) and vaccination (10.46 g shot^-1). Plastic dominated the waste at 76.7%, followed by paper. The additional management of waste from households with persons under quarantine is likely to reduce infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) - contaminated waste. Thorough assessment is recommended for the establishment of regional collaboration to secure COVID-19 waste treatment capacity. These findings will support COVID-19 waste planning in Vietnam in association with pandemic scenarios and could be used as a reference by other developing countries for pandemic control.

Integrated approach for enhanced bio-oil recovery from disposed face masks through co-hydrothermal liquefaction with Spirulina platensis grown in wastewater

Currently, the enormous generation of contaminated disposed face masks raises many environmental concerns. The present study provides a novel route for efficient crude bio-oil production from disposed masks through co-hydrothermal liquefaction (Co-HTL) with Spirulina platensis grown in wastewater. Ultimate and proximate analysis confirmed that S. platensis contains relatively high nitrogen content (9.13%dw), which decreased by increasing the mask blend ratio. However, carbon and hydrogen contents were higher in masks (83.84 and 13.77%dw, respectively). In addition, masks showed 29.6% higher volatiles than S. platensis, which resulted in 94.2% lower ash content. Thermal decomposition of masks started at a higher temperature (≈330 °C) comparing to S. platensis (≈208 °C). The highest bio-oil yield was recorded by HTL of S. platensis and Co-HTL with 25% (w/w) masks at 300 °C, which showed insignificant differences with each other. GC/MS analysis of the bio-oil produced from HTL of algal biomass showed a high proportion of nitrogen- and oxygen-containing compounds (3.6% and 11.9%, respectively), with relatively low hydrocarbons (17.4%). Mask blend ratio at 25% reduced the nitrogen-containing compounds by 55.6% and enhanced the hydrocarbons by 43.7%. Moreover, blending of masks with S. platensis enhanced the compounds within the diesel range in favor of gasoline and heavy oil. Overall, the present study provides an innovative route for enhanced bio-oil production through mask recycling coupled with wastewater treatment.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13399-021-01891-2.

Integrated approach for enhanced bio-oil recovery from disposed face masks through co-hydrothermal liquefaction with Spirulina platensis grown in wastewater

Currently, the enormous generation of contaminated disposed face masks raises many environmental concerns. The present study provides a novel route for efficient crude bio-oil production from disposed masks through co-hydrothermal liquefaction (Co-HTL) with Spirulina platensis grown in wastewater. Ultimate and proximate analysis confirmed that S. platensis contains relatively high nitrogen content (9.13%dw), which decreased by increasing the mask blend ratio. However, carbon and hydrogen contents were higher in masks (83.84 and 13.77%dw, respectively). In addition, masks showed 29.6% higher volatiles than S. platensis, which resulted in 94.2% lower ash content. Thermal decomposition of masks started at a higher temperature (≈330 °C) comparing to S. platensis (≈208 °C). The highest bio-oil yield was recorded by HTL of S. platensis and Co-HTL with 25% (w/w) masks at 300 °C, which showed insignificant differences with each other. GC/MS analysis of the bio-oil produced from HTL of algal biomass showed a high proportion of nitrogen- and oxygen-containing compounds (3.6% and 11.9%, respectively), with relatively low hydrocarbons (17.4%). Mask blend ratio at 25% reduced the nitrogen-containing compounds by 55.6% and enhanced the hydrocarbons by 43.7%. Moreover, blending of masks with S. platensis enhanced the compounds within the diesel range in favor of gasoline and heavy oil. Overall, the present study provides an innovative route for enhanced bio-oil production through mask recycling coupled with wastewater treatment.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13399-021-01891-2.

Personal protective equipment (PPE) pollution driven by the COVID-19 pandemic in Cox's Bazar, the longest natural beach in the world

The extensive use of personal protective equipment (PPE) driven by the COVID-19 pandemic has become an important contributor to marine plastic pollution. However, there are very few studies quantifying and characterizing this type of pollution in coastal areas. In the present study, we monitored the occurrence of PPE (face masks, bouffant caps, and gloves) discarded in 13 sites along Cox's Bazar beach, the longest naturally occurring beach in the world. The vast majority of the items were face masks (97.9%), and the mean PPE density across sites was 6.29 × 10^-3 PPE m^-2. The presence of illegal dumping sites was the main source of PPE, which was mainly located on touristic/recreational beaches. Fishing activity contributed to PPE pollution at a lower level. Poor solid waste management practices in Cox's Bazar demonstrated to be a major driver of PPE pollution. The potential solutions and sustainable alternatives were discussed.

Municipal solid waste management during COVID-19 pandemic: effects and repercussions

The COVID-19 pandemic has an adverse effect on the environment. This epidemic's effect on the waste composition and management and the impacts of municipal solid waste management (MSWM) on disease transmission or controlling are considered a compelling experience of living in the COVID-19 pandemic that can effectively control the process. This systematic review research was conducted to determine the effects of COVID-19 on the quantity of waste and MSWM. Searches were conducted in three databases (using keywords covid 19, coronaviruses, and waste), and among the published articles from 2019 to 2021, 56 ones were selected containing information on the quantity and waste management during the COVID-19 pandemic. The results showed that COVID-19 caused the quantity variation and composition change of MSW. COVID-19 also has significant effects on waste recycling, medical waste management, quantity, and littered waste composition. On the other hand, the COVID-19 pandemic has changed waste compounds' management activities and waste generation sources. Recognizing these issues can help plan MSWM more efficiently and reduce virus transmission risk through waste.