Microwave as an emerging technology for the treatment of biohazardous waste: A mini-review

Environmental and economic assessments of industry-level medical waste disposal technologies - A case study of ten Chinese megacities

Medical waste (MW) is exploding due to the COVID-19 pandemic, posing a significant environmental threat, and leading to the urgent requirement for affordable and environmentally friendly MW disposal technologies. Prior research on individual MW disposal plants is region-specific, applying these results to other regions may introduce bias. In this study, major MW disposal technologies in China, i.e., incineration technologies (pyrolysis incineration and rotary kiln incineration), and sterilization technologies (steam sterilization, microwave sterilization, and chemical disinfection) with residue landfill or incineration were analyzed from an industry-level perspective via life cycle assessment (LCA), life cycle costing (LCC) and net present value (NPV) methods. Life cycle inventories and economic cost data for 4-5 typical companies were selected from 128 distinct enterprises and academic sources for each technology. LCA results show that microwave sterilization with residue incineration has the lowest environmental impact, emitting only 480 kg CO2 eq. LCC and NPV analyses indicate that steam sterilization with landfilling is the most economical, yielding revenues of 1,210 CNY/t and breaking even in the first year. Conversely, pyrolysis and rotary kiln incineration break even between the 4th and 5th years. Greenhouse gas emissions from the MW disposal in ten cities with the largest MW production in 2020 increased by 7% over 2019 to 43,800 tons and other pollutants increased by 6% to 12%. Economically, Shanghai exhibits the highest cost-effectiveness, while Nanjing delivers the lowest. It can be observed that the adoption of optimal environmental technologies has resulted in a diminution of greenhouse gas emissions by 279,000 tons and energy conservation of 1.76 billion MJ.

Inactivation of pathogenic microorganisms in water by electron beam excitation multi-wavelength ultraviolet irradiation: Efficiency, influence factors and mechanism

Due to the limitations of traditional ultraviolet (UV) in microbial inactivation in water, it is necessary to explore a more suitable and efficient UV disinfection method. In this study, an electron beam excitation multi-wavelength ultraviolet (EBE-MW-UV) system was established and aims to analyze its differential microbial inactivation capabilities in comparison to single-wavelength UV-LEDs in waterborne applications. Furthermore, the inactivation mechanisms of this system on microorganisms were explored. The results showed that EBE-MW-UV had significantly higher inactivation effects on the Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Candida albicans in water compared to UV-LEDs (p＜0.05), and the inactivation effect of EBE-MW-UV on Escherichia coli and Pseudomonas aeruginosa at the same UV dose was 3.8 and 1.9 log higher than that of UV-LEDs, respectively, EBE-MW-UV exhibited better inactivation effects on Gram-negative bacteria. Further research found that, under the majority of irradiation doses, neither EBE-MW-UV nor UV-LEDs were significantly affected by the concentration of suspended solids (5 and 20 mg/L) or humic acids (2 and 5 mg/L) in the water. Mechanism analysis revealed that during the disinfection process of EBE-MW-UV, microbial DNA and proteins were initially damaged, which prevented the occurrence of dark repair and led to bacterial inactivation. In addition, UV irradiation led to the production of additional reactive oxygen species (ROS) inside the cells, increasing cell membrane permeability and exacerbating membrane damage. This was accompanied by a decrease in energy metabolism and depletion of ATP, ultimately resulting in microbial inactivation. Therefore, EBE-MW-UV demonstrated more effective disinfection than single-wavelength UV-LEDs, showing great potential. Our research gives new insights into the characteristics of multiple wavelength ultraviolet, and provides scientific basis for the selection of new light sources in the field of ultraviolet disinfection.

Biomedical waste plastic: bacteria, disinfection and recycling technologies-a comprehensive review

Plastic recycling reduces the wastage of potentially useful materials as well as the consumption of virgin materials, thereby lowering the energy consumption, air pollution by incineration, soil and water pollution by landfilling. Plastics used in the biomedical sector have played a significant role. Reducing the transmission of the virus while protecting the human life in particular the frontline workers. Enormous volumes of plastics in biomedical waste have been observed during the outbreak of the pandemic COVID-19. This has resulted from the extensive use of personal protective equipment such as masks, gloves, face shields, bottles, sanitizers, gowns, and other medical plastics which has created challenges to the existing waste management system in the developing countries. The current review focuses on the biomedical waste and its classification, disinfection, and recycling technology of different types of plastics waste generated in the sector and their corresponding approaches toward end-of-life option and value addition. This review provides a broader overview of the process to reduce the volume of plastics from biomedical waste directly entering the landfill while providing a knowledge step toward the conversion of "waste" to "wealth." An average of 25% of the recyclable plastics are present in biomedical waste. All the processes discussed in this article accounts for cleaner techniques and a sustainable approach to the treatment of biomedical waste.

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Selection of healthcare waste management treatment using fuzzy rough numbers and Aczel-Alsina Function

The COVID-19 pandemic led to an increase in healthcare waste (HCW). HCW management treatment needs to be re-taken into focus to deal with this challenge. In practice, there are several treatments of HCW with their advantages and disadvantages. This study is conducted to select the appropriate treatment for HCW in the Brčko District of Bosnia and Herzegovina. Six HCW management treatments are analyzed and observed through twelve criteria. Ten-level linguistic values were used to bring this evaluation closer to human thinking. A fuzzy rough approach is used to solve the problem of inaccuracy in determining these values. The OPA method from the Bonferroni operator is used to determine the weights of the criteria. The results of the application of this method showed that the criterion Environmental Impact ( C 4 ) received the highest weight, while the criterion Automation Level ( C 8 ) received the lowest value. The ranking of HCW management treatments was performed using MARCOS methods based on the Aczel-Alsina function. The results of this analysis showed that the best-ranked HCW management treatment is microwave (A6) while landfill treatment (A5) is ranked worst. This study has provided a new approach based on fuzzy rough numbers where the Bonferroni function is used to determine the lower and upper limits, while the application of the Aczel-Alsina function reduced the influence of decision-makers on the final decision because this function stabilizes the decision-making process.

Energy-saving COVID-19 biomedical plastic waste treatment using the thermal - Catalytic pyrolysis

The rate of Biomedical waste generation increases exponentially during infectious diseases, such as the SARS-CoV-2 virus, which burst in December 2019 and spread worldwide in a very short time, causing over 6 M casualties worldwide till May 2022. As per the WHO guidelines, the facemask has been used by every person to prevent the infection of the SARS-CoV-2 virus and discarded as biomedical waste. In the present work, a 3-ply facemask was chosen to be treated using the solvent, which was extracted from the different types of waste plastics through the thermal-catalytic pyrolysis process using a novel catalyst. The facemask was dispersed in the solvent in a heating process, followed by dissolution and precipitation of the facemask in the solvent and by filtration of the solid facemask residue out of the solvent. The effect of peak temperature, heating rate, and type of solvent is observed experimentally, and it found that the facemask was dissolved completely with a clear supernate in the solvent extracted from the (polypropylene + poly-ethylene) plastic also saved energy, while the solvent from ABS plastic was not capable to dissolute the facemask. The potential of the presented approach on the global level is also examined.

Waste management model for COVID-19: recommendations for future threats

The change in habits and lifestyle of citizens during health crisis like COVID-19 pandemic has resulted in an unprecedented increase in the struggles for solid waste management across the globe. Not only underdeveloped and developing economies are struggling with the challenges posed by mounting piles of infectious waste but even developed countries are adversely affected in similar manner. The routine waste management strategies followed by various countries are overturned due extremely altered trends in the amount and type of waste generated by households and medical facilities. The aim of this paper is to study and list the best available waste management policies adopted by some developing, developed and underdeveloped economies. The listed case studies were selected due to some unique steps undertaken for solid waste disposal during pandemic. The findings revealed that the guidelines issued by WHO for waste management of corona virus infected waste were followed by these nations and certain additional preventive steps were taken. Due to unavailability of single framework as prescribed by international authorities, various sustainable steps taken by individual countries to curb the pandemic menace can be useful in the present context. Few of these measures can be permanently adopted at global level by other nations for handling the pandemic like situations efficiently in pandemic situations.

Comparison of microwave and autoclave treatment for biomedical waste disinfection

As the world is facing a Covid-19 pandemic, this virus teaches a lesson about the importance of on-site disinfection. On-site disinfection/sterilization with real-time monitoring of biomedical waste generated from the medical facilities is mandatory to prevent hospital-acquired infection (HAI). In this study, the life cycle assessment of two technologies, i.e., microwave (radiation-based) and autoclave (steam-based) were performed to summarize the inside-out evaluation of both technologies in terms of efficiency, efficacy, and cost-effectiveness. The results of disinfection efficacy indicated a log 10 reduction (almost 100%) in the vegetative load of microorganisms compared to the control, showing a similar level of disinfection efficacy of both strategies. Additionally, both technologies were compared on several parameters, and it was discovered that the autoclave uses more time and resources than the microwave. The total cost of an autoclave to the government is approximately double that of a microwave, while the operational cost of an autoclave is more than double that of a microwave. The findings from this study indicate that MACS may be used as a dry technique of biomedical disinfection, and its portability, tunability, and compactness make it a suitable alternative for biomedical disinfection and sterilization.

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The influence of COVID-19 pandemic on biomedical waste management, the impact beyond infection

Excessive population outbursts and associated xenobiotic interventions contribute overproduction of waste materials across the world. Among these waste materials biomedical wastes (BMW) make a significant contribution. The huge accumulation of BMW is not only meant for successive environmental pollution but increases health hazards by cross-contamination and reoccurrence of different fatal infections. The management of BMW gaining continuous attention to the scientific communities for their intriguing potentiality towards public health concerns. Although, world health organization (WHO) and other public health and environmental societies formulate different guidelines for the disposal machinery of BMW but the proper implementation of those rules in public sectors in developing countries is very difficult. In this situation, the sudden prevalence of pandemic like, COVID-19 further worsen such conditions. Huge disposition of medical wastes during COVID-19 detection, treatment, and precautionary measures not only increases the risk of reoccurrence of infection but puts us also in front of a huge challenge of efficient management of these BMW. In this respect, the present review focus on an overview of BMW, existing BMW management, probable consequences of COVID-19 pandemic on the waste management system, and future perspectives.

Biomedical waste generation and management during COVID-19 pandemic in India: challenges and possible management strategies

The COVID-19 pandemic has resulted in the massive generation of biomedical waste (BMW) and plastic waste (PW). This sudden spike in BMW and PW has created challenges to the existing waste management infrastructure, especially in developing countries. Safe disposal of PW and BMW is essential; otherwise, this virus will lead to a waste pandemic. This paper reviews the generation of BMW and PW before and during the COVID-19 pandemic, the regulatory framework for BMW management, policy interventions for COVID-19-based BMW (C-BMW), the capacity of BMW treatment and disposal facilities to cope with the challenges, possible management strategies, and perspectives in the Indian context. This study indicated that policy intervention helped minimize the general waste treated as C-BMW, especially during the second pandemic. Inadequacy of common BMW treatment facilities' (CBMWTFs) capacity to cope with the BMW daily generation was observed in some states resulting in compromised treatment conditions. Suggestions for better management of BMW and PW include decontamination of used personal protective equipment (PPEs) and recycling, alternate materials for PPEs, segregation strategies, and use of BMW for co-processing in cement kilns. All upcoming CBMWTFs should be equipped with higher capacity and efficient incinerators for the sound management of BMW. Post-pandemic monitoring of environmental compartments is imperative to assess the possible impacts of pandemic waste.

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.

Circular Economy in Conjunction with Treatment Methodologies in the Biomedical and Dental Waste Sectors

In this review, life cycle assessment (LCA) principles are coupled with circular economy (CE) in order to address LCA examples in the biomedical sector worldwide. The objectives were (1) to explore the application of LCA in the medical, pharmaceutical, and dental fields; (2) to describe the ways of biomedical waste management; (3) to emphasize on the problem of dental waste in private and public dental sectors; and (4) to propose ways of “green circulation” of the dental waste. A literature search was performed using the Google Scholar, PubMed, and Scopus search engines covering the period from January 2000 until May 2020, corresponding to articles investigating the LCA and circular economy principles and legislation for biomedical and dental waste, their management options, and modern ways of recycling. The results showed that incineration seems to be the best management way option involved despite the mentioned drawbacks in this technology. Different adopted models are well defined for the dental field based on the 3Rs’ module (reduce, reuse, recycle). Replacing disposable products with reusable ones seems to be a good way to tackle the problem of waste in medical and dental sectors. Interventions on the selection and better biomedical and dental waste management will ensure eco-medicine and eco-dentistry of the future. These new terms should be the new philosophies that will change the way these fields operate in the future for the benefit of the professionals/patients and the community.

Review of Current Healthcare Waste Management Methods and Their Effect on Global Health

Healthcare is a rapidly growing industry as medical treatments become more sophisticated, more in demand due to increasing incidence of chronic disease and more widely available worldwide. This booming industry is also creating more waste than ever before and, as such, there is a growing need to treat and dispose of this waste. Healthcare waste (HCW) disposal includes a multitude of disposal methods, including incineration, landfilling and chemical treatments. These rudimentary methods and their growing use present their own problems that negatively impact both the environment and, in turn, damage public health, thus contributing to a global healthcare crisis. The aim of this review was to examine the current HCW disposal methods in place and the harmful effects they have on the environment and on public health. The findings accumulated in this review demonstrate a heavy reliance on basic, low tech HCW disposal techniques and uncovered the negative impacts of these methods. There is a notable lack of employment of "greener" HCW disposal methods on a largescale due to cost, access and feasibility. Despite innovations in HCW disposal, there is no scalable, global green solution at present. Further, the review highlights that global health consequences of HCW disposal methods often differ depending on how developed the country is.

Nanoparticles impact in biomedical waste management

Effectual management of biomedical waste is obligatory for healthy human beings and for a safe environment. Mismanagement of biomedical waste is a community health problem. Safe and persistent methods for the management of biomedical waste are of vital importance. This article reviews the classification of biomedical waste, sources, colour-coding system of biomedical waste and salient features of biomedical waste rules in 2016, and the future prospective of nanoparticles. The untreated disposal of biomedical waste is associated with a huge amount of risk, so the efficient treatment for biomedical waste is most imperative. The review also highlights the current methods for disposal of biomedical waste, biological treatments given to biomedical waste water in the effluent treatment plant, and impacts due to the current method. Management of biomedical waste is a great challenge in developed and developing countries. To manage the biomedical waste there is a need for cost-effective, ecofriendly and less contaminating approaches for a greener and safe environment. The awareness regarding waste management is of great interest not only for the community but also for associated employees.

Microwave Technologies: An Emerging Tool for Inactivation of Biohazardous Material in Developing Countries

Inappropriate treatment and disposal of waste containing biohazardous materials occurs especially in developing countries and can lead to adverse effects on public and occupational health and safety, as well as on the environment. For the treatment of biohazardous waste, microwave irradiation is an emerging tool. It is a misbelief that microwave devices cannot be used for inactivation of solid biohazardous waste; however, the inactivation process, and especially the moisture content, has to be strictly controlled, particularly if water is required to be added to the process. Appropriate control allows also inactivation of waste containing inhomogeneous compositions of material with low fluid/moisture content. Where appropriate, especially where control of transport of waste cannot be guaranteed, the waste should be inactivated directly at the place of generation, preferably with a closed waste collection system. In waste containing sufficient moisture, there are direct useful applications, for example the treatment of sewage sludge or human feces. A number of examples of microwave applications with impacts for developing countries are presented in this review. In respect to energy costs and environmental aspects, microwave devices have clear advantages in comparison to autoclaves.