A review on medical waste treatment in COVID-19 pandemics: Technologies, managements and future strategies.

Since the outbreak of COVID-19 few years ago, the increasing of the number of medical waste has become a huge issue because of their harmful impact to environment. A major concern associated to the limitation of technologies for dealing with medical waste, especially conventional technologies, are overcapacities since pandemic occurs. Moreover, the outbreak of new viruses from post COVID-19 should become a serious attention to be prevented not only environmental issues but also the spreading of viruses to new pandemic near the future. The high possibility of an outbreak of new viruses and mutation near the future should be prevented based on the experience associated with the SARS-CoV-2 virus in the last 3 yr. This review presented information and strategies for handling medical waste during the outbreak of COVID-19 and post-COVID-19, and also information on the current issues related to technologies, such as incineration, pyrolysis/gasification, autoclaves and microwave treatment for the dealing with high numbers of medical waste in COVID-19 to prevent the transmission of SARS-CoV-2 virus, their advantages and disadvantages. Plasma technology can be considered to be implemented as an alternative technology to deal with medical waste since incinerator is usually over capacities during the pandemic situation. Proper treatment of specific medical waste in pandemics, namely face masks, vaccine vials, syringes, and dead bodies, are necessary because those medical wastes are mediums for transmission of the SARS-CoV-2 virus. Furthermore, emission controls from incinerator and plasma are necessary to be implemented to reduce the high concentration of CO2, NOx, and VOCs during the treatment. Finally, future strategies of medical waste treatment in the perspective of potential outbreak pandemic from new mutation viruses are discussed in this review paper.Implications: Journal of the air and waste management association may consider our review paper to be published. In this review, we give important information related to the technologies, managements and strategies for handling the medical waste and control the transmission of SARS-CoV-2 virus, starting from proper technology to control the high number of medical waste, their pollutants and many strategies for controlling the spreading of SARS-CoV-2 virus. Moreover, this review also describes some strategies associated with control the transmission not only the SARS-CoV-2 virus but also the outbreak of new viruses near the future.

Inertization of metals and hydrogen production as a byproduct from water hyacinth and water lettuce via plasma pyrolysis.

Water hyacinth and water lettuce have been extensively used for phytoremediation of metals and metalloids. However, the reasonable disposal of phytoremediation plants is a difficult problem. This study aims to reduce metals and metalloids from water hyacinth and water lettuce, and produce hydrogen (H2) and methane (CH4) via an atmospheric-pressure microwave plasma reactor based on the circular economy concept. Inertization of metals and metalloids can be obtained by more than 60% for both water hyacinth and water lettuce. H2 and CH4 production of water hyacinth and water lettuce were 56.28%/57.30% and 3.75%/2% of volume fractions, respectively. Furthermore, total VOCs concentrations from the effluent gas were detected only at the values of 0.511% (water hyacinth) and 0.08% (water lettuce) of volume fractions, respectively. Overall, water hyacinth and water lettuce treated by atmospheric-pressure microwave plasma showed the potential of H2 and CH4 production as a by-product for alternative energy and inertization of metals/metalloids for the phytoremediation plants.

A review on vitrification technologies of hazardous waste.

Vitrification technology provides a solution for the issue of safe disposal of hazardous waste containing harmful chemical composition and organic pollutants. This review discusses application of vitrification technologies to treat hazardous waste including, asbestos, fly ash, electronic sludge, nuclear waste, medical waste and radioactive waste. Vitrification processes via Joule heating, microwave heating, plasma technology, electric arc furnaces and incinerators are compared herein. Stabilization of hazardous waste can be achieved by vitrification with the addition of flux agents/additives. Furthermore, crystalline structures, containing the silicate-glass network, are formed as a result of vitrification, depending on the type of flux agents/additives used. In addition, the concentration of heavy metals can be degraded in the final residue and leaching resistance can be achieved. Moreover, energy consumption, pollution prevention and the foreground of the practical application of vitrification are discussed. Vitrification with the advantage of encapsulating pollutants from the hazardous waste is proven to be a promising approach for hazardous waste treatment.

Degradation of contaminants in plasma technology: An overview.

The information of plasma technologies applications for environmental clean-up on treating and degrading metals, metalloids, dyes, biomass, antibiotics, pesticides, volatile organic compounds (VOCs), bacteria, virus and fungi is compiled and organized in the review article. Different reactor configurations of plasma technology have been applied for reactive species generation, responsible for the pollutants removal, hydrogen and methane production and microorganism inactivation. Therefore, in this review article, the reactive species from discharge plasma are presented here to provide the insight into the environmental applications. The combinations of plasma technology with flux agent and photocatalytic are also given in this review paper associated with the setup of the plasma system on the removal process of metals, VOCs, and microorganisms. Furthermore, the potential of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) inactivation via plasma technology is also described in this review paper. Detailed information of plasma parameter configuration is given to support the influence of the critical process in the plasma system to deal with contaminants.

Application of plasma technology for treating e-waste: A review.

This review details the current information on e-waste treatment using plasma technology. The current status of e-waste treatment via plasma technology from the scientific literature is presented herein, namely, moist paste battery, galvanic sludge, resin, printed circuit board, and semiconductor industries. The concept of plasma technology, classification of e-waste, contaminants of e-waste (metals, metalloids, and VOCs), and vitrification of the final product are presented herein. This review paper focuses on fusing flux agents to vitrify e-waste. Furthermore, this paper covers laboratory-scale investigations, plasma technology benefits, and reuse of material from plasma post-treatment. The use of plasma technology combined with flux agents could be recommended to eliminate contaminants from e-waste. Materials from plasma post-treatment may also be applied in environmental reuse applications.

Economic and environmental evaluation of flux agents in the vitrification of resin waste: A SWOT analysis.

Flux agents play an important role in the pyrolysis treatment of vitrifying hazardous wastes. Among these is plasma jets, a cost-less flux agent derived from shell powder which can be used to create vitrification. It is a promising option to be applied in the vitrification of elements and to remove the VOCs of hazardous waste, namely, resin from PCB scrap in an atmospheric-pressure microwave plasma reactor. In this study, a laboratory scale experiment was conducted. The experiment was performed in the pyrolysis of resin which was added with flux agents. The economic evaluation of the flux agents, and the circular economy concept of the final residue derived from the plasma pyrolysis was then analyzed post treatment. To test the strength and weakness of the experiment, the SWOT analysis was performed. The outcome helped in the understanding of the cost-less flux agent used in the pyrolysis treatment of hazardous waste. Results showed that fusing shell powder in resin was better for improving the removal efficiency of VOCs, such as benzene and toluene as well as toxic metals than compared to other flux agents such as limestone and quartz sand. Moreover, the final residue of resin was found to fulfil the concept of circular economy where it could be reused as an absorbent of methyl blue, thereby indicating good absorption performance, from 1 ppm-100 ppm. The twelve strategies that were derived from the SWOT analysis could be used as information outlining the current internal and external condition for the development and application of shell powder. Shell powder, as a cost-less flux agent, has the potential for enhancing waste management and circular economy when used in the pyrolysis treatment of future hazardous wastes.

Effect of shell powder on removal of metals and volatile organic compounds (VOCs) from resin in an atmospheric-pressure microwave plasma reactor.

Resin has been widely used for thermosetting printed circuit boards (PCBs) and is a key part of e-waste from scrap PCBs. It requires appropriate treatment because of its harmful elements (metals and metalloids) and organic compounds that are toxic to human health and the environment. The purpose of this study is to eliminate volatile organic compounds (VOCs) and elements (metals and metalloids) in resin via the use of powdered snail shell (Babylonia formosae) in an atmospheric-pressure microwave plasma reactor. Shell powder plays a significant role in the destruction of benzene and toluene with removal efficiency 98.8 % and 100 %, respectively, compared to quartz sand with removal efficiency 44.9 %. A high ratio of shell powder increases the inertization of metals and metalloids by more than 96 %. The crystalline structures of these materials are dominated by calcite formations (CaCO3), confirming the elimination of metals and metalloids. Raman spectroscopy shows that the shell powder vitrifies these elements. The use of shell powder is thus recommended to degrade hazardous substances and to vitrify elements from resin in plasma pyrolysis.