Medical Waste Incinerator Research Articles

Medical Waste Incineration Ash Waste: Impact On Environmental Health And Its Potential To Be Used For Paving Blocks

ABSTRACT : It is known that medical waste has increased in recent years due to the Covid-19 pandemic, which was followed by an increase in ash from burning medical waste processing using incinerators. The objective of this study is to determine the impact of using medical waste incineration ashes on health and the environment, as well as the potential for using solidification techniques to make the ash into paving blocks. The ash used was obtained from a medical waste processing facility in Surakarta, Indonesia's Central Java. The test object was created using seven different combinations of ash, sand, and cement with a water-cement ration of 0.5 and cured for 28 days. The optimum compressive strength condition was determined as the basis for the composition of medical waste incineration ash as a mixture of paving block raw materials, which was then tested for the content of heavy metal compounds using the SNI 8808: 2019 method. According to research, the ash from medical waste incineration contains heavy metal compounds such as Pb, Ni, Cu, and Cd and has the potential to be used as a mortar mixture. Six of the seven mortar compositions with the addition of incineration medical waste ash met the compressive strength requirements of SNI 03-0691-1996 for category D paving blocks to be used in parks and other places.

Medical Waste Incineration Fly Ash as a Mineral Filler in Dense Bituminous Course in Flexible Pavements.

Medical waste incineration fly ash (MWIFA) contains heavy metals that are toxic by nature and pose numerous health risks. The paper deals with the suitability of MWIFA as a mineral filler in the bituminous layer as an alternative to conventional stone dust (SD) through an appropriate combination of engineering and environmental assessments. Engineering parameters, such as Marshall stability, stability loss, flow, unit weight, air voids (Va), voids filled with asphalt (VFA), and voids in the mineral aggregate (VMA) of the asphalt mixtures, were evaluated with varying filler ratios, from 2% to 10%. All parameters for both fillers at optimum bitumen content satisfied the Marshall Mix Design criteria. The optimum bitumen contents of all filler ratios were within the standard limit recommended by the Bangladesh Roads and Highways Department. It was found that mixes prepared with MWIFA can resist moisture effects, making them durable in the monsoon. The mixes with 5.5% MWIFA as mineral filler performed the best, whereas 9% SD filler was required to achieve similar performance. The environmental test results show no environmental restriction on stabilizing the MWIFA into paving mixtures. The mobility of heavy metals (As, Pb, Cu, Cr, Ni, Cd, Hg, and Zn) from the asphalt-MWIFA mix was insignificant. The cumulative concentrations of heavy metals (Cd, Ni, Zn, Cu, and Pb) from long-term leaching tests were far below the Dutch regulatory limit (U1). MWIFA can be considered an eco-friendly and sustainable mineral filler for the dense bituminous pavement layer.

Emission control and phase migration of PCDD/Fs in a rotary kiln incinerator: hazardous vs medical waste incineration

Emission control and phase migration of PCDD/Fs in a rotary kiln incinerator: hazardous vs medical waste incineration

Conversion of medical waste into value-added products using a novel integrated system with tail gas treatment: Process design, optimization, and thermodynamic analysis

The COVID-19 pandemic has generated substantial medical waste (MW), posing risks to society. Based on widespread MW incineration, this study proposes an integrated system with tail gas treatment to convert MW into value-added products with nearly zero emissions. Herein, steam generators and supercritical CO2 cycles were used to recover energy from MW to produce high-temperature/pressure steam and electricity. A simple power generation cycle achieved a net electricity efficiency of 22.4% through optimization. Thermodynamic analysis revealed that the most energy and exergy loss occurred in incineration. Furthermore, a pressurized reactive distillation column purified the resultant tail gas. The effects of inlet temperature, pressure, liquid/gas ratio, and recycle ratio on the removal and conversion efficiencies of NO2 and SO2 were evaluated. Nearly 100% of the SO2 and 75% of the NO2 generated by the incineration of MW have been converted into their acid forms. Based on the proposed tail gas treatment unit, high-purity CO2 (∼98% purity) was finally obtained.

Experimental assessment of an indirect method to measure the post-combustion flue gas flow rate in waste-to-energy plant based on multi-point measurements

In waste-to-energy plants, the determination of the flue gas flow rate in the post-combustion section is of the utmost importance, e.g., for the verification of the compliance to the minimum residence time requirements (tres>2s) or for the control of flue gas treatment reactant injection, but the harsh conditions (high temperature and content of pollutants) do not allow for a direct measurement. The present work reports an experimental assessment of an indirect approach to estimate the flue gas flow rate in the post-combustion section of a rotary kiln plant with reduced uncertainty. This method consists on the direct measurement of the flow rate at a “colder” section of the plant (the boiler outlet) combined to the simultaneous measurements of flue gas composition measurements upstream and downstream of the boiler. From these measurements it is then possible to determine the mass of false air and to retrieve the actual flue gas flow-rate in the post-combustion chamber. A massive experimental campaign has been conducted at a full-scale medical waste incinerator, in which flue gas flow rate was estimated at different waste loads and ambient conditions. The results show that the percentage of false air can be significant and simply neglecting it can lead to substantial under-performance of the plant. Issues related to the practical implementation of the methods are illustrated in detail and the possibility to extend the methodology towards an online determination of post-combustion flue gas flow rate is discussed.

Medical Waste Management and Design of a Low-Cost Incinerator for Reduction of Environmental Pollution in a Multi-System Hospital

Pollution of the environment and inappropriate management of medical wastes are major challenges facing developing countries and this must be tackled with recent technology for public health, enhanced natural ecosystems, and a better environment. This research is a two-step process that involves the assessment of the existing Hospital waste management practices in a multi-system Hospital in Ado-Ekiti, Nigeria. Excess air, kerosene (auxiliary fuel), single chamber, Batch-fed (Manual feeding), and controlled air incinerator were designed. Wastes were loaded once at the beginning of the combustion cycle followed by combustion, ash burnout, cool down, and ash removal to assist medical waste management. Findings revealed that personnel involved in handling medical waste were equipped with inadequate protective gear. Medical waste was handled together with municipal waste and both wastes were incinerated in an open dumpsite without engineered sanitary landfill at disposal locations constituting a nuisance with a high risk of pollution to the surrounding environment. The incinerator was designed for a waste load of 269 kg.day-1. It consists of four zones; the waste and combustion zone (2.7 m × 1.8 m × 1 m), the ash zone (0.23 m height), the combustion fumes and one-second retention zone (0.43 m height) as well as the excess air zone (0.46 m height). This low-cost medical waste incinerator has a lot of improvement, operational effectiveness, and efficiency to the currently available techniques. Viable recommendations made will improve the state of environmental health and reduce the harmful effects of medical waste.

Medical and healthcare waste generation, storage, treatment and disposal: a systematic scoping review of risks to occupational and public health

Systems to safely store, handle, treat and dispose of medical (healthcare) waste are well developed in the 21st century. Yet, across many parts of the Global South (low-income and middle-income countries) such systems, resources and knowhow are lacking; to the extent that medical waste could pose a serious threat to the health, safety and lives of millions of healthcare workers and waste handlers who frequently interact with this category of materials. We present here a novel scope and dimension to investigating specifically the risks and hazards to people who come into contact with medical waste, focusing on activity types and established medical practice. A systematic scoping review of evidence (PRISMA-Scr) was used to critically analyze, compare and summarize data. Prevalent combinations of hazards, exposure and risk are semi-quantitatively scored and ranked. Our results signpost three core topics posing a major risk to human health: (1) Open, uncontrolled burning and rudimentary incineration of medical waste by waste handlers who have to make difficult choices between burning or discarding on land (e.g. in dumpsites) from where it risks pathogen infection; (2) A small but non-negligible trade in reused medical equipment (e.g. hypodermic needles), proliferated by a cohort of waste reclamation specialists (sub-group of waste pickers); and (3) The mismanagement of medical sharps at the point of generation, handling and storage in the Global North and South. A combination of immediate action and further research are recommended to address and inform on these topics which threaten the health and mortality of millions.

PM2.5-bound polyhalogenated carbazoles (PHCZs) in urban Beijing, China: Occurrence and the source implication

Polyhalogenated carbazoles (PHCZs) are recently raising much attention due to their toxicity and ubiquitous environmental distribution. However, little knowledge is known about their ambient occurrences and the potential source. In this study, we developed an analytical method based on GC-MS/MS to simultaneously determine 11 PHCZs in PM2.5 from urban Beijing, China. The optimized method provided low method limit of quantifications (MLOQs, 1.45–7.39 fg/m3) and satisfied recoveries (73.4%–109.5%). This method was applied to analyze the PHCZs in the outdoor PM2.5 (n = 46) and fly ash (n = 6) collected from 3 kinds of surrounding incinerator plants (steel plant, medical waste incinerator and domestic waste incinerator). The levels of ∑11PHCZs in PM2.5 ranged from 0.117 to 5.54 pg/m3 (median 1.18 pg/m3). 3-chloro-9H-carbazole (3-CCZ), 3-bromo-9H-carbazole (3-BCZ), and 3,6-dichloro-9H-carbazole (36-CCZ) were the dominant compounds, accounting for 93%. 3-CCZ and 3-BCZ were significantly higher in winter due to the high PM2.5 concentration, while 36-CCZ was higher in spring, which may be related to the resuspending of surface soil. Furthermore, the levels of ∑11PHCZs in fly ash ranged from 338 to 6101 pg/g. 3-CCZ, 3-BCZ and 36-CCZ accounted for 86.0%. The congener profiles of PHCZs between fly ash and PM2.5 were highly similar, indicating that combustion process could be an important source of ambient PHCZs. To the best of our knowledge, this is the first research providing the occurrences of PHCZs in outdoor PM2.5.

Na2O induced stable heavy metal silicates phase transformation and glass network depolymerization

The pollution of heavy metals and chlorine salts widely exists in solid/hazardous waste, while the stable heavy metal silicates limit the heavy metals removal. This work proposed mechanism of Na2O induced stable heavy metal silicates phase transformation and glass network depolymerization to promote heavy metals chlorination volatilization. Medical waste incineration slag (MWI S) containing heavy metal silicates was used as typical sample. Compared with the control, Cu and Zn volatilization efficiencies sharply increased from 77.54% to 92.22% and 18.70% to 93.82% at 3% Na2CO3, 1200 °C, 40 min. It showed that Na2O successfully induced phase transformation from stable Zn2SiO4 and CuSiO3 to ZnO and CuO easy to react with chloride by destroying the Si–O of Zn–O–Si and Cu–O–Si, respectively. Meanwhile, Na2O effectively destructed Si–O bond to depolymerize the glass network, resulting in the percentage of Q0 and Q1 increase from 25.14% to 38.29%, reducing melt viscosity and improvement of volatilization environment to form bigger bubbles. Medical waste incineration fly ash (MWI FA) was applied as Na source to further verify that the mechanism was significantly enhance Cu and Zn volatilization efficiencies. This study provided new method to reduce heavy metal residues in glass products prepared by melting treatment of solid/hazardous wastes.

Characteristics and resource availability of Zinc-rich fly ash generated from medical waste through rotary and plasma thermal treatment

Fly ash from medical waste (MW) thermochemical treatment is disposed of in concrete landfills due to its well-known pollution property, while its recycling potential is ignored. This study is the first to explore the environmental characteristics, resource availability, and recovery method of medical waste incineration fly ash (MW-IFA) and medical waste plasma vitrification fly ash (MW-PFA) in China. Features of high chloride levels (28.27–42.89%) and richness in Zn (3.15–7.53%) were observed in all fly ash samples. Notably, low-calcium MW-IFA and MW-PFA may posed higher environmental risks due to much higher zinc leaching concentrations (1621.83–5163.97 mg/L) than high-calcium MW-IFA (2.58–5.02 mg/L). Moreover, the resource availability of Zn measured by water washing, acid leaching and thermal treatment was similar, with the range of 20.69–96.84%, 60.89–90.57%, 60.17–96.82%. Hence, considering avoiding excessive energy consumption, the MW fly ash dissolution and recovery (MWFADR) technology, combining water washing and acid leaching processes, was proposed for ZnO and crystal salt production. The results of this work highlight the recovery potential of Zn and Cl in MW fly ash and propose an environmentally and economically sound solution.

Effectiveness of Charcoal Adsorbent in Flue Gas Filters for PCB Reduction in Smoke from Hospital Incinerators

The release of gas-phase polychlorinated biphenyls (PCBs) as one of the persistent organic pollutants (POPs) is an unfortunate result of combustion, especially from medical waste incinerators. This tends to make incinerators unpopular. The idea of a cheaply available air pollution control device fitted to incinerator chimneys can justify the continued use of incinerators. A gas filter unit, consisting of 3 filter beds with activated charcoal as an adsorbent, was designed, constructed, and fitted onto an existing incinerator at a university hospital in Ghana. Flue gas from the incinerator was sampled before and after the filter beds, using cylindrically-shaped mini-polyurethane foam (mini-PUF) samplers, and the analytes in the samples were then Soxhlet-extracted, purified, and analyzed for certain PCBs using the gas chromatography-mass spectrometer (GC-MS) technique. Twelve of the 14 indicators PCBs analyzed in the smoke samples were present, and 11 of them saw mean reductions ranging from 3.67% to 54.9% by the charcoal filter beds. These were PCB 18, PCB 28, PCB 31, PCB 44, PCB 101, PCB 118, PCB 138, PCB149, PCB 153, PCB 170, and PCB180. The gaseous concentrations of PCBs before filtration ranged from 0.0000788 ng/m3 for PCB 180 to 0.00129 ng/m3 for PCB 153. After the filtration by the charcoal adsorbent, they ranged from 0.00003734 ng/m3 for PCB 170 to 0.00112016 ng/m3 for PCB 153. The highest mean reduction of 54.9% came from the homologue, PCB 180, whilst the homologue with a dioxin-like character (PCB 118) saw a 22.44% reduction. This suggests that dioxins and other dioxin-like compounds are most likely adsorbed by the charcoal adsorbent. This gas filter unit should further be investigated for its effectiveness at removing other dioxin-like PCBs, dioxins, and furanes and for testing the effectiveness of thermophilic bacterial strains that can further metabolize these POPs into less harmful products.

A Study on the Improvement of Energy Recovery and Utilization of Residual Heat from Medical Waste Incinerators

A Study on the Improvement of Energy Recovery and Utilization of Residual Heat from Medical Waste Incinerators

Controlling effect of TiO2 carrier on formed vanadium species for effective catalytic oxidization of chlorobenzene

Catalytic oxidization of the dioxins is critical to the atmosphere since medical-waste incineration is globally increased due to COVID-19. Vanadium supported TiO2 is the most-widely investigated catalyst. However, previous reports usually investigated V-Ti relationships after vanadate was loaded on TiO2 and an activation was completed. In comparison, this work emphasizes on the influence of TiO2 surface chemistries on properties of formed vanadium species during a thermal activation. The vanadate loaded TiO2 are detailedly analyzed by both experimental characterizations and theoretical calculations. As a result, TiO2 with more Ti4+ is inclined to be reductive, and promotes the formation of more low-valence vanadium and surface vacancies. On the contrary, TiO2 with more Ti3+ is inclined to be oxidative, and promotes the formation of more lattice oxygens and high-valence vanadium. When they were compared in catalytic oxidization of chlorobenzene, the Ti4+-induced catalyst attains a conversion of 98.0 % at 250 °C, far bigger than that (11.3 %) of the Ti3+-induced catalyst. The main result of this work helps readers to understand the process of the catalyst preparation, which is in favor of producing a more effective catalyst by regulating the catalyst carrier.

EVALUATION OF THE ENVIRONMENTAL IMPACTS OF MEDICAL TRAINING: THE CASE OF THE MADINGRING DISTRICT MEDICAL CENTER, NORTH CAMEROON

Purpose: The environment is increasingly threatened by human activities. The purpose of this study is to assess the impact of the different activities carried out at Madingring Medical Center on the various environmental components.
 Methodology: To do this, the identification, characterization, and evaluation of the impacts were carried out during several field works using the Léopold and Fecteau matrices. The analysis of the waste management system was done using the Ishikawa 5M diagram.
 Findings: During the study, the real and potential impacts were identified on the various environments. The incineration of medical waste is classified as hazardous and the poor management of toilets emits polluting and toxic substances into the air, as well as unpleasant odors that modify air quality. The presence of stagnant water from the activities of the medical center due to the lack of good drainage degrades soil quality. Added to this, there is a development of algae and moss on the site. Concerning waste management, it appears that the Center does not have an environmental permit and a waste management plan, the sorting carried out is approximate, hazardous waste is incinerated illegally and others are dumped in landfills, contributing to environmental pollution. For each impact identified, corrective measures have been proposed and may make it possible to mitigate or eliminate the negative effects and improve the positive aspects, by implementing the environmental specifications.
 Unique contribution to theory, practice and policy: At the end of this study, some recommendations were made. These include training of medical staff in best practices and techniques for medical waste management, monitoring of the implementation of regulations on hospital waste management in Cameroon, information and sensitization of users on the social and environmental impacts of environmental degradation, as well as the best practices and behaviors to adopt within health facilities, the use of bins for the collection and sorting of waste, the creation of a pre-collection unit of waste within the health centers of Cameroon in general and those of Madingring in particular.

Design and Life Cycle Assessment of small-scale medical waste incinerator equipped with Porous Radiant Burner for remote areas

ABSTRACT In this paper, the design of a Small-scale Medical Waste Incinerator (SMWI) equipped with an LPG-operated Porous Radiant Burner (PRBLPG) is presented as a solution for disposing of medical waste generated in remote areas. Based on simple mass and heat balance analysis, SMWI having primary and secondary chambers with a volume of 1 and 0.754 m3 is designed. The proposed SMWI is evaluated for its environmental impact by performing a Life Cycle Assessment (LCA) and compared with an SMWI equipped with an Electric Heater (SMWI–EH). The total primary energy required for the construction of SMWI is 48285.56 MJ. It is found that the damage caused by the operation of PRBLPG in SMWI is lesser when compared to that of an Electric Heater (EH). In SMWI–PRB, LPG consumption contributed to about 17488.27 kg CO2−eq in the global warming category, whereas in the case of SMWI–EH, electricity consumption contributed to about 243766.11 kg CO2−eq. The operation of SMWI–PRB showed a reduction of about 54% in the resource utilisation category in comparison with SMWI–EH. The results obtained from the LCA study indicated that PRBLPG is a better option as an auxiliary heating device in SMWI than EH due to its environmental superiority.

Introducing a design concept for a hazardous medical waste incinerator, in light of environmental requirements

Introducing a design concept for a hazardous medical waste incinerator, in light of environmental requirements

Method development for determination of polyhalogenated carbazoles in industrial waste through gas chromatography/triple quadrupole tandem mass spectrometry.

Polyhalogenated carbazoles (PHCZs) are dioxin-like compounds that are ubiquitous in the environment. However, their unintentional emissions from industrial sources have received little attention and there is no method available for determination of PHCZs in industrial waste. This research develops a method for determination of PHCZs in industrial waste. In this research, a glass column packed with activated silica serves as a rapid and efficient clean-up pretreatment for purification. An isotope dilution gas chromatography/triple quadrupole tandem mass spectrometry method was established for simultaneous determination of eleven PHCZs in industrial samples. The regression coefficients of the standard curves for the congeners were all >0.99. The method detection limit ranged from 1.46 to 3.82 ng/mL for liquid samples and from 0.009 to 0.021 ng/g for solid samples. The precision described by the relative standard deviation ranged from 2.4% to 18.4% for liquid samples and from 5.5% to 35.8% for solid samples. The recovery ranges for the liquid and solid samples were 82%-123% and 83%-137%, respectively. 3-Chlorocarbazole (3-CCZ) and 36-dichlorocarbazole (36-CCZ) can be detected in both chemical bottom liquid from vinyl chloride production and fly ash from medical waste incineration by this method. An efficient method is established for determination of PHCZs from industrial waste. The discovery of 3-CCZ and 36-CCZ highlights the importance of identification of potential industrial sources of PHCZs and clarification of their contribution to environmental risks. Our method could be applied to investigate industrial emission of PHCZs.

A Study on the Method of Calculating the Dioxin Emission Factor of Municipal Waste and Medical Waste Incineration Facilities

Dioxin is unintentionally generated during waste incineration and heat treatment processes. The Stockholm Convention conducts research, development, and monitoring to eradicate persistent organic pollutants (POPs), so some countries are currently calculating dioxin emissions. Emissions are also being calculated in Korea, and we would like to improve the dioxin calculation method currently in use. In this study, two different calculation methods were used and compared. Calculation method A is now in use, and data measured on the same day was used as the calculation factor. Calculation method B was developed, where the average of the annual data was used as the calculation factor. The emission factors were calculated using methods A and B for municipal waste incineration facilities with a 2 t/h or higher processing rate. The method A results were 81 ~ 204 ng I-TEQ/ton, and the method B results were 79 ~ 284 ng I-TEQ/t. Also, the emission factors were calculated using both methods for medical waste incineration facilities with a processing rate of 1 t/h or higher. The method A results were 834 ~ 2,737 ng I-TEQ/t, and the method B results were 737 ~ 2,049 ng I-TEQ/ton. The range of fluctuations was small. In the future, if the facility operation data of small incineration facilities are confirmed, it is judged that comparative analysis is also helpful.

Increasing carbon, nutrient and trace metal accumulation driven by development in a mangrove estuary in south Asia

Mangrove forests sequester organic carbon, nutrients and toxic metals sorbed to fine sediment, and thus restrict the mobility of pollutants through estuarine environments. However, mangrove removal and environmental degradation caused by industrial activity and urban growth can impact the ability of mangrove communities to provide these critical ecosystem services. Here, we use sediment profiles from an impacted tropical estuary in southwest India to provide a c. 70-year record of carbon, nutrient and trace metal burial in the context of rapid urban development and the systemic removal of mangrove communities. Our results show that carbon and nutrient accumulation rates increase sharply during the 1990's in accordance with the high rates of deforestation. Nitrogen and phosphorus accumulation rates increased fourfold and twofold, respectively, during the same period. Organic carbon accumulation was fivefold higher than the global average during this period, reflecting intense deforestation during the last three decades. The enrichment of Hg, Zn, Pb, Mo, Ni, Cu and Mn demonstrate clear anthropogenic impact starting in the 1950's and peaking in 1990. Mercury, the trace metal with the highest enrichment factor, increased sevenfold in the most recent sediments due to increased fossil fuel emissions, untreated water and incineration of medical waste and/or fertilizers used in aquaculture. Organic carbon isotope (δ13C) and C:N molar ratios indicate shifts to more terrestrial-derived source of organic matter in the most recent sediments reflecting growing deforestation of which may be prevalent in southeast Asia due to increasing development. This study emphasizes the critical role played by mangrove ecosystems in attenuating anthropogenically-derived pollutants, including carbon sequestration, and reveals the long-term consequences of mangrove deforestation in the context of rapidly developing economies.

A Review of Medical Waste Management Systems in the Republic of Korea for Hospital and Medical Waste Generated from the COVID-19 Pandemic

With the increasing generation of medical waste worldwide, managing medical waste has become crucial, given its potential environmental and public health risks. Previously in the Republic of Korea, medical waste was often mixed with municipal waste and disposed of in residential landfills or unsuitable treatment facilities (e.g., improperly managed incinerators). Environmental regulators and waste producers have made extensive efforts in recent years to improve waste management at healthcare facilities. This study presents an overview of the status of medical waste management in Korea and discusses information on the generation, composition, separation, transportation, and treatment of medical waste. Incineration was confirmed to be the most preferred treatment method for medical waste and was the only one used until late 2005. Large-scale medical waste incinerators are used for treating medical waste from most medical facilities in Korea; however, with increasing regulations on toxic air emissions (e.g., dioxins and furans), air emission standards are being tightened for all existing small-scale incineration facilities without air pollution control. Since medical waste usually contains various plastic materials such as polyvinyl chloride, these incinerators are highly likely to emit toxic air pollutants if improperly operated and managed. Waste minimization and recycling, control of toxic air emissions from medical waste incinerators, and alternative treatment methods to incineration are seen as major challenges. Incineration capacity cannot be expanded as quickly as the rising quantities of medical waste in Korea; thus, there is a growing need to reconsider the overall management system. Accordingly, we examined various medical waste treatment policies and methods that are being implemented in other countries, in addition to the main strategy of waste management. To determine preferable directions for the improvement of the medical waste management system, we investigated and compared the status of domestic and foreign waste management and proposed directions for improvement, focusing on several issues related to the current medical waste management system in Korea.