Engineering and Physical Bases of Development and Creation of Plasmochemical Reactors for Mobile Facilities for Medical Waste Disposal

This paper presents the results of the development and creation of plasma-chemical reactors for mobile and stationary installations for the destruction and disposal of solid, liquid, gaseous and mixed medical waste based on the domestic plasma generator PUN-1, with air as the plasma-forming gas. The design and principle of operation of plasma-chemical reactors installed on mobile experimental and industrial plants “Plazmon-1,2,3”, as well as the main features of the plasma waste disposal process are described.

Pyrolysis characteristics of rubber compositions in medical waste

Thermogravimetric study of rubber compositions （operating glove and catheter） in medical waste was carried out using the thermogravimetric analyser （TGA）,at the heating rate of 20 ℃/min in a stream of N2.The results indicate that the decomposition process of operating glove appears an obvious mass loss stage at 250-485 ℃,while catheter has two obvious stages at 240-510 ℃ and 655-800 ℃,respectively; both samples present endothermic pyrolysis reaction; the decomposition of operating glove and the first mass loss stage of catheter are in agreement with natural rubber pyrolysis; the second mass loss stage of catheter corresponds to CaCO3 decomposition.Based on the experimental results,a novel two-step four-reaction model was established to simulate the whole continuous processes,which could more satisfactorily describe and predict the pyrolysis processes of rubber compositions,being more mechanistic and conveniently serving for the engineering.

Dual Torch Plasma Arc Furnace for Medical Waste Treatment

In this paper, characteristics of a treatment and operated at atmospheric pressure dual torch plasma arc used for hazardous waste are studied, and also compared with those of the multi-torch plasma arc and the single torch plasma arc. The dual torch plasma arc is generated between the cathode and anode with argon as the working gas. The temperature distributions of the plasma arc are measured using a spectroscope and line pair method with the assumption of local thermodynamic equilibrium （LTE） for the DC arc current I=100 A and argon flow rate Q = 15 slpm. The measurements show that the temperatures of the dual torch arc plasma in the regions near the cathode, the anode and the center point are 10,000 K, 11,000 K and 9,000 K, respectively. And the high temperature region of the multi torch plasma arc is of double or much wider size than that of a conventional dual torch plasma arc and single plasma torch. Based on the preceding studies, a dual torch plasma arc furnace is developed in this study. The measured gas temperature at the center region of the argon arc is about 11,000 K for the case of I=200 A and Q=30 slpm operated in atmosphere.

Experimental study on co-pyrolysis characteristics of typical medical waste compositions

Thermal decomposition of 21 kinds of binary mixtures between typical medical compositions was investigated under nitrogen conditions by dynamic thermogravimetric analysis(TGA) at 25–800 °C. The weighed sum method(WSM) coupled with thermal analysis was applied to study the interaction between components. Then, co-pyrolysis kinetic model of the binary mixtures(tube for transfusion(TFT) and gauze) was established to verify the reliability of conclusions. The results show the follows. 1) Strong or weak interactions are shown between binary mixtures containing polyvinyl chloride(PVC), the main ingredient of TFT. The addition of other medical waste could enhance first stage decomposition of TFT. While, the secondary stage pyrolysis may be suppressed or enhanced or not affected by the addition. 2) There exists no interaction between catheter and other component, the DTG peak temperature representing Ca CO3 decomposition in catheter fraction is obviously lower than that of pure catheter; while,the shape of DTG peak keeps unchanged. 3) No evident reaction occurs between the other mix-samples, it is considered that their co-pyrolysis characteristics are linear superposition of mono-component pyrolysis characteristics.

Thermogravimetric characteristics and different kinetic models for medical waste composition containing polyvinyl chloride-transfusion tube

Thermogravimetric study of medical transfusion tube （MTT） waste containing polyvinyl chloride （PVC） was carried out using the thermogravimetric analyser （TGA） with N2, at different heating rates of 5, 10, 20, 30, 50 ℃/min. The purpose is to obtain pyrolysis characteristics and kinetic parameters of medical waste. The experimental results indicate that the pyrolysis behavior of the MTT sample is in agreement with its main ingredient of PVC, appearing two stair stepping stages. The influence of the additives in MTT on pyrolysis behavior was also revealed, which could improve MTT pyrolysis at lower temperature in the first stage, and cause obvious unsmoothness and asymmetry of the second DTG peak. Four n-order kinetic models of Coats-Redfern, Ozawa, Kissinger and Freeman-carroll were used to get the kinetic parameters. Furthermore, a novel ＂two-step four-reaction model＂ was established to simulate the whole continuous process. The different methods and the kinetic parameters thus obtained were discussed and compared with each other in literatures. The reasons of deviation among kinetic values were tried to be elucidated. The new established model could more satisfactorily describe the pyrolysis process of MTT, being more mechanistic and conveniently serving for the engineering.

Investigation and Analysis of Rural Medical Waste Management

Objective: The aim is to understand the status of rural medical waste management and problems and to make recommendations. Methods: The questionnaire survey, interviews and comparative analysis are used. Results: Compared with urban medical waste management, rural medical waste management is weaker in classification, unified recycle, disposals, protect measures of related personnel, regulations and policies of awareness. Conclusion: It is recommended to improve policies and regulations of rural medical waste management, strengthen rural infrastructures and facilities, improve supervision and innovates means of supervision.

Medical Waste Treatment Station Selection Based on Linguistic q-Rung Orthopair Fuzzy Numbers

During the COVID-19 outbreak,the use of single-use medical supplies increased significantly.It is essential to select suitable sites for establishing medical waste treatment stations.It is a big challenge to solve the medical waste treatment station selection problem due to some conflicting factors.This paper proposes a multi-attribute decision-making(MADM)method based on the partitioned Maclaurin symmetric mean(PMSM)operator.For the medical waste treatment station selection problem,the factors or attributes(these two terms can be interchanged.)in the same clusters are closely related,and the attributes in different clusters have no relationships.The partitioned Maclaurin symmetric mean function(PMSMF)can handle these complex attribute relationships.Hence,we extend the PMSM operator to process the linguistic q-rung orthopair fuzzy numbers(Lq-ROFNs)and propose the linguistic q-rung orthopair fuzzy partitioned Maclaurin symmetric mean(Lq-ROFPMSM)operator and its weighted form(Lq-ROFWPMSM).To reduce the negative impact of unreasonable data on the final output results,we propose the linguistic q-rung orthopair fuzzy partitioned dual Maclaurin symmetric mean(Lq-ROFPDMSM)operator and its weighted form(Lq-ROFWPDMSM).We also discuss the characteristics and typical examples of the above operators.A novel MADM method uses the Lq-ROFWPMSM operator and the Lq-ROFWPDMSM operator to solve the medical waste treatment station selection problem.Finally,the usability and superiority of the proposed method are verified by comparing it with previous methods.

Effects of Nursing Intervention Based on Transtheoretical Model of Behavioral Change on Disposal of Home Medical Waste in Diabetic Patients

[Objectives]To explore the effects of nursing intervention on the disposal of home medical waste for diabetic patients.[Methods]A total of 118 diabetic patients with insulin injection at home who visited a community service center in Shiyan City during November 2020 and September 2021 were selected as the research objects to implement the intervention,and the medical waste knowledge,attitude scores and standardized medical waste disposal were compared before and after the intervention.[Results]After the intervention,the patient's medical waste knowledge score was significantly higher than that before the intervention,and the medical waste disposal attitude score was significantly higher than that before the intervention.[Conclusions]If the nursing intervention based on Transtheoretical Model(TTM)of Behavioral Change penetrates deep into patients'families and communities,it is helpful to improve the knowledge and attitude of diabetic patients on home medical waste disposal,and regulate their home medical waste disposal behavior.

The Hospital Assessment Tool： An Integrated Solution to Evaluate and Reduce Solid Medical Waste

The Hospital Assessment Tool （HAT） is an assessment technique that provides technical support to the healthcare industry for accessing solid waste generation, selecting products, and work practices to eliminate or reduce environmental hazards and solid waste, and to maintain quality patient care. Since 2007, this tool has been applied as part of an innovative partnership between the Lucas County Solid Waste Management District and College of Engineering of the University of Toledo. The purpose of this paper is to provide a complete overview and framework of this program and the HAT so that other institutions may learn from it and adopt similar concepts to help reduce solid waste generation and improve economic conditions in their regions. A focus of this paper is a discussion of a case study that details the process and results of an assessment conducted at a large hospital in Northwest, Ohio, USA. Also, included in this paper is a discussion of the project＇s background, a comparison to similar project＇s between colleges and government agencies, and results and benefits of the program, and an overview of the opportunities and barriers to this type of research. The project demonstrates that through a cooperative effort and a creative alliance, businesses, governments, universities, and industries can work together to improve environmental quality, reduce waste, and improve profitability. The project also educates college students through practical, real-world environmental work experience and trains them to become future environmental leaders

Emergy Evaluation of Treatment Methods for Solid Medical Waste in Bujumbura-Burundi

Introduction: Treatment of solid medical waste (SMW) is a complex task requiring the proper practices with specific treatment methods corresponding to each type of SMW during pretreatment and final treatment. This study targeted three treatment methods identified as the main used by the majority of health care facilities (HCFs) and treating a large amount of SMW. It aimed: 1) to evaluate the current practices by calculating the emergy investment and emergy costs that are required to treat one ton of SMW through the three treatment methods and 2) to evaluate and compare better technologies and provide policy suggestions for the final treatment of SMW in Burundi. Materials and Methods: This study used the emergy methodology to evaluate the relative efficiencies of three treatment methods used for to treat SMW in twelve HCFs in Bujumbura. Results and Conclusion: The total emergy input was 1.36E+20 seJ/yr, 3.54E+17 seJ/yr, and 1.681E+18 seJ/yr for low temperature incinerator, landfill and organic pit, respectively. Conclusion: Rapid improvement of organic pit by ensuring its maintenance, the gradual replacement of low temperature incinerator by high temperature incinerator with air control pollution and landfill by sanitary landfill are highly recommended by respecting its maintenance (fence, roof and monitoring evaluation) for reducing the risk.

Analysis of Health Workers’ Perceptions on Medical Waste Management in Tanzanian Hospitals

This paper presents the perceptions of health workers (HWs) on medical waste management (MWM) issues in Tanzanian hospitals. The perceived total waste generation rates were lower than the actual measurements. Administrators perceived lower rates than implementers. The results indicated three categories of medical waste which are given due attention, that is, sharps waste, pathological and infectious waste. Other wastes like radioactive, chemical, pharmaceutical, pressurized containers receive very little attention. Container colour coding and labelling was negligible, while improvised containers are still in use. Medical waste is transported within hospitals manually, with little efforts on mechanized transportation. Poor waste storage was observed, while the prominent medical waste treatment technologies are medium temperature incinerators. Off-site transportation of medical waste is practiced, where the waste is finally dumped or buried. The hospitals are currently utilizing public-private partnership schemes for MWM in only one aspect of off-site transportation. Three main problems which require high attention include: Weaknesses in hospital management, poor MWM infrastructure, and lack of skills and knowledge on MWM among HWs. Knowledge and awareness among HWs on health hazards associated with poor MWM is low (with exception of cholera, HIV and typhoid). Few PPE types are supplied and used in the hospitals, leading to poor diseases prevention. There is also low knowledge among HWs on administrative issues related to MWM in Tanzanian hospitals.

A queueing-inventory model to control the congestion of patients and medical waste in the medical centers, a case study

During epidemics,controlling the patients’congestion is a way to reduce disease spreading.Raising medical demands converts hospitals into one of the sources of disease outbreaks.The long patient waiting time in queues to receive medical services leads to more casualties.The rise of patients increases their waste,which is another source of disease outbreak.In this study,a mathematical model is developed to control patients’congestion in a medical center and manage their waste,considering environmental issues.Besides a queueing system controlling the patients’congestion in the treatment center,another queue is considered for vehicles.An inventory model is employed to prevent waste accumulation.The developed model is solved and reaches an exact solution in small size,and obtains an acceptable solution in large size using the Grasshopper algorithm.A case study is considered to demonstrate the model’s applicability.Also,Sensitivity analysis and valuable managerial insights are presented.

Detoxifying PCDD/Fs and heavy metals in fly ash from medical waste incinerators with a DCdouble arc plasma torch

Medical waste incinerator （MWI） fly ash is regarded as a highly toxic waste because it contains high concentrations of heavy metals anddioxins, including polychlorinateddibenzo-p-dioxins （PCDDs） and polychlorinateddibenzofurans （PCDFs）. Therefore fly ash from MWI must be appropriately treated before beingdischarged into the environment. A melting process based on adirect current thermal plasma torch has beendeveloped to convert MWI fly ash into harmless slag. The leaching characteristics of heavy metals in fly ash and vitrified slag were investigated using the toxicity characteristic leaching procedure, while the content of PCDD/Fs in the fly ashes and slags was measured using method 1613 of the US EPA. The experimental results show that thedecomposition rate of PCDD/Fs is over 99% in toxic equivalent quantity value and the leaching of heavy metals in the slag significantlydecreases after the plasma melting process. The produced slag has a compact and homogeneous microstructure withdensity of up to2.8 g/cm3 .

Suggested guidelines for emergency treatment of medical waste during COVID-19:Chinese experience

During the period of COVID-19,the medical waste disposal capacity is seriously inadequate.The main technical process of the municipal solid waste incineration system is the same as that of the medical waste incineration system.Under the conditions of optimizing the technological process,improving the supporting facilities,and controlling the co-processing ratio,the municipal solid waste incinerator(grate furnace)co-processing medical waste is feasible.Some suggested guidelines for emergency treatment of medical waste from COVID-19 have been provided by China.

Study on HCI removal for medical waste pyrolysis and combustion using a TG-FTIR analyzer

Under both pyrolysis and combustion condition, HCl removal efficiency for medical waste with Cabased additives was semi-quantitatively studied by means of TG-FTIR. Additionally, the difference of HCl removal efficiency for PVC and medical waste was compared. Experimental results showed that： 1） Thermal degradation of medical waste mainly took place in two steps under both pyrolysis and combustion condition; 2） HC1 emitted at both two steps and HCl concentration increased with the increased of Cl ratio in the medical waste; 3） for the same additive, HCI concentration decreased with the increased of additives amount, that is to say, HCI removal efficiency of medical waste increased as the increased of Ca/Cl molar ratio. Fourth, when Ca（OH）2 was used as additive, HCl removal efficiency for medical waste combustion was a little higher than that for medical waste pyrolysis, but either CaCO3 or CaO was used as additive, it was just opposite, more specifically, when CaCO3 was used as additive with Ca/CI= 1.3, HC1 removal efficiency was 5.49% under pyrolysis condition, but that was only 4.24% under combustion condition. Fifth, under the same Ca/CI molar ratio, HCl removal efficiency for PVC was higher than that for medical waste under both pyrolysis and combustion condition, more specifically, when Ca（OH）2 was used as additive with Ca/Cl-1, HCl removal efficiency was 64.51% for PVC, but that was only 27.66% for medical waste pyrolysis with 4% Cl under pyrolysis condition .

Medical waste management in Iraq:a case study of Baghdad

There is a lack of information about medical waste management in Iraq.This study aims to monitor and evaluate the cur-rent situation of medical waste management in Baghdad as it represents the capital and the biggest populated city in Iraq.About 32%of hospitals are located in Baghdad.Ten state-owned hospitals in Baghdad with the biggest bed capacity were investigated.The study used structured interviews with staff in charge of waste management in the sampled hospitals to col-lect data.The results showed that the generation rate of medical waste in the ten hospitals was 0.5 kg/(bed·day).The study also found that there were insufficient,ineffective,and improper isolation,collection,storing,processing,and safe disposal of medical wastes in the sampled public hospitals of Baghdad.The study recommended that the Iraqi Ministry of Health takes extensive and quick effective measures to better monitor and evaluate medical waste management and provide ongoing training to personnel responsible for waste management in the hospitals.

Incineration experiment of medical waste of novel coronavirus pneumonia(COVID-19)in a mobile animal carcass incinerator

Incineration experiment of medical waste was carried out in a mobile animal carcass incinerator.Simulated medical waste(69%cotton,1.5%wood product,4.5%mask and 25%moisture)was used as raw material.The temperature trend of first and second combustion chamber,the operating conditions and the emission characteristics of gaseous pollutants were studied.The results indicated that the temperature of first combustion chamber can be maintained at 550-650℃ without external heating,while in the final stage a burner was used to realize the burnout of material.The temperature of the second combustion chamber was always lower than that of the first combustion after the burner stopped working.The concentration of CO emission in flue gas was high due to the low disposal efficiency of the mobile incinerator,while NOX and SO2 emission concentrations were far below the standard limit value(GB 18484-2001).

Estimation of Different Categories of Healthcare Waste Generated at Two Different Hospital Categories in Four Hospitals in Dar es Salaam City

This study aims to estimate the quantity of healthcare waste categorically generated in four different healthcare in Dar es Salaam city namely, Muhimbili National Hospital, Mwananyamala Regional Referral Hospital, Temeke Regional Referral Hospital and Ilala Regional Referral Hospital to evaluate the quantities of medical waste generated based on their level and capacity. Waste was collected in different categories of non-infectious, sharps, infectious, infectious plastics, and pathological waste which were measured daily for fourteen (14) consecutive days in all hospitals by using a weighting scale and observational checklist to document related waste management information and the assessment of the healthcare waste generation in each hospital. The average general healthcare waste generation rate per healthcare ranges from 298.9 kg/day to 1554.4 kg/day. The high fluctuation in general medical waste was established to be attributed to specialization difference between one hospital to the other, and the large number of in-patients and out patients between hospitals. The overall average sharps waste generation rate was established to range from 8.5 ± 2.7 - 13.9 ± 1.8 kg/day. Higher values of sharps waste generated observed at Muhimbili hospital are due to emergency cases referred to from other hospitals located within the city and from the surrounding districts and other regions of the country. The results from this study, raise alarm to hospital administrators, and other health stakeholders working in related fields to give special attention and priority in setting a related share in their budgets for proper management of medical waste in their health facilities.

Fuzzy MCDM Model for Selection of Infectious Waste Management Contractors

Healthcare supply chains are under pressure to drive down costs because of digital business,shifting customer needs and new competition.Medical waste generated from medical facilities includes medical activities and daily-life activities of patients and their family members.According to statistics of the Department of Health EnvironmentalManagement,Vietnam currently has more than 13,500 medical facilities,including hospitals from central to provincial and district levels and private hospitals and medical facilities.Preventive medicine generates about 590 tons of medical waste/day and is estimated to be about 800 tons/day.Medical waste includes ordinary medical waste and hazardous medical waste;in which ordinary medical waste accounts for about 80%–90%,only about 10%–20%is hazardous medical waste including infectious waste and non-infectious hazardous waste.This is an environmental and occupational health issue that needs attention in developing countries like Vietnam.Handling large amounts of medical waste to ensure environmental and personal hygiene,doing so inefficiently creates potential hazards to the environment and increases operating costs.However,hospitals lack objective criteria and methods to evaluate and select the most optimal infectious medical waste,relying instead on their own subjective assessment and prior experience.Therefore,the author proposed a fuzzy multicriteria decision making(MCDM)model including Fuzzy Analytic hierarchy process(FAHP)and the Weighted Aggregated Sum-Product Assessment(WASPAS)for infectious medical waste contractors’selection in this research.The proposed Fuzzy MCDM method is in-tended to provide a more efficient,accurate method in the selection of infectious medical waste contractors than subjective assessment methods,thus reduce potential risks to hospitals.The results of this study can be applied to evaluate and select contractors in other industries.

传染病流行期间定点收治医院医疗废弃物的“闭环式”管理

介绍传染病流行期间定点收治医院医疗废弃物的“闭环式”收、储、运模式,以及气化式回转窑无害化处理的工艺特点,为其他医院的医疗废弃物处理提供参考。