Disinfection Of Devices Research Articles

Design and Analysis of a Novel Ultraviolet-C Device for Surgical Face Mask Disinfection.

This paper deals with the design of a compact sanitization device and the definition of a specific protocol for UV-C disinfection of a surgical face mask. The system was designed considering the material properties, face mask shape, and UV-C light distribution. DIALux software was used to evaluate the irradiance distribution provided by the lamps emitting in the UV-C range. The irradiance needed for UV-C-decontaminated bacteria and virus, and other contaminating pathogens, without compromising their integrity and guaranteeing inactivation of the bacteria, was evaluated. The face mask’s material properties were analyzed with respect to UV-C exposure in terms of physicochemical properties, breathability, and bacterial filtration performance. Information on the effect of time-dependent passive decontamination at room temperature storage was provided. Single and multiple cycles of UV-C sanitization did not adversely affect respirator breathability and bacterial filtration efficiency. This multidisciplinal approach may provide important information on how it is possible to correctly sanitize a face mask and, in case of shortage, safely reuse the face mask.

Cold plasma as a fast acting alternative disinfection method

Abstract Cold plasma disinfection is a cost-efficient and, above all, fast way of disinfecting even complex products. There are already approaches where plasma disinfection is used for wound treatment or hand disinfection. The ionization of a gas results in a number of physical and chemical processes that have a damaging effect on microorganisms. Especially in the field of medical device reprocessing, a tool that can reliably disinfect even very complex products in a short time would be a great asset. In this work, the potential of a newly developed cold plasma disinfection device was tested for the reduction of microbiological contamination and thus the disinfecting effect. In order to examine this microbiological reduction 3D printed scaffolds with contaminated test plates were used. This was done with different concentrations of the bacteria in the cold plasma disinfection process to determine the maximum germ reduction effect. In a first test run, the maximum effect of germ reduction was achieved with log 3.6. By making further changes and increasing the disinfection cycles, it was possible to increase the germ reduction to log 4.7. If these values are confirmed and can be improved by further modifications (e.g. increasing the plasma concentration), cold plasma technology represents a very good alternative to conventional disinfection methods.

Would it be helpful to infection control professionals to have the FDA regulate whole-room UVC devices?

A 2-question survey was performed at the 2022 Annual Meeting of the Association of Professionals in Infection Control (APIC) regarding whole-room ultraviolet C (UVC) disinfection devices. Ninety-six questionnaires were completed. About 82.3% indicated FDA regulation of UVC devices would help them, 5.2% responded they would not, and 12.5% were neutral. About 84.4% ranked thoroughness of disinfection as the most important attribute of a whole-room UVC device. And 13.5% indicated ease of use and time required as most important.

A New Culture Method for the Detection of Non-Tuberculous Mycobacteria in Water Samples from Heater-Cooler Units and Extracorporeal Membrane Oxygenation Machines.

The isolation of non-tuberculous mycobacteria (NTM) from cultures is particularly laborious due to the potential overgrowth of coexisting non-acid fast bacilli. To reduce the overgrowth of these non-mycobacterial organisms, a decontamination step with NaOH or cetylpyridinium chloride is highly recommended before plating the samples on the culture medium. However, due to their toxicity, decontamination solutions tend to decrease NTM recovery from clinical and environmental samples. Here, we tested an alternative method for NTM recovery based on the use of NTM Elite agar, a selective medium that does not require a decontamination step. Using NTM Elite agar, we were able to detect non-tuberculous mycobacteria in 27.7% (30/108) of water samples analyzed. The average time to NTM detection was 18 days, but some strains required longer to grow, perhaps due to the stressful environmental conditions (periodical disinfection of devices). NTM Elite agar’s effectiveness in inhibiting background flora was proven by the isolation of NTM from samples with and without background flora, showing no statistically significant differences in detection rates for different total viable counts of background flora (p = 0.4989). In conclusion, our findings indicate that effective NTM recovery from HCU- and ECMO-derived water samples can be achieved via filtration and direct culture of the filters on NTM Elite agar. This simple procedure can speed up laboratory work and provide an improved method, successfully resulting in low contamination and high detection rate, in addition to being less time-consuming. Its sensitivity and lack of a decontamination step make this protocol particularly useful for monitoring the effectiveness of device disinfection in hospital settings, even in the presence of low NTM loads. Reading timeframes should probably be extended to 7 weeks (i.e., well beyond the standard 4 weeks advised by the manufacturer), in order to isolate even the slow-growing mycobacteria. However, an extended incubation period is not necessary for exclusion of M. chimaera contamination of the devices, as M. chimaera isolation times do not generally exceed 3 weeks.

Efficiency of a multi-barrier household system for surface water treatment combining a household slow sand filter to a Mesita Azul® ultraviolet disinfection device

Low-cost household technologies for water treatment are crucial to improving drinking water quality and preventing health, social and economic impacts, mostly in middle- and low-income regions. This work assessed the removal efficiency of physical-chemical and bacteriological parameters from river water by a multi-barrier household water treatment system for 113 consecutive days. This system combines a pre-treatment step through a non-woven synthetic blanket, filtration by an intermittent household slow sand filter (HSSF) and a Mesita Azul® ultraviolet disinfection device. In general, the water quality was improved by the evaluated system. Turbidity was removed by an average of 73% (ranging from 33 to 94%), total coliforms (TC) of 3.88 log10 (ranging from 2.22 to 5.16 log10) and E. coli of 2.49 log10 (ranging from 1.81 to 3.30 log10). Filtration improvement was mostly correlated to HSSF biofilm development and influent water quality. Characterisation of HSSF schmutzdecke demonstrated a predominance of organic content, and a higher presence of carbohydrates than proteins on the sand and the blanket. Ultraviolet disinfection with Mesita Azul® inactivated most of the remaining bacteria after filtration and no regrowth was observed after 15 days of disinfection. In conclusion, the multi-barrier household water treatment system was efficient in treating river water, reducing risks of microbial contamination to achieve safe drinking water.

Positive Airway Pressure Device Care and Cleaning Practices in the Pediatric Home.

Regular care and cleaning of positive airway pressure (PAP) devices are important for maintaining equipment in the home. Illness and hospitalization have occurred from inadequate cleaning and use of tap water in the humidifier. In recent years, ozone and ultraviolent-light disinfection devices have been advertised for cleaning home PAP equipment. Our clinic provides instructions; however, cleaning practices performed in the home are unknown. A survey of home cleaning practices for PAP equipment was conducted in a pediatric sleep clinic during 2019-2020. Survey domains were method, cleaning and replacement frequency for each component, type of water used, instruction preferences, and demographics. The primary aim was to identify home PAP cleaning practices and compare with provided instructions. The secondary aim was to determine if respiratory-related symptoms (eg, congestion, runny nose, sneezing, coughing) occurred or increased with PAP use or inadequate cleaning. The survey was completed by 96 respondents. Most reported weekly cleaning of mask (36, 38%), tubing (41, 43%), and humidifier (31, 33%) with soap and water as the primary method for each. The majority used distilled water in the humidifier (74, 77%) and reported respiratory symptoms did not occur with PAP use (64, 67%). Very few indicated a device was used to clean equipment. No associations were found between length of time for PAP use and cleaning practices. There was a moderately low correlation between age and cleaning. Increased age was associated with decreased cleaning frequency (r = 0.20, P = .048). Care and cleaning practices of home PAP equipment varied from instructions provided in clinic. Most reported at least weekly cleaning of items for which daily cleaning is recommended. Few reported using a device for cleaning or having respiratory symptoms from PAP treatment.

The Use of Energy­Saving Ultraviolet Electrical Equipment in Agriculture

It was noted that the optical radiation in the ultraviolet (UV) range plays an important role in agricultural production, and a lack of it leads to the deterioration of animal productivity.Research purpose The study aims to substantiate the parameters of energy-saving agricultural electrical equipment operating in the ultraviolet range.Materials and methods The study shows that it is possible to create a universal therapeutic irradiator based on LEDs with a wavelength of 310 nanometers. The calculation methods are given. The parameters of UV devices for premises disinfection are substantiated. It has been found out that UV radiation increases the polymerization rate of paint coatings and facilitates the creation of energy-saving optical insect traps.Results and discussion The paper provides some examples of own-developed energy-saving systems and their use for the therapeutic irradiation of animals. The replacement of LE-30 fluorescent lamps with LEDs has resulted in a 13-fold reduction in electricity consumption. It has been found out that the use of bactericidal irradiators in poultry houses reduces not only the concentration of microorganisms but also the content of carbon dioxide and ammonia. The use of own-developed irradiators for photochemical polymerization of paint coatings reduces the curing time by 2 times. Optical insect traps have been created based on LEDs with a wavelength of 385 nanometers and the best pulsation frequency of the light source has been determined at 100 hertz.Conclusions The equipment has been developed and the parameters for irradiators operating in the range of 254-390 nanometers were substantiated for a variety of their applications in agriculture.

Device for Identifying the UV Emission Spectrum.

Nowadays, the disinfection of classrooms, shopping malls, and offices has become an important part of our lives. One of the most effective disinfection methods is ultraviolet (UV) radiation. To ensure the disinfection device has the required wavelength spectrum, we need to measure it with dedicated equipment. Thus, in this work, we present the development of a UV spectrum detector capable of identifying UV wavelength spectrums, with a wide range of probes and the ability to transmit data to a PC for later evaluation of the results. The device was developed with four UV sensors: one for UV-A, one for UV-B, one for UV-C, and one with a wide range of detection of UVA, with a built-in transimpedance amplifier. An Arduino Nano development board processes all the acquired data. We developed a custom light source containing seven UV LEDs with different central wavelengths to calibrate the device. For easy visualization of the results, custom PC software was developed in the Processing programming medium. For the two pieces of electronics—the UV detector and calibration device—3D-printed housings were created to be ergonomic for the end-user. From the price point of view, this device is affordable compared to what we can find on the market.

Experimental Investigation of the Effects of UV-C Irradiation Air Disinfection Device on Pathogens

Bu çalışmada, virüs, bakteri, küf ve mantar gibi insan sağlığına zararlı organizmaları yok etmek ve iç ortam hava kalitesinin yükseltilmesi amacı ile, UV-C lamba, EU4, EU9 ve karbon filtre içeren hava temizleme cihazı tasarlanmıştır. Tasarımı yapılan deney cihazının, ofis ortamında bulunması muhtemel farklı tip patojenler üzerindeki etkinliği hesaplanmıştır. Cihazın etkinliğinin ölçülebilmesi için deneysel çalışmalar gerçekleştirilmiştir. Deneyler TS EN ISO/IEC 17025 standartları kapsamında gerçekleştirilmiştir. Test içeriği EN ISO 14698-1:2003 standartları kapsamında planlanmıştır. Dezenfeksiyon cihazının 1 saatlik çalışması sonucunda ortamdaki patojen miktarında %23 oranında bir azalma gözlemlenmiştir. Hesaplanan değerler ile deneysel sonuçlar karşılaştırıldığında tutarlı sonuçlar elde edilmiştir.

Ultraviolet-C radiation: A supplemental tool for disinfection.

In response to the COVID-19 pandemic, healthcare facilities have purchased more ultraviolet-C (UVC) disinfection devices than in previous years. This article discusses the safety and efficacy of UVC disinfection in healthcare settings.

Aqualuz: a new solar disinfection device for treatment of cistern water

Abstract We conducted field, laboratory and modeling studies to evaluate the efficiency of a new solar disinfection (SODIS) device called Aqualuz for the removal of Escherichia coli (EC) from cistern water in the Brazilian semiarid, for different solar exposure–water temperature conditions. The results indicated EC contamination (100–300 MPN/100 mL) in all tests performed. As compared to the literature, lower exposure times (2.5–4.0 h) and solar radiations (250–410 W/m²) were sufficient for EC elimination. Then, assuming the complete-mix approach and first-order kinetics, it was possible to adjust EC decay rate constants (k) considering three different models: constant k-value, k as a function of water temperature and a new formulation for k as a function of both solar radiation and water temperature. All models performed well with normalized root mean squared logarithmic error (NRMSLE) lower than 20%, but the best fitting was obtained with the new approach. A new relationship between solar radiation and water temperature was also obtained, which allowed model simulations of EC decay for 34 municipalities in the Brazilian northeast, resulting in a color map for the region depicting the exposure periods of 1.8–5.6 h for reaching a 3-log reduction.

In-duct grating-like dielectric barrier discharge system for air disinfection

In the context of spreading Coronavirus disease 2019 (COVID-19), the combination of heating, ventilation, and air-conditioning (HVAC) system with air disinfection device is an effective way to reduce transmissible infections. Atmospheric-pressure non-equilibrium plasma is an emerging technique for fast pathogen aerosol abatement. In this work, in-duct disinfectors based on grating-like dielectric barrier discharge (DBD) plasmas with varied electrode arrangements were established and evaluated. The highest airborne bacterial inactivation efficiency was achieved by ‘vertical’ structure, namely when aerosol was in direct contact with the discharge region, at a given discharge power. For all reactors, the efficiency was linearly correlated to the discharge power (R2 =0.929–0.994). The effects of environmental factors were examined. Decreased airflow rates boosted the efficiency, which reached 99.8% at the velocity of 0.5 m/s with an aerosol residence time of ~3.6 ms. Increasing humidity (relative humidity (RH)=20–60%) contributed to inactivation efficacy, while high humidity (RH=70%−90%) led to a saturated efficiency, possibly due to the disruption of discharge uniformity. As suggested by the plasma effluent treatment and scavenger experiments, gaseous short-lived chemical species or charged particles were concluded as the major agents accounting for bacterial inactivation. This research provides new hints for air disinfection by DBD plasmas.

Point-of-use photocatalytic device for water disinfection under visible light using ZnO/Gypsum@alginate beads

A working prototype for point-of-use device for water disinfection under visible light using reusable photocatalytic beads is demonstrated. The device could disinfect antibiotic resistant Salmonella enterica serovar in water within 120 min under visible light using 3.0 g/L of ZnO/G@alginate beads·H2O2, •OH and O2•− are envisaged as the notable reactive oxygen species which promoted irreversible impairment of bacterial cell membrane. Treated water had no noticeable impact on gut health of administered animal suggesting the bio-safety of the process. Without any notable decline in performance, ZnO/G@alginate beads are used for 9 consecutive cycles. Prototype is further validated by disinfection of other water borne bacteria viz. Staphylococcus aureus, Escherichia coli and Shigella flexneri and is effective in disinfection of fecal coliform in raw surface water samples. Proposed device may find its use as an off-grid water disinfection system appropriate for most pregnable rural populations and individuals living in remote localities.

Disinfecting Efficacy of an Ozonated Water Spray Chamber: Scientific Evidence of the Total and Partial Biocidal Effect on Personal Protective Equipment and in Vitro Analysis of a Viral Experimental Model

ABSTRACT Due to the high recurrence of microbial infections, developing new technologies for preventing the dissemination of pathogens is essential, especially to prevent infection in humans. Thus, devices for the decontamination of surfaces reduce not only the spread of pathogens in the environment, but provide greater security and protection for communities. Ozone (O3) is a substance capable of reducing or eliminating several types of microorganisms owing to its biocidal capacity, including when it is dissolved in water. The objective of this study was to develop an instant decontamination device using ozonated water. To confirm its biocidal action and verify the device’s efficacy, the reduction of the microbial load of important pathogens on personal protective equipment (PPE) was assessed. In addition, in order to confirm the biocidal action of ozonated water against SARS-CoV-2, in vitro tests on a viral model of Gammacoronavirus were performed. The results showed the efficacy of ozonated water in the disinfection device at concentration ranges of 0.3–0.6 mg/L and 0.7–0.9 mg/L of ozonated water, with growth reductions above 2 log10 for both concentration ranges tested and inactivation fractions above 60% (0.3–0.6 mg/L) and 80% (0.7–0.9 mg/L), with a high proportion of the tested PPE showing 100% microbial reduction. In vitro results for the evaluation of ozonated water in a viral model showed a 99.9% reduction percentage in the concentration range of 0.3 to 0.5 mg/L and a 99% reduction in the concentration range of 0.6 to 0.8 mg/L, with a 5.10 log EDI50/mL and 6.95 log EDI50/mL reduction, respectively. The instant decontamination system developed in this study proved effective for microbial reduction, and we confirmed the potential of ozonated water as a biocidal agent. Therefore, the proposed decontamination device could be considered as a tool for reducing contamination on surfaces using ozonated water.

Bactericidal efficacy of non-thermal plasma activation against Aeromonas hydrophila and immunological responses of koi (Cyprinus carpio haematopterus)

In the aquaculture industry, an efficient and safe water purification system is important to prevent mass mortality by virulent pathogens. As extensive use of traditional methods (e.g.: povidone-iodine, ozone, ultraviolet irradiation, formalin, and chlorine dioxide) have adverse effects on cultured fish, an appropriate and alternative water purification method is vital for the sustainability of the industry. Non-thermal plasma technology has been successfully used for various biomedical purposes (e.g: food sterilization, medical device disinfection, wound healing, cancer therapy, etc.) and has great potential to be used as a sterilizing system. However, few studies have been conducted on its usefulness in the aquaculture industry. In this study, we investigated the bactericidal efficacy of plasma-activated water induced by non-thermal plasma and its histopathological as well as immunological adverse effects on koi. A highly virulent Aeromonas hydrophila SNU HS7, which caused massive mortality of koi, was used for this study. Non-thermal plasma was applied for 10 min to the fish tanks with 1.2 × 109 CFU/mL SNU HS7 using PLMB-20 system to confirm the sterilization efficacy and to observe the survival and immunological reaction of koi for 14 days. As a result, gross pathological, histopathological, and immunological investigations did not reveal any significant adverse effects in fish as compared to the control groups. To the best of our knowledge, this is the first study showing that non-thermal plasma can be used for sterilization of rearing water without giving significant physiological damage to the fish, even under the assumption of extreme situations. As plasma can effectively sterilize not only bacteria but also other unknown pathogens, the results of this study are showing a promising future in purifying water in aquaculture practice.

Disinfection of wastewater with ultraviolet light on devices of the cyclic principle of action

The article presents a diagram of a device for ultraviolet disinfection of wastewater of a cyclic principle of action, which allows you to control the time of liquid processing and, accordingly, the dose of ultraviolet radiation. The device consists of the following structural elements: round-section body; ultraviolet lamps attached to the inner surface of the housing walls; inlet and outlet pipelines with shut-off and control valves; level gauge made in the form of a float. One cycle of operation of the device consists of filling the body, processing (disinfecting) the original liquid, and emptying the body. Control tests of this device were carried out in the process of purifying wastewater from a cattle breeding complex. During the tests of this device, it was revealed that the effluents treated with ultraviolet light with a generally accepted radiation dose of 30 mJ/cm2 do not meet the requirements of sanitary and hygienic standards, since the number of viable helminth eggs at the outlet is 54.2% of their initial value, and the effect of complete deworming can be achieved only at a dose of ultraviolet radiation of at least 45 mJ/cm2.

DISINFECTION OF SOIL AND SUBSTRATE BY INFRARED RADIATION WITH AN AUTONOMOUS POWER SUPPLY SYSTEM

Thermal energy occupies a special place in human life. In most cases, the waste heat is irretrievably lost. This lost resource is no longer worth anything, so its reuse will contribute to both reducing the energy crisis and protecting the environment. For this reason, new ways of converting thermal energy into electrical energy are more relevant today than ever. The use of electric energy and power supply of installations are important in the agro-industrial complex, especially the use of an autonomous power supply system for process automation. (Research purpose) The research purpose is to develop the devices for disinfection of soil and substrate by infrared radiation in protected soil with the utilization of heat from the infrared emitters using Peltier thermoelectric generators. (Materials and methods) The article presents the operation of the developed device. (Results and discussion) During the operation of the installation, the cases of the infrared emitters are heated to a temperature of 500 degrees Celsius, and this thermal energy is released into the atmosphere. To increase the energy efficiency of this installation, infrared radiators are covered with a sealed steam jacket from above, water is poured inside, is heating up, evaporates and settles on the dome, thereby transferring heat from the covers of infrared radiators to the dome. Peltier thermoelectric generators are installed on the dome, which are designed to convert thermal energy into electrical energy, Peltier elements are connected in series and in parallel. The electricity received from the Peltier elements enters the battery, accumulates and is spent on the operation of devices for automatic control of soil and substrate disinfection, which makes it possible for the installation to operate autonomously. (Conclusions) For the functioning of the device is used the utilization of heat losses from the operation of infrared emitters using Peltier thermoelectric generators.

Experimental studies of a seed disinfection device

This article deals with one of the most pressing problems at present - reducing seed germination loss during storage in grain bins. The quality of the grain determines the germination rate of the seed and its maturity. However, anyone involved in agriculture can say with certainty that seed treatment before planting - “seed disinfection” - is just as important. Seed disinfection is a targeted procedure that aims to protect the seed economically and ecologically. Special preparations (pesticides) and their combinations are used for this purpose. The equipment used for seed disinfection in many plants does not always meet modern agrotechnical requirements of treatment quality, consequently it is necessary to develop technology and design of technical means with justification of its design and technological parameters. During the work, experimental methods such as simulation, observation, experiment were used. On the basis of this, the technological scheme and design of the unit for disinfection of grain in the flow when putting in storage was obtained and the optimal parameters of the proposed device were determined.

Ergonomics-oriented operation, maintenance and control of indoor air environment for public buildings

<p indent=0mm>In response to the construction process of Healthy China, it is rather important to create a safe, healthy and energy-efficient indoor environment for public buildings. The public building space is often densely populated, with a large flow of people and many types of air pollution, which presents non-uniform dynamic distribution characteristics. This brings great challenges to the control of indoor air safety, especially during the pandemic period of COVID-19. Excessive ventilation may not only cause large energy waste, but also lead to cross-contamination and even cluster of infection. In this paper, an operation and maintenance (O&M) control system for indoor air safety is developed based on the core concepts and basic methods of human ergonomics. In this system, one of the important human environmental variables is focused for control, i.e., indoor air pollution level. Especially after the outbreak of COVID-19, droplets and droplet nuclei from respiration are the most significant air pollution categories required for mitigation. Towards the efficient control of air pollution in large public buildings, it should further take into account the interaction of human, equipment and machines (i.e., ventilation, air purification and disinfection and intelligent control system) and building environment. Firstly, on the basis of the online monitoring of indoor air pollution concentration and personnel flow, the non-uniform dynamic distribution of indoor pollutants and personnel can be obtained by using the non-uniform and low-dimensional rapid prediction models and computer vision processing. Then, the optimal setting results of ventilation parameters (e.g., ventilation modes, supply air rate, etc.) can be outputted by the environmental control decision system. Finally, based on a combination of monitoring sensors, controllers and actuator hardware equipment (at the location of fans or dampers), the intelligent regulation and control of ventilation system can be realized, aimed at minimizing energy consumption and reducing pollutant concentration and exposure level. Meanwhile, the air purification and disinfection system (especially for the disinfection of virus particles) are operated under the condition of the ventilated environment, which can serve as a powerful auxiliary to the maintenance of indoor air safety. The workflow and effect of the O&M control system are demonstrated by an engineering application case of the front hall in the International Convention and Exhibition Center. The results indicate that the non-uniform and low-dimensional rapid prediction model for pollutant concentration is effective for the ventilation control with the average prediction difference of 11.9%. The implementation of the intelligent ventilation system can reduce the risk of human infection to less than 4%, and its energy-saving ratio for the ventilation can be as high as about 45%. Through optimizing the layout strategies of disinfection devices based on the intelligent ventilation control, the space accessibility of negative oxygen ions can be well accepted, to further increase the removal efficiency of air pollution. The calculated value of space disinfection rate is more than 99%, which can further reduce the risk of infection by 1–2 orders of magnitude. This study can provide an important reference for the promotion and upgrading of O&M control system for indoor air safety.

Disinfection of drinking water with ozone by the method of electrodispersion

This article analyzes the existing methods for disinfecting drinking water with ozone and identifies their disadvantages. The substantiation of the method of water disinfection with ozone using electrodispersion is given. The description of the technological scheme of water disinfection using the method of electrodispersion is given. The description of the design of the electric spray is given. The results of production tests of a device for water disinfection on the water of open reservoirs and artesian wells are presented.