Effective Decontamination Method Research Articles

Екологічні аспекти відновлення довкілля: комплексний спосіб дезактивації радіоактивно забруднених ґрунтів

The purpose of the research: development and development of a new effective method of decontamination of radiation-contaminated soils to reduce the negative impact of radionuclides on the environment and human health. Research materials and methods: The research object is sandy soil contaminated with radiocesium. Research methods are applied - X-ray diffractometry, dispersion analysis, gamma spectrometry. Results: a complex method for cleaning of radioactively contaminated soil is proposed, which combines plasma-chemical treatment of the «soil – water» suspension with subsequent separation of the cleaned soil and coagulation-sorption cleaning of the formed supernatant. The supernatant contains a dispersion in the aqueous phase of micro- and nanoparticles that contain radioactive substances. The principle of heterocoagulation was used for the deposition of the solid phase, which reduces the migration of radioactive particles into the dispersion medium, using a positively charged colloid of iron hydroxide (III) as a coagulant. For deactivation of the liquid phase of the supernatant, a complex sorbent based on iron hydroxide micro- and nanoparticles modified with nickel-potassium ferrocyanides and highly dispersed layered aluminosilicates was used. At the same time, the degree of decontamination of the soil is 91.6%, and that of the supernatant is ≈98%. This method allows to get purified soil that can be used in soil reclamation processes, as well as purified water. Multiple use of process water is envisaged, which prevents additional contamination of the environment with radioactive substances. Radioactive sludge is suitable for compaction and further storage in radioactive waste storage facilities. Conclusions: Based on the results of this study, a new effective method of soil decontamination was developed and worked out, which is an effective and promising approach in combating the consequences of accidents at nuclear power plants and other sources of radiation pollution. It allows to effectively remove radioactive substances from soil and water, reducing the negative impact on the environment and human health. The main advantages of the method are its high efficiency, the possibility of reusing process water, as well as reducing the amount of radioactive waste that requires further treatment and storage. The proposed approach is an important step in preserving ecosystems and ensuring the safety of life and health of the population.

Effects of Gamma Radiation on Microbial Load and Chemical Constituents from Stem Barks of Luehea ochrophylla

Gamma radiation is an effective method for microbial decontamination of plant materials. However, this treatment can induce changes in the chemical structure of plant constituents. Stem barks of Luehea ochrophylla were exposed to different doses of gamma radiation to evaluate decontamination efficiency and changes in chemical composition of plant material including phenolic fraction. The major microbial contaminants of non-irradiated samples were isolated and identified as the fungal species Eurotium chevalieri L. Mangin and Lecythophora decumbens. The dose of 5.0 kGy was effective to achieve total decontamination of the stem barks of L. ochrophylla. The formation of free radicals was verified in the plant material using electron paramagnetic resonance spectroscopy, and was supposed to be related to the trans-aconitic acid, a plant constituent. It was the only secondary metabolite to have its concentration significantly altered with radiation in phenolic fraction, as observed by liquid chromatography with diode array detector coupled to mass spectroscopy (LC-DAD-MS). The trans-aconitic acid was isolated and exposed to gamma radiation in aqueous medium. Its concentration decreased after exposition to a dose of 3.0 kGy, corroborating the supposition of its degradation. Citric acid was the main radiolytic product formed by irradiation of trans-aconitic acid in the presence of water.

Enhanced removal of cesium from hydrobiotite using polyacrylonitrile (PAN)-based nickel ferrocyanide beads

The desorption of cesium (Cs) from contaminated clay minerals remains challenging because of the restricted efficiency of the removal process. Therefore, in the present study, a bead-type adsorbent was added during the conventional acid washing process to improve the removal of Cs+ from a clay mineral. As the Cs+ adsorbent, polyacrylonitrile-based nickel potassium hexacyanoferrate (NiFC-PAN) was used to selectively adsorb Cs+ in a strongly acidic solution containing competing ions. To prevent erosion of the adsorbent under harsh environmental conditions and to facilitate the separation of clay particles, PAN was deliberately constructed as large beads. The synthesized adsorbent (NiFC/PAN in a 2:1 ratio) showed high selectivity for Cs+, with a maximum capacity for Cs+ adsorption of 162.78 mg/g in 0.5 M HNO3 solution. Because the NiFC-PAN demonstrated greater Cs+ selectivity than the clay mineral (hydrobiotite, HBT), the addition of NiFC-PAN during the acid washing significantly increased Cs+ desorption (73.3%) by inhibiting the re-adsorption of Cs+ on the HBT. The radioactivity of 137Cs-HBT was substantially decreased from 209 to 27 Bq/g by the acid treatment in the presence of NiFC-PAN, corresponding to a desorption efficiency of 87.1%. Therefore, these results suggest that the proposed technique is a potentially useful and effective method for decontamination of radioactive clay.

Перспективы использования метода фиторемедиации для дезактивации загрязненных радионуклидами территорий

Soil contamination with radionuclides, the main cause of which is the accident at the Chernobyl nuclear power plant, is one of the most dangerous negative environment impact factors. Phytoremediation including cultivation of «energy» crops is an effective method for decontamination of territories contaminated with radionuclides. The advantage of this approach is the possibility of using biomass as a renewable source of green energy in combination with the gradual reclamation of polluted soils. A promising crop for the purposes of phytoremediation is willow, the fast-growing species of which provide a high yield of biomass from a production plantation. A problematic issue is the safe use of willow biomass. The assessment of the conditions for the transition of radioactive cesium into willow biomass was carried out on the territories of Belarus contaminated after the Chernobyl accident. Experiments have shown that the predicted content of 137Cs in the wood of a fast-growing willow is significantly lower than the level allowed for wood fuel according to the standards established for the Republic of Belarus (740 Bq/kg). Even at the level of soil pollution at which they are removed from agricultural use (40 Ci/km2), the content of 137Cs in wood will be from 35 to 120 Bq/kg (depending on the dose of potash fertilizers).

Methods guides based on dogma not science: an example from microbiota restoration

Methods guides are useful for new researchers in a field and/or more established researchers needing to stay up‐to‐date with the best available methods. However, issues may arise where methods guides rely on outdated methodologies rather than progressing good science. We use a recent example of two methods guides for avoiding contamination in the emerging field of microbiota restoration studies, where ultraviolet (UV) “sterilization” was recommended for sample collection tubes. UV treatment is not an effective method of decontamination and may actually lead to contamination as a consequence of extended exposure to the aerobiome and other laboratory contamination before, during and after UV‐light exposure. Indeed, the use of appropriate tubes negates the need for such decontamination. Although well intended, guidance materials that contain omissions or inaccurate recommendations may lead to inaccurate research findings. This example highlights the important need for such guides to be based on up‐to‐date scientific evidence, not simply dogma.

Surface DBD plasma microbubble reactor for degrading methylene blue

Water contaminants such as endocrine inhibitors, pharmaceuticals, and chlorine treatment by-products are only recently being identified as significant hazards to human health. Since current chlorine treatment does not address many of these compounds and conventional ozone processing is not seen as an economic alternative, water adjacent plasma treatment has been investigated as a more efficient and effective decontamination method. This work investigates the use of a surface dielectric barrier discharge electrode as a reduced discharge voltage portable plasma water treatment method. The gas passes through holes in the electrodes, normal to the discharge surface, so that the entire cross-sectional area of the feed gas is exposed to plasma, prior to passing through a hydrophobic filter and bubbling into the water. The decontamination effectiveness is quantified by measuring the degradation of methylene blue with absorption spectroscopy. Studies of the different processing parameters (treatment time, solution volume, initial concentration, electrode-filter distance, and gas flow rate) clarify the potential range of performance for this plasma treatment configuration. The setup has a yield energy of 0.45 g/kW·h at 25 ml of 1 mg/100 ml methylene blue treated over 5 minutes for a 92% degradation. The degradation rate is dependent upon the volume ratio of air to methylene blue solution, suggesting a first order chemical reaction process. The reaction rate is increased by increasing the quantity of either reactant. There is no change in the degradation between when the plasma is 1 mm or 1 cm from the water surface.

Potential of the novel Siberian antiseptic “Anavidin” for prophylaxis of mastitis of cows

The most effective method of prevention of purulent process is rational usage of antiseptics and disinfectants with prophylaxis aim. The aim of this study was to evaluate the effectiveness of the antibacterial activity of the antiseptic Anavidin when exposed to various objects on farms. As research objects of the external environment of the farm (operating tables, sinks, walls, lamps, faucets, equipment, door handles). Prosessing objects of external farm facilities as the zone of high risk to communicate infection by 1% water solution of anavidin has shown the reducing of the percentage of inoculation 4 times (p =0,001) for certain. Нas been discovered utter disapearence of sanitary significant species from 32,6 % to zero. Prosessing by 1% water solution of anavidin for wet cleaning farm facilities and equipment contacted with udder allow to decrease semination of the examined objects. That prosessing is effective method of decontamination of prophylaxis mastitis. Bacteriological study of semination of the teet cups after prosessing by 1% water solution of anavidin has shown reducing the contamination of microorganisms from 60% to 0. Water solution of anavidin doesn’t damage products made of metall, plastic and rubber. Substantially reduce time of sterilization.

Rainwater Harvesting Practices and Its Effectiveness in Kathmandu Metropolitan City

Water scarcity has been a major problem of Kathmandu Metropolitan City (KMC). Different interventions are being attempted to solve this problem including the highly discussed Melamchi Drinking Water supply project. Thus, so rainwater harvesting (RWH) could be a promising approach to satisfy water to some extent. The study has aimed to assess the status of rainwater harvesting practices in KMC and to examine its effectiveness in overcoming the water shortage. A total of 244 households were surveyed covering 32 wards of KMC through random sampling method and semi structured questionnaire forms were laid for the data collection. The annual rainfall data of interval 30 years (1990-2019) of KMC, collected from department of Hydrology and Meteorology for trend analysis. Study revealed 58.2% of households are practicing RWH and among them 63.2% installed RWH system more than five years ago. About 63% of households are practicing roof top harvesting which is found to be more convenient in terms of cost and space. Strong positive correlation (R2=0.876, r=0.942) was observed among amount of water harvested and space occupied by RWH system and was statistically significant (P <0.05). Harvested water is found mainly used for household’s chores, flushing toilets and watering the garden. Majority (95.8%) of respondents did not prefer harvested water for drinking due to its poor water quality, high contamination and bad odor and taste. About 73.2% of the respondents decontaminate harvested water before using and filtration (63%) is found to be most common and effective method for decontamination. Despite of challenges like leakages of storages and gutters, about 87.3% of respondents are strongly satisfied with RWH system as it reduced the municipal water supply bill and provides excess water for the sanitation. Furthermore, the trend analysis showed increment of rainfall in the area by 1.21 mm per annum. Study regarding governmental incentives for the installation of RWH system, availability and accessibility of quality products, training on installation and sanitary management of RWH system would help to shed further light in the aspects of RWH.

High voltage atmospheric cold plasma decontamination of Salmonella enteritidis on chicken eggs

Salmonella enteritidis (SE) accounts for more than 70% of Salmonella spp. infections in humans with a primary source being chicken eggs, that can result from post-lay SE cross-contamination of the shell from contaminated equipment or the environment. The objective of this study was to apply a HVACP treatment that can achieve a minimum 5-log reduction in SE on the surface of artificially inoculated shell eggs with an initial bacterial load of 108 CFU/egg, after a previous disinfection. Optimized HVACP treatment conditions were an indirect treatment with air at 60% humidity at 100 kV for one minute treatment and six hours post-treatment or alternatively, five minutes of treatment and four hours post-treatment. Egg quality parameters of Haugh unit (HU), pH, color, and vitelline membrane and shell strength were tested under the optimized conditions and showed no significant difference (p > 0.05) between treated and untreated eggs.Industrial relevance: Missing information for a possible scale up of a cold plasma system for egg surface decontamination has been addressed by an optimization of HVACP treatment focused on treatment and post-treatment time, essential parameters to have into account in the food industry. These results demonstrate that HVACP is an effective decontamination method for SE on chicken shell eggs and provides a baseline for a future scale up of the process, showing that different combinations of treatment variables can achieve the desired decontamination without affecting to key quality parameters of the egg such as Haugh Unit or vitelline membrane strength.

Inactivation strategies for SARS-CoV-2 on surgical masks using light-activated chemical dyes

BackgroundMethylene blue (MB) and riboflavin (RB) are light-activated dyes with demonstrated antimicrobial activity. They require no specialized equipment, making them attractive for widespread use. Due to COVID-19-related worldwide shortages of surgical masks, simple, safe, and effective decontamination methods for reusing masks have become desirable in clinical and public settings.Material and methodsWe examined the decontamination of SARS-CoV-2 Beta variant on surgical masks and Revolution-Zero Environmentally Sustainable (RZES) reusable masks using these photoactivated dyes. We pre-treated surgical masks with 2 MB concentrations, 2 RB concentrations, and 2 combinations of MB and RB. We also tested 7 MB concentrations on RZES masks.ResultsPhotoactivated MB consistently inactivated SARS-CoV-2 at >99.9% for concentrations of 2.6 µM or higher within 30 min on RZES masks and 5 µM or higher within 5 min on disposable surgical masks. RB alone showed a lower, yet still significant inactivation (∼93-99%) in these conditions.DiscussionMB represents a cost-effective, rapid, and widely deployable decontamination method for SARS-CoV-2. The simplicity of MB formulation makes it ideal for mask pre-treatment in low-resource settings.ConclusionsThe results demonstrate that MB effectively decontaminates SARS-CoV-2 at concentrations above 5 µM on surgical masks and above 10 µM on RZES masks.

In-situ construction of BiOCl/Ag3PO4 heterojunction for enhanced photocatalytic activity

Environmental pollution caused by organic pollutants including persistent organic pollutants (POPs) has attracted increasing attention. It is highly necessary to develop an effective decontamination method. Herein, we reported the construction and characterization of BiOCl/Ag3PO4 (BAP) heterojunction via hydrothermal method. The interaction between BiOCl and Ag3PO4 in BAP promoted effectively the separation and transfer of photogenerated carriers, thereby resulting in the enhanced photocatalytic activity. BAP could effectively photo-degrade organic pollutants including POPs. Superoxide radical (O2−) served as the most active specie in decontamination process. A possible photo-degradation mechanism by BAP was proposed.

Dry Heat as a Potential Decontamination Method on the Filtration Efficiency of Filtering Facepiece Respirators.

Filtering facepiece respirators have been widely used in the fields of occupational health and public hygiene, especially during the COVID-19 pandemic. In particular, disposable respirators have been in high demand, and the waste generated from these disposable products poses a problem for the environment. Here, we aimed to test a practical decontamination method to allow for the reuse of KN95 respirators. In this study, three types of KN95 respirators were heated at 80 °C and 90 °C for different durations (15 min, 30 min, 45 min, 1 h, 2 h, 3 h, 4 h, 6 h, 8 h, 10 h, and 24 h). The filtration efficiencies of the tested KN95 respirators before and after heating were measured, and the changes in microstructure were imaged with a scanning electron microscope (SEM). In addition, a neural network model based on the nonlinear autoregressive with external input (NARX) to predict the filtration efficiency of the KN95 respirator was established. The results show that the temperature and time of dry heating affected particle prevention. The higher the temperature and the longer the heating time, the more obvious the decline in the filtration efficiency of the respirators. When the heating temperature reached 100 °C, the respirator may be no longer suitable for reuse. These results show that a dry heat temperature between 70 °C and 90 °C, and a heating time between 30 min and 2 h is assumed to be a suitable and effective decontamination method for respirators.

Methicillin-Resistant Staphylococcus aureus Contamination of Frequently Touched Objects in Intensive Care Units: Potential Threat of Nosocomial Infections.

Background Bacterial contamination in intensive care units is an important risk factor associated with increasing incidences of nosocomial infections. This study was conducted to study the bacterial colonization on commonly touched objects of intensive care units and antibiotic resistance pattern of bacterial isolates. Methods This study was conducted in different intensive care units of Manipal Teaching Hospital, Pokhara, Nepal. A total of 235 swabs were collected from surfaces of bed rails, monitors, door handles, IV stands, telephone sets, nursing stations, medicine trolleys, sphygmomanometers, wash basin taps, dressing drums, stethoscopes, pulse oximeters, ventilators, defibrillators, and stretchers. Isolation, identification, and antibiotic susceptibility tests of the bacteria were performed following standard microbiological techniques. Results Of 235 samples, bacterial growth was observed in 152 samples. A total of 90 samples of Staphylococcus aureus were isolated from 235 samples. Most of the sampling sites included in this study were found contaminated with S. aureus. The highest number of S. aureus was cultured from the surface of bed rails. Of the total S. aureus isolates, 54.4% (49/90) were methicillin-resistant Staphylococcus aureus (MRSA). Vancomycin resistance was detected among 8.1% MRSA isolates (4/49). Acinetobacter species were the commonest Gram-negative bacterial isolate. Conclusion Bacterial contamination of the objects/instruments of the ICU was recorded to be high. The most common contaminating bacteria were S. aureus with a high percentage of MRSA and emergence of VRSA. Periodic microbiological surveillance, detection of contaminated sites, and effective decontamination methods would minimize the colonization by potential pathogens and their transmission.

Square-Wave Alternating Voltage for Enhancing Cr(VI) Reduction in a Carbon Fiber-Based Flow-Through Electrode System

Electrochemical reduction with a flow-through electrode system (FES) has been regarded as an effective method for water decontamination. However, under a direct voltage (DV) power supply, the reduction efficiencies were strongly limited by the gas bubbles generated in porous electrodes and the electrostatic repulsion between the negatively charged pollutants and cathode. Herein, square-wave alternating voltages (SWAV) were applied to regulate the anodic–cathodic polarities of electrodes for eliminating the gas accumulation in porous electrodes and enhancing the mass transfer efficiency. Under the optimized SWAV parameters, the Cr(VI) reduction and energy efficiency were increased obviously to ∼86 and 84% as compared with the 20%–30% Cr(VI) reduction and 30%–50% energy efficiency under the DV power supply. With periodically altering the anode to cathode, localized H+ and Cr(VI) species were formed on the anodic interface via H2O oxidation and Cr(VI) adsorption, which were further in situ reduced for enhancing the Cr(VI) mass transfer and reduction efficiencies. In addition, O2 species generated via H2O oxidation was also in situ reduced to H2O2 species, hence promoting the Cr(VI) reduction and operation stability for most Cr(VI) reduction with a stable energy efficiency (∼82%) over a 10 day operation (8 mg/L Cr(VI) and 500 L/m2/h flux). The successful application of SWAV may derive similar decontamination strategies, especially for electrically charged pollutants with the H+ or OH– ions as reactants.

Potential risk of Bacillus cereus in spices in Turkey

Spices are widely used all over the world in food preparation to give taste, smell and color as well as to preserve food products. Bacillus cereus is a common contaminant in spices which can cause food poisoning due to its toxins. This study focused on determining the presence of B. cereus as well as the toxin profiles of the strains. A total of 203 packaged and unpackaged spice samples were collected during the study. B. cereus prevalence was determined as 31.5%. Also, B. thuringiensis was identified in five samples (2.5%). The prevalence of B. cereus in non-irradiated spices (41.5%) was found significantly higher than the irradiated ones (20.7%) (p < 0.05). Moreover, the isolates were examined for nine toxin genes, and entFM (94%) was found as the most abundant gene, followed by cytK (60%) and hblD (60%) genes. No cesB gene was found in isolates. Among the strains only a B. thurgiensis isolate was found to have eight toxin genes. The results show that B. cereus is a potential public health risk in spices. Considering the possibility of contamination of foods by B. cereus via spices, effective decontamination methods should be applied and precautions should be taken to control growing of B. cereus and forming toxins during food preparation and pre-serving stages. • Prevalence of B. cereus in spices was 31.5%. • B. thuringiensis was identified in 5 of 203 (2.5%) spice samples. • EntFM (94%), cytK (60%) and hblD (60%) were the most abundant toxin genes. • No cesB gene was found in isolates (0/89). • The contamination in non-irradiated spices was significantly higher (p < 0.05).

Efficacy of Different Sterilization Techniques for Toothbrush Decontamination: An Ex Vivo Study.

BackgroundContaminated toothbrushes can cause several oral and systemic illnesses. This study aimed to identify the most rapid, effective, and affordable method for toothbrush decontamination. In addition, the most prevalent bacterial species colonizing toothbrushes were determined.MethodologyToothbrushes were collected after two weeks of use by 55 volunteers. The bacterial count was measured before and after sterilization using 0.2% chlorhexidine gluconate, 0.1% Listerine, 70% white alcohol, 10% povidone-iodine, 1% sodium hypochlorite, 2% glutaraldehyde, ultraviolet radiation, microwave irradiation, 3% hydrogen peroxide, and 100% white vinegar, with tap water rinse as the control.ResultsA marked reduction in the bacterial count was observed pre- and post-sterilization. All sterilization methods were effective for toothbrush disinfection. Sterilization using 2% glutaraldehyde and 3% hydrogen peroxide solutions resulted in the most significant reduction in the mean bacterial count and percentage reduction in the total bacterial count, respectively. The toothbrush samples were also colonized by several different types of bacteria. The most common colonizing bacterial species included Bacillus subtilis (28% prevalence), Sacrina (26% prevalence),and Streptococcus pneumoniae (24% prevalence).ConclusionsBecause bacterial contamination cannot be eliminated and different species colonize toothbrush surfaces, cleaning and disinfection are essential to prevent disease transmission.

Decontamination of E. coli and S. epidermidis on Cloth Masks with Ultraviolet Germicidal Irradiation

Spurred by a global pandemic, precautions have been taken by the general public to slow the spread of the respiratory virus called COVID-19. As Cloth Masks have become staples in protection during this time, it is important to understand any limitations that could arise when using a product. Several studies have found that certain methods of decontaminating Cloth Masks, so they may be reused safely, can result in slight degradation. This study analyzes the decontamination method of Ultraviolet Germicidal Irradiation (UVGI) on Cloth Masks that have different ply counts. Using both Escherichia coli and Staphylococcus epidermidis, three different masks were contaminated with bacterial colonies then put through a session of UVGI to sterilize the fabric. Once the session was over, masks were collected and analyzed for effectiveness of decontamination and changes in fabric pore size. It was found that when decontaminating the Cloth Masks, regardless of the bacteria they have been contaminated with, there was a positive correlation between the number of plies a mask had to the amount of bacteria able to be decontaminated. Additionally, there was a negative relationship between the number of plies a mask had and the degradation of the material over time. UVGI provides an effective method of decontamination for Cloth Masks now that its benefits and limitations have been understood.

Reasons behind failed prehospital intubation attempts while combining C-MAC videolaryngoscope and Frova introducer.

High first-pass success rate is achieved with the routine use of C-MAC videolaryngoscope and Frova introducer. We aim to identify potential reasons and subgroups associated with failed intubation attempts, analyse actions taken after them and study possible complications. We conducted a retrospective observational study of adult intubated patients at a single helicopter emergency medical service unit in southern Finland between 2016 and 2018. We collected data on patient characteristics, reasons for failed attempts, complications and follow-up measures from a national helicopter emergency medical service database and from prehospital patient records. 1011 tracheal intubations were attempted. First attempt was successful in 994 cases (FPS 994/1011, 98.3%), 15 needed a second or third attempt and two a surgical airway (non-FPS 17/1011, 1.7%, 95% CI 1.0-2.7). The failed first attempt group had heterogenous characteristics. The most common cause for a failed first attempt was obstruction of the airway by vomit, food, mucus or blood (10/13, 76%). After the failed first attempt, there were six cases (6/14, 43%) of deviation from the protocol and the most frequent complications were five cases (5/17, 29%) of hypoxia and four cases (4/17, 24%) of hypotension. When a protocol combining the C-MAC videolaryngoscope and Frova introducer is used, the most common reason for a failed first attempt is an airway blocked by gastric content, blood or mucus. These findings highlight the importance of effective airway decontamination methods and questions the appropriateness of anatomically focused pre-intubation assessment tools when such protocol is used.

Peroxymonosulfate activation by a metal-free biochar for sulfonamide antibiotic removal in water and associated bacterial community composition

Antibiotic sulfamethoxazole (SMX) has been commonly found in various water matrices, therefore effective decontamination method is urgently needed. Metal-free pristine coconut-shell-derived biochar (CSBC), synthesized by thermochemical conversion at 700 °C, was used for activating peroxymonosulfate (PMS), an oxidant, to degrade SMX, a sulfonamide antibiotic, in water. SMX degradation, maximized at 0.05 mM concentration, was 85% in 30 min at pH 5.0 in the presence of 150 mg L−1 of CSBC. Remarkably, SMX removal reached 99% in a chloride-rich CSBC/PMS system. SMX degradation was mainly attributed to the role of CSBC in enhancing PMS activation to produce combined radical (SO4•−/HO•) and nonradical (1O2) reaction pathways. The most abundant genus in the CSBC/PMS system was Methylotenera, which belonged to the Proteobacteria phylum. Thus, from a perspective of biowaste-to-resource recycling and circular bioeconomy view point, CSBC is a potential catalytic activator of PMS for the removal of sulfonamide antibiotics from aqueous environments.

Dry-fog decontamination of microbiological safety cabinets after activities with SARS-CoV-2: cycle development and process validation for dry fogging with peroxyacetic acid.

Background: Technical protection measures for laboratory activities involving biological agents include biological safety cabinets (BSC) that may be contaminated. In the case of diagnostic activities with SARS-CoV-2, this may also affect BSC that are operated at protection level 2; therefore, decontamination of all contaminated surfaces of the BSC may be required. In addition to fumigation with hydrogen peroxide (H2O2), dry fogging of H2O2-stabilized peroxyacetic acid (PAA) represents another alternative to fumigation with formalin. However, to prove their efficacy, these alternatives need to be validated for each model of BSC.Methods: The validation study was performed on 4 different BSCs of Class II A2 using the “Mini Dry Fog” system.Results: An aerosol concentration of 0.03% PAA and 0.15% H2O2 during a 30 min exposure was sufficient to inactivate SARS-CoV-2. Effective concentrations of 1.0% PAA and 5% H2O2 were required to decontaminate the custom-prepared biological indicators loaded with spores of G. stearothermophilus and deployed at 9 different positions in the BSC. Commercial spore carriers were easier to inactivate by a factor of 4, which corresponded to a reduction of 106 in all localizations.Conclusions: Dry fogging with PAA is an inexpensive, robust, and highly effective decontamination method for BSCs for enveloped viruses such as SARS-CoV-2. The good material compatibility, lack of a requirement for neutralization, low pH – which increases the range of efficacy compared to H2O2 fumigation – the significantly shorter processing time, and the lower costs argue in favor of this method.