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BackgroundIn the context of the SARS-CoV-2 pandemic, reuse of personal protective equipment, specifically that of medical face coverings, has been recommended. The reuse of these typically single-use only items necessitates procedures to inactivate contaminating human respiratory and gastrointestinal pathogens. We previously demonstrated decontamination of surgical masks and respirators contaminated with infectious SARS-CoV-2 and various animal coronaviruses via low concentration- and short exposure methylene blue photochemical treatment (10 µM methylene blue, 30 minutes of 12,500-lux red light or 50,000 lux white light exposure).MethodsHere, we describe the adaptation of this protocol to the decontamination of a more resistant, non-enveloped gastrointestinal virus and demonstrate efficient photodynamic inactivation of murine norovirus, a human norovirus surrogate.ResultsMethylene blue photochemical treatment (100 µM methylene blue, 30 minutes of 12,500-lux red light exposure) of murine norovirus-contaminated masks reduced infectious viral titres by over four orders of magnitude on surgical mask surfaces.Discussion and ConclusionsInactivation of a norovirus, the most difficult to inactivate of the respiratory and gastrointestinal human viruses, can predict the inactivation of any less resistant viral mask contaminant. The protocol developed here thus solidifies the position of methylene blue photochemical decontamination as an important tool in the package of practical pandemic preparedness.

Recreational boating activities enable aquatic invasive species (AIS) dispersal among disconnected lakes, as invertebrates and plants caught on or contained within watercraft and equipment used in invaded waterbodies can survive overland transport. Resource management agencies worldwide recommend decontaminating watercraft and equipment using high water pressure, rinsing with hot water, or air-drying for up to seven days to inhibit this mode of secondary spread. There is a lack of studies on the efficacy of these methods under realistic conditions and considering feasibility for recreational boaters. Hence, we conducted experiments addressing this knowledge gap using AIS present in Ontario, namely zebra mussels (Dreissena polymorpha), banded mystery snails (Viviparus georgianus), spiny waterfleas (Bythotrephes cederstroemi), Eurasian watermilfoil (Myriophyllum spicatum), Carolina fanwort (Cabomba caroliniana), and European frogbit (Hydrocharis morsus-ranae). Washing at high pressures of 900-1200 psi removed the most biological material (90%) from surfaces. Brief (

The efficient remediation of heavy metal complexes in water has become a difficult and challenging task owing to their high stability and strong mobility. In this study, a novel strategy was employed for highly efficient removal of Cu-citrate by using intimately coupled photocatalysis and biodegradation (ICPB) system with non-woven cotton fabric as a carrier. Experimental results showed that the ICPB system caused 94% Cu removal, which was higher than those of single photocatalysis. After 5 cycles, Cu removal efficiency could still reach 78% within 5 h. The existence of 0-40 mg/L citrate had negligible influence, whereas the presence of 60-100 mg/L citrate exhibited a limited adverse effect on Cu removal (∼70%). The decomplexation of Cu-citrate was realized via the function of free radicals and microorganisms. Two main processes, such as bio-adsorption of Cu2+ by microorganisms, deposition of Cu0 on the surface of material, played important role in Cu removal from aqueous solution. The dominant microorganisms in the system were Proteobacteria, Actinobacteria, Bacteroidetes, Chloroflexi, Chlorophyta, Planctomycetes, and Verrucomicrobia. Furthermore, the performance of ICPB system was also validated through treatment of other heavy metal complexes. This study provided a feasible strategy for the decontamination of heavy metal complexes in wastewater.

The landfill leachate is considered a toxic effluent composed of recalcitrant contaminants that requires innovative alternatives for its decontamination. Coupling between advanced oxidation processes (AOPs) and aerobic biological treatments are highlighted in this research. Therefore, a bibliographic review of the research made from 2010 to 2021 was developed. These combined alternatives were applied in leachates, and it is oriented towards the analysis of knowledge gaps, trends, and future proposals of the treatment combined that contribute to researchers who wish to work on the subject. These kinds of treatments were chosen due to a bibliometric analysis made. Also, the information was searched in several scientific database. This work was found to be unpublished, as no reviews were found so far that agglomerate studies of coupling between photocatalytic and aerobic biological processes to treat leachates. Besides, AOPs are ideal for treating wastewater of complex composition, however, when it is used as the only treatment, they are usually unprofitable, which justifies their coupling with biological treatments. Subsequently, it was determined that the knowledge main gap is the lack of documentation of treatment costs, which makes it difficult to implement on a real scale. In addition to this, the couplings trends are towards doping with metallic and non-metallic ions of the catalyst used in the photocatalytic process to improve the efficiency of these. Finally, future research should work on finding alternatives that allow the optimization of the resources used in the combined systems and on promoting the recovery of existing products in the leachate.

Background During shortages of filtering face pieces (FFP) in a pandemic, it is necessary to implement a method for safe reuse or extended use. Our aim was to develop a simple, inexpensive and ecological method for decontamination of disposable FFPs that preserves filtration efficiency and material integrity. Material and methods Contamination of FFPs (3M Aura 9320+) with SARS-CoV-2 (1.15 × 104 PFUs), Enterococcus faecium (>106 CFUs), and physiological nasopharyngeal flora was performed prior to decontamination by submersion in a solution of 6 % acetic acid and 6 % hydrogen peroxide (6%AA/6%HP solution) over 30 minutes. Material integrity was assessed by testing the filtering efficiency, loss of fit and employing electron microscopy. Results and Discussion Decontamination with the 6%AA/6%HP solution resulted in the complete elimination of SARS-CoV-2, E. faecium and physiological nasopharyngeal flora. Material characterization post-treatment showed neither critical material degradation, loss of fit or reduction of filtration efficiency. Electron microscopy revealed no damage to the fibers, and the rubber bands’ elasticity was not affected by the decontamination procedure. No concerning residuals of the decontamination procedure were found. Conclusion The simple application and widespread availability of 6%AA/6%HP solution for decontaminating disposable FFPs make this solution globally viable, including developing and third world countries.

AIM: This study aimed to validate the efficacy of hydrogen peroxide vapor (HPV) decontamination technology set up in a biosafety level 3 (BSL-3) laboratory on surrogates and hazard group 3 (HG3) agents. METHODS AND RESULTS: The HPV decontamination system (Bioquell) was assessed with both qualitative and quantitative methods on (1) spore surrogates (Geobacillus stearothermophilus, Bacillus atrophaeus, and Bacillus thuringiensis) in the BSL-3 laboratory and in the material airlock and on (2) HG3 agents (Bacillus anthracis; SARS-CoV-2, Venezuelan equine encephalitis virus [VEE], and Vaccinia virus) in the BSL-3 laboratory. Other HG3 bacteria likely to be handled in the BSL-3 laboratory (Yersinia pestis, Burkholderia mallei, Brucella melitensis, and Francisella tularensis) were excluded from the HPV decontamination assays as preliminary viability tests demonstrated the total inactivation of these agents after 48 h drying on different materials. CONCLUSIONS: The efficacy of HPV decontamination was validated with a reduction in viability of 5–7 log(10) for the spores (surrogates and B. anthracis), and for the enveloped RNA viruses. Vaccinia showed a higher resistance to the decontamination process, being dependent on the biological indicator location in the BSL-3 laboratory.

The applications of fumigation and the challenges that high-containment facilities face in achieving effective large volume decontamination are well understood. The Biosecurity Research Institute at Kansas State University sought to evaluate a novel system within their biosafety level 3 (BSL-3) and animal biosafety level 3 agriculture (ABSL-3Ag) facility.The system chosen for this study is the CURISAfter cycle optimization, the smaller laboratory had a total of 60 BIs over two treatments that demonstrated a greater than 6-log reduction of bacterial spores. The larger laboratory (192 BIs) and the necropsy suite (206 BIs) had no BIs positive for spore growth when incubated at 60°C for 24 h per manufacturer's specifications.Overall successful results through multiple components of this study demonstrate that the HHP device, paired with the pulsed 7% H

The application of organic photocatalysts towards the oxidation of pollutants in water is hampered by different limitations such as their insolubility in the media. Herein, we report that the grafting of a photo-organocatalyst into mesoporous silica materials is an ideal approach to obtain effective catalysts. Thereby, the photocatalyst 10-phenylphenothiazine (PTH) was easily anchored into three different mesoporous silica-based materials (MSN, MSU-2 and SBA-15) with different particle sizes and pore sizes through an amide bond formation. The materials were characterized using IR analysis, solid-state X-ray diffraction, porosity and microscopy (SEM and TEM) techniques, showing that PTH is immobilized inside the pores of the materials and its optical properties are maintained after the anchoring. Although homogeneous PTH was inactive in water media, the three photocatalytic materials were active for the degradation of pollutants. SBA-15-AP-PTH exhibited the highest catalytic performance towards the degradation of acetaminophen and diclofenac under solar irradiation, finding in this manner a new strategy for the decontamination of pollutants.

Paper sheets represent one of the infection risk sources inside educational and administrative institutions under biological pandemics. So, the present study aimed to validate the efficiency of gamma radiation or dry heat techniques to sterilize contaminated paper sheets with different indicator pathogens while retaining their structure. The results showed that gamma radiation at 6, 12, or 24 kGy can successfully kill Gram-positive bacteria such as Bacillus cereus and Staphylococcus aureus, Gram-negative bacteria such as Escherichia coli and Salmonella typhi, and fungi such as Candida albicans. Moreover, dry heating at 100 °C for 60 min, 150 °C for 30 min, or 200 °C for 15 min can be successful in paper decontamination of all tested species. Surprisingly, scanning electron microscopy (SEM) micrographs proved that gamma radiation at 6 kGy, dry heat at 100 °C for 60 min or 150 °C for 30 min or 200 °C for 15 min, is suitable for paper sheet sterilization while maintaining their structure. Ultimately, dry heat is a simple, effective, fast, safe, and inexpensive technique for paper sterilization. It may be used as a precautionary step inside educational institutions, especially during written examination periods, to ensure a safe life for academic members during biological pandemics such as COVID-19.

Background Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has led to over 170?million cases worldwide with over 33.2?million cases and 594,000 deaths in the US alone as of May 31st, 2021. The pandemic has also created severe shortages of personal protective equipment, particularly of filtering facepiece respirators (FFRs). The Centers for Disease Control and Prevention (CDC) has issued recommendations to help conserve FFRs, as well as crisis standards, including four criteria required for decontamination of the traditionally single use respirators. This review is designed to provide an overview of the current literature on vaporized hydrogen peroxide (vHP), hydrogen peroxide gas plasma (HPGP), and aerosolized hydrogen peroxide (aHP) with respect to each of the four CDC decontamination criteria. Methods PubMed and Medrxiv were queried for relevant articles. All articles underwent a title and abstract screen as well as subsequent full text screen by two blinded reviewers if indicated. Results Searches yielded 195 papers, of which, 79 were found to be relevant. Of those, 23 papers presented unique findings and 8 additional articles and technical papers were added to provide a comprehensive review. Overall, while there are potential concerns for all 3 decontamination methods, we found that vHP has the most evidence supporting its use in FFR decontamination consistent with CDC recommendation. Conclusions Future research is recommended to evaluate biological inactivation and real world fit failures after FFR reuse.

An automated truck wash study was conducted at a large layer hen facility to determine the effectiveness of a modified decontamination system for sanitizing semi-trucks and other farm vehicles. The commercial automated power washing system was modified with a fixed gantry that applied a chlorine dioxide (ClO2) disinfectant rinse as the truck exited the biosecurity facility. The truck decontamination study included the primary study plus one smaller Bacillus atrophaeus spore study, as well as air and water sampling. The goal of the field study was to determine the effectiveness of a two-stage automated decontamination system for sanitizing a large, semi-tractor trailer. The primary study objective was to evaluate two power washing techniques (power wash only with a surfactant or power wash with surfactant and a ClO2 rinse). The second objective was to evaluate the decontamination methods on four coupon materials (glass, painted metal, plastic, rubber) to determine the effectiveness of the two-stage wash system on inoculated coupons. The third objective was to determine the effectiveness of the decontamination methods on coupon locations on the truck (front windshield, middle side of trailer, undercarriage). The fourth objective was to determine the effectiveness of the decontamination methods on coupon surface type (coupons coated with or without synthetic grime). The primary study evaluated 48 decontamination treatments to assess their ability to inactivate the MS2 bacteriophage, which is the viral surrogate selected for the study. The results show that the two-stage decontamination treatments increased log10 reduction of the MS2 phage. Log10 reduction increased an average of 247% and 118% for the non-grimed and grimed coupons, respectively, when comparing the automated wash with and without ClO2 rinse across all locations and material types. The average log10 reduction increased from 0.94 to 1.89 for the automated wash and the automated wash + ClO2 rinse, respectively, for the grimed coupons, across all coupon locations and materials. The average log10 reduction increased from 1.23 to 2.17 for the automated wash without ClO2 and the automated wash + ClO2 rinse, respectively, for the non-grimed coupons, across all coupon locations and materials. These results show that combining the ClO2 disinfectant rinse with the automated power wash increased viral efficacy by an average of one log (grimed coupons). Evaluation of the two-stage tuck decontamination system confirms that combining a power wash with a disinfectant rinse increases the ability of the system to sanitize transport trucks and increase farm biosecurity.

Large-scale disasters at nuclear power plants (NPP) and their consequences are still the subject of discussion by the world scientific community, which makes mankind recognize the unsolved problem of radiation pollution. Accordingly, the search for new effective biocomposite materials with high sorption capacity to eliminate harmful effects associated with radiation contamination of large territories is an urgent task on a global scale. This paper is devoted to the study of processes of decontamination of areas contaminated with radionuclides, the search for new mechanisms of fixation of radionuclides and heavy metals in the soil using the matrix material of different genesis. To intensify the process of radionuclide fixation in the soil-plant system the method consisting of introducing into the soil the organic-mineral biocomposite based on sewage sludge and phosphogypsum after anaerobic fermentation was proposed. It is necessary to further study the processes of sorption, radionuclides solubilization due to complexation with organic agents present in matrix materials of different nature. Mechanisms of radionuclide and heavy metal fixation using matrix material of different genesis were analyzed and a general model was formed. The direction of integration of radionuclide-contaminated soil decontamination technologies into the process of ecological, social, and economic development of the territories under rehabilitation after the accidents at the Chernobyl NPP and Fukushima-1 NPP is proposed.

The objective of this work is to study the coupling power of hydrogen peroxide and ozone (Peroxone) on the decontamination of soil contaminated by Total Petroleum Hydrocarbons (TPH). The oxidation takes place simultaneously by the exchange of electrons, which will activate the decomposition of hydrogen peroxide into OH radicals. In this study, we examined the effect of various parameters (level of contamination, type of soil, and age of contamination). The results obtained showed the potential of chemical oxidation on the cleaning of soils contaminated by hydrocarbons and that the structure of this chemical has a crucial impact on the elimination kinetics.

Organophosphorus compounds play an important role in the modern chemical industry and have a broad range of applications as flame retardants, agrochemicals and chemical warfare. Unfortunately, they still present a big concern from a safety and security perspective considering their high toxicity to the human and the environment. Because of the former record and the persisting risks of some of these chemicals being used as weapons of mass destruction, the Chemical Weapons Convention implemented by the Organisation for the Prohibition of Chemical Weapons, scheduled a wide range of them as substances subject to a stringent verification regime. The existing practices for production, detection and decontamination or destruction of unwanted organophosphorus compounds require high safety and security standards, which not always can be attained only by sound management practices. The present review highlights the contribution made by the emerging research and early technology development in the field of green chemistry concerning these chemicals. Firstly, the advances regarding safe synthesis of these compounds are covered not only due to their extensive legal commercial use but also for reference chemicals in verification processes. Aspects such as greener starting reactants, microwave irradiation, electrochemical synthesis and the use of ionic liquids are among the most promising alternatives. Another topic addressed is the decontamination of such toxic agents in the case of undesired stockpiles for example, seeking their safe neutralization using milder conditions. The use of catalysts (derived from enzymes, metal-organic framework, polyoxometalates, nanomaterials, polymers, etc) and continuous flow systems stands out. Finally, greener detection of organophosphorus compounds is presented, relevant for inspection procedures regarding prohibited use or misuse. This focused on sustainable preparation, faster and cheaper architecture with lower detection limits and relying on integrated systems for multiple response and facile application such as wearable. Overall, the developments summarized provide a guide for the researchers and industry working in the field, while also attracting the attention of the policy makers to the undisclosed potential of green chemistry in this security sensitive domain. Albeit all the progress, it´s imperative the continuous efforts for further development of intrinsically safer, more efficient and sustainable technologies in this field.

The main objective was to develop a wipe sampling test to measure surface contamination of the most frequently used antineoplastic drugs (ADs) in Swedish healthcare and furthermore to develop an analysis method sensitive enough to assess low levels of contamination. Two wipe sampling tests with separate sample processing methods assessing i) cyclophosphamide (CP), ifosfamide (IF), 5-fluorouracil (5-FU), etoposide (ETO), gemcitabine (GEM) and cytarabine (CYT) (Wipe Test 1), and ii) GEM, CYT and methotrexate (MTX) (Wipe Test 2), respectively were developed by optimization of absorption and extraction efficiencies using different wipe tissue materials, tissue wetting solution and extraction solvents. A fast LC-MS/MS method was developed for simultaneous detection of the studied ADs. The limit of quantification for the method was between 0.04 to 2.4 ng/wipe sample (0.10 to 6.1 pg/cm2 for an area of 400 cm2) and at 50 ng/sample the within-day precision was between 1.3-15%, and the accuracy between 102-127%. Wipe Test 1 was applied in an assessment of cleaning efficiency of five different cleaning solutions (formic acid, water, sodium hydroxide, ethanol and sodium dodecyl sulfate (SDS) for removal of ADs from surfaces made of stainless steel or plastic. For CP, IF, 5-FU, GEM and CYT 92% of the AD were removed regardless of surface and cleaning solution. In conclusion, a user-friendly assessment method to measure low levels of seven ADs in the work environment was developed and validated. Assessment of the decontamination efficiency of cleaning solutions concerning removal of ADs from stainless steel showed that efficiencies differed depending on the AD with water being the least effective cleaning agent. The results suggests that a combination of different cleaning agents including detergent and a solution with an organic component would be optimal to efficiently remove the measured ADs from surfaces in the workplace.

Hydrophobic cellulose laurate (CL) with high degree of substitution has been successfully synthesized. The mechanical property, water-resistance, antimicrobial activity, barrier properties and food decontamination of cellulose-laurate-curcumin films (CL-Cux, x = 0.1, 0.5, and 1) were investigated. The results showed that the mechanical properties of CL-Cux hardly change after soaking in water for 24 h, probably due to the strong hydrophobicity of cellulose laurate. CL-Cu1 represented a good photoinduced antibacterial effect against S. aureus. After irradiation of white light at 60 mW·cm−2 for 20 min, the inhibition efficiency reached to 95 ± 2.02%, probably owing to the generated active 1O2. In comparison with CL-Cu1 stored in natural light, the bacteriostatic effect of CL-Cu1 in dark storage was better, and the inhibition rate of CL-Cu1 remained 80 ± 1.22 at 60th day. The stabler excited state of curcumin in hydrophobic cellulose laurate was probably assigned to inhibition of tautomerism or conformational transition, which was beneficial to the generation of singlet oxygen. CL-Cu1 can significantly inhibit the growth of TVBN and TVC values of chilled meat upon white light irradiation, indicating the potential application of cellulose-laurate-curcumin films in food decontamination.

Plasma-activated water (PAW) is a novel and promising alternative to traditional food sanitizers. Recently, the inactivation efficacy of PAW has been demonstrated on a wide range of food products against foodborne pathogens, spoilage microorganisms, and harmful chemicals. The effectiveness of PAW relies on various factors related to the plasma generation mechanisms, the target microorganisms, and the food matrix. The inactivation mechanisms of PAW are attributed to the damage of cell integrity and intracellular components by various reactive oxygen and nitrogen species (RONS). Utilization of plasma-activated liquids and hurdle technologies can enhance the inactivation efficacy and diversify the application of this technology. Scaling-up of PAW is still at the very beginning stage and needs further studies before industrial application.

This study investigated the decolorization of Remazol Black (RBB) using a TiO2 photocatalyst modified by S and Co co-doped TiO2 (S-Co-TiO2) from a single precursor. X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and UV–Vis specular reflectance spectroscopy were used to characterize the photocatalysts. The results revealed that the band-gap energy of the doped and co-doped TiO2 decreased, with the S-Co-TiO2 8% showing the greatest one, and was found to be 2.78 eV while undoped TiO2 was 3.20 eV. The presence of S and Co was also identified through SEM-EDX. An activity study on RBB removal revealed that the S-Co-TiO2 photocatalyst showed the best result compared to undoped TiO2, S-TiO2, and Co-TiO2. The S-Co-TiO2 8% photocatalyst reduced RBB concentration (20 mg L−1) up to 96% after 90 min of visible light irradiation, whereas S-TiO2, Co-TiO2, and undoped TiO2 reduced it to 89%, 56%, and 39%, respectively. A pH optimization study showed that the optimum pH of RBB decolorization by S-Co-TiO2 was 3.0, the optimum mass was 0.6 g L−1, and reuse studies show that S-Co-TiO2 8% has the potential to be used repeatedly to remove colored pollutants. The results obtained indicate that the modification of S, Co co-doped titania synthesized using a single precursor has been successfully carried out and showed excellent characteristics and activity compared to undoped or doped TiO2.

Polymerase chain reaction (PCR) is one of the most commonly used methods in diagnostic and molecular biology. However, DNA contamination can lead to incorrect results. This poses a major problem, especially in the monitoring of genetically modified organisms (GMOs). We investigated DNA contamination in 16 commercial Taq DNA polymerase reagents. Many of the Taq DNA polymerase reagents were contaminated with the 16S rRNA gene and an ampicillin resistance gene (bla). We attempted to decontaminate the Taq DNA polymerase reagents using UV, γ-ray, and electron-ray irradiation, as well as nylon membrane and FTA card treatment. UV irradiation reduced the activity of Taq DNA polymerase. Various wavelengths of γ-ray and electron-ray irradiation had no decontamination effect. However, 24-h treatment with three nylon membrane disks removed DNA contamination. FTA card treatment, which has membrane-like functions, also removed decontamination but decreased enzyme activity. We further confirmed that the nylon membrane-treated Taq DNA polymerase reagent could be used in the detection of the bla and NPTII genes in genetically modified E. coli. These results are useful for future monitoring of GMOs.

The accident at Fukushima Daiichi Nuclear Power Plant caused radioactive materials to spread outside the plant. To limit exposure in the area, air dose rates have been measured. When the dose rate exceeded the acceptable upper bound, the area was decontaminated by stripping the soil and washing roads. Immediately after the accident, it was not clear how much of an effect outdoor contamination had on dose rates inside houses. This paper discusses the effect of outdoor contamination on indoor air dose rates and factors influencing those dose rates based upon actual measurements taken of a wooden house standing on flat land in the area around the power plant. In addition, the effects of indoor horizontal distribution, height distribution, and decontamination are discussed using simple model simulations. As a result, the following was found, although within the range of air dose rates and location conditions measured in this study. Horizontal variation in indoor air dose rates decreases monotonically toward the centre of the house. Once decontamination has been performed, the overall dose rate decreases and variation becomes smaller. This trend is thought to be mainly due to expansion of a low-dose area. Vertical changes in indoor air dose rates are not straightforward. It is estimated that the dose rate decreases near the ground surface, then tends to increase going higher and finally decreases even higher up. This change in dose rates is thought to be due to the effect of radioactive materials permeating the soil. Recognition of the effects of these factors is important when estimating indoor air dose rates because indoor air dose rates are affected by the degree of decontamination, house size, and degree of penetration of radionuclides into the soil.

The effects of different species and concentrations’ signal molecules on aerobic activated sludge system were investigated through batch experiments. Results showed that the fastest NH4+-N oxidization rate and the most extracellular polymeric substances (EPS) secretion were obtained by adding 5 nmol/L N-hexanoyl-L-homoserine lactone (C6-HSL) into the aerobic activated sludge. Further study investigated the correlation among N-acyl-homoserine lactones-mediated quorum sensing (AHLs-mediated QS), nutrient removal performances and microbial communities with the long-term addition of 5 nmol/L C6-HSL. It was found that C6-HSL-manipulation could enhance the stability and optimize the decontamination performance of aerobic granular sludge (AGS) system. Microbial compositions considerably shifted with long-term C6-HSL-manipulation. Exogenous C6-HSL-manipulation inhibited quorum quenching-related (QQ-related) activities and enhanced QS-related activities during the stable period. The proposed C6-HSL-manipulation might be a potential technology to inhibit the growth of harmful bacteria in AGS, which could provide a theoretical foundation for the realization of more stable biological wastewater treatments.

Objectives To evaluate the efficacy of two decontamination protocols on cyclophosphamide surface contamination and to explore its lasting effect 30 days later. Methods All sampling sites that were systematically contaminated with cyclophosphamide in 2017–2020 were included, from a convenience sample of centers. The first decontamination protocol consisted of four steps, each with 20 mL and a Wypall® wipe: detergent, sodium hypochlorite 2%, isopropyl alcohol 70% and water. The second decontamination protocol consisted of eight steps, each with 15 mL and a Micronsolo® microfibre wipe: detergent, sodium hypochlorite 2%, isopropyl alcohol 70%, water and then a second round with each of the four products. A first sampling was done at the end of a regular working day (T0), a second immediately following decontamination (T1) and a third 30 days later (T2) after regular operations. Cyclophosphamide was quantified by ultra-performance liquid chromatography – tandem mass spectrometry (limit of detection 0.001 ng/cm2). Results Seventeen sampling sites were included: six biological safety cabinet (BSC) front grilles, eight floors in front of BSCs and three cyclophosphamide storage shelves. The second protocol was more effective; however they both failed to completely remove all cyclophosphamide traces. BSCs and floors were found to be contaminated again 30 days later, at similar concentrations than at T0. A lasting effect was observed on the cyclophosphamide storage shelves that were less prone to be contaminated again. Conclusions Periodic decontamination with many cleaning steps is necessary on all surfaces, including those less frequently contaminated. Regular surface monitoring identifies systematically contaminated areas.

The purpose of this review was to assess the literature regarding the decontamination of resin cement before the luting procedure in order to provide clinicians with a comparative overview of decontamination effects. A total of 19 articles were selected for inclusion in this review. The results indicated that bonding effectiveness is reduced due to residual adhesion inhibitors such as saliva, blood, hemostatic agents, and temporary/provisional cement. Self-etching and self-adhesive systems tend to be more negatively affected by adhesion inhibitors than do etch and rinse systems. Cleaning with an ultrasonic scaler or rotating brush have demonstrated conflicting effects in several studies. Some studies have reported that phosphoric acid has negative effects and recommend mild acid for decontamination. The application of phosphoric acid followed by sodium hypochlorite has been shown to help avoid negative effects. Alumina blasting has been investigated as a mechanical cleaning method in a relatively large number of experiments, most of which have confirmed its effectiveness. An intraoral cleaner containing functional monomers that has become commercially available in recent years is a promising method in clinical practice because it can easily and effectively remove temporary adhesive material. In addition, adhesion inhibitors can be easily removed from resin-coated dentin surfaces. ispartof: JAPANESE DENTAL SCIENCE REVIEW vol:57 pages:147-153 ispartof: location:Netherlands status: published

Peri-implant diseases are caused by bacterial biofilm colonizing implant surfaces. Prevention and management of peri-implant mucositis and peri-implantitis rely on effective biofilm removal. This study aimed to evaluate biofilm removal and cytocompatibility following chemo-mechanical surface decontamination of biofilm-coated titanium discs. Biofilm-coated (Streptococcus gordonii) discs, with either non-modified (smooth) or modified (rough) surfaces, were instrumented using a sterile gauze soaked in one out of four solutions: saline (NaCl), alkaline electrized water (AEW), citric acid (CA) or N-acetyl-l-cysteine (NAC). Non-contaminated, untreated titanium discs served as controls (C). Residual deposits (bacteria and gauze fibers) and cytocompatibility for osteoblast-like cells were evaluated using SEM and immunofluorescence. Cytotoxicity was assessed using WST-8 assay and immunofluorescence. All protocols were equally effective in removing bacteria from smooth surfaces, while AEW and CA were found to be superior at rough surfaces. AEW and NAC were superior in promoting cytocompatibility over NaCl. NAC and CA had a strong cytotoxic effect on osteoblast-like and fibroblast cells. In conclusion, AEW may be beneficial in the decontamination of implant surfaces, effectively removing bacterial biofilm and restoring cytocompatibility.

Pool scrubbing is conducted to remove contaminated aerosols/particles released from nuclear power generation systems in severe accidents. Gas-entrained particles pass through the pools in three stages: 1) injection into the pools through a vent, 2) decontamination process in bubbles rising in the pools, and 3) secondary entrainment into the atmosphere at the pool surface. The particle separations in the rising bubble swarm constitute the primary process for aerosol decontamination. The dynamics of the particles contained in the rising bubble swarm are crucial. Numerical modeling of particle transportation in bubbles in three-phase systems is complex and challenging. This study aimed to investigate the particle flow dynamics in scrubbing pools to understand the particle decontamination mechanism, which can guide equipment design to achieve high aerosol separation efficiency. In this study, particle decontamination in bubbles is simulated by using the Eulerian–Lagrangian method. This numerical method is used to investigate the mechanisms of flow dynamics, coagulation, and separation of particles in the bubbles, as well as the particle decontamination affected by the operation parameters such as the bubble velocity, and gas and particle properties. In addition, the decontamination factor is predicted for aerosol particles in the small bubbles of the rising swarm, which agrees with the calculated experimental DF of the bubble swarm.

OBJECTIVES Decontamination of biofilm-colonized rough implant surfaces remains challenging. We investigated the effect of airflow with glycine powder (AFG) on decontamination of mature oral multispecies biofilm from a sandblasted and acid etched (SLA) titanium surface. MATERIALS AND METHODS Subgingival dental plaque was cultured on SLA disks anaerobically for 21 days. AFG with various settings and distances was applied directly on the disks with or without previous rinse of 0.9% NaCl. The specimens were then analyzed through scanning electron microscope and remaining bacteria on the implant surface were quantified and statistically compared. RESULTS Mature oral biofilm with cocci and rods as major morphotypes, as well as spiral- and filamentous-shaped organisms, was formed on the untreated disks. Saline rinsing removed the thick biofilm layer but left numerous of coccoid bacteria in rough surface pits. AFG effectively removed most of the bacteria from the pits. Both 25% and 50% power settings were equally effective at 3-mm distance. With 50% power, AFG successfully removed bacteria at both 3- and 6-mm distance. When AFG was applied on native biofilm without prior rinsing with saline, it effectively removed the biofilm including bacteria in the pits. CONCLUSION Application of AFG appears effective in removing bacteria from rough implant surfaces.

The presence of diverse pollutants in water has been threating human health and aquatic ecosystems on a global scale. For more than a century, chemical oxidation using strongly oxidizing species was one of the most effective technologies to destruct pollutants and to ensure a safe and clean water supply. However, the removal of increasing amount of pollutants with higher structural complexity, especially the emerging micropollutants with trace concentrations in the complicated water matrix, requires excessive dosage of oxidant and/or energy input, resulting in a low cost-effectiveness and possible secondary pollution. Consequently, it is of practical significance but scientifically challenging to achieve selective oxidation of pollutants of interest for water decontamination. Currently, there are a variety of examples concerning selective oxidation of pollutants in aqueous systems. However, a systematic understanding of the relationship between the origin of selectivity and its applicable water treatment scenarios, as well as the rational design of catalyst for selective catalytic oxidation, is still lacking. In this critical review, we summarize the state-of-the-art selective oxidation strategies in water decontamination and probe the origins of selectivity, that is, the selectivity resulting from the reactivity of either oxidants or target pollutants, the selectivity arising from the accessibility of pollutants to oxidants via adsorption and size exclusion, as well as the selectivity due to the interfacial electron transfer process and enzymatic oxidation. Finally, the challenges and perspectives are briefly outlined to stimulate future discussion and interest on selective oxidation for water decontamination, particularly toward application in real scenarios.

Contact with continuous belt conveyors during processing results in opportunities for pathogenic and spoilage microorganisms to contaminate meat products. The objective of this project is to investigate the germicidal response on the surface of food-grade conveyor belt materials treated with pulsed ultraviolet (PUV) light. Four conveyor belt types including: a stainless-steel chain-link belt, a polytetrafluoroethylene (PTFE)-coated fabric belt, a solid pliable polymer belt, and a rigid-linked polymer belt, were evaluated for the inactivation of Escherichia coli K12-NSR strain and lactic acid bacteria (LAB). Prior to bacterial inoculation, samples were classified as soiled or unsoiled, based on the presence or absence of pork intramuscular fluid on the surfaces of the conveyor samples. Using a variable speed conveyor, equipped with a Xenon flashlamp positioned 10-cm above the surface, each belt sample was exposed to PUV light at three fixed conveyor speeds: 3.05, 15.24, and 30.48 cm/sec, resulting in a total energy exposure of 3.31, 0.66 and 0.33 J/cm2, respectively. For samples inoculated with E. coli K12-NSR, the surface condition (soiled or unsoiled) by treatment interaction was significant for microbial inactivation on the surface of the rigid polymer linked belt (P 10 CFU/cm2 for E. coli K12-NSR and 0.63 to 4.61 Log10 CFU/cm2 for LAB for the evaluated treatment parameters. The results of this project demonstrate that PUV light is an effective means of decontamination for conveyor belts during food processing.

Environmental contamination is one of the key issues of developing countries in recent days, and several types of methods and technologies have been developed to overcome these issues. This paper highlights the importance of decontamination in a contaminated environment that normally precedes protection, detection and identification followed by medical support. Further, this paper especially focuses on individual and collective NBC decontamination required on navy ships and correspondingly presents solutions (viable and economical) through the use of indigenously developed decontamination equipment. The paper also highlights the integration of various decontamination technologies with pre-existing ship decontamination systems, indicating the need for various decontaminants. Finally, we will also focus on new decontamination systems based on nanomaterials and enzymes and their utilization.

In this study, an N-chloramide-modified reactive copolymer, chlorinated poly (4-vinylbenzenesulfonamide-co-methyl methacrylate) (PVMCl), was designed and synthesized for rapid and efficient detoxif...

Rational design of advanced adsorbed materials with hierarchically porous architecture, high surface area, and macroscopic shapeability is of great significance for boosting their potential in practical applications. Herein, a monolithic iron metal-organic gel/bacterial cellulose (denoted as Fe-MOG/BC) composite has been successfully fabricated based on an ultrafast, scalable, aqueous-based synthetic strategy at room temperature. As expected, the resulting Fe-MOG/BC aerogel possesses a three-dimensional (3D) hierarchically porous microstructure and abundant active sites, being ultralight, water-fast, and mechanically robust. Benefiting from these unique structural characteristics, the resulting Fe-MOG/BC composite exhibits superb saturated sorption capacity (495 mg g-1) toward arsenate, outperforming other reported nanoadsorbents. Further, the Fe-MOG/BC aerogel enables efficient decontamination of 5 ppm of As(V) to below the permitted threshold in drinking water (10 ppb) within 30 min, accompanied by excellent selectivity and reusability. Significantly, as an efficient filter unit, the Fe-MOG/BC aerogel (0.1 g) can continuously treat 3900 mL wastewater (spiked with 1 ppm As(V)) to the safe level. Such an excellent As(V) decontamination capability of Fe-MOG/BC together with the ease, low cost, and scalable production prefigures its huge prospects for practical wastewater remediation.

To evaluate the effect of routinely used physical decontamination methods on the surface characteristics of zirconia implants and subsequent ability of bacteria to adhere in vitro.Physical decontamination methods commonly used in peri-implantitis therapy and routine implant maintenance can potentially alter zirconia implant surfaces.Acid-etched zirconia discs were instrumented with titanium curette (TC), plastic curette, air abrasive device, ultrasonic scaler (US) with stainless steel tip. Following instrumentation, surface topography, and surface elemental composition was analyzed using 3D-laser scanning microscopy and energy-dispersive X-ray spectroscopy, respectively. Subsequently, plaque biofilm was cultured on zirconia discs for 48 h and bacterial adhesion assessed using a turbidity test and scanning electron microscopy.A significant difference in surface roughness was observed between the US and control group (p 0.05). The US and TC caused gray surface discolouration on zirconia discs due to deposition of metallic residue as confirmed by X-ray spectroscopy. No significant difference in bacterial adhesion was noted among all treatment groups (p 0.05).TC and US with stainless steel tips should be used with caution due to deposition of metallic residue on the surface. Air abrasive devices and plastic curettes caused minimal surface alterations and are, therefore, safer for zirconia implant decontamination.

Due to threats posed by Chemical Warfare Agents (CWAs) and accidents with Toxic Industrial Chemicals (TICs), the need for highly effective skin decontamination remains relevant. Reactive Skin Decontamination Lotion (RSDL), composed of Dekon 139 and 2,3-butanedione monoxime, has been shown highly effective against CWAs and TICs. This systematic review compares RSDL efficacy to other decontaminating agents. Online search engines PubMed, Web of Science, and Embase were explored, and all literature containing quantitative data, comparing RSDL to other decontaminating agents, investigated. Year of publication, type of study (in vitro or in vivo), model (animal or human), toxin tested, and result of each relevant article were recorded. In total, 15 relevant papers, comprising a total of 18 experimental models, were identified. Nine studies concluded that RSDL was the most effective decontaminant tested against the toxin of interest. Four studies concluded that RSDL was not the most effective decontaminant tested against the toxin of interest. The remaining 5 studies concluded RSDL displayed similar efficacy to at least one of the other decontaminating agents tested against the toxin of interest. There is substantial evidence supporting the efficacy of RSDL as a decontaminating agent. However, there remains to be insufficient data on this important topic, and limitations on the usefulness of current data, when applied to the broad array of potential exposures.

Dispersants with a low environmental impact are necessary for oil spill remediation. Thus, the biosurfactant produced by the bacterium Pseudomonas cepacia CCT6659 using industrial waste and formulated using a method of adding food preservative was evaluated for its toxicity against the vegetable Allium cepa and aquatic species such as the freshwater fish Poecilia vivipara and the bivalve Anomalocardia brasiliana. The biosurfactant was also applied in the removal of hydrophobic contaminant in sand and soils, in sea stones, in the dispersion and in the bioremediation of oil in seawater. The surfactant was considered to be of low toxicity for the bioindicators evaluated. As a petroderivative removal agent, the formulated tensoactive reached 76.55 % removal in soil and 84.50 % in sea stones. The biosurfactant was able to disperse 96.00 % of oil in seawater and promoted an increase in the biodegradation of oil by 70.00 % during a bioremediation process carried out in seawater. Therefore, the formulated biosurfactant presents suitable conditions for application as a dispersing agent in the decontamination of terrestrial and aquatic environments impacted by oil spills in substitution of chemical and toxic compounds.

Cada año se vierten millones de metros cúbicos de aguas residuales a los cuerpos de agua, las cuales son tratadas de forma inadecuada, siendo estos procedimientos ineficientes para alcanzar lo requerido por la ley o para uso dentro de los procesos industriales. En estos casos, y debido a la escasez del hídrico, se está recurriendo al uso de los procesos de oxidación avanzada como tratamiento alternativo. Estos procesos se basan en procesos fisicoquímicos capaces de producir cambios profundos en la estructura química de los contaminantes, involucrando la generación y uso de especies transitorias de gran poder oxidante, principalmente el radical hidroxilo, el cual puede ser generado por medios fotoquímicos o por otras formas de energía y posee alta efectividad para la oxidación de materia orgánica. Esta revisión tiene como objetivo realizar un análisis de la influencia de los tratamientos en el proceso de descontaminación.

Background The COVID-19 pandemic highlighted the need for evidence-based approaches to decontamination and reuse of N95 filtering facepiece respirators (FFRs). We sought to determine whether vapourized hydrogen peroxide (VHP) reduced SARS-CoV-2 bioburden on FFRs without compromising filtration efficiency. We also investigated coronavirus HCoV-229E as a surrogate for decontamination validation testing. Methods N95 FFRs were laced with SARS-CoV-2 or HCoV-229E and treated with VHP in a hospital reprocessing facility. After sterilization, viral burden was determined using viral outgrowth in a titration assay, and filtration efficiency of FFRs was tested against ATSM F2299 and NIOSH TEB-STP-APR-0059. Results Viable SARS-CoV-2 virus was not detected after VHP treatment. One replicate of the HCoV-229E laced FFRs yielded virus after processing. Unexpired N95 FFRs retained full filtration efficiency after VHP processing. Expired FFRs failed to meet design-specified filtration efficiency and therefore are unsuitable for reprocessing. Discussion In-hospital VHP is an effective decontaminant for SARS-CoV-2 on FFRs. Further, filtration efficiency of unexpired respirators is not affected by this decontamination process. Conclusions VHP is effective in inactivating SARS-CoV-2 on FFRs without compromising filtration efficiency. HCoV-229E is a suitable surrogate for SARS-CoV-2 for disinfection studies.

During public health crises like the COVID-19 pandemic, ultraviolet-C (UV-C) decontamination of N95 respirators for emergency reuse has been implemented to mitigate shortages. Pathogen photoinactivation efficacy depends critically on UV-C dose, which is distance- and angle-dependent and thus varies substantially across N95 surfaces within a decontamination system. Due to nonuniform and system-dependent UV-C dose distributions, characterizing UV-C dose and resulting pathogen inactivation with sufficient spatial resolution on-N95 is key to designing and validating UV-C decontamination protocols. However, robust quantification of UV-C dose across N95 facepieces presents challenges, as few UV-C measurement tools have sufficient (1) small, flexible form factor, and (2) angular response. To address this gap, we combine optical modeling and quantitative photochromic indicator (PCI) dosimetry with viral inactivation assays to generate high-resolution maps of “on-N95” UV-C dose and concomitant SARS-CoV-2 viral inactivation across N95 facepieces within a commercial decontamination chamber. Using modeling to rapidly identify on-N95 locations of interest, in-situ measurements report a 17.4 ± 5.0-fold dose difference across N95 facepieces in the chamber, yielding 2.9 ± 0.2-log variation in SARS-CoV-2 inactivation. UV-C dose at several on-N95 locations was lower than the lowest-dose locations on the chamber floor, highlighting the importance of on-N95 dose validation. Overall, we integrate optical simulation with in-situ PCI dosimetry to relate UV-C dose and viral inactivation at specific on-N95 locations, establishing a versatile approach to characterize UV-C photoinactivation of pathogens contaminating complex substrates such as N95s.

Introduction and Aim:Purpose of this study is to sensitize healthcare givers about the significance of toothbrush acting as fomites and this study aimed at highlighting importance of disinfecting in-use toothbrushes. Material and Method:This was a randomized control trial involving 30 patients. 15 were given distilled water and 15 were given 70% ethyl alcohol for disinfecting in-use toothbrushes, which were then microbiologically tested after 7 days of use. Results:Finding of this study showed 70% alcohol was highly effective in decontaminating used toothbrushes. Conclusion:In-use toothbrushes become highly contaminated after use and can act as fomites for transmitting infections. Thus, proper instructions for use of toothbrushes should be given to patients and public.

Elemental mercury exposure can result in significant toxicity. Source decontamination and remediation are often required after larger elemental mercury exposures, but the details of these processes are infrequently reported. In the case described herein, a 64-year-old woman and her husband were exposed to elemental mercury in their home after the husband purchased it online for the purpose of recreational barometer calibration. After the mercury reportedly spilled during the calibration process, a vacuum cleaner was used to decontaminate the affected surface; this led to extensive mercury contamination of the home. The couple was relocated from the home while remediation occurred over the course of several weeks. Vacuum cleaning of an elemental mercury spill can lead to extensive volatilization and recirculation of mercury vapor. For smaller mercury spills, careful removal of visible mercury beads by using an eyedropper, cardboard, and masking tape is recommended. Larger spills require professional decontamination and remediation and may necessitate involvement of governmental resources. Vacuum cleaning should not be used as an initial method of decontamination after elemental mercury exposure. Careful attention to source decontamination can reduce the emotional and financial costs associated with extensive remediation after elemental mercury exposure.

Microbiological quality of four different cultivars (viz., Deglet Noor, Dabbas, Barni and Lulu) of date palm fruits imported into Bangladesh was evaluated. The microbiological quality analysis revealed that the date palm fruit samples are contaminated with bacteria and fungi. Among the studied samples, total aerobic plate count varied from 6.85 ×106 cfu/g to 4.14×107 cfu/g. The maximum bacterial load was observed in 'Dabbas' cultivar and lowest bacteria load was found in 'Lulu' cultivar. The total yeast and mold count ranged from 1.08×103 cfu/g to 6.94 ×104 cfu/g. The maximum yeast and mold count was found in 'Deglet Noor' cultivar whereas this count was lowest in 'Lulu' cultivar. Twenty-two bacterial isolates were randomly selected and identified based on their morphological, cultural and biochemical characteristics. Among the bacterial isolates, Providencia rettgeri was most prevalent (18.18%). The identity of one of the P. rettgeri isolates was confirmed by its 16S rRNA gene sequence comparison and subsequent molecular phylogenetic analysis. The presence of pathogenic bacteria in the imported date palm fruits indicates that they are not suitable for direct human consumption. To improve the microbiological quality of the date palm fruits, several easily available substances were tested as decontaminating agent. The study revealed that commercially available vinegar acts as an excellent decontaminating agent against date palm fruit-associated bacteria. Bangladesh J. Bot. 50(3): 641-649, 2021 (September)

International guidelines stipulate that autoclavation is necessary to sterilize surgical equipment. World Health Organization (WHO) guidelines for decontamination of medical devices require four levels of decontamination: cleaning, low- and high-level disinfection, as well as sterilization. Following disasters, there is a substantial need for wound care surgery. This requires prompt availability of a significant volume of instruments that are adequately decontaminated. Ideally, they should be sterilized using an autoclave, but due to the resource-limited field context, this may be impossible. The aim of this study was therefore to identify whether there are portable and less resource-demanding techniques to decontaminate surgical instruments for safe wound care surgery in disasters. A scoping review was chosen, and searches were performed in three scientific databases, grey literature, and included data from organizations and journals. Articles were scanned for decontamination techniques feasible for use in the resource-scarce disaster setting given that: they achieved at least high-level disinfected instruments, were portable, and did not require electricity. A total of 401 articles were reviewed, yielding 13 articles for inclusion. The study identified three techniques: pressure cooking, boiling, and liquid chemical immersion, all achieving either sterilized or high-level disinfected instruments. It was concluded that besides autoclaves, there are less resource-demanding decontamination techniques available for safe wound surgery in disasters. This study provides systematic information to guide optimal standard setting for sterilization of surgical material in resource-limited disaster settings.

BACKGROUND: Public transportation has been linked to an increase in the risk of coronavirus disease 2019 transmission. The effective decontamination system using aerosolized hydrogen peroxide can mitigate the transmission risk from using public transportation. AIM: The aim of this study was to develop and validate an effective decontamination system for public transport. METHODS: The experimental research was performed in 13 inter-city public buses. The aerosol generator with ultrasonic atomizer was used in the experiment. The validation process for disinfection was conducted using both a chemical indicator (CI) and spore discs biological indicator (inoculated with 106 Geobacillus stearothermophilus enclosed in glassine envelopes). The CIs and biological indicators were marked by number and placed in nine locations on each bus. The decontamination cycle was developed by analyzed of various aerosolized and decomposition period. Both concentrations of hydrogen peroxide, 5% and 7%, were used for comparison. RESULTS: In an aerosolized period, both concentrations of hydrogen peroxide at 30 min were effective for sporicidal 6-log reductions. The decontamination cycle totaled 100 min, based on a 70 min average decomposition time. CONCLUSIONS: The automated hydrogen peroxide aerosolized system is a highly effective and safe method of decontaminating public buses.

The US CDC has recognized moist-heat as one of the most effective and accessible methods of decontaminating N95 masks for reuse in response to the persistent N95 mask shortages caused by the COVID-19 pandemic. However, it is challenging to reliably deploy this technique in healthcare settings due to a lack of smart technologies capable of ensuring proper decontamination conditions of hundreds of masks simultaneously. To tackle these challenges, we developed an open-source wireless sensor platform---VeriMask1 ---that facilitates per-mask verification of the moist-heat decontamination process. VeriMask is capable of monitoring hundreds of masks simultaneously in commercially available heating systems and provides a novel throughput-maximization functionality to help operators optimize the decontamination settings. We evaluate VeriMask in laboratory and real-scenario clinical settings and find that it effectively detects decontamination failures and operator errors in multiple settings and increases the mask decontamination throughput. Our easy-to-use, low-power, low-cost, scalable platform integrates with existing hospital protocols and equipment, and can be broadly deployed in under-resourced facilities to protect front-line healthcare workers by lowering their risk of infection from reused N95 masks. We also memorialize the design challenges, guidelines, and lessons learned from developing and deploying VeriMask during the COVID-19 Pandemic. Our hope is that by reflecting and reporting on this design experience, technologists and front-line health workers will be better prepared to collaborate for future pandemics, regarding mask decontamination, but also other forms of crisis tech.

In this study, we report the application of pulsed electrochemistry to enhanced water decontamination by electrochemical oxidation. By applying square current waveforms, the alternating pulse-on/-o...