scholarly journals Mitigation of Airborne PRRSV Transmission with UV Light Treatment: Proof-of-Concept

Agriculture ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 259
Author(s):  
Peiyang Li ◽  
Jacek A. Koziel ◽  
Jeffrey J. Zimmerman ◽  
Jianqiang Zhang ◽  
Ting-Yu Cheng ◽  
...  
Keyword(s):  
Uv Light ◽  
Pilot Scale ◽  
Respiratory Syndrome Virus ◽  
Two Stage ◽  
Short Treatment ◽  
Log Reduction ◽  
Stage Models ◽  
One Stage ◽  
Order Of Magnitude ◽  
Uv C

Proper treatment of infectious air could potentially mitigate the spread of airborne viruses such as porcine reproductive and respiratory syndrome virus (PRRSV). The objective of this research is to test the effectiveness of ultraviolet (UV) in inactivating aerosolized PRRSV, specifically, four UV lamps, UV-A (365 nm, both fluorescent and LED-based), “excimer” UV-C (222 nm), and germicidal UV-C (254 nm), were tested. The two UV-C lamps effectively irradiated fast-moving PRRSV aerosols with short treatment times (<2 s). One-stage and two-stage UV inactivation models estimated the UV doses needed for target percentage (%) reductions on PRRSV titer. UV-C (254 nm) dose needed for 3-log (99.9%) reduction was 0.521 and 0.0943 mJ/cm2, respectively, based on one-stage and two-stage models. An order of magnitude lower UV-C (222 nm) doses were needed for a 3-log reduction, i.e., 0.0882 and 0.048 mJ/cm2, based on one-stage and two-stage models, respectively. However, the cost of 222 nm excimer lamps is still economically prohibitive for scaling-up trials. The UV-A (365 nm) lamps could not reduce PRRSV titers for tested doses up to 4.11 mJ/cm2. Pilot-scale or farm-scale testing of UV-C on PRRSV aerosols simulating barn ventilation rates are recommended based on its effectiveness and reasonable costs comparable to HEPA filtration.

scholarly journals Mitigation of Airborne PRRSV Transmission with UV Light Treatment: Proof-of-concept

2021 ◽  
Author(s):  
Peiyang Li ◽  
Jacek A. Koziel ◽  
Jeffrey J. Zimmerman ◽  
Jianqiang Zhang ◽  
Ting-Yu Cheng ◽  
...  
Keyword(s):  
Uv Light ◽  
Pilot Scale ◽  
Respiratory Syndrome Virus ◽  
Two Stage ◽  
Short Treatment ◽  
Log Reduction ◽  
Stage Models ◽  
One Stage ◽  
Order Of Magnitude ◽  
Uv C

Proper treatment of infectious air could potentially mitigate the spread of airborne viruses such as porcine reproductive and respiratory syndrome virus (PRRSV). The objective of this research is to test the effectiveness of ultraviolet (UV) in inactivating aerosolized PRRSV, specifically, four UV lamps, UV-A (365 nm, both fluorescent and LED-based), "excimer" UV-C (222 nm), and germicidal UV-C (254 nm), were tested. The two UV-C lamps effectively irradiated fast-moving PRRSV aerosols with short treatment times (&lt;2 s). One-stage and two-stage UV inactivation models estimated the UV doses needed for target percentage (%) reductions on PRRSV titer. UV-C (254 nm) dose needed for 3-log (99.9%) reduction was 0.521 and 0.0943 mJ/cm2, respectively, based on one-stage and two-stage models. An order of magnitude lower UV-C (222 nm) doses were needed for a 3-log reduction, i.e., 0.0882 and 0.048 mJ/cm2, based on one-stage and two-stage models, respectively. However, the cost of 222-nm excimer lamps is still economically prohibitive for scaling-up trials. The UV-A (365 nm) lamps could not reduce PRRSV titers for tested doses up to 4.11 mJ/cm2. Pilot-scale or farm-scale testing of UV-C on PRRSV aerosols simulating barn ventilation rates are recommended based on its effectiveness and reasonable costs comparable to HEPA filtration.

Comparative study of methanogens in one- and two-stage anaerobic digester treating food waste

2014 ◽  
Vol 30 (6) ◽  
pp. 515-523 ◽  
Author(s):  
Marta Kinnunen ◽  
Daniel Hilderbrandt ◽  
Stefan Grimberg ◽  
Shane Rogers ◽  
Sumona Mondal
Keyword(s):  
Food Waste ◽  
Methane Production ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Quantitative Polymerase Chain Reaction ◽  
Methanogenic Archaea ◽  
Pilot Scale ◽  
Shannon Index ◽  
Production Rates ◽  
Two Stage ◽  
One Stage

AbstractChanges in methanogenic archaea were investigated in pilot-scale experiments during one- and two-stage mesophilic anaerobic digestion (AD) of food waste. Methane yields were 379.7±75.3 liters of methane per kg of volatile solids [L-CH4(kg-VS)−1] added to the system, during one-stage operation, and 446±922 L-CH4(kg-VS)−1added during two-stage operation. Populations of methanogenic archaea were monitored quantitatively by targeting the functional gene for methyl-coenzyme-M reductase (mcrA) using real-time quantitative polymerase chain reaction techniques. During one-stage operation, meanmcrAgene concentrations were 2.48×109±2.7×109copies ml−1. Two-stage operation yielded meanmcrAgene concentrations of 9.85×108±8.2×108copies ml−1in the fermentation and 1.76×1010±8.5×109copies ml−1in the methanogenesis reactors, respectively. Diversity of archaea in the methanogenic reactors was investigated by denaturing gradient gel electrophoresis targeting the V3 region of 16S rRNA of archaea. The Shannon index (H) was 2.98 for one-stage operation and 7.29 for two-stage operation, suggesting greater archaeal diversity in the two-stage AD. The fivefold increase in methanogenic archaea populations during the two-stage operation, as indicated bymcrAgene concentration, corresponded to an increase in methane production rates. While the diversity may also be related to the stability of the microbial bioprocesses and improved methane production rates, the correlation between diversity and production rates should be studied further.

Pilot-Scale Continuous Ultrasonic Cleaning Equipment Reduces Listeria monocytogenes Levels on Conveyor Belts

2009 ◽  
Vol 72 (2) ◽  
pp. 408-411 ◽  
Author(s):  
RIINA TOLVANEN ◽  
JANNE LUNDÉN ◽  
ARI HÖRMAN ◽  
HANNU KORKEALA
Keyword(s):  
Listeria Monocytogenes ◽  
Ultrasonic Treatment ◽  
Treatment Time ◽  
Conveyor Belt ◽  
Pilot Scale ◽  
T Test ◽  
Cleaning Efficiency ◽  
Short Treatment ◽  
Ultrasonic Cleaning ◽  
Log Reduction

Ultrasonic cleaning of a conveyor belt was studied by building a pilot-scale conveyor with an ultrasonic cleaning bath. A piece of the stainless steel conveyor belt was contaminated with meat-based soil and Listeria monocytogenes strains (V1, V3, and B9) and incubated for 72 h to allow bacteria to attach to the conveyor belt surfaces. The effect of ultrasound with a potassium hydroxide–based cleaning detergent was determined by using the cleaning bath at 45 and 50°C for 30 s with and without ultrasound. The detachment of L. monocytogenes from the conveyor belt caused by the ultrasonic treatment was significantly greater at 45°C (independent samples t test, P &lt; 0.001) and at 50°C (independent samples t test, P = 0.04) than without ultrasound. Ultrasonic cleaning efficiency was tested with different cleaning durations (10, 15, 20, and 30 s) and temperatures (30, 45, and 50°C). The differences in the log reduction between cleaning treatments were analyzed by analysis of variance with Tamhane's T2 posthoc test using SPSS (Chicago, IL). The lengthening of the treatment time from 10 to 30 s did not significantly increase the detachment of L. monocytogenes (ANOVA 0.633). At 30°C and at the longest time tested (30 s), the treatment reduced L. monocytogenes counts by only 2.68 log units. However, an increase in temperature from 30 to 50°C improved the effect of the ultrasonic treatment significantly (P &lt; 0.01). Ultrasonic cleaning for 10 s at 50°C reduced L. monocytogenes counts by more than 5 log units. These results indicate that ultrasonic cleaning of a conveyor belt is effective even with short treatment times.

scholarly journals Rapid, dose-dependent and efficient inactivation of surface dried SARS-CoV-2 by 254 nm UV-C irradiation

2021 ◽  
Vol 26 (42) ◽  
Author(s):  
Natalia Ruetalo ◽  
Ramona Businger ◽  
Michael Schindler
Keyword(s):  
High Titre ◽  
Short Exposure ◽  
Low Doses ◽  
Dose Dependency ◽  
Viral Titre ◽  
Log Reduction ◽  
Order Of Magnitude ◽  
The Relationship ◽  
Uv C ◽  
Dose Dependent

Background: The COVID-19 pandemic urges for cheap, reliable, and rapid technologies for disinfection and decontamination. One frequently proposed method is ultraviolet (UV)-C irradiation. UV-C doses necessary to achieve inactivation of high-titre SARS-CoV-2 are poorly defined. Aim: We investigated whether short exposure of SARS-CoV-2 to UV-C irradiation sufficiently reduces viral infectivity and doses necessary to achieve an at least 6-log reduction in viral titres. Methods: Using a box and two handheld systems designed to decontaminate objects and surfaces, we evaluated the efficacy of 254 nm UV-C treatment to inactivate surface dried high-titre SARS-CoV-2. Results: Drying for 2 hours did not have a major impact on the infectivity of SARS-CoV-2, indicating that exhaled virus in droplets or aerosols stays infectious on surfaces for at least a certain amount of time. Short exposure of high titre surface dried virus (3–5*10^6 IU/ml) with UV-C light (16 mJ/cm2) resulted in a total inactivation of SARS-CoV-2. Dose-dependency experiments revealed that 3.5 mJ/cm2 were still effective to achieve a > 6-log reduction in viral titres, whereas 1.75 mJ/cm2 lowered infectivity only by one order of magnitude. Conclusions: SARS-CoV-2 is rapidly inactivated by relatively low doses of UV-C irradiation and the relationship between UV-C dose and log-viral titre reduction of surface residing SARS-CoV-2 is nonlinear. Our findings emphasize that it is necessary to assure sufficient and complete exposure of all relevant areas by integrated UV-C doses of at least 3.5 mJ/cm2 at 254 nm. Altogether, UV-C treatment is an effective non-chemical option to decontaminate surfaces from high-titre infectious SARS-CoV-2.

scholarly journals Pilot scale study on UV-C inactivation of bacterial endospores and virus particles in whole milk: evaluation of system efficiency and product quality

2022 ◽  
Author(s):  
Pranav Vashisht ◽  
Brahmaiah Pendyala ◽  
Ankit Patras ◽  
Vybhav Vipul Sudhir Gopisetty ◽  
Ramasamy Ravi
Keyword(s):  
Pilot Scale ◽  
Microbial Inactivation ◽  
Dean Number ◽  
Experimental Conditions ◽  
Virus Particles ◽  
Dean Flow ◽  
Log Reduction ◽  
Bacterial Endospores ◽  
Whole Milk ◽  
Uv C

UV-C processing of whole milk (WM) using a designed pilot scale Dean flow system was conducted at flow rates (11.88, 23.77, and 47.55 gph), Reynolds number ranges from 2890-11562 and the Dean number (at curved region) calculated as (648-2595) to inactivate bacterial endospores and virus particles. Biodosimetry studies were conducted to quantify the reduction equivalent fluence at selected experimental conditions. Results revealed that the dose distribution improved as flow rate increases, attributed to increase in Dean effects and turbulence intensity. Microbial inactivation studies conducted at 47.55 gph showed 0.91 (stdev:0.15) and 2.14 (stdev:0.19) log reduction/ pass for B. cereus endospores and T1UV phage. Linear inactivation trend was observed against number of passes which clearly demonstrates equivalent dose delivery during each pass. Lipid peroxidation value and volatile profile did not change significantly at UV dose of 60 mJ/cm 2. Lower E EO value signifies the higher electrical efficiency of the system.

scholarly journals Anaerobic stabilisation of urine diverting dehydrating toilet faeces (UDDT-F) in urban poor settlements: biochemical energy recovery

2019 ◽  
Vol 9 (2) ◽  
pp. 289-299
Author(s):  
Joy Riungu ◽  
Mariska Ronteltap ◽  
Jules B. van Lier
Keyword(s):  
Methane Production ◽  
Urban Poor ◽  
Energy Recovery ◽  
Biogas Production ◽  
Plug Flow ◽  
Pilot Scale ◽  
Biochemical Methane Potential ◽  
Two Stage ◽  
One Stage ◽  
Methane Potential

Abstract Biochemical energy recovery using digestion and co-digestion of faecal matter collected from urine diverting dehydrating toilet faeces (UDDT-F) and mixed organic market waste (OMW) was studied under laboratory- and pilot-scale conditions. Laboratory-scale biochemical methane potential (BMP) tests showed an increase in methane production with an increase in OMW fraction in the feed substrate. In subsequent pilot-scale experiments, one-stage and two-stage plug flow digester were researched, applying UDDT-F:OMW ratios of 4:1 and 1:0, at about 10 and 12% total solids (TS) slurry concentrations. Comparable methane production was observed in one-stage (Ro-4:1,12%) (314 ± 15 mL CH4/g VS added) and two-stage (Ram-4:1,12%) (325 ± 12 mL CH4/g VS added) digesters, when applying 12% TS slurry concentration. However, biogas production in Ram-4:1,12% digester (571 ± 25 mL CH4/g VS added) was about 12% higher than in Ro-4:1,12%, significantly more than the slight difference in methane production, i.e. 3–4%. The former was attributed to enhanced waste solubilisation and increased CO2 dissolution, resulting from mixing the bicarbonate-rich methanogenic effluent for neutralisation purposes with the low pH (4.9) influent acquired from the pre-acidification stage. Moreover, higher process stability was observed in the first parts of the plug flow two-stage digester, characterised by lower VFA concentrations.

Two Stage Sludge Stabilization

1987 ◽  
Vol 19 (7) ◽  
pp. 1247-1250 ◽  
Author(s):  
N. J. Dichtl
Keyword(s):  
Residence Time ◽  
Pilot Scale ◽  
Preliminary Treatment ◽  
Combined Method ◽  
Two Stage ◽  
Advantages And Disadvantages ◽  
One Stage ◽  
Sludge Stabilization ◽  
Mesophilic Digestion ◽  
Theoretical Considerations

For the stabilization of sludges, theoretical considerations were used to determine a multiple stage ‘Method of Procedure', in order to estimate the advantages and disadvantages of such a procedure. For the procedure, combinations of mesophilic digestion with preceding aerobic-thermophilic or aerobic-mesophilic preliminary treatment as well as anaerobic-thermophilic preliminary treatment, were carried out at a technical pilot scale, in order to quantify the expected advantages compared to one-stage mesophilic digestion. It appeared that, depending on the aim of the process, a two-stage or combined method would give clear advantages either in respect of minimized residence time and desired disinfection, or in respect of all costs for the process.

On a mixed model analysis of multi-environment variety trials: a reconsideration of the one-stage and the two-stage models and analyses

2015 ◽  
Vol 58 (2) ◽  
pp. 433-465 ◽  
Author(s):  
T. Caliński ◽  
S. Czajka ◽  
Z. Kaczmarek ◽  
P. Krajewski ◽  
W. Pilarczyk ◽  
...  
Keyword(s):  
Mixed Model ◽  
Model Analysis ◽  
Two Stage ◽  
Mixed Model Analysis ◽  
Variety Trials ◽  
Stage Models ◽  
One Stage ◽  
The One

Molecular genetic background of haemophilia A patients with discrepancy between one-stage and two-stage factor VIII assays

2010 ◽  
Vol 30 (S 01) ◽  
pp. S153-S155
Author(s):  
D. Delev ◽  
S. Pahl ◽  
J. Driesen ◽  
H. Brondke ◽  
J. Oldenburg ◽  
...  
Keyword(s):  
Factor Viii ◽  
Genetic Background ◽  
Molecular Genetic ◽  
Haemophilia A ◽  
Two Stage ◽  
One Stage

Plasma Factor V Activation Is Prevented by Activated Protein C in the Presence of Phospholipid Vesicles, Not Platelets

1993 ◽  
Vol 69 (02) ◽  
pp. 124-129 ◽  
Author(s):  
Susan Solymoss ◽  
Kim Thi Phu Nguyen
Keyword(s):  
Western Blotting ◽  
Protein C ◽  
Thrombin Generation ◽  
Blood Platelets ◽  
Activated Protein C ◽  
Phospholipid Vesicles ◽  
Factor V ◽  
Two Stage ◽  
One Stage ◽  
Plasma Factor

SummaryActivated protein C (APC) is a vitamin K dependent anticoagulant which catalyzes the inactivation of factor Va and VIIIa, in a reaction modulated by phospholipid membrane surface, or blood platelets. APC prevents thrombin generation at a much lower concentration when added to recalcified plasma and phospholipid vesicles, than recalcified plasma and platelets. This observation was attributed to a platelet associated APC inhibitor. We have performed serial thrombin, factor V one stage and two stage assays and Western blotting of dilute recalcified plasma containing either phospholipid vesicles or platelets and APC. More thrombin was formed at a given APC concentration with platelets than phospholipid. One stage factor V values increased to higher levels with platelets and APC than phospholipid and APC. Two stage factor V values decreased substantially with platelets and 5 nM APC but remained unchanged with phospholipid and 5 nM APC. Western blotting of plasma factor V confirmed factor V activation in the presence of platelets and APC, but lack of factor V activation with phospholipid and APC. Inclusion of platelets or platelet membrane with phospholipid enhanced rather than inhibited APC catalyzed plasma factor V inactivation. Platelet activation further enhanced factor V activation and inactivation at any given APC concentration.Plasma thrombin generation in the presence of platelets and APC is related to ongoing factor V activation. No inhibition of APC inactivation of FVa occurs in the presence of platelets.

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