scholarly journals Advances in Legionella Control by a New Formulation of Hydrogen Peroxide and Silver Salts in a Hospital Hot Water Network

Pathogens ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 209 ◽  
Author(s):  
Luna Girolamini ◽  
Ada Dormi ◽  
Tiziana Pellati ◽  
Paolo Somaroli ◽  
Davide Montanari ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Water Environment ◽  
Hot Water ◽  
Plate Count ◽  
Water Network ◽  
Silver Salts ◽  
Microbiological Parameters ◽  
Contamination Levels ◽  
New Formulation

Legionella surveillance is an important issue in public health, linked to the severity of disease and the difficulty associated with eradicating this bacterium from the water environment. Different treatments are suggested to reduce Legionella risk, however long-term studies of their efficiency are lacking. This study focused on the activity of a new formulation of hydrogen peroxide and silver salts, WTP828, in the hospital hot water network (HWN) to contain Legionella contamination during two years of treatment. The effectiveness of WTP828 was tested measuring physical-chemical and microbiological parameters such as Legionella, Pseudomonas aeruginosa (P. aeruginosa), and a heterotopic plate count (HPC) at 36 °C. Legionella isolates were identified by serotyping and genotyping. WTP 828 induced a reduction in Legionella–positive sites (60% to 36%) and contamination levels (2.12 to 1.7 log10 CFU/L), with isolates belonging to L. pneumophila SG1 (ST1 and ST104), L. anisa and L. rubrilucens widely distributed in HWN. No relevant contamination was found for other parameters tested. The long-term effect of WTP828 on Legionella containment suggest the easy and safe application of this disinfectant, that combined with knowledge of building characteristics, an adequate environmental monitoring and risk assessment plan, become the key elements in preventing Legionella contamination and exposure.

scholarly journals The Effect of Hydrogen Peroxide on Reducing the Colonization of Legionella spp. in a Hospital Water Network

2017 ◽  
Author(s):  
Beatrice Casini ◽  
Francesco Aquino ◽  
Michele Totaro ◽  
Mario Miccoli ◽  
Irio Galli ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
General Hospital ◽  
Legionella Pneumophila ◽  
Hot Water ◽  
Water Network ◽  
Progressive Reduction ◽  
Complete Control ◽  
Food Grade ◽  
Legionella Species ◽  
The Mean

Objectives: To evaluate the effectiveness of hydrogen peroxide (HP) use in the hospital water network disinfection to control Legionella spp. colonization. Methods: Following the detection of high levels of Legionella contamination in a 136-bed general hospital water network, an HP treatment of the hot water (25 mg/L) was adopted. During a period of 34 months, the effectiveness of HP on Legionella colonization was assessed. Legionella was isolated in accordance with ISO-11731 and identification was carried out by sequencing of the mip gene. Results: Before HP treatment L.pneumophila sg 2-15 was isolated in all sites with a mean count of 9950±8279 CFU/L. After one month of HP-treatment, we observed the disappearance of L. pneumophila 2-15, however other Legionella species never cultured before appeared; Legionella pneumophila 1 was isolated in 1 out of 4 sampling sites (2,000 CFU/L) and other non-pneumophila species in all sites (mean load 3,000 ±2887 CFU/L). Starting from September 2013, HP-treatment was modified adding food-grade polyphosphates and in the following months we observed a progressive reduction of the mean load of all species (p<0.05), until to a substantial disappearing of Legionella colonization. Conclusion: Hydrogen peroxide demonstrated a good efficacy in controlling Legionella. Although in the initial phases of treatment it seemed unable to eliminate all the species, by keeping HP levels to 25 mg/L and adding food-grade polyphosphates, a progressive and complete control of colonisation was obtained.

scholarly journals Germination pretreatments to break hard-seed dormancy in Astragalus cicer L. (Fabaceae)

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2621 ◽  
Author(s):  
Joseph M. Statwick
Keyword(s):  
Hydrogen Peroxide ◽  
Seed Germination ◽  
Seed Dormancy ◽  
Rare Species ◽  
Population Viability ◽  
Hot Water ◽  
Physical Damage ◽  
Hard Seed ◽  
Astragalus Cicer

Conservationists often propagate rare species to improve their long-term population viability. However, seed dormancy can make propagation efforts challenging by substantially lowering seed germination. Here I statistically compare several pretreatment options for seeds of Astragalus cicer L.: unscarified controls and scarification via physical damage, hot water, acid, and hydrogen peroxide. Although only 30% of unscarified seeds germinated, just physical scarification significantly improved germination, whereas one treatment, hot water, resulted in no germination at all. I recommend that rare species of Astragalus, as well as other hard-seeded legumes, be pretreated using physical scarification. Other methods may require considerable optimization, wasting precious time and seeds.

Microbial Decontamination of Beef and Sheep Carcasses by Steam, Hot Water Spray Washes, and a Steam-Vacuum Sanitizer

1996 ◽  
Vol 59 (2) ◽  
pp. 127-135 ◽  
Author(s):  
WARREN J. DORSA ◽  
CATHERINE N. CUTTER ◽  
GREGORY R. SIRAGUSA ◽  
MOHAMMAD KOOHMARAIE
Keyword(s):  
Hot Water ◽  
Plate Count ◽  
Water Spray ◽  
Bacterial Populations ◽  
E Coli ◽  
Beef Carcasses ◽  
Aerobic Plate Count ◽  
Contamination Levels ◽  
Initial Contamination ◽  
Temperature Water

Three separate studies were conducted to determine the effectiveness of various temperature water spray washes (Wt), wash and steam combinations (WtS), and vacuum and wash combinations (VWt) for reducing fecal bacteria on sheep and beef carcasses. Wt of 15.6, 54.4, and 82.2°C were administered to sheep carcasses contaminated with feces, using a hand-held spray nozzle. Initial carcass bacterial populations of approximately 2.5, 4, and 6 log CFU/cm2 were subjected to all wash combinations. W82.2 and W82.2S reduced 6 log CFU/cm2 bacterial populations as much as 4.0 log cycles. When carcasses were subjected to WtS and W82.2, the initial contamination levels (4 and 6 log CFU/cm2) had little effect on final bacterial levels (2.7 to 3.3 log CFU/cm2). However, uninoculated carcasses with initial bacterial populations of 2.5 log CFU/cm2 experienced a 1.5-log-cycle reduction when subjected to WtS and W82.2. It is possible that hydration of a carcass before and during interventions affords some protection to bacteria. The next study used a commercial carcass washer to apply a hot water (72°C), low pressure (20 psi) wash in combination with a high pressure (125 psi), warm water (30°C) wash (W72/30). Reductions on beef of 2.7, 3.3, and 3.4 log cycles for aerobic plate count (APC), coliforms, and E. coli populations, respectively, were observed. When a commercial steam-vacuum was used in conjunction with W72/30, reductions of 3.1, 4.2, and 4.3 log cycles for APC, coliforms, and E. coli populations, respectively, were achieved. Implementation of these interventions could reduce the amount of trimming needed on carcass-processing lines and would increase the microbial safety of beef carcasses.

Bleaching optimization at WestRock mill in Covington, Virginia

TAPPI Journal ◽  
2016 ◽  
Vol 15 (9) ◽  
pp. 581-586 ◽  
Author(s):  
RICARDO B. SANTOS ◽  
PETER W. HART ◽  
DOUGLAS C. PRYKE ◽  
JOHN VANDERHEIDE
Keyword(s):  
Hydrogen Peroxide ◽  
Sodium Hydroxide ◽  
Chlorine Dioxide ◽  
Capital Expenditures ◽  
Equipment Repair ◽  
Optimization Program ◽  
Hardwood Pulp ◽  
Improved Performance

The WestRock mill in Covington, VA, USA, initiated a long term diagnostic and optimization program for all three of its bleaching lines. Benchmarking studies were used to help identify optimization opportunities. Capital expenditures for mixing improvement, filtrate changes, equipment repair, other equipment changes, and species changes were outside the scope of this work. This focus of this paper is the B line, producing southern hardwood pulp in a D(EP)DD sequence at 88% GE brightness. The benchmarking study and optimization work identified the following opportunities for improved performance: nonoptimal addition of caustic and hydrogen peroxide to the (EP) stage, carryover of D0 filtrate to the (EP) stage, and carryover of (EP) filtrate to the D1 stage. As a result of actions the mill undertook to address these opportunities, D0 kappa factor decreased about 5%, sodium hydroxide consumption in the (EP) stage decreased about 35%, chlorine dioxide consumption in the D1 stage decreased about 25%, and overall bleaching cost decreased about 15%.

scholarly journals Transformation of Contaminants of Emerging Concern (CECs) during UV-Catalyzed Processes Assisted by Chlorine

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1432
Author(s):  
Edyta Kudlek
Keyword(s):  
Hydrogen Peroxide ◽  
Water Samples ◽  
Water Environment ◽  
Toxicity Assessment ◽  
Contaminants Of Emerging Concern ◽  
Post Processing ◽  
Processing Water ◽  
Living Organisms ◽  
Trace Concentrations ◽  
By Products

Every compound that potentially can be harmful to the environment is called a Contaminant of Emerging Concern (CEC). Compounds classified as CECs may undergo different transformations, especially in the water environment. The intermediates formed in this way are considered to be toxic against living organisms even in trace concentrations. We attempted to identify the intermediates formed during single chlorination and UV-catalyzed processes supported by the action of chlorine and hydrogen peroxide or ozone of selected contaminants of emerging concern. The analysis of post-processing water samples containing benzocaine indicated the formation of seven compound intermediates, while ibuprofen, acridine and β-estradiol samples contained 5, 5, and 3 compound decomposition by-products, respectively. The number and also the concentration of the intermediates decreased with the time of UV irradiation. The toxicity assessment indicated that the UV-catalyzed processes lead to decreased toxicity nature of post-processed water solutions.

scholarly journals The projected impacts of smart decline on urban runoff contamination levels

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Rui Zhu ◽  
Galen Newman
Keyword(s):  
Land Use ◽  
Green Infrastructure ◽  
Prediction Models ◽  
Stormwater Runoff ◽  
Baseline Scenario ◽  
Vacant Land ◽  
Smart Decline ◽  
Contamination Levels ◽  
Indirect Impacts

AbstractThere has been mounting interest about how the repurposing of vacant land (VL) through green infrastructure (the most common smart decline strategy) can reduce stormwater runoff and improve runoff quality, especially in legacy cities characterized by excessive industrial land uses and VL amounts. This research examines the long-term impacts of smart decline on both stormwater amounts and pollutants loads through integrating land use prediction models with green infrastructure performance models. Using the City of St. Louis, Missouri, USA as the study area, we simulate 2025 land use change using the Conversion of Land Use and its Effects (CLUE-S) and Markov Chain urban land use prediction models and assess these change’s probable impacts on urban contamination levels under different smart decline scenarios using the Long-Term Hydrologic Impact Assessment (L-THIA) performance model. The four different scenarios are: (1) a baseline scenario, (2) a 10% vacant land re-greening (VLRG) scenario, (3) a 20% VLRG scenario, and (4) a 30% VLRG scenario. The results of this study illustrate that smart decline VLRG strategies can have both direct and indirect impacts on urban stormwater runoff and their inherent contamination levels. Direct impacts on urban contamination include the reduction of stormwater runoff and non-point source (NPS) pollutants. In the 30% VLRG scenario, the annual runoff volume decreases by 11%, both physical, chemical, and bacterial pollutants are reduced by an average of 19%, compared to the baseline scenario. Indirect impacts include reduction of the possibility of illegal dumping on VL through mitigation and prevention of future vacancies.

scholarly journals Biofilm reduction potential of 0.02% polyhexanide irrigation solution in several types of urethral catheters

BMC Urology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Florian H. H. Brill ◽  
Julia Hambach ◽  
Christian Utpatel ◽  
Diana C. Mogrovejo ◽  
Henrik Gabriel ◽  
...  
Keyword(s):  
Membrane Filtration ◽  
Saline Solution ◽  
Bacterial Biofilm ◽  
Plate Count ◽  
Vitro Assay ◽  
Significant Difference ◽  
Irrigation Solution ◽  
Clinically Relevant Bacteria

Abstract Background Long-term use of urethral catheters is associated with high risk of urinary tract infection (UTI) and blockage. Microbial biofilms are a common cause of catheter blockage, reducing their lifetime and significantly increasing morbidity of UTIs. A 0.02% polyhexanide irrigation solution developed for routine mechanical rinsing shows potential for bacterial decolonization of urethral catheters and has the potential to reduce or prevent biofilm formation. Methods Using an in vitro assay with standard market-leading types of catheters artificially contaminated with clinically relevant bacteria, assays were carried out to evaluate the biofilm reduction and prevention potential of a 0.02% polyhexanide solution versus no intervention (standard approach) and irrigation with saline solution (NaCl 0.9%). The efficiency of decolonization was measured through microbial plate count and membrane filtration. Results Irrigation using a 0.02% polyhexanide solution is suitable for the decolonization of a variety of transurethral catheters. The effect observed is significant compared to irrigation with 0.9% saline solution (p = 0.002) or no treatment (p = 0.011). No significant difference was found between irrigation with 0.9% saline solution and no treatment (p = 0.74). Conclusions A 0.02% polyhexanide solution is able to reduce bacterial biofilm from catheters artificially contaminated with clinically relevant bacteria in vitro. The data shows a reduction of the viability of thick bacterial biofilms in a variety of commercially available urinary catheters made from silicone, latex-free silicone, hydrogel-coated silicone and PVC. Further research is required to evaluate the long-term tolerability and efficacy of polyhexanide in clinical practice.

Enhanced Long-Term Color Stability of Teeth Treated with Hydrogen Peroxide and Non-Thermal Atmospheric Pressure Plasma Jets

2014 ◽  
Vol 11 (11) ◽  
pp. 1010-1017 ◽  
Author(s):  
Seoul Hee Nam ◽  
Hyun Wook Lee ◽  
Jin Woo Hong ◽  
Hae June Lee ◽  
Gyoo Cheon Kim
Keyword(s):  
Hydrogen Peroxide ◽  
Atmospheric Pressure ◽  
Atmospheric Pressure Plasma ◽  
Color Stability ◽  
Plasma Jets ◽  
Pressure Plasma

Long-term oral n-acetylcysteine reduces exhaled hydrogen peroxide in stable COPD

2005 ◽  
Vol 18 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Fernando De Benedetto ◽  
Antonio Aceto ◽  
Beatrice Dragani ◽  
Antonella Spacone ◽  
Stefano Formisano ◽  
...  
Keyword(s):  
Hydrogen Peroxide

Long term durability of crosslinked polyethylene tubing used in chlorinated hot water systems

1999 ◽  
Vol 28 (6) ◽  
pp. 309-313 ◽  
Author(s):  
T.S. Gill ◽  
R.J. Knapp ◽  
S.W. Bradley ◽  
W.L. Bradley
Keyword(s):  
Water Systems ◽  
Hot Water ◽  
Polyethylene Tubing
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