Automatic environmental disinfection with hydrogen peroxide and silver ions versus manual environmental disinfection with sodium hypochlorite: a multicentre randomized before-and-after trial

2017 ◽  
Vol 97 (2) ◽  
pp. 175-179 ◽  
Author(s):  
D. Mosci ◽  
G.W. Marmo ◽  
L. Sciolino ◽  
C. Zaccaro ◽  
R. Antonellini ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Sodium Hypochlorite ◽  
Silver Ions ◽  
Before And After ◽  
Environmental Disinfection

scholarly journals Evaluation of the efficiency of some disinfectants on the viability of Hymenolepis nana eggs isolated from wastewater and faecal sludge in Yaounde (Cameroon): importance of some abiotic variables

2021 ◽  
Author(s):  
Fotseu Kouam Arnold Landry ◽  
Ajeagah Gideon Aghaindum ◽  
Amoah Isaac Dennis ◽  
Okoa Amougou Thérèse Nadège ◽  
Tsomene Namekong Pierre
Keyword(s):  
Hydrogen Peroxide ◽  
Sodium Hypochlorite ◽  
Optical Microscope ◽  
Parasitic Infections ◽  
Contributory Factor ◽  
Chemical Parameters ◽  
Hymenolepis Nana ◽  
Physico Chemical ◽  
Before And After ◽  
Set Up

Abstract Hymenolepis nana is responsible for many parasitic infections in tropical areas, with its persistence in aquatic environments as major contributory factor. A study aimed at demonstrating the effectiveness of some disinfectants on the viability of Hymenolepis nana eggs was conducted in microcosm. Sampling consisted of taking wastewater and sewage sludge samples in sterilized containers and then transporting to the laboratory of Hydrobiology and Environmental Sciences for the determination of Hymenolepis nana eggs using standard protocols. The experimental set-up consisted of five replicates, four tests and a control. The test samples were successively treated with four disinfectants (calcium chlorite, hydrogen peroxide, gypsum and sodium hypochlorite). The physico-chemical parameters were measured before and after disinfection. The samples were then observed under an optical microscope after concentration of the sample through sedimentation and McMaster technique. The viability of the eggs was determined using incubation and staining techniques. The analysis revealed that, the selected disinfectants significantly reduced the physico-chemical parameters with an average yield ranging from 79.24 ± 19.43% to 99.24 ± 1.47%). These physico-chemical parameters can significantly influence the treatment of Hymenolepis nana eggs either by absorbing the disinfectant or by constituting a protective barrier for the eggs, and the physico-chemical nature of the disinfectant strongly influences the formation of disinfection by-products. Calcium chlorite showed a greater effectiveness in reducing eggs viability with efficiency rates of 93.12 ± 9.12% followed by hydrogen peroxide (89.57 ± 14.55%), sodium hypochlorite (82.51 ± 14.39%) and gypsum (80.85 ± 12.88%). The results obtained with gypsum are almost similar to those obtained with other disinfectants (calcium chlorite, hydrogen peroxide and sodium hypochlorite) and clearly show that this disinfectant can be used in water treatment because, unlike other chemical disinfectants, it has no known toxic effects.

scholarly journals Comparison of Various Cold Sterilization Techniques on Routinely used Carbide Burs and Diamond Points

2017 ◽  
Vol 7 (3) ◽  
pp. 97-102
Author(s):  
Suganthi Ranganathan ◽  
Chaitra Koppal Renukanath
Keyword(s):  
Hydrogen Peroxide ◽  
Sodium Hypochlorite ◽  
Culture Media ◽  
Brain Heart Infusion ◽  
Control Group ◽  
Microbial Count ◽  
Group I ◽  
Significant Difference ◽  
Before And After ◽  
Post Hoc

ABSTRACT Aim The aim of this study is to compare the various cold sterilization techniques for sterilizing dental burs and diamond points by assessing the microbial growth in culture media on them before and after sterilization. Materials and methods The following four disinfectants were used: 2% glutaraldehyde, 5.2% sodium hypochlorite, hydrogen peroxide, and 70% ethanol. There were two main groups taken as group I-carbide burs and group II-diamond burs. A total of 48 samples were collected, 12 samples per disinfectant. Each sample has two burs collected from same patient. One acts as control group which means only microbial count was deter- mined without disinfection. The other one would be determined as microbial count before and after disinfection. The microbial assessment was done using brain heart infusion (BHI) broth and counted by plating in chocolate blood agar and MacConkey agar. Results The obtained results were statistically analyzed by one-way analysis of variance (ANOVA) test and post hoc test. The results revealed that there was statistically significant difference between sodium hypochlorite and surgical spirit, sodium hypochlo- rite and hydrogen peroxide. There was no statistically significant difference between sodium hypochlorite and glutaraldehyde. Conclusion The results of this study revealed that sodium hypochlorite and glutaraldehyde are most effective than hydro- gen peroxide, and surgical spirit is the least effective disinfectant. However, there was clinical significance in level of disinfection of all four disinfectants. How to cite this article Ranganathan S, Manvi S, Gopalakrishna S, Renukanath CK. Comparison of Various Cold Sterilization Tech- niques on Routinely used Carbide Burs and Diamond Points. Int J Prosthodont Restor Dent 2017;7(3):97-102.

Antimicrobial Effect of 940 nm Diode Laser based on Photolysis of Hydrogen Peroxide in the Treatment of Periodontal Disease

2018 ◽  
Vol 69 (8) ◽  
pp. 2081-2088 ◽  
Author(s):  
Alin Alexandru Odor ◽  
Edwin Sever Bechir ◽  
Deborah Violant ◽  
Victoria Badea
Keyword(s):  
Hydrogen Peroxide ◽  
Laser Therapy ◽  
Diode Laser ◽  
Antimicrobial Effect ◽  
The Other ◽  
Control Group ◽  
Group 4 ◽  
Periodontal Bacteria ◽  
Severe Periodontitis ◽  
Before And After

Moderate and severe periodontitis represents a challenge in the non-surgical periodontal therapy. Due to the lack of evidence regarding the antimicrobial effectiveness of 940 nm diode laser in periodontal treatment, this study aimed to evaluate the antimicrobial effect of hydrogen peroxide (H2O2) photolysis performed with 940 nm diode laser in the treatment of moderate and severe periodontitis. Twenty-five patients with 100 teeth were selected for this pilot study. The test teeth were randomly assigned to one of the four treatment groups: Group 1: scaling and root planning (SRP) (control group); and the following experimental groups: Group 2: H2O2; Group 3: 940 nm diode laser therapy; Group 4: 940 nm diode laser therapy and H2O2. Clinical examinations, like probing depth (PD), clinical attachment level (CAL) and bleeding on probing (BOP) were performed before and after the treatment. The microbiological evaluation, effectuated before and after the treatment, included nine periodontal bacteria species and investigated by means of real-time PCR assay. The clinical and bacterial differences in the tested groups, was assessed between control group and the other three experimental groups, as well as between the experimental groups. The total bacteria load was reduced for all four studied groups. Group 4 (diode laser + H2O2) showed significant bacterial reduction of the major periodontal bacteria like Pg., Tf., Td., Pi., Pm., Fn (p[0.001) than the other 3 groups (p]0.001). Also the periodontal clinical parameters, like PD, CAL and BOP showed a significant reduction after the photolysis of H2O2 with the 940 nm diode laser (p[0.001). Differences between tested groups showed a significant beneficial results in regard to Group 4.It is suggested that the photoactivation of H2O2 with the 940 nm diode laser can be used successfully in adjunctive to the non-surgical periodontal treatment as a bactericidal tool.

Decomposition of hydrogen peroxide on nickel-silver two-component catalyst

1984 ◽  
Vol 49 (10) ◽  
pp. 2222-2230 ◽  
Author(s):  
Viliam Múčka ◽  
Rostislav Silber
Keyword(s):  
Hydrogen Peroxide ◽  
Chemical Properties ◽  
Silver Ions ◽  
Surface Concentration ◽  
Chloride Ions ◽  
Nickel Silver ◽  
Silver Catalysts ◽  
Physico Chemical ◽  
Low Degree ◽  
Defective Crystal

The catalytic and physico-chemical properties of low-temperature nickel-silver catalysts with nickel oxide concentrations up to 43.8% (m/m) are examined via decomposition of hydrogen peroxide in aqueous solution. The mixed catalysts prepared at 250°C are composed of partly decomposed silver carbonate or oxide and nickel carbonate or hydroxide decomposed to a low degree only and exhibiting a very defective crystal structure. The activity of these catalysts is determined by the surface concentration of silver ions, which is affected by the nickel component present. The latter also contributes to the thermal stability of the catalytic centres of the silver component, viz. the Ag+ ions. The concentration of these ions varies with the temperature of the catalyst treatment, the activity varies qualitatively in the same manner, and the system approaches the Ag-NiO composition. The catalytic centres are very susceptible to poisoning by chloride ions. A previous exposition of the catalyst to a gamma dose of 10 kGy from a 60Co source has no measurable effect on the physico-chemical properties of the system.

Antimicrobial Effects of Novel H2O2-Ag+ Complex on Membrane Damage to Staphylococcus aureus,Escherichia coli and Salmonella typhimurium

2021 ◽  
Author(s):  
Bing Han ◽  
Xiaoyu Han ◽  
Mengmeng Ren ◽  
Yilin You ◽  
Jicheng Zhan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Hydrogen Peroxide ◽  
Staphylococcus Aureus ◽  
Salmonella Typhimurium ◽  
Membrane Damage ◽  
Bactericidal Effect ◽  
E Coli ◽  
Bacterial Cell Membrane ◽  
Time Kill ◽  
Environmental Disinfection

Diseases caused by harmful microorganisms pose a serious threat to human health. Safe and environment-friendly disinfectants are, therefore, essential in preventing and controlling such pathogens. This study aimed to investigate the antimicrobial activity and mechanism of a novel hydrogen peroxide and silver (H 2 O 2 -Ag + ) complex (HSC) in combatting Staphylococcus aureus ATCC 29213, Escherichia coli O157:H7 NCTC 12900 and Salmonella typhimurium SL 1344. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values against S. aureus were found to be 0.014 % H 2 O 2 -3.125 mg/L Ag + , while 0.028 % H 2 O 2 -6.25 mg/L Ag + for both E. coli and S. typhimurium . Results of the growth curve assay and time-kill trial suggest that the HSC could inhibit the growth of the tested bacteria, as 99.9 % of viable cells were killed following treatment at the 1 MIC for 3 h. Compared with Oxytech D10 disinfectant (0.25 % H 2 O 2 -5 mg/L Ag + ), the HSC exhibited better antibacterial efficacy at a lower concentration (0.045 % H 2 O 2 -10 mg/L Ag + ). The mechanism of antibacterial action of HSC was found including the disruption of the bacterial cell membrane, followed by entry into the bacteria cell to reduce intracellular adenosine triphosphate (ATP) concentration, and inhibit the activity of antioxidases, superoxide dismutase (SOD) and catalase (CAT). The enhanced bactericidal effect of hydrogen peroxide combined with silver indicates a potential for its application in environmental disinfection, particularly in the food industry.

The Influence of Purification of Ethyl Acrylate on the Properties of Cement Matrix

2010 ◽  
Vol 150-151 ◽  
pp. 1143-1151
Author(s):  
Chau Lee ◽  
Nian Fu Wang ◽  
Meng Xun Xiem
Keyword(s):  
Hydrogen Peroxide ◽  
Early Stage ◽  
Setting Time ◽  
Ethyl Acrylate ◽  
Cement Matrix ◽  
Strength Development ◽  
Final Setting Time ◽  
Before And After ◽  
Analysis Of Performance ◽  
Acrylate Polymer

This research mainly probes into the analysis of performance and assessment that ethyl acrylate polymer is applied to the cement matrix. The result shows that, before and after the purification, ethyl acrylate can increase the flowability of modified mortar, and with the increasing the dosage of polymer, the flowability is getting better. But if the dosage of hydrogen peroxide used to remove the residua alcohol is excessive, it is easy to cause high mortar viscosity, and that is unfavorable to the flowability. According to the setting time of the mortar under normal consistency, the result shows that the ethyl acrylate before the purification, has retarding effects on both initial and final setting time. With the increasing the dosage of polymer, it takes longer for both setting time. Besides, because hydrogen peroxide has accelerative effect, the purified ethyl acrylate can shorten the setting time of initial and final setting time. However, over dosage of hydrogen peroxide can easily lead to poor strength development in later stage. Using purified ethyl acrylate can overcome the shortcoming of lower strength of 3、7- day early stage. when hydrogen peroxide consumption is 0.5% of the total amount of acid and alcohol, the ethyl acrylate has the positive effect on improving the compressive strength. Finally, among the comprehensive assessments of the mortar testing results, EH0.5-0.1 has the significant effect of modification.

scholarly journals Impact of two disinfectants on detachment of Enterococcus faecalis from polythene in aquatic microcosm

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
C. Lontsi Djimeli ◽  
A. Tamsa Arfao ◽  
V Rossi ◽  
N Nsulem ◽  
V Raspal ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Cell Adhesion ◽  
Enterococcus Faecalis ◽  
Sodium Hypochlorite ◽  
Growth Phases ◽  
Planktonic Cells ◽  
Stationary Growth ◽  
Experimental Conditions ◽  
The Impact ◽  
Aquatic Microcosm

<p><strong>After cell adhesion processes in microcosm, the impact of sodium hypochlorite (NaOCl) and hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) on the detachment of <em>Enterococcus faecalis </em>from polythene fragments immersed in water under stationary and dynamic conditions was assessed. The abundance of planktonic cells was also evaluated. The density of <em>E. faecalis</em> adhered in absence of disinfectant fluctuated between 2 and 4 units (Log CFU/cm<sup>2</sup>). </strong><strong>After living in disinfected water, </strong><strong>the density of <em>E. faecalis</em> remained adhered to polythene sometimes reached 2 units (Log CFU/Cm<sup>2</sup>)</strong><strong>. </strong><strong>This highest abundance of cells remained adhered was recorded with cells coming from the lag, exponential and stationary growth phases in water treated with 0.5‰ NaOCl. In H<sub>2</sub>O<sub>2</sub> disinfected water, the highest value was recorded at all cells growth phases with 5‰ H<sub>2</sub>O<sub>2 </sub>concentration. Adhered <em>E. faecalis</em> cells have been sometimes completely or partially decimated respectively by NaOCl and H<sub>2</sub>O<sub>2</sub> treated water. Considering separately each experimental condition, it was noted that increasing the concentration of disinfectant caused a significant decrease (P≤0.01) in abundance of cells stay adhered after living in water disinfected by the two disinfectants. Changes in disinfectant concentrations in different experimental conditions had an impact on the detachment of <em>E. faecalis</em> cells from the substrates. </strong></p>

scholarly journals A Fuzzy MADM Approach for Selecting the Best Cyanide Removal Method from a Gold Mine Wastewater

2021 ◽  
Author(s):  
Mohammad Hayati ◽  
Seyed Mohammad Seyed Alizadeh Ganji ◽  
Seyed Hadi Shahcheraghi
Keyword(s):  
Hydrogen Peroxide ◽  
Decision Making ◽  
Sodium Hypochlorite ◽  
Fuzzy Topsis ◽  
Gold Mine ◽  
Calcium Hypochlorite ◽  
Gold Mines ◽  
Removal Method ◽  
Fuzzy Delphi ◽  
Cyanide Removal

Abstract The cyanidation process is the most common method applied for the extraction of gold and silver in the hydrometallurgy industry, in which, sodium cyanide is used as a leaching agent. Therefore, the wastewater of gold mines contains a wide variety of cyanide ions needing to be removed before these wastewaters can be discharged to the receiving environments. In this study, a fuzzy multi-attribute decision-making approach (Fuzzy Delphi AHP and Fuzzy TOPSIS) was used for selecting the best cyanide removal method from the wastewater of Muteh gold mine. According to the experts' opinion, three methods including calcium hypochlorite, hydrogen peroxide and sodium hypochlorite were selected as alternatives. Then, by introducing the criteria influencing decision making, including cyanide removal ability, cost of process, amount of material consumed, time, pH, ease of performance and safety, and performing separated experiments, the criteria for each of three methods were determined. Finally, sodium hypochlorite was proposed as the best method for eliminating cyanide from wastewater. It was found that the rank of methods was as sodium hypochlorite (0.517) > calcium hypochlorite (0.474) > hydrogen peroxide (0.463).

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