Comparison of Organic Tissue Dissolution Capacities of Sodium Hypochlorite and Chlorine Dioxide

2010 ◽  
Vol 36 (2) ◽  
pp. 272-274 ◽  
Author(s):  
Funda Kont Cobankara ◽  
Hatice Buyukozer Ozkan ◽  
Arslan Terlemez
Keyword(s):  
Sodium Hypochlorite ◽  
Chlorine Dioxide ◽  
Organic Tissue

Comparative evaluation of disinfection mechanism of sodium hypochlorite, chlorine dioxide and electroactivated water on Enterococcus faecalis

LWT ◽  
2019 ◽  
Vol 102 ◽  
pp. 205-213 ◽  
Author(s):  
Zeynep Girgin Ersoy ◽  
Ozge Dinc ◽  
Buse Cinar ◽  
Sedef Tunca Gedik ◽  
Anatoli Dimoglo
Keyword(s):  
Enterococcus Faecalis ◽  
Sodium Hypochlorite ◽  
Chlorine Dioxide ◽  
Comparative Evaluation

scholarly journals Oxidation of Citalopram with Sodium Hypochlorite and Chlorine Dioxide: Influencing Factors and NDMA Formation Kinetics

Molecules ◽  
2019 ◽  
Vol 24 (17) ◽  
pp. 3065
Author(s):  
Juan Lv ◽  
Yan Wang ◽  
Na Li
Keyword(s):  
Sodium Hypochlorite ◽  
Chlorine Dioxide ◽  
Wastewater Treatment Plants ◽  
Ph Value ◽  
High Reactivity ◽  
Secondary Effluent ◽  
Water Matrix ◽  
Formation Kinetics ◽  
Operational Variables ◽  
Two Stages

The highly prescribed antidepressant, citalopram, as one of newly emerging pollutants, has been frequently detected in the aquatic environment. Citalopram oxidation was examined during sodium hypochlorite (NaOCl) and chlorine dioxide (ClO2) chlorination processes since conventional wastewater treatment plants cannot remove citalopram effectively. Citalopram has been demonstrated to form N-nitrosodimethylamine (NDMA) during chlorination in our previous study. Further investigation on NDMA formation kinetics was conducted in the present study. Influences of operational variables (disinfectant dose, pH value) and water matrix on citalopram degradation, as well as NDMA generation, were evaluated. The results indicated high reactivity of citalopram with NaOCl and ClO2. NDMA formation included two stages during CIT oxidation, which were linear related with reaction time. NaOCl was more beneficial to remove CIT, but it caused more NDMA formation. Increasing disinfectant dosage promoted citalopram removal and NDMA formation. However, no consistent correlation was found between citalopram removal and pH. Contrary to the situation of citalopram removal, NDMA generation was enhanced when citalopram was present in actual water matrices, especially in secondary effluent. DMA, as an intermediate of citalopram chlorination, contributed to NDMA formation, but not the only way.

scholarly journals Ground and surface water for drinking: a laboratory study on genotoxicity using plant tests

2012 ◽  
Vol 1 (1) ◽  
pp. 7 ◽  
Author(s):  
Donatella Feretti ◽  
Elisabetta Ceretti ◽  
Bianca Gustavino ◽  
Ilaria Zerbini ◽  
Claudia Zani ◽  
...  
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
Sodium Hypochlorite ◽  
Chlorine Dioxide ◽  
Molar Ratio ◽  
Positive Effects ◽  
Genotoxic Potential ◽  
Micronucleus Tests ◽  
Products Of Reaction ◽  
Positive Results

Surface waters are increasingly utilized for drinking water because groundwater sources are often polluted. Several monitoring studies have detected the presence of mutagenicity in drinking water, especially from surface sources due to the reaction of natural organic matter with disinfectant. The study aimed to investigate the genotoxic potential of the products of reaction between humic substances, which are naturally present in surface water, and three disinfectants: chlorine dioxide, sodium hypochlorite and peracetic acid. Commercial humic acids dissolved in distilled water at different total organic carbon (TOC) concentrations were studied in order to simulate natural conditions of both ground water (TOC=2.5 mg/L) and surface water (TOC=7.5 mg/L). These solutions were treated with the biocides at a 1:1 molar ratio of C:disinfectant and tested for genotoxicity using the anaphase chromosomal aberration and micronucleus tests in <em>Allium cepa,</em> and the <em>Vicia faba</em> and <em>Tradescantia </em>micronucleus tests. The tests were carried out after different times and with different modes of exposure, and at 1:1 and 1:10 dilutions of disinfected and undisinfected humic acid solutions. A genotoxic effect was found for sodium hypochlorite in all plant tests, at both TOCs considered, while chlorine dioxide gave positive results only with the <em>A.cepa</em> tests. Some positive effects were also detected for PAA (<em>A.cepa</em> and <em>Tradescantia</em>). No relevant differences were found in samples with different TOC values. The significant increase in all genotoxicity end-points induced by all tested disinfectants indicates that a genotoxic potential is exerted even in the presence of organic substances at similar concentrations to those frequently present in drinking water.

Effect of Passive Ultrasonic Activation on Organic Tissue Dissolution from Simulated Grooves in Root Canals Using Sodium Hypochlorite with or without Surfactants and EDTA

2017 ◽  
Vol 43 (7) ◽  
pp. 1161-1165 ◽  
Author(s):  
Roberto Estevez ◽  
Antonio J. Conde ◽  
Oliver Valencia de Pablo ◽  
Francisco de la Torre ◽  
Giampiero Rossi-Fedele ◽  
...  
Keyword(s):  
Sodium Hypochlorite ◽  
Ultrasonic Activation ◽  
Root Canals ◽  
Organic Tissue

An Evaluation of Historical Bleaching with Chlorine Dioxide Gas, Sodium Hypochlorite, and Chloramine-T at the Fogg Art Museum

2012 ◽  
Vol 33 (3-4) ◽  
Author(s):  
Theresa Smith
Keyword(s):  
Twentieth Century ◽  
Formic Acid ◽  
Sodium Hypochlorite ◽  
Chlorine Dioxide ◽  
Art Museum ◽  
Sodium Chlorite ◽  
Chlorine Dioxide Gas ◽  
Brightness Reversion ◽  
Chloramine T

AbstractIn the mid-twentieth century, drawings by Jean-Auguste-Dominique Ingres at the Fogg Art Museum were treated with chemical bleaches such as chlorine dioxide gas, sodium hypochlorite, and chloramine-T. Fifty years later, the darkened condition of the drawings was attributed to bleaching with chlorine dioxide gas. This paper discusses the three methods developed by Rutherford John Gettens to generate chlorine dioxide gas from sodium chlorite, formaldehyde and formic acid, examines the use of these bleaching methods to treat Ingres drawings at the Fogg, and discusses the sodium hypochlorite and chloramine-T bleaching methods also in use at the time. The treatments of two Ingres drawings are compared and evaluated in light of later bleaching studies and the current condition of each drawing. All of these historical bleaching methods, as practiced on the works studied, contributed to the darkening and colour/brightness reversion of drawings.

Degradation of herbicides (ametryn and isoproturon) during water disinfection by means of two oxidants (hypochlorite and chlorine dioxide)

1997 ◽  
Vol 35 (4) ◽  
pp. 129-136 ◽  
Author(s):  
A. Lopez ◽  
G. Mascolo ◽  
G. Tiravanti ◽  
R. Passino
Keyword(s):  
Aqueous Solution ◽  
Reaction Time ◽  
Sodium Hypochlorite ◽  
Chlorine Dioxide ◽  
Hydrolysis Product ◽  
Water Disinfection ◽  
Experimental Conditions ◽  
Molar Ratios ◽  
Chemical Structures ◽  
Opposite Trend

The paper reports the results of an investigation aimed to find out the number and the chemical structures of byproducts which form during the reactions occurring in aqueous solution between two very common disinfectants, sodium hypochlorite (NaClO) and chlorine dioxide (ClO2), and two herbicides widely used in agriculture and frequently found in groundwaters: ametryn and isoproturon. Under controlled experimental conditions [T=20°C, pH=7, reaction-time = 48h, herbicide/disinfectant molar ratios: 0.05 and 0.05×10−2], ametryn reactions with chlorine dioxide much slower than with sodium hypochlorite, whereas the opposite trend has been observed for isoproturon. In any case, however, the higher the reagents concentration the faster the reactions. As for reaction byproducts, they have been detected by HPLC and identified by HPLC-MS. In particular, ametryn (R-S-CH3) reaction with NaClO gives rise to the consecutive formation of four derivatives: the sulphoxide (R-SO-CH3), the sulphone (R-SO2-CH3), the sulphonate ester (R-O-SO2-CH3) and its hydrolysis product (R-OH). Within the fixed reaction time (48h), ametryn reaction with ClO2 forms only the sulphoxide derivative (R-SO-CH3). As for isoproturon, it reacts with both oxidants forming aromatic-ring substituted derivatives. In particular, during the reactions with NaClO and ClO2, four and two (chlorinated and/or hydroxylated) derivatives are respectively formed.

Reduction of Listeria monocytogenes and Salmonella Typhimurium on Blueberries through Brief Exposure to Antimicrobial Solutions Coupled with Freezing

2019 ◽  
Vol 82 (6) ◽  
pp. 926-930 ◽  
Author(s):  
DAVID F. BRIDGES ◽  
SHRAVANI TADEPALLI ◽  
RYAN ANDERSON ◽  
RONG ZHANG ◽  
VIVIAN C. H. WU
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Salmonella Typhimurium ◽  
Sodium Hypochlorite ◽  
Chlorine Dioxide ◽  
Acid Treatment ◽  
Frozen Storage ◽  
Short Exposure ◽  
Antimicrobial Effectiveness

ABSTRACT This study evaluated the efficacy of different brief-exposure antibacterial washes (≤3 min) coupled with frozen storage against Listeria monocytogenes and Salmonella Typhimurium on blueberries. Inoculated berries where treated with sodium hypochlorite (NaOCl, 200 ppm), chlorine dioxide (15 ppm), ozone (3 and 5 ppm), or lactic acid (2%) for short exposure times (10 s, 1 min, or 3 min), and antibacterial effectiveness was determined with or without an additional freezing hurdle (−12°C, 1 week). Wash treatments alone resulted maximum log reductions from 1.0 to 2.8, while the additional freezing step increased this to a range from 3.7 to 6.6. The greatest reduction of L. monocytogenes (6.6 log) and Salmonella Typhimurium (5.3 log) was observed after freezing combined with 3 min of exposure to 2% lactic acid or 200 ppm of NaOCl, respectfully. After treatment, no residue was measured by the methodologies used. However, lactic acid treatment resulted in changes of color and aroma. In conclusion, wash treatments of blueberries using short exposure times had antimicrobial effectiveness (1.0 to 2.8 log reductions) and can be enhanced by coupling with freezing. HIGHLIGHTS

Removal of Organic Micropollutants from Contaminated Groundwater by Oxidation and Stripping

1987 ◽  
Vol 22 (1) ◽  
pp. 187-196 ◽  
Author(s):  
L. Simovic ◽  
J.P. Jones
Keyword(s):  
Hydrogen Peroxide ◽  
Sodium Hypochlorite ◽  
Chlorine Dioxide ◽  
Chemical Oxidation ◽  
Appropriate Technology ◽  
Contaminated Groundwater ◽  
Organic Micropollutants ◽  
Air Stripping ◽  
Groundwater Samples ◽  
Iron Sulphate

Abstract In 1984, Environment Canada carried out a bench scale study on the removal of organic micropollutants from contaminated groundwater. The groundwater samples were obtained from the Special Waste Compound at Gloucester Landfill Site, near Ottawa, Ontario. The objective of the study was to evaluate the effectiveness of chemical oxidation to destroy the organic micropollutants present in this groundwater. Comparison was made between the results of ozonation and the air stripping effects. The oxidants evaluated were ozone (O3), sodium hypochlorite (NaOCl), chlorine dioxide (ClO2) and hydrogen peroxide (H2O2) with hydrated iron sulphate FeSO4 7H2O (Fenton’s reagent). The organics present in the contaminated groundwater included the following, predominantly volatile, compounds: bromodichloro-methane, bromoform, 1,1,1-trichloroethane, chloroform, 1,1-dichloroethane, dichloromethane, 1,2-dichloroethane, 1,1-dichloroethylene, and trichloroethylene. The process variables investigated were pH and oxidant dosage. The significance of low and high values of these variables was examined by using a full 22 factorial design. From the results, it appeared that the best removal efficiency was achieved by using ozone as an oxidant. However, during the experiments, it was observed that the ozonation process was being confounded with the air stripping process. Chlorine dioxide and hydrogen peroxide, in that order, were determined to be less effective oxidants. Sodium hypochlorite was found to be the least effective oxidant in this study. The results of this study demonstrated that air stripping was the most appropriate technology for the removal of the organic compounds from this groundwater.

Sign in / Sign up

Export Citation Format

Share Document