EFFICACY OF CHLORINE DIOXIDE AND SODIUM HYPOCHLORITE IN REUSE WATER DISINFECTION

2018 ◽  
Vol 17 (3) ◽  
pp. 711-720 ◽  
Author(s):  
Leo Kunigk ◽  
Rubens Gedraite ◽  
Cynthia Jurkiewicz Kunigk
Keyword(s):  
Sodium Hypochlorite ◽  
Chlorine Dioxide ◽  
Water Disinfection ◽  
Reuse Water

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.

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 EFFECTS OF TEMPERATURE AND CHANGING DISINFECTANTS ON STEEL WATER PIPES CORROSION: CASE STUDY OF MASHHAD, IRAN

2020 ◽  
Vol 5 (2) ◽  
pp. 65-71
Author(s):  
Mobin Rahimi-Golkhandan ◽  
Shahnaz Danesh ◽  
Ali Davoodi
Keyword(s):  
Potassium Permanganate ◽  
Sodium Hypochlorite ◽  
Positive Impact ◽  
Water Disinfection ◽  
Decision Makers ◽  
Water Pipe ◽  
Steel Pipes ◽  
Water Pipes ◽  
Corrosion Of Steel ◽  
The Impact

Water pipe corrosion inflicts big health problems and financial damages to societies. Temperature, pH, type, and dosage of oxidants, and DO are some of the key factors that affect water pipe corrosion. The aim of this research is to assess the impacts of temperature (15 and 25oC), dosage of potassium permanganate (0, 1 and 2 mg/L) and sodium hypochlorite (0, 0.5 and 1 mg/L) on corrosion of steel pipes. To measure the corrosion of steel specimens, OCP, EIS and potentiodynamic polarization tests were conducted. The results showed a direct relationship between temperature and corrosion rate. A 10-degree raise in the temperature, caused a 25% increase in corrosion current density (CCD). Adding sodium hypochlorite to the solution, decreases CCD by around 50%. Moreover, potassium permanganate proved to have a positive impact on reducing CCD by up to 21%. The results demonstrate that simultaneous usage of NaClO and KMnO4 for water disinfection can have beneficial impact on corrosion of steel pipes. Finally, our analysis suggests that when combined with KMnO4, lower dosage of NaClO significantly increases polarization resistance. The findings of this research highlight the impact of disinfectants on steel water pipes corrosion in different temperatures and supports water infrastructure decision-makers in more effective rehabilitation and maintenance of water pipes. Further, our results inform decision-makers for a more effective infrastructure design and resilience planning to random failures caused by corrosion.

Disinfection By-Products (DBPs) in Drinking Water from Eight Systems Using Chlorine Dioxide

2008 ◽  
Vol 43 (1) ◽  
pp. 11-22 ◽  
Author(s):  
Rocio Aranda Rodriguez ◽  
Boniface Koudjonou ◽  
Brian Jay ◽  
Guy L. LeBel ◽  
Frank M. Benoit
Keyword(s):  
Drinking Water ◽  
Chlorine Dioxide ◽  
Distribution System ◽  
Cold Water ◽  
Spatial Variations ◽  
Water Disinfection ◽  
Limited Information ◽  
Disinfection Process ◽  
The One ◽  
By Products

Abstract A study was initiated to determine the presence of organic disinfection by-products (DBPs) in drinking water treated with chlorine dioxide (ClO2). One potential advantage for the use of ClO2 as a disinfectant is the reduced formation of organic DBPs. Generally, water treated with ClO2 produces chlorite and chlorate ions, but there is limited information regarding the presence of halogenated organic DBPs. Eight systems that use chlorine dioxide as part of the water disinfection process were investigated. All systems in this study applied chlorine as a primary or secondary disinfectant in addition to ClO2. To evaluate seasonal and spatial variations, water samples were collected during cold water (February to March 2003) and warm water (July to August 2003) months at five sites for each system: raw water (R, before treatment), treated water (T, after treatment but before distribution), and three points along the same distribution line (D1, D2, D3). Sampling and analysis were conducted according to established protocols. A suite of 27 organic DBPs including haloacetic acids (HAA), trihalomethanes (THM), haloacetonitriles (HAN), haloketones, haloacetaldehydes (HA), chloropicrin, and cyanogen chloride were examined. In addition, the concentration of oxyhalides (chlorite and chlorate ions) and auxiliary parameters were also determined. Chlorite was found in treated (T) and distributed (Dx) waters. The chlorite ion levels decreased along the distribution system (T > D1 > D2 > D3). At T sites, the levels ranged from 10 to 870 µg/L (winter), and from 300 to 1,600 µg/L (summer). Chlorite was not found in treated or distributed water in the one system that used ozone. Chlorate ion levels ranged from 20 to 310 µg/L (winter), and 80 to 318 µg/L (summer). Chlorate levels remained relatively constant throughout the distribution system. THM and eight HAA (HAA8) accounted for approximately 85% of the total DBPs (wt/wt) analyzed, followed by total HA (up to 7%) and HAN (3%). THM in distributed water were found at concentrations between 1.8 and 30.6 µg/L (winter), and 3.3 and 93.6 µg/L (summer). For HAA8, the levels ranged from 13 to 52 µg/L (winter), and 16 to 111 µg/L (summer). Chloral hydrate ranged from 0.2 to 5.2 µg/L (winter), and 0.4 to 12.2 µg/L (summer). The temporal and spatial variations observed in previous studies were confirmed in the current study as well.

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.

scholarly journals Disposal of waste generated during drinking water disinfection with electrolytic sodium hypochlorite

2019 ◽  
Vol 138 ◽  
pp. 01028
Author(s):  
A.Yu. Skryabin
Keyword(s):  
Sodium Hypochlorite ◽  
Large Scale ◽  
Environmental Safety ◽  
Water Disinfection ◽  
Scale Production ◽  
Table Salt ◽  
Electrolytic Production ◽  
Water Treatment Plants ◽  
Large Scale Production ◽  
Drinking Water Disinfection

The present article is concerned with the problems of recycling and reuse of waste generated in the electrolytic production of sodium hypochlorite at water treatment plants. New engineering solutions aimed at ensuring environmental safety and lack of waste during large-scale production of sodium hypochlorite from aqueous solutions of common table salt are recommended herein.

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.

Characterization of dissolved organic matter and disinfection characteristics of source water from the Pearl River

2007 ◽  
Vol 7 (2) ◽  
pp. 205-212
Author(s):  
Z.Y. Zhao ◽  
J.D. Gu ◽  
H.B. Li
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Chlorine Dioxide ◽  
Anthropogenic Activities ◽  
Apparent Molecular Weight ◽  
Water Disinfection ◽  
Size Exclusion ◽  
Pearl River ◽  
Source Water ◽  
Raw Water

Source water samples were collected from Guangzhou segment of Pearl River and filtered through Amicon® YC-05, YM-1, YM-3, YM-10, YM-30, YM-100 and ZM-500 membranes sequentially after pre-treatment. The apparent molecular weights of the 8 fractions were calibrated using high-performance size exclusion chromatograph (HPSEC) and they ranged from 0.36 to 182.6 kDa. These fractionated isolates and the raw water were disinfected by chlorine or chlorine dioxide to determine their disinfection characteristics. Results showed that apparent molecular weight of the main dissolved organic matter (DOM) in the RO isolate of water sample was less than 360 Da and this part of the DOM was mainly from anthropogenic activities and contamination of wastewater. RO fraction was the controlling factor for the raw water disinfection process according to the THMs concentrations detected. Disinfection by chlorine dioxide produced less THMs that by chlorine.

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