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.

Prevention of bacterial growth in a long-distance water supply system: control of disinfection capacity

2003 ◽  
Vol 3 (1-2) ◽  
pp. 223-225
Author(s):  
R. Fischeder ◽  
W. Weber
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
Redox Potential ◽  
Bacterial Growth ◽  
Chlorine Dioxide ◽  
System Control ◽  
Water Production ◽  
Long Distance ◽  
Growth Measurement ◽  
Drinking Water Production

Drinking water has to be wholesome and clean, free from chemical and, most of all, microbiological contaminants. The German Landeswasserversorgung (LW), a long distance water supplier, uses surface water and water influenced by surface water as well as groundwater for drinking water production. A combination of several treatment steps including flocculation, sedimentation, ozonation, in-line filtration and, finally, disinfection with chlorine dioxide guarantees a drinking water of perfect quality. Since the water transport through several main and subsidiary pipes of an overall length of about 500 kilometres can take up to four days, the disinfection capacity must be sufficient to prevent bacterial growth. Measurement of the redox potential in addition to measurement of chlorine dioxide concentrations has proved to be a helpful parameter for the surveillance of the disinfection capacity. Many years of experience show that keeping the redox potential above a level of 650 mV guarantees the prevention of bacterial growth and an efficient disinfection.

Enhanced removal of manganese in organic-rich surface water by combined sodium hypochlorite and potassium permanganate during drinking water treatment

RSC Advances ◽  
2015 ◽  
Vol 5 (35) ◽  
pp. 27970-27977 ◽  
Author(s):  
Wenzheng Yu ◽  
Luiza Campos ◽  
Tong Shi ◽  
Guibai Li ◽  
Nigel Graham
Keyword(s):  
Drinking Water ◽  
Organic Matter ◽  
Water Treatment ◽  
Surface Water ◽  
Potassium Permanganate ◽  
Sodium Hypochlorite ◽  
Drinking Water Treatment ◽  
High Concentration

Combination of KMnO4and NaClO is beneficial and synergistic for removing Mn2+in water with high concentration of organic matter.

Nanofiltration of colored surface water: Quebec's experience

2003 ◽  
Vol 3 (5-6) ◽  
pp. 15-22
Author(s):  
P. Kouadio ◽  
M. Tétrault
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
Membrane Fouling ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Quebec City ◽  
Water Regulation ◽  
Eastern Canada

Three colored surface water nanofiltration pilot-scale projects were conducted in the province of Quebec (eastern Canada), between November 2000 and March 2002, by the company H2O Innovation (2000) inc., for the municipalities of Lac Bouchette, Latulipe-et-Gaboury and Charlesbourg (now part of Quebec City). Results indicated that nanofiltration permeate quality has an advance on present drinking water regulation standard in Quebec, but important membrane fouling occurred. Fouling can be controlled by pretreatment and optimization of the operating conditions.

Occurrence of 1,4-dioxane and MTBE in drinking water sources in Japan

2006 ◽  
Vol 6 (2) ◽  
pp. 47-53 ◽  
Author(s):  
D. Simazaki ◽  
M. Asami ◽  
T. Nishimura ◽  
S. Kunikane ◽  
T. Aizawa ◽  
...  
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
Water Samples ◽  
Quality Standards ◽  
Raw Water ◽  
Water Quality Standards ◽  
Butyl Ether ◽  
Water Treatment Plants ◽  
Standard Value ◽  
Surface Water Samples

Nationwide surveys of 1,4-dioxane and methyl-t-butyl ether (MTBE) levels in raw water used for the drinking water supply were conducted at 91 water treatment plants in Japan in 2001 and 2002, prior to the revision of the drinking water quality standards. 1,4-dioxane was widely and continuously detected in raw water samples and its occurrence was more frequent and its concentrations higher in groundwater than in surface water. However, its maximum concentration in raw water was much lower than its new standard value (50 μg/L), which was determined as a level of 10−5 excessive cancer risk to humans. Trace levels of MTBE were also detected in several surface water samples.

Applying Bacteriological Parameters for Evaluating Underground Water Quality

1988 ◽  
Vol 20 (11-12) ◽  
pp. 425-428 ◽  
Author(s):  
H. T. El-Zanfaly ◽  
A. M. Shabaan
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Samples ◽  
Anaerobic Bacteria ◽  
Underground Water ◽  
Faecal Coliforms ◽  
Bacterial Pollution ◽  
Important Approach ◽  
Positive Results ◽  
Faecal Streptococci

A total of 111 water samples were drawn from 15 wells. These samples were subjected to bacteriological examinations to determine the suitability of the monitored wells as source for drinking water. Significant levels of bacterial pollution indicators were detected in the underground water samples during the period of study. Total bacterial counts ranged between 10-104CFU/ml. Faecal streptococci was the most common and detected in 9 6% of water samples. Lower percentages of samples (92, 55 and 45%) were contaminated with total coliforms, faecal coliforms and total clostridia, respectively. Faecal coliforms: faecal streptococci was less than 0.7 in 86% of the examined samples. Anaerobic bacteria were detected in the examined well water samples. Only 101 water samples were tested for anaerobic spore-formers and all showed positive results. Most examined wells do not meet the water quality standards for drinking water. Accordingly, the necessity of controllin bacterial pollution in ground-water through disinfection was clearly confirmed. Testing the underground water for more than one indicator represents an important approach for water quality assurance.

Barcelona's water supply improvement: the brine collector of the Llobregat river

1994 ◽  
Vol 30 (10) ◽  
pp. 221-227 ◽  
Author(s):  
Jordi Martín-Alonso
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Salt Mine ◽  
Water Production ◽  
Public Work ◽  
Drinking Water Production ◽  
Llobregat River

The Llobregat is a 156 km long river, which supplies 35% of the Barcelona's drinking water needs from the Sant Joan Despí Water Treatment Plant. Since the establishment of the Salt Mine Works in the Llobregat basin in 1923, a progressive salinization of the water sources has been recorded. The operation of the Brine Collector, as a public work carried out by Aigües de Barcelona (AGBAR), started in 1989; it enabled a very significant improvement in the quality of the surface water used for drinking-water production.

INDICATIONS OF SURFACE WATER CONTAMINATION OF DRINKING WATER IN THE SAGARMATHA NATIONAL PARK, NEPAL

2017 ◽  
Author(s):  
Klaus Neumann ◽  
◽  
Kirsten N. Nicholson ◽  
Carolyn B. Dowling ◽  
Leah Wood ◽  
...  
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
National Park ◽  
Water Contamination ◽  
Surface Water Contamination ◽  
Sagarmatha National Park

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.

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