Back to pre-disinfection of highly polluted waters

2002 ◽  
Vol 2 (3) ◽  
pp. 219-226
Author(s):  
N. Narkis ◽  
A. Katz-Stoller
Keyword(s):  
Drinking Water ◽  
Chlorine Dioxide ◽  
Surface Waters ◽  
Pathogenic Microorganisms ◽  
Organic Substances ◽  
Ammonium Ions ◽  
Chlorine Disinfection ◽  
Main Disadvantage ◽  
Polluted Waters ◽  
By Products

The initial pre-disinfection was one of the stages that most contributed to the formation of a large number of halogenated disinfection by-products (DBPs). The threat and awareness to the formation of chlorine disinfection by-products, refrained from using pre-disinfection with chlorine in the treatment of contaminated raw waters, to be used as drinking water. The main purpose of this research was to study whether chlorine dioxide can be used for pre-disinfection in the treatment of highly polluted wastewaters and surface waters. Chlorine dioxide was found suitable, as a replacement for chlorine, for disinfection of water containing natural organic substances, effluents’ organic materials and ammonium ions, due to its advantages, and especially because it is an effective disinfectant for killing pathogenic microorganisms and destroying viruses. Chlorine dioxide does not form THMs and barely creates chloroorganic compounds. However, the main disadvantage of the chlorine dioxide is the creation of undesirable chlorite and chlorate ions, which are suspected of being toxic. This research showed that the undesirable chlorite ions can be removed completely by adding Fe+2, which reduces ClO2- to the harmless Cl-, and is oxidized to Fe+3, to form the ferric polyhydroxo complexes, that can be used as the flocculant, in the next flocculation step, for the achievement of safer drinking water.

Habitat Association of Klebsiella Species

1985 ◽  
Vol 6 (2) ◽  
pp. 52-58 ◽  
Author(s):  
Susan T. Bagley
Keyword(s):  
Drinking Water ◽  
Gastrointestinal Tract ◽  
Surface Waters ◽  
Industrial Effluents ◽  
Opportunistic Pathogen ◽  
Habitat Associations ◽  
Habitat Association ◽  
Klebsiella Species ◽  
Almost All ◽  
Polluted Waters

AbstractThe genus Klebsiella is seemingly ubiquitous in terms of its habitat associations. Klebsiella is a common opportunistic pathogen for humans and other animals, as well as being resident or transient flora (particularly in the gastrointestinal tract). Other habitats include sewage, drinking water, soils, surface waters, industrial effluents, and vegetation. Until recently, almost all these Klebsiella have been identified as one species, ie, K. pneumoniae. However, phenotypic and genotypic studies have shown that “K. pneumoniae” actually consists of at least four species, all with distinct characteristics and habitats. General habitat associations of Klebsiella species are as follows: K. pneumoniae—humans, animals, sewage, and polluted waters and soils; K. oxytoca—frequent association with most habitats; K. terrigena— unpolluted surface waters and soils, drinking water, and vegetation; K. planticola—sewage, polluted surface waters, soils, and vegetation; and K. ozaenae/K. rhinoscleromatis—infrequently detected (primarily with humans).

Understanding the Role of Chlorine and Ozone to Control Postharvest Diseases in Fruit and Vegetables: A Review

2020 ◽  
Vol 16 (4) ◽  
pp. 455-461
Author(s):  
Gabriela M. Baia ◽  
Otniel Freitas-Silva ◽  
Murillo F. Junior
Keyword(s):  
Chlorine Dioxide ◽  
Broad Spectrum ◽  
Fruits And Vegetables ◽  
Low Cost ◽  
Residual Effects ◽  
Pathogenic Microorganisms ◽  
Postharvest Diseases ◽  
Post Harvest ◽  
By Products

Fruits and vegetables are foods that come into contact with various types of microorganisms from planting to their consumption. A lack or poor sanitation of these products after harvest can cause high losses due to deterioration and/ or pathogenic microorganisms. There are practically no post-harvest fungicides or bactericides with a broad spectrum of action that have no toxic residual effects and are safe. However, to minimize such problems, the use of sanitizers is an efficient device against these microorganisms. Chlorine is the most prevalent sanitizing agent because of its broad spectrum, low cost and well-established practices. However, the inevitable formation of disinfection by-products, such as trihalomethanes (THMs) and haloacetic acids (HAAs), is considered one of the main threats to food safety. Alternative sanitizers, such as chlorine dioxide (ClO2) and ozone, are becoming popular as a substitute for traditional post-harvest treatments. Thus, this review addresses the use of chlorine, chlorine dioxide and ozone emphasizing aspects, such as usage, safe application, spectrum of action and legislation. In order to ensure the quality and safety of final products, the adoption of well-prepared sanitation and sanitation programs for post-harvest fruits and vegetables is essential.

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.

Disinfection by-products of chlorine dioxide (chlorite, chlorate, and trihalomethanes): Occurrence in drinking water in Qatar

Chemosphere ◽  
2016 ◽  
Vol 164 ◽  
pp. 649-656 ◽  
Author(s):  
Fatima Al-Otoum ◽  
Mohammad A. Al-Ghouti ◽  
Talaat A. Ahmed ◽  
Mohammed Abu-Dieyeh ◽  
Mohammed Ali
Keyword(s):  
Drinking Water ◽  
Chlorine Dioxide ◽  
By Products

Progress on Drinking Water Treatment with Chlorine Dioxide

2013 ◽  
Vol 848 ◽  
pp. 255-258 ◽  
Author(s):  
Yu Zhong Guo ◽  
Yan Zhen Yu ◽  
Ming Li ◽  
Guang Yong Yan
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Chlorine Dioxide ◽  
Drinking Water Treatment ◽  
Water Disinfection ◽  
Water Quality Standards ◽  
Water Pretreatment ◽  
Detection Technology ◽  
Filter Water ◽  
By Products

By the reason of strong responses activity and oxidation ability, Chlorine dioxide as oxidant and disinfectant has been applied to peroxidation and disinfection more and more widely.In this paper, it give an account of the preparation of chlorine dioxide, as oxidants to raw water pretreatment, used in filter water disinfection ,the detection technology of chlorine dioxide and disinfection by-products, the water quality standards formulated by domestic and overseas chlorine dioxide in using chlorine dioxide, and summarized progress on drinking water treatment with chlorine dioxide .

scholarly journals Deactivation of Caenorhabditis elegans nematodes in drinking water by PMS/UV-C: Efficiency and mechanisms

2021 ◽  
Author(s):  
Taoqin Chen ◽  
Jinzhe Li ◽  
Longqian Xu ◽  
Dong Zhang ◽  
Zheng Wang ◽  
...  
Keyword(s):  
Drinking Water ◽  
Caenorhabditis Elegans ◽  
Tap Water ◽  
Water Tank ◽  
Mechanism Study ◽  
Nematode Caenorhabditis Elegans ◽  
Chlorine Disinfection ◽  
Promising Strategy ◽  
Uv C ◽  
By Products

Abstract The occurrence an d infestations of chlorine-resistant invertebrates in drinking water distributions have attracted concerns on water quality in China, making effective deactivation imperative. This study presents a no vel strategy for nematode ( Caenorhabditis elegans ) deactivation using peroxymonosulfate (PMS)/UV-C. The results indicated that 100% deactivation efficiency was obtained under optimal conditions. An acidic pH and 0.25 mg/L Fe(II) were beneficial to the PMS/UV-C-triggered deactivation of nematodes. A mechanism study demonstrated that was activated by UV-C to produce · OH and · SO 4 - , which resulted in oxidative stress and stimulated the occurrence of cell apoptosis, leading to nematode deactivation. The results reveal PMS/UV-C as an alternative to chlorination in water treatment plants (WTP) or an emergency application when chlorine-resistant invertebrates breed in a second-supply water tank, is a promising strategy for disinfection. This approach afforded the advantages of avoiding the production of chlorine disinfection by-products (DBP) and greater efficacy of nematode deactivation. This work will provide ideas for on-going research efforts into chlorine-resistant invertebrate deactivation, and eventually achieve the direct drinking of municipal tap water.

Effects of combined calcium hypochlorite and chlorine dioxide on drinking water quality in Qatar and disinfection by-products formation

2017 ◽  
Vol 100 ◽  
pp. 333-339 ◽  
Author(s):  
Elsamoul H. Mohamed ◽  
Hassan I. Nimir ◽  
Joseph A. Cotruvo ◽  
Mustafa M. Osman
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Chlorine Dioxide ◽  
Drinking Water Quality ◽  
Calcium Hypochlorite ◽  
By Products
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