ControllingGiardiaspp. andCryptosporidiumspp. in drinking water by microbial reduction processes

2001 ◽  
Vol 28 (S1) ◽  
pp. 67-80 ◽  
Author(s):  
Gordon R Finch ◽  
Miodrag Belosevic
Keyword(s):  
Drinking Water ◽  
Ultraviolet Radiation ◽  
Chlorine Dioxide ◽  
Reduction Process ◽  
Microbial Reduction ◽  
Waterborne Diseases ◽  
Human Pathogens ◽  
Cryptosporidium Spp ◽  
Wide Range ◽  
Waterborne Viruses

Drinking water microbial reduction has evolved from simple, effective chlorination to control waterborne diseases such as cholera and typhoid fever to advanced systems using ozone, chlorine dioxide, ultraviolet radiation, and combinations of disinfectants to control waterborne diseases such as poliomyelitis, hepatitis, giardiasis, and cryptosporidiosis. Giardia spp. and Cryptosporidium spp. have posed a major challenge to the water industry from a variety of perspectives. They occur in low concentrations in source waters, their infective doses in humans are low when compared with typical waterborne viruses and bacteria, they are difficult to inactivate with chlorine compounds, and they are difficult to determine if they are dead when detected in the environment or after microbial reduction in water treatment. However, Giardia spp. and Cryptosporidium spp. are readily controlled by ozone or ultraviolet radiation over a wide range of water-quality conditions. Chlorine dioxide provides a simple alternative to chlorine in some circumstances. Using modern microbial reduction process design techniques such as the integrated disinfection design framework (IDDF) ensures the provision of drinking water with a low risk of transmitting human pathogens to the consumer.Key words: ozone, chlorine dioxide, chlorine, ultraviolet, disinfection, microbial reduction, drinking water, Giardia, Cryptosporidium, parasite.

Removal methods of nematoda contained in the effluent of activated carbon

2002 ◽  
Vol 2 (3) ◽  
pp. 183-190 ◽  
Author(s):  
N. Matsumoto ◽  
T. Aizawa ◽  
S. Ohgaki ◽  
T. Hirata ◽  
K. Toyooka ◽  
...  
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Ultraviolet Radiation ◽  
Uv Radiation ◽  
21St Century ◽  
Chlorine Dioxide ◽  
Membrane Filtration ◽  
Sand Filtration ◽  
Uv Dose ◽  
Physical Treatments

Effects of various alternative disinfectants, e.g. chlorine dioxide, ozone, ultraviolet radiation and chloramine, either alone or in combination with other physical treatments like sand filtration and membrane filtration, on the inactivation and removal of nematoda were studied. Ozone and chloramines were found to be effective for nematoda inactivation. Filtration alone was unable to remove nematoda completely. But the combination of UV radiation and sand filtration turned out to be very effective in the removal of nematoda from drinking water. 90% inactivation of nematoda needed a UV dose of (D10-value) 135 mJ/cm2, while 99% inactivation required 232.5 (135 + 97.5) mJ/cm2. This study was a part of a five-year national research project “Advanced Aqua Clean Technology for 21st Century” (ACT21).

scholarly journals Comparison of commercial analytical techniques for measuring chlorine dioxide in urban desalinated drinking water

2015 ◽  
Vol 13 (4) ◽  
pp. 970-984 ◽  
Author(s):  
T. A. Ammar ◽  
K. Y. Abid ◽  
A. A. El-Bindary ◽  
A. Z. El-Sonbati
Keyword(s):  
Drinking Water ◽  
Chlorine Dioxide ◽  
Distribution System ◽  
Analytical Techniques ◽  
Regulatory Compliance ◽  
Analytical Technique ◽  
Accuracy And Precision ◽  
Wide Range ◽  
Chlorine Dioxide Disinfection ◽  
Selection Of

Most drinking water industries are closely examining options to maintain a certain level of disinfectant residual through the entire distribution system. Chlorine dioxide is one of the promising disinfectants that is usually used as a secondary disinfectant, whereas the selection of the proper monitoring analytical technique to ensure disinfection and regulatory compliance has been debated within the industry. This research endeavored to objectively compare the performance of commercially available analytical techniques used for chlorine dioxide measurements (namely, chronoamperometry, DPD (N,N-diethyl-p-phenylenediamine), Lissamine Green B (LGB WET) and amperometric titration), to determine the superior technique. The commonly available commercial analytical techniques were evaluated over a wide range of chlorine dioxide concentrations. In reference to pre-defined criteria, the superior analytical technique was determined. To discern the effectiveness of such superior technique, various factors, such as sample temperature, high ionic strength, and other interferences that might influence the performance were examined. Among the four techniques, chronoamperometry technique indicates a significant level of accuracy and precision. Furthermore, the various influencing factors studied did not diminish the technique's performance where it was fairly adequate in all matrices. This study is a step towards proper disinfection monitoring and it confidently assists engineers with chlorine dioxide disinfection system planning and management.

The formation and control of emerging disinfection by-products of health concern

2009 ◽  
Vol 367 (1904) ◽  
pp. 4077-4095 ◽  
Author(s):  
Stuart W. Krasner
Keyword(s):  
Drinking Water ◽  
Chlorine Dioxide ◽  
Drinking Water Treatment ◽  
Treated Wastewater ◽  
Health Concern ◽  
Treatment Processes ◽  
Wide Range ◽  
And Control ◽  
Emerging Dbps ◽  
By Products

When drinking water treatment plants disinfect water, a wide range of disinfection by-products (DBPs) of health and regulatory concern are formed. Recent studies have identified emerging DBPs (e.g. iodinated trihalomethanes (THMs) and acids, haloacetonitriles, halonitromethanes (HNMs), haloacetaldehydes, nitrosamines) that may be more toxic than some of the regulated ones (e.g. chlorine- and bromine-containing THMs and haloacetic acids). Some of these emerging DBPs are associated with impaired drinking water supplies (e.g. impacted by treated wastewater, algae, iodide). In some cases, alternative primary or secondary disinfectants to chlorine (e.g. chloramines, chlorine dioxide, ozone, ultraviolet) that minimize the formation of some of the regulated DBPs may increase the formation of some of the emerging by-products. However, optimization of the various treatment processes and disinfection scenarios can allow plants to control to varying degrees the formation of regulated and emerging DBPs. For example, pre-disinfection with chlorine, chlorine dioxide or ozone can destroy precursors for N -nitrosodimethylamine, which is a chloramine by-product, whereas pre-oxidation with chlorine or ozone can oxidize iodide to iodate and minimize iodinated DBP formation during post-chloramination. Although pre-ozonation may increase the formation of trihaloacetaldehydes or selected HNMs during post-chlorination or chloramination, biofiltration may reduce the formation potential of these by-products.

Deep-Amplicon Sequencing(DAS) to evidence the presesence of human pathogens in drinking water

2020 ◽  
Author(s):  
Laura Moreno-Mesonero ◽  
Jorge García Hernández ◽  
Yolanda Moreno ◽  
PATRICIA SOLER
Keyword(s):  
Drinking Water ◽  
Amplicon Sequencing ◽  
Human Pathogens

Coagulation/flocculation/ultrafiltration for natural organic matter removal in drinking water production

2004 ◽  
Vol 4 (5-6) ◽  
pp. 215-222 ◽  
Author(s):  
A.R. Costa ◽  
M.N. de Pinho
Keyword(s):  
Drinking Water ◽  
Organic Matter ◽  
Natural Organic Matter ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane Surface ◽  
Water Production ◽  
Cellulose Acetate Membranes ◽  
Wide Range ◽  
Drinking Water Production

Membrane fouling by natural organic matter (NOM), namely by humic substances (HS), is a major problem in water treatment for drinking water production using membrane processes. Membrane fouling is dependent on membrane morphology like pore size and on water characteristics namely NOM nature. This work addresses the evaluation of the efficiency of ultrafiltration (UF) and Coagulation/Flocculation/UF performance in terms of permeation fluxes and HS removal, of the water from Tagus River (Valada). The operation of coagulation with chitosan was evaluated as a pretreatment for minimization of membrane fouling. UF experiments were carried out in flat cells of 13.2×10−4 m2 of membrane surface area and at transmembrane pressures from 1 to 4 bar. Five cellulose acetate membranes were laboratory made to cover a wide range of molecular weight cut-off (MWCO): 2,300, 11,000, 28,000, 60,000 and 75,000 Da. Severe fouling is observed for the membranes with the highest cut-off. In the permeation experiments of raw water, coagulation prior to membrane filtration led to a significant improvement of the permeation performance of the membranes with the highest MWCO due to the particles and colloidal matter removal.

Lead removal from drinking water - development and validation of point-of-use treatment devices

2002 ◽  
Vol 2 (5-6) ◽  
pp. 209-216
Author(s):  
R. Sublet ◽  
A. Boireau ◽  
V.X. Yang ◽  
M.-O. Simonnot ◽  
C. Autugelle
Keyword(s):  
Drinking Water ◽  
Fixed Bed ◽  
Field Testing ◽  
Lead Removal ◽  
Ministry Of Health ◽  
Point Of Use ◽  
Taste And Odor ◽  
Wide Range ◽  
Lead Levels ◽  
Safety Considerations

Two lead removal water filters were developed to lower lead levels in drinking water below 10 μg.L-1 in order to meet the new regulation given by the European Directive 98-83, applicable in December 2013. An appropriate adsorbent was selected through a stringent research program among a wide range of media, and is composed of a synthetic zeolite and an activated carbon. Two prototypes were developed: the first is a faucet-mounted filter which contains a fixed bed of the adsorbent and a hollow fiber bundle, while the second is an under-sink cartridge made of a porous extruded block of carbon and adsorbent. Both are able to treat at least 1,000 litres of any water containing on average 100 to 150 μg Pb.L-1, by lowering the lead concentration below 10 μg.L-1. Once their safety considerations were addressed by an independent laboratory according to the French Ministry of Health recommendations, 20 prototypes were installed at consumers' taps in northeastern France. Their performance in terms of lead removal, HPC control and bad taste and odor reduction was followed for 6 months. This field testing program resulted in the validation of both prototypes which meet the new French Ministry of Health recommendations and assures that the filtered water is fully ED 98-83 compliant. Their commercialization will be launched first in France in middle 2002.

scholarly journals The occurrence and control of waterborne viruses in drinking water treatment: a review

Chemosphere ◽  
2021 ◽  
pp. 130728
Author(s):  
Li Chen ◽  
Yang Deng ◽  
Shengkun Dong ◽  
Hong Wang ◽  
Pan Li ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Drinking Water Treatment ◽  
Waterborne Viruses ◽  
And Control

Occurrence of pathogenic microorganisms in the Saint Lawrence River (Canada) and comparison of health risks for populations using it as their source of drinking water

2000 ◽  
Vol 46 (6) ◽  
pp. 565-576 ◽  
Author(s):  
Pierre Payment ◽  
Aminata Berte ◽  
Michèle Prévost ◽  
Bruno Ménard ◽  
Benoît Barbeau
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Drinking Water Treatment ◽  
Fecal Coliforms ◽  
Giardia Infection ◽  
Bacterial Indicators ◽  
Treatment Practices ◽  
Water Treatment Plants ◽  
Wide Range ◽  
Annual Risk

A 300-km portion of the Saint Lawrence hydrological basin in the province of Québec (Canada) and 45 water treatment plants were studied. River water used by drinking water treatment plants was analyzed (6-L sample volumes) to determine the level of occurrence of bacterial indicators (total coliforms, fecal coliforms, and Clostridium perfringens) and pathogens (Giardia lamblia, Cryptosporidium, human enteric viruses). Pathogens and bacterial indicators were found at all sites at a wide range of values. Logistic regression analysis revealed significant correlations between the bacterial indicators and the pathogens. Physicochemical and treatment practices data were collected from most water treatment plants and used to estimate the level of removal of pathogens achieved under cold (0°C-4°C) and warm (20°C-25°C) water temperature conditions. The calculated removal values were then used to estimate the annual risk of Giardia infection using mathematical models and to compare the sites. The estimated range of probability of infection ranged from 0.75 to less than 0.0001 for the populations exposed. Given the numerous assumptions made, the model probably overestimated the annual risk, but it provided comparative data of the efficacy of the water treatment plants and thereby contributes to the protection of public health.Key words: public health, drinking water, health risk, pathogen occurrence.

scholarly journals Interaction between typical sulfonamides and bacterial diversity in drinking water

2018 ◽  
Vol 16 (6) ◽  
pp. 914-920 ◽  
Author(s):  
Qing Wu ◽  
Shuqun Li ◽  
Xiaofei Zhao ◽  
Xinhua Zhao
Keyword(s):  
Drinking Water ◽  
Community Structure ◽  
Microbial Community ◽  
Bacterial Community ◽  
Bacterial Diversity ◽  
Microbial Community Structure ◽  
Antibiotic Use ◽  
Community Diversity ◽  
Wide Range ◽  
Growth Of Bacteria

Abstract The abuse of antibiotics is becoming more serious as antibiotic use has increased. The sulfa antibiotics, sulfamerazine (SM1) and sulfamethoxazole (SMZ), are frequently detected in a wide range of environments. The interaction between SM1/SMZ and bacterial diversity in drinking water was investigated in this study. The results showed that after treatment with SM1 or SMZ at four different concentrations, the microbial community structure of the drinking water changed statistically significantly compared to the blank sample. At the genus level, the proportions of the different bacteria in drinking water may affect the degradation of the SM1/SMZ. The growth of bacteria in drinking water can be inhibited after the addition of SM1/SMZ, and bacterial community diversity in drinking water declined in this study. Furthermore, the resistance gene sul2 was induced by SM1 in the drinking water.

scholarly journals Kinome Expansion in theFusarium oxysporumSpecies Complex Driven by Accessory Chromosomes

mSphere ◽  
2018 ◽  
Vol 3 (3) ◽  
Author(s):  
Gregory A. DeIulio ◽  
Li Guo ◽  
Yong Zhang ◽  
Jonathan M. Goldberg ◽  
H. Corby Kistler ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Species Complex ◽  
Severe Disease ◽  
Cellular Responses ◽  
Human Pathogens ◽  
Content Type ◽  
Evolutionary Forces ◽  
Environmental Signal ◽  
Wide Range ◽  
Opportunistic Fungal Pathogen

ABSTRACTTheFusarium oxysporumspecies complex (FOSC) is a group of soilborne pathogens causing severe disease in more than 100 plant hosts, while individual strains exhibit strong host specificity. Both chromosome transfer and comparative genomics experiments have demonstrated that lineage-specific (LS) chromosomes contribute to the host-specific pathogenicity. However, little is known about the functional importance of genes encoded in these LS chromosomes. Focusing on signaling transduction, this study compared the kinomes of 12F. oxysporumisolates, including both plant and human pathogens and 1 nonpathogenic biocontrol strain, with 7 additional publicly available ascomycete genomes. Overall,F. oxysporumkinomes are the largest, facilitated in part by the acquisitions of the LS chromosomes. The comparative study identified 99 kinases that are present in almost all examined fungal genomes, forming the core signaling network of ascomycete fungi. Compared to the conserved ascomycete kinome, the expansion of theF. oxysporumkinome occurs in several kinase families such as histidine kinases that are involved in environmental signal sensing and target of rapamycin (TOR) kinase that mediates cellular responses. Comparative kinome analysis suggests a convergent evolution that shapes individualF. oxysporumisolates with an enhanced and unique capacity for environmental perception and associated downstream responses.IMPORTANCEIsolates ofFusarium oxysporumare adapted to survive a wide range of host and nonhost conditions. In addition,F. oxysporumwas recently recognized as the top emerging opportunistic fungal pathogen infecting immunocompromised humans. The sensory and response networks of these fungi undoubtedly play a fundamental role in establishing the adaptability of this group. We have examined the kinomes of 12F. oxysporumisolates and highlighted kinase families that distinguishF. oxysporumfrom other fungi, as well as different isolates from one another. The amplification of kinases involved in environmental signal relay and regulating downstream cellular responses clearly setsFusariumapart from otherAscomycetes. Although the functions of many of these kinases are still unclear, their specific proliferation highlights them as a result of the evolutionary forces that have shaped this species complex and clearly marks them as targets for exploitation in order to combat disease.

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