Special Issue "Water Microbial Pollution and Disinfection"

A special issue of International Journal of Environmental Research and Public Health (ISSN 1660-4601).

Deadline for manuscript submissions: closed (31 December 2015).

Special Issue Editors

Prof. Nicholas Frederick Gray
Website
Guest Editor
Trinity Centre for the Environment, School of Natural Sciences, Trinity College, University of Dublin, Dublin 2, Ireland
Interests: biological wastewater treatment; river pollution control and assessment; drinking water treatment; sustainability
Special Issues and Collections in MDPI journals
Prof. Dr. Panagiotis Karanis
Website
Guest Editor
University of Nicosia Medical School, CY-1700, Nicosia, Cyprus
Interests: water-borne pathogens; waste and drinking water treatment; outbreaks; disinfection; public health; climate changes and infectious diseases; diagnostic techniques and detection
Special Issues and Collections in MDPI journals

Special Issue Information

Dear colleagues,

For nearly a century, both wastewater and water treatment have had a similar and clear objectives, which is the protection of public health by the reduction and disinfection of pathogens in the human water cycle, the so-called barrier approach to public health.  However, with emphasis in wastewater treatment increasingly focused on environmental protection during the 1970s, the concept of pathogen control became a secondary, almost forgotten, objective. The failure to set microbial emission standards on effluents discharged from wastewater treatment plants is a reflection of this. The introduction of universal drinking water quality standards at about the same time, incorporating physico-chemical standards, also meant that water treatment priorities and practices were altered, with a greater reliance on water disinfection to deal with any pathogen threat, which has led to some notable treatment failures, resulting in major pathogen outbreaks. Today, new technologies are offering exciting possibilities to deal with pathogens more effectively.

However, the threat to our water supplies from waterborne pathogens, including plant and livestock pathogens, is greater than ever. New pathogens are constantly emerging and the threat from plasmid transfer during wastewater treatment increasing antibiotic resistance in bacterial pathogens, global travel, intensive agriculture, and proliferation of rural housing have all have increased the pressure on our water treatment plants in terms of pathogen reduction. The use of indicator organisms has proven to be unreliable, especially when predicting the presence of other pathogens, such as the protozoan pathogens and viruses.   While the adoption of water security and safety plans have made a significant difference in the control of pathogens, a rapidly growing global family, increasing water demand that is leading to water scarcity and an increasing reliance on water reuse, we are at critical levels of risk from waterborne pathogens.

You are invited to contribute to help create a unique dialogue that aims to explore the problems and propose the solutions to supplying safe, pathogen-free, drinking water in a rapidly changing society and planet.

Prof. Dr. Nicholas Frederick Gray
Prof. Dr. Panagiotis Karanis
Guest Editors

Manuscript Submission Information

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Keywords

  • waterborne pathogens
  • public health
  • wastewater treatment
  • drinking water
  • disinfection techniques
  • water treatment and supply
  • water safety plans
  • risk assessment

Published Papers (13 papers)

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Research

Open AccessArticle
Use of Walnut Shell Powder to Inhibit Expression of Fe2+-Oxidizing Genes of Acidithiobacillus Ferrooxidans
Int. J. Environ. Res. Public Health 2016, 13(5), 461; https://doi.org/10.3390/ijerph13050461 - 30 Apr 2016
Cited by 3
Abstract
Acidithiobacillus ferrooxidans is a Gram-negative bacterium that obtains energy by oxidizing Fe2+ or reduced sulfur compounds. This bacterium contributes to the formation of acid mine drainage (AMD). This study determined whether walnut shell powder inhibits the growth of A. ferrooxidans. First, [...] Read more.
Acidithiobacillus ferrooxidans is a Gram-negative bacterium that obtains energy by oxidizing Fe2+ or reduced sulfur compounds. This bacterium contributes to the formation of acid mine drainage (AMD). This study determined whether walnut shell powder inhibits the growth of A. ferrooxidans. First, the effects of walnut shell powder on Fe2+ oxidization and H+ production were evaluated. Second, the chemical constituents of walnut shell were isolated to determine the active ingredient(s). Third, the expression of Fe2+-oxidizing genes and rus operon genes was investigated using real-time polymerase chain reaction. Finally, growth curves were plotted, and a bioleaching experiment was performed to confirm the active ingredient(s) in walnut shells. The results indicated that both walnut shell powder and the phenolic fraction exert high inhibitory effects on Fe2+ oxidation and H+ production by A. ferrooxidans cultured in standard 9K medium. The phenolic components exert their inhibitory effects by down-regulating the expression of Fe2+-oxidizing genes and rus operon genes, which significantly decreased the growth of A. ferrooxidans. This study revealed walnut shell powder to be a promising substance for controlling AMD. Full article
(This article belongs to the Special Issue Water Microbial Pollution and Disinfection)
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Open AccessArticle
Isolation and Characterization of Aquatic-Borne Klebsiella pneumoniae from Tropical Estuaries in Malaysia
Int. J. Environ. Res. Public Health 2016, 13(4), 426; https://doi.org/10.3390/ijerph13040426 - 15 Apr 2016
Cited by 8
Abstract
Klebsiella pneumoniae is an opportunistic pathogen that is responsible for causing nosocomial and community-acquired infections. Despite its common presence in soil and aquatic environments, the virulence potential of K. pneumoniae isolates of environmental origin is largely unknown. Hence, in this study, K. pneumoniae [...] Read more.
Klebsiella pneumoniae is an opportunistic pathogen that is responsible for causing nosocomial and community-acquired infections. Despite its common presence in soil and aquatic environments, the virulence potential of K. pneumoniae isolates of environmental origin is largely unknown. Hence, in this study, K. pneumoniae isolated from the estuarine waters and sediments of the Matang mangrove estuary were screened for potential virulence characteristics: antibiotic susceptibility, morphotype on Congo red agar, biofilm formation, presence of exopolysaccharide and capsule, possession of virulence genes (fimH, magA, ugE, wabG and rmpA) and their genomic fingerprints. A total of 55 strains of K. pneumoniae were isolated from both human-distributed sites (located along Sangga Besar River) and control sites (located along Selinsing River) where less human activity was observed, indicated that K. pneumoniae is ubiquitous in the environment. However, the detection of potentially virulent strains at the downstream of Kuala Sepetang village has suggested an anthropogenic contamination source. In conclusion, the findings from this study indicate that the Matang mangrove estuary could harbor potentially pathogenic K. pneumoniae with risk to public health. More studies are required to compare the environmental K. pneumoniae strains with the community-acquired K. pneumoniae strains. Full article
(This article belongs to the Special Issue Water Microbial Pollution and Disinfection)
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Open AccessArticle
Chitosan Coagulation to Improve Microbial and Turbidity Removal by Ceramic Water Filtration for Household Drinking Water Treatment
Int. J. Environ. Res. Public Health 2016, 13(3), 269; https://doi.org/10.3390/ijerph13030269 - 27 Feb 2016
Cited by 24
Abstract
The use of porous ceramic filters is promoted globally for household water treatment, but these filters are ineffective in removing viruses from water. In order to increase virus removal, we combine a promising natural coagulant, chitosan, as a pretreatment for ceramic water filters [...] Read more.
The use of porous ceramic filters is promoted globally for household water treatment, but these filters are ineffective in removing viruses from water. In order to increase virus removal, we combine a promising natural coagulant, chitosan, as a pretreatment for ceramic water filters (CWFs) and evaluate the performance of this dual barrier water treatment system. Chitosan is a non-toxic and biodegradable organic polymer derived by simple chemical treatments from chitin, a major source of which is the leftover shells of crustacean seafoods, such as shrimp, prawns, crabs, and lobsters. To determine the effectiveness of chitosan, model test water was contaminated with Escherichia coli K011 and coliphage MS2 as a model enteric bacterium and virus, respectively. Kaolinite clay was used to model turbidity. Coagulation effectiveness of three types of modified chitosans was determine at various doses ranging from 5 to 30 mg/L, followed by flocculation and sedimentation. The pre-treated supernatant water was then decanted into the CWF for further treatment by filtration. There were appreciable microbial removals by chitosan HCl, acetate, and lactate pretreatment followed by CWF treatment, with mean reductions (95% CI) between 4.7 (±1.56) and 7.5 (±0.02) log10 for Escherichia coli, and between 2.8 (±0.10) and 4.5 (±1.04) log10 for MS2. Turbidity reduction with chitosan treatment and filtration consistently resulted in turbidities < 1 NTU, which meet turbidity standards of the US EPA and guidance by the World Health Organization (WHO). According to WHO health-based microbial removal targets for household water treatment technology, chitosan coagulation achieved health protective targets for both viruses and bacteria. Therefore, the results of this study support the use of chitosan to improve household drinking water filtration processes by increasing virus and bacteria reductions. Full article
(This article belongs to the Special Issue Water Microbial Pollution and Disinfection)
Open AccessArticle
Behavior Change without Behavior Change Communication: Nudging Handwashing among Primary School Students in Bangladesh
Int. J. Environ. Res. Public Health 2016, 13(1), 129; https://doi.org/10.3390/ijerph13010129 - 14 Jan 2016
Cited by 38
Abstract
Behavior change communication for improving handwashing with soap can be labor and resource intensive, yet quality results are difficult to achieve. Nudges are environmental cues engaging unconscious decision-making processes to prompt behavior change. In this proof-of-concept study, we developed an inexpensive set of [...] Read more.
Behavior change communication for improving handwashing with soap can be labor and resource intensive, yet quality results are difficult to achieve. Nudges are environmental cues engaging unconscious decision-making processes to prompt behavior change. In this proof-of-concept study, we developed an inexpensive set of nudges to encourage handwashing with soap after toilet use in two primary schools in rural Bangladesh. We completed direct observation of behaviors at baseline, after providing traditional handwashing infrastructure, and at multiple time periods following targeted handwashing nudges (1 day, 2 weeks, and 6 weeks). No additional handwashing education or motivational messages were completed. Handwashing with soap among school children was low at baseline (4%), increasing to 68% the day after nudges were completed and 74% at both 2 weeks and 6 weeks post intervention. Results indicate that nudge-based interventions have the potential to improve handwashing with soap among school-aged children in Bangladesh and specific areas of further inquiry are discussed. Full article
(This article belongs to the Special Issue Water Microbial Pollution and Disinfection)
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Open AccessArticle
An Environmentally Friendly Method for Testing Photocatalytic Inactivation of Cyanobacterial Propagation on a Hybrid Ag-TiO2 Photocatalyst under Solar Illumination
Int. J. Environ. Res. Public Health 2015, 12(12), 15819-15833; https://doi.org/10.3390/ijerph121215023 - 11 Dec 2015
Cited by 2
Abstract
Cyanobacteria were inactivated under sunlight using mixed phase silver (Ag) and deposited titanium dioxide (TiO2) coated on the surface of diatomite (DM) as a hybrid photocatalyst (Ag-TiO2/DM). The endpoints of dose-response experiments were chlorophyll a, photosynthetic efficiency, and flow [...] Read more.
Cyanobacteria were inactivated under sunlight using mixed phase silver (Ag) and deposited titanium dioxide (TiO2) coated on the surface of diatomite (DM) as a hybrid photocatalyst (Ag-TiO2/DM). The endpoints of dose-response experiments were chlorophyll a, photosynthetic efficiency, and flow cytometry measurements. In vitro experiments revealed that axenic cultures of planktonic cyanobacteria lost their photosynthetic activity following photocatalyzed exposure to sunlight for more than 24 h. Nearly 92% of Microcystis aeruginosa cells lost their photosynthetic activity, and their cell morphology was severely damaged within 24 h of the reaction. Preliminary carbon-14 (14CO3−2) results suggest that the complete inactivation of cyanobacteria arises from damage to cell wall components (peroxidation). A small concomitant increase in cell wall disorder and a consequent decrease in cell wall functional groups increase the cell wall fluidity prior to cell lysis. A high dosage of Ag-TiO2/DM during photocatalysis increased the concentration of extracellular polymeric substances (EPSs) in the Microcystis aeruginosa suspension by up to approximately 260%. However, photocatalytic treatment had a small effect on the disinfection by-product (DBP) precursor, as revealed by only a slight increase in the formation of trihalomethanes (THMs) and haloacetic acids (HAAs). Full article
(This article belongs to the Special Issue Water Microbial Pollution and Disinfection)
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Open AccessArticle
Bacteria that Travel: The Quality of Aircraft Water
Int. J. Environ. Res. Public Health 2015, 12(11), 13938-13955; https://doi.org/10.3390/ijerph121113938 - 30 Oct 2015
Cited by 3
Abstract
The travelling population is increasing globally year on year. International tourist arrival figures reached 1087 million in 2013 and 1133 million in 2014; of which 53% and 54% respectively accounted for air transport. The water on board aircraft is sourced from surface or [...] Read more.
The travelling population is increasing globally year on year. International tourist arrival figures reached 1087 million in 2013 and 1133 million in 2014; of which 53% and 54% respectively accounted for air transport. The water on board aircraft is sourced from surface or ground water; piped to a central filling point and distributed to each aircraft by water service vehicles at the home base or at the destination airport. The purpose of this study was to ascertain the microbial, chemical (pH; Total and Free chlorine) and physical (temperature) quality of water from two aircraft, long- and short-haul, as well as from the original water source and the water service vehicle. A total of 154 water samples were collected and analysed. Long-haul flights were found to be significantly poorer in terms of microbial quality than short haul flights (p = 0.015). Furthermore, correlation and regression analysis showed that the water service vehicle was a significant source of increased microbial load in aircraft. Microbial diversity was also demonstrated, with 37 bacterial species identified belonging to eight classes: γ-Proteobacteria; β-Proteobacteria; α-Proteobacteria; Bacilli; Actinobacteria; Flavobacteria; Sphingobacteria and Cytophaga; using phenotypic and 16S rDNA sequence-based analysis. We present a novel quantified study of aircraft-related potable water supplies. Full article
(This article belongs to the Special Issue Water Microbial Pollution and Disinfection)
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Open AccessArticle
Lactic Acid Fermentation, Urea and Lime Addition: Promising Faecal Sludge Sanitizing Methods for Emergency Sanitation
Int. J. Environ. Res. Public Health 2015, 12(11), 13871-13885; https://doi.org/10.3390/ijerph121113871 - 29 Oct 2015
Cited by 14
Abstract
In this research, three faecal sludge sanitizing methods—lactic acid fermentation, urea treatment and lime treatment—were studied for application in emergency situations. These methods were investigated by undertaking small scale field trials with pit latrine sludge in Blantyre, Malawi. Hydrated lime was able to [...] Read more.
In this research, three faecal sludge sanitizing methods—lactic acid fermentation, urea treatment and lime treatment—were studied for application in emergency situations. These methods were investigated by undertaking small scale field trials with pit latrine sludge in Blantyre, Malawi. Hydrated lime was able to reduce the E. coli count in the sludge to below the detectable limit within 1 h applying a pH > 11 (using a dosage from 7% to 17% w/w, depending faecal sludge alkalinity), urea treatment required about 4 days using 2.5% wet weight urea addition, and lactic acid fermentation needed approximately 1 week after being dosed with 10% wet weight molasses (2 g (glucose/fructose)/kg) and 10% wet weight pre-culture (99.8% pasteurised whole milk and 0.02% fermented milk drink containing Lactobacillus casei Shirota). Based on Malawian prices, the cost of sanitizing 1 m3 of faecal sludge was estimated to be €32 for lactic acid fermentation, €20 for urea treatment and €12 for hydrated lime treatment. Full article
(This article belongs to the Special Issue Water Microbial Pollution and Disinfection)
Open AccessArticle
Indoor Heating Drives Water Bacterial Growth and Community Metabolic Profile Changes in Building Tap Pipes during the Winter Season
Int. J. Environ. Res. Public Health 2015, 12(10), 13649-13661; https://doi.org/10.3390/ijerph121013649 - 27 Oct 2015
Cited by 10
Abstract
The growth of the bacterial community harbored in indoor drinking water taps is regulated by external environmental factors, such as indoor temperature. However, the effect of indoor heating on bacterial regrowth associated with indoor drinking water taps is poorly understood. In the present [...] Read more.
The growth of the bacterial community harbored in indoor drinking water taps is regulated by external environmental factors, such as indoor temperature. However, the effect of indoor heating on bacterial regrowth associated with indoor drinking water taps is poorly understood. In the present work, flow cytometry and community-level sole-carbon-source utilization techniques were combined to explore the effects of indoor heating on water bacterial cell concentrations and community carbon metabolic profiles in building tap pipes during the winter season. The results showed that the temperature of water stagnated overnight (“before”) in the indoor water pipes was 15–17 °C, and the water temperature decreased to 4–6 °C after flushing for 10 min (“flushed”). The highest bacterial cell number was observed in water stagnated overnight, and was 5–11 times higher than that of flushed water. Meanwhile, a significantly higher bacterial community metabolic activity (AWCD590nm) was also found in overnight stagnation water samples. The significant “flushed” and “taps” values indicated that the AWCD590nm, and bacterial cell number varied among the taps within the flushed group (p < 0.01). Heatmap fingerprints and principle component analyses (PCA) revealed a significant discrimination bacterial community functional metabolic profiles in the water stagnated overnight and flushed water. Serine, threonine, glucose-phosphate, ketobutyric acid, phenylethylamine, glycerol, putrescine were significantly used by “before” water samples. The results suggested that water stagnated at higher temperature should be treated before drinking because of bacterial regrowth. The data from this work provides useful information on reasonable utilization of drinking water after stagnation in indoor pipes during indoor heating periods. Full article
(This article belongs to the Special Issue Water Microbial Pollution and Disinfection)
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Open AccessArticle
Evaluation of Membrane Ultrafiltration and Residual Chlorination as a Decentralized Water Treatment Strategy for Ten Rural Healthcare Facilities in Rwanda
Int. J. Environ. Res. Public Health 2015, 12(10), 13602-13623; https://doi.org/10.3390/ijerph121013602 - 27 Oct 2015
Cited by 7
Abstract
There is a critical need for safe water in healthcare facilities (HCF) in low-income countries. HCF rely on water supplies that may require additional on-site treatment, and need sustainable technologies that can deliver sufficient quantities of water. Water treatment systems (WTS) that utilize [...] Read more.
There is a critical need for safe water in healthcare facilities (HCF) in low-income countries. HCF rely on water supplies that may require additional on-site treatment, and need sustainable technologies that can deliver sufficient quantities of water. Water treatment systems (WTS) that utilize ultrafiltration membranes for water treatment can be a useful technology in low-income countries, but studies have not systematically examined the feasibility of this technology in low-income settings. We monitored 22 months of operation of 10 WTS, including pre-filtration, membrane ultrafiltration, and chlorine residual disinfection that were donated to and operated by rural HCF in Rwanda. The systems were fully operational for 74% of the observation period. The most frequent reasons for interruption were water shortage (8%) and failure of the chlorination mechanism (7%). When systems were operational, 98% of water samples collected from the HCF taps met World Health Organization (WHO) guidelines for microbiological water quality. Water quality deteriorated during treatment interruptions and when water was stored in containers. Sustained performance of the systems depended primarily on organizational factors: the ability of the HCF technician to perform routine servicing and repairs, and environmental factors: water and power availability and procurement of materials, including chlorine and replacement parts in Rwanda. Full article
(This article belongs to the Special Issue Water Microbial Pollution and Disinfection)
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Open AccessArticle
Investigation of Legionella Contamination in Bath Water Samples by Culture, Amoebic Co-Culture, and Real-Time Quantitative PCR Methods
Int. J. Environ. Res. Public Health 2015, 12(10), 13118-13130; https://doi.org/10.3390/ijerph121013118 - 19 Oct 2015
Cited by 7
Abstract
We investigated Legionella contamination in bath water samples, collected from 68 bathing facilities in Japan, by culture, culture with amoebic co-culture, real-time quantitative PCR (qPCR), and real-time qPCR with amoebic co-culture. Using the conventional culture method, Legionella pneumophila was detected in 11 samples [...] Read more.
We investigated Legionella contamination in bath water samples, collected from 68 bathing facilities in Japan, by culture, culture with amoebic co-culture, real-time quantitative PCR (qPCR), and real-time qPCR with amoebic co-culture. Using the conventional culture method, Legionella pneumophila was detected in 11 samples (11/68, 16.2%). Contrary to our expectation, the culture method with the amoebic co-culture technique did not increase the detection rate of Legionella (4/68, 5.9%). In contrast, a combination of the amoebic co-culture technique followed by qPCR successfully increased the detection rate (57/68, 83.8%) compared with real-time qPCR alone (46/68, 67.6%). Using real-time qPCR after culture with amoebic co-culture, more than 10-fold higher bacterial numbers were observed in 30 samples (30/68, 44.1%) compared with the same samples without co-culture. On the other hand, higher bacterial numbers were not observed after propagation by amoebae in 32 samples (32/68, 47.1%). Legionella was not detected in the remaining six samples (6/68, 8.8%), irrespective of the method. These results suggest that application of the amoebic co-culture technique prior to real-time qPCR may be useful for the sensitive detection of Legionella from bath water samples. Furthermore, a combination of amoebic co-culture and real-time qPCR might be useful to detect viable and virulent Legionella because their ability to invade and multiply within free-living amoebae is considered to correlate with their pathogenicity for humans. This is the first report evaluating the efficacy of the amoebic co-culture technique for detecting Legionella in bath water samples. Full article
(This article belongs to the Special Issue Water Microbial Pollution and Disinfection)
Open AccessArticle
Prevalence and Molecular Characteristics of Waterborne Pathogen Legionella in Industrial Cooling Tower Environments
Int. J. Environ. Res. Public Health 2015, 12(10), 12605-12617; https://doi.org/10.3390/ijerph121012605 - 12 Oct 2015
Cited by 7
Abstract
Cooling towers are a source of Legionnaires’ disease. It is important from a public health perspective to survey industrial cooling towers for the presence of Legionella. Prospective surveillance of the extent of Legionella pollution was conducted at factories in Shijiazhuang, China between [...] Read more.
Cooling towers are a source of Legionnaires’ disease. It is important from a public health perspective to survey industrial cooling towers for the presence of Legionella. Prospective surveillance of the extent of Legionella pollution was conducted at factories in Shijiazhuang, China between March 2011 and September 2012. Overall, 35.7% of 255 industrial cooling tower water samples showed Legionella-positive, and their concentrations ranged from 100 Colony-Forming Units (CFU)/liter to 88,000 CFU/liter, with an average concentration of 9100 CFU/liter. A total of 121 isolates were obtained. All isolates were L. pneumophila, and the isolated serogroups included serogroups 1 (68 isolates, 56.2%), 6 (25, 20.7%), 5 (12, 9.9%), 8 (8, 6.6%), 3 (6, 5.0%) and 9 (2, 1.6%). All 121 isolates were analyzed by pulsed-field gel electrophoresis (PFGE) and 64 different patterns were obtained. All 121 isolates were analyzed sequence-based typing (SBT), a full 7-allele profile was obtained from 117 isolates. One hundred and seventeen isolates were divided into 49 sequence types. Two virulence genes, lvh and rtxA, are analyzed by polymerase chain reaction (PCR). 92.6% (112/121) and 98.3% (119/121) isolates carried lvh and rtxA respectively and 90.9% (110/121) of tested isolates carried both genes. Our results demonstrated high prevalence and genetic polymorphism of L. pneumophila in industrial cooling tower environments in Shijiazhang, China, and the SBT and virulence gene PCR results suggested that the isolates were pathogenic. Improved control and prevention strategies are urgently needed. Full article
(This article belongs to the Special Issue Water Microbial Pollution and Disinfection)
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Open AccessArticle
Quality of Drinking Water Treated at Point of Use in Residential Healthcare Facilities for the Elderly
Int. J. Environ. Res. Public Health 2015, 12(9), 11163-11177; https://doi.org/10.3390/ijerph120911163 - 09 Sep 2015
Cited by 5
Abstract
Municipal tap water is increasingly treated at the point of use (POU) to improve the acceptability and palatability of its taste. The aim of this study was to assess the bacteriologic and nutritional characteristics of tap water treated at the point of use [...] Read more.
Municipal tap water is increasingly treated at the point of use (POU) to improve the acceptability and palatability of its taste. The aim of this study was to assess the bacteriologic and nutritional characteristics of tap water treated at the point of use in residential healthcare facilities for the elderly. Two types of POU devices were used: microfiltered water dispensers (MWDs) and reverse-osmosis water dispensers (ROWDs). All samples of water entering the devices and leaving them were tested for the bacteriological parameters set by Italian regulations for drinking water and for opportunistic pathogens associated with various infections in healthcare settings; in addition, the degree of mineralization of the water was assessed. The results revealed widespread bacterial contamination in the POU treatment devices, particularly from potentially pathogenic species. As expected, the use of ROWDs led to a decrease in the saline content of the water. In conclusion, the use of POU treatment in healthcare facilities for the elderly can be considered advisable only if the devices are constantly and carefully maintained. Full article
(This article belongs to the Special Issue Water Microbial Pollution and Disinfection)
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Open AccessArticle
Vertical Distribution of Bacterial Community Diversity and Water Quality during the Reservoir Thermal Stratification
Int. J. Environ. Res. Public Health 2015, 12(6), 6933-6945; https://doi.org/10.3390/ijerph120606933 - 17 Jun 2015
Cited by 18
Abstract
Reservoir thermal stratification drives the water temperature and dissolved oxygen gradient, however, the characteristic of vertical water microbial community during thermal stratification is so far poorly understood. In this work, water bacterial community diversity was determined using the Illumina Miseq sequencing technique. The [...] Read more.
Reservoir thermal stratification drives the water temperature and dissolved oxygen gradient, however, the characteristic of vertical water microbial community during thermal stratification is so far poorly understood. In this work, water bacterial community diversity was determined using the Illumina Miseq sequencing technique. The results showed that epilimnion, metalimnion and hypolimnion were formed steadily in the JINPEN drinking water reservoir. Water temperature decreased steadily from the surface (23.11 °C) to the bottom (9.17 °C). Total nitrogen ranged from 1.07 to 2.06 mg/L and nitrate nitrogen ranged from 0.8 to 1.84 mg/L. The dissolved oxygen concentration decreased sharply below 50 m, and reached zero at 65 m. The Miseq sequencing revealed a total of 4127 operational taxonomic units (OTUs) with 97% similarity, which were affiliated with 15 phyla including Acidobacteria, Actinobacteria, Armatimonadetes, Bacteroidetes, Caldiserica, Chlamydiae, Chlorobi, Chloroflexi, Cyanobacteria, Firmicutes, Gemmatimonadetes, Nitrospirae, Planctomycetes, Proteobacteria, and Verrucomicrobia. The highest Shannon diversity was 4.41 in 45 m, and the highest Chao 1 diversity was 506 in 5 m. Rhodobacter dominated in 55 m (23.24%) and 65 m (12.58%). Prosthecobacter dominated from 0.5 to 50 m. The heat map profile and redundancy analysis (RDA) indicated significant difference in vertical water bacterial community composition in the reservoir. Meanwhile, water quality properties including dissolved oxygen, conductivity, nitrate nitrogen and total nitrogen have a dramatic influence on vertical distribution of bacterial communities. Full article
(This article belongs to the Special Issue Water Microbial Pollution and Disinfection)
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