scholarly journals ANALYSIS OF THE LEVEL AND RATE OF LEGIONELLA PNEUMOPHILA CONTAMINATION OF HOT WATER SUPPLY SYSTEMS IN THE THERAPEUTIC-AND-PROPHYLACTIC INSTITUTIONS OF MOSCOW

2012 ◽  
Vol 17 (1) ◽  
pp. 10-14
Author(s):  
O. A. Gruzdeva ◽  
N. N. Filatov ◽  
O. V. Sadretdinova ◽  
T. I. Karpova ◽  
Yu. E. Dronina ◽  
...  
Keyword(s):  
Water Supply ◽  
Legionella Pneumophila ◽  
Risk Group ◽  
Hot Water ◽  
Water Supply Systems ◽  
Healthcare Facilities ◽  
Prophylactic Measures ◽  
Hot Water Supply ◽  
High Level ◽  
Supply Systems

The specific features of Legionella colonization of water supply systems were studied in the large healthcare facilities (HCF) of Moscow. Examination of 16 buildings of 5 Moscow multidisciplinary HCFs, including their risk-group units, revealed the high level (68%) of Legionella pneumophila contamination of hot water supply systems. Among the Legionella pneumophila strains circulating in the hot water supply systems of Moscow HCFs, there was a preponderance of its serogroup 6 (44%), 5 (26%), and 1 (13%) strains. The findings suggest that it is necessary to arrange a set of prophylactic measures for microbiological monitoring and protection of water systems in the HCFs, which are aimed at preventing nosocomial legionellosis.

scholarly journals Legionella spp. Colonization in Water Systems of Hotels Linked with Travel-Associated Legionnaires’ Disease

2021 ◽  
Author(s):  
Antonios Papadakis ◽  
Maria Keramarou ◽  
Dimosthenis Chochlakis ◽  
Vassilios Sandalakis ◽  
Varvara Mouchtouri ◽  
...  
Keyword(s):  
Water Supply ◽  
Legionella Pneumophila ◽  
Cold Water ◽  
Water Systems ◽  
Hot Water ◽  
Water Supply Systems ◽  
Water Safety ◽  
Surveillance Network ◽  
Hot Water Supply ◽  
Supply Systems

Hotel water systems colonized with Legionella spp. have been the source of travel-associated Legionnaires’ disease and cases, clusters or outbreaks continue to be reported worldwide each year. A total of 132 hotels linked with travel-associated Legionnaires’ disease, as reported through the European Legionnaires’ Disease Surveillance Network, were inspected and tested for Legionella spp. during 2000–2019 by the public health authorities of the island of Crete (Greece). A total of 3,311 samples were collected: 1,885 (56.93%) from cold water supply systems, 1,387 (41.89%) from hot water supply systems, 37 (1.12%) were swab samples and two (0.06%) were soil. Of those, 685 (20.69%), were collected from 83 (62.89%) hotels, testing positive (≥ 50CFU/L) for Legionella pneumophila) serogroups 1-10, 12-14 and non-pneumophila species (L. anisa, L. erythra, L. tusconensis, L. taurinensis, L. birminghamensis, L. rubrilucens, L. londiniesis, L. oakridgensis, L. santicrusis, L. brunensis, L. maceacherii). The most frequently isolated L. pneumophila serogroups were 1 (27.92%) and 3 (17.08%). Significantly higher isolation rates were obtained from hot water supply systems (25.96%) versus cold water systems (16.98%) and swab samples (13.51%). A Relative Risk (R.R.) > 1 (p < 0.0001) was calculated for hot water temperature <55 °C (R.R.: 4.43), chlorine concentrations <0.2 mg/L (R.R.: 2.69), star rating <4 (R.R.: 1.73) and absence of Water Safety Plan implementation (R.R.: 1.57).

scholarly journals Legionella spp. Colonization in Water Systems of Hotels Linked with Travel-Associated Legionnaires’ Disease

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2243
Author(s):  
Antonios Papadakis ◽  
Maria Keramarou ◽  
Dimosthenis Chochlakis ◽  
Vassilios Sandalakis ◽  
Varvara A. Mouchtouri ◽  
...  
Keyword(s):  
Water Supply ◽  
Legionella Pneumophila ◽  
Cold Water ◽  
Water Systems ◽  
Hot Water ◽  
Water Supply Systems ◽  
Surveillance Network ◽  
Legionnaires Disease ◽  
Hot Water Supply ◽  
Supply Systems

Hotel water systems colonized with Legionella spp. have been the source of travel-associated Legionnaires’ disease, and cases, clusters and outbreaks continue to be reported worldwide each year. A total of 132 hotels linked with travel-associated Legionnaires’ disease, as reported through the European Legionnaires’ Disease Surveillance Network, were inspected and tested for Legionella spp. during 2000–2019 by the public health authorities of the island of Crete (Greece). A total of 3311 samples were collected: 1885 (56.93%) from cold water supply systems, 1387 (41.89%) from hot water supply systems, 37 (1.12%) were swab samples and two (0.06%) were soil. Of those, 685 (20.69%), were collected from 83 (62.89%) hotels, testing positive (≥50 CFU/L) for Legionella pneumophila) serogroups 1–10, 12–14 and non-pneumophila species (L. anisa, L. erythra, L. tusconensis, L. taurinensis, L. birminghamensis, L. rubrilucens, L. londiniesis, L. oakridgensis, L. santicrusis, L. brunensis, L. maceacherii). The most frequently isolated L. pneumophila serogroups were 1 (27.92%) and 3 (17.08%). Significantly higher isolation rates were obtained from hot water supply systems (25.96%) versus cold water systems (16.98%) and swab samples (13.51%). A Relative Risk (R.R.) > 1 (p < 0.0001) was calculated for hot water temperature <55 °C (R.R.: 4.43), chlorine concentrations <0.2 mg/L (R.R.: 2.69), star ratings <4 (R.R.: 1.73) and absence of Water Safety Plan implementation (R.R.: 1.57).

A New Technology to Prevent the Formation of Limescale in Hot Water Supply Systems

2020 ◽  
Vol 841 ◽  
pp. 36-40
Author(s):  
Mardan Jalilov ◽  
Ayten Jalilova ◽  
Gulnar Feyziyeva ◽  
Makhanim Azimova
Keyword(s):  
Drinking Water ◽  
Water Supply ◽  
Hot Water ◽  
Water Supply Systems ◽  
Water Requirements ◽  
Quality Of Water ◽  
Hot Water Supply ◽  
Calcium And Magnesium ◽  
Supply Systems

Given that the quality of water supplied to hot water supply systems must meet drinking water requirements, it is also important that the water preparation process is of great importance. The quality of that water is also important in terms of preventing the formation of heat in hot water systems. It is known that the main cause of the formation of water is the presence of calcium and magnesium cations and bicarbonate and sulfate anions in water. The traditional methods for preventing the limescale include the combination of calcium and magnesium cations from the water and replacing them with cations that are not easy to resolve at high temperatures. The quality of water treated by these methods does not meet drinking water requirements. Taking these into account, the Cl-anionizationprocess of drinking water has been developed in high-tech anionite technology. According to this technology, the first water from the city water gridis processed through anionite and activated carbon filters, which are mechanically charged with high anionite. The treated water is then cleaned out of microbes and bacteria through the ultraviolet disinfection equipment and delivered to the operator according to the quality requirements for drinking water. In the chlorine-anionization process, most of the sulfate and bicarbonate anions in water change to chlorine anions and their solidity remains constant. Thus, the density of the limescale-forming anions in the water decreases sharply and it meets the quality indicators of drinking water. High-grade anionite in the filter (8÷12) is regenerated by NaCl solution. The filtration rate of the solution from the anionite is determined depending on the concentration of calcium cations contained in the salt given for regeneration. Regeneration mode is such that the CaCO3 combination does not crumble when the anionite layer is formed. It is known that the temperature of the heated water in the hot water supply system does not exceed (60÷70)°C. In this case, the decomposition of limescale at Hc<2 mg-eq/l (carbonate hardness) is not observed. As carbonate hardness increases to 4 mg/l, the thin layer in the system shows a collapse. The basic element of the proposed technological schemeCl-anionite filter was applied at ADA University in Baku and positive results were obtained. Early observed collapse of pipes has been prevented and the working regime of hot water heaters has improved. A high-performance anionite such as A200EMBCl, which is a major ingredient of the UK's Purelite, and then the Russian-made AB-17-8 high-anionite anions have been used on the device.

Performance of a gas engine driven heat pump for hot water supply systems

Energy ◽  
2011 ◽  
Vol 36 (5) ◽  
pp. 2883-2889 ◽  
Author(s):  
E. Elgendy ◽  
J. Schmidt ◽  
A. Khalil ◽  
M. Fatouh
Keyword(s):  
Water Supply ◽  
Heat Pump ◽  
Hot Water ◽  
Water Supply Systems ◽  
Gas Engine ◽  
Hot Water Supply ◽  
Supply Systems
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