DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, C.; Brigmon, R.

Legionnaires disease is a pneumonia caused by the inhalation of the bacterium Legionella pneumophila. The majority of illnesses have been associated with cooling towers since these devices can harbor and disseminate the bacterium in the aerosolized mist generated by these systems. Historically, Savannah River Site (SRS) cooling towers have had occurrences of elevated levels of Legionella in all seasons of the year and in patterns that are difficult to predict. Since elevated Legionella in cooling tower water are a potential health concern a question has been raised as to the best control methodology. In this work we analyze available chemical,more » biological, and atmospheric data to determine the best method or key parameter for control. The SRS 4Q Industrial Hygiene Manual, 4Q-1203, 1 - G Cooling Tower Operation and the SRNL Legionella Sampling Program, states that 'Participation in the SRNL Legionella Sampling Program is MANDATORY for all operating cooling towers'. The resulting reports include L. pneumophila concentration information in cells/L. L. pneumophila concentrations >10{sup 7} cells/L are considered elevated and unsafe so action must be taken to reduce these densities. These remedial actions typically include increase biocide addition or 'shocking'. Sometimes additional actions are required if the problem persists including increase tower maintenance (e.g. cleaning). Evaluation of 14 SRS cooling towers, seven water quality parameters, and five Legionella serogroups over a three-plus year time frame demonstrated that cooling tower water Legionella densities varied widely though out this time period. In fact there was no one common consistent significant variable across all towers. The significant factors that did show up most frequently were related to suspended particulates, conductivity, pH, and dissolved oxygen, not chlorine or bromine as might be expected. Analyses of atmospheric data showed that there were more frequent significant elevated Legionella concentrations when the dew point temperature was high--a summertime occurrence. However, analysis of the three years of Legionella monitoring data of the 14 different SRS Cooling Towers demonstrated that elevated concentrations are observed at all temperatures and seasons. The objective of this study is to evaluate the ecology of L. pneumophila including serogroups and population densities, chemical, and atmospheric data, on cooling towers at SRS to determine whether relationships exist among water chemistry, and atmospheric conditions. The goal is to more fully understand the conditions which inhibit or encourage L. pneumophila growth and supply this data and associated recommendations to SRS Cooling Tower personnel for improved management of operation. Hopefully this information could then be used to help control L. pneumophila growth more effectively in SRS cooling tower water.« less

Development of a new CARD-FISH protocol for quantification of Legionella pneumophila and its application in two hospital cooling towers.

PubMed

Kirschner, A K T; Rameder, A; Schrammel, B; Indra, A; Farnleitner, A H; Sommer, R

2012-06-01

Open cooling towers are frequent sources of infections with Legionella pneumophila. The gold standard for the detection of Leg. pneumophila is based on cultivation lasting up to 10 days and detecting only culturable cells. Alternative fluorescence in situ hybridization (FISH) protocols have been proposed, but they result in faint fluorescence signals and lack specificity because of cross-hybridization with other Legionella species. Our aim was thus to develop a new FISH protocol for rapid and specific detection of Leg. pneumophila in water samples. A novel catalysed reporter deposition FISH (CARD-FISH) protocol for the detection of Leg. pneumophila was developed, which significantly enhanced signal intensity as well as specificity of the probe through the use of a novel competitor probe. The developed protocol was compared with the culture method for monitoring the seasonal development of culturable and nonculturable Leg. pneumophila in two hospital cooling tower systems. Seasonal fluctuations of Leg. pneumophila concentrations detected via CARD-FISH were related to the development of the total bacterial community in both cooling towers, with temperature and biocide as the main factors controlling this development. Our results clearly showed that the majority of the Leg. pneumophila cells were in a nonculturable state. Thus, detection of Leg. pneumophila with culture methods may underestimate the total numbers of Leg. pneumophila present. Rapid, sensitive and specific detection and quantification of Leg. pneumophila in water systems is prerequisite for reliable risk estimation. The new protocol significantly improves current methodology and can be used to monitor and screen for Leg. pneumophila concentrations in cooling towers or other water systems. © 2012 The Authors. Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

Biocorrosion of mild steel and copper used in cooling tower water and its control.

PubMed

Li, Xiao Lei; Narenkumar, Jayaraman; Rajasekar, Aruliah; Ting, Yen-Peng

2018-03-01

The present study describes the biocorrosion of mild steel (MS1010) and pure copper (Cu) in cooling water environments (both field and lab study). Electrochemical and surface analyses of both metals were carried out to confirm the corrosion susceptibility in the presence of bacteria and inhibitor. Surface analysis of the MS and Cu coupons revealed that biofilm was developed with increasing exposure time in the field study. In the lab study, accumulation of extracellular polymeric substance over the metal surface was noticed and led to the severe pitting type of corrosion on both metal surfaces. Besides, the anti-corrosive study was carried out using the combinations of commercial corrosion inhibitor (S7653-10 ppm) with biocide (F5100-5 ppm), and the results reveal that the corrosion rate of MS and Cu was highly reduced to 0.0281 and 0.0021 mm/year (inhibitor system) than 0.1589 and 0.0177 mm/year (control system). Inhibition efficiency for both metals in the presence of inhibitor with biocide was found as 82 and 88% for MS and Cu, respectively. The present study concluded that MS was very susceptible to biocorrosion, compared to copper metal in cooling water environment. Further, the combination of the both inhibitor and biocide was effectively inhibiting the biocorrosion which was due to its antibacterial and anti-corrosive properties.

A comparison of legionella and other bacteria concentrations in cooling tower water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cappabianca, R.M.; Jurinski, N.B.; Jurinski, J.B.

1994-05-01

A field study was conducted in which water samples collected from air conditioning cooling water reservoirs of high-rise buildings throughout an urban area were assayed for Legionella and for total bacteria. Buildings included within the study had ongoing biocidal treatment programs for the cooling towers. Separate sample analyses were performed to measure the viable colony concentrations of total bacteria and of Legionella in the process waters. The occurrence and viable counts of Legionella in 304 environmental water samples were determined by inoculating them onto plates of buffered charcoal yeast extract (BCYE) agar medium (a presumptive screening method). The samples weremore » collected during summer months between July and September. BCYE plate cultures of 50 (16.4%) of the samples yielded Legionella with viable counts ranging from 2 to 608 colony forming units per milliliter. In the water samples, 281 (92.4%) yielded viable counts of bacteria that ranged from 9 to 1.2 x 10{sup 6} per milliliter. This study demonstrates that Legionella are commonly present in the water of air conditioning cooling towers and that there is no significant correlation between concurrently sampled culture plate counts of Legionella and total bacteria plate counts. Correspondingly, there is no demonstrated validity for use of total bacterial counts as an inferential surrogate for the concentration of Legionella in the water. 19 refs., 3 figs., 1 tab.« less

Comprehensive Evaluation of Biological Growth Control by Chlorine-Based Biocides in Power Plant Cooling Systems Using Tertiary Effluent

PubMed Central

Chien, Shih-Hsiang; Dzombak, David A.; Vidic, Radisav D.

2013-01-01

Abstract Recent studies have shown that treated municipal wastewater can be a reliable cooling water alternative to fresh water. However, elevated nutrient concentration and microbial population in wastewater lead to aggressive biological proliferation in the cooling system. Three chlorine-based biocides were evaluated for the control of biological growth in cooling systems using tertiary treated wastewater as makeup, based on their biocidal efficiency and cost-effectiveness. Optimal chemical regimens for achieving successful biological growth control were elucidated based on batch-, bench-, and pilot-scale experiments. Biocide usage and biological activity in planktonic and sessile phases were carefully monitored to understand biological growth potential and biocidal efficiency of the three disinfectants in this particular environment. Water parameters, such as temperature, cycles of concentration, and ammonia concentration in recirculating water, critically affected the biocide performance in recirculating cooling systems. Bench-scale recirculating tests were shown to adequately predict the biocide residual required for a pilot-scale cooling system. Optimal residuals needed for proper biological growth control were 1, 2–3, and 0.5–1 mg/L as Cl2 for NaOCl, preformed NH2Cl, and ClO2, respectively. Pilot-scale tests also revealed that Legionella pneumophila was absent from these cooling systems when using the disinfectants evaluated in this study. Cost analysis showed that NaOCl is the most cost-effective for controlling biological growth in power plant recirculating cooling systems using tertiary-treated wastewater as makeup. PMID:23781129

Comprehensive Evaluation of Biological Growth Control by Chlorine-Based Biocides in Power Plant Cooling Systems Using Tertiary Effluent.

PubMed

Chien, Shih-Hsiang; Dzombak, David A; Vidic, Radisav D

2013-06-01

Recent studies have shown that treated municipal wastewater can be a reliable cooling water alternative to fresh water. However, elevated nutrient concentration and microbial population in wastewater lead to aggressive biological proliferation in the cooling system. Three chlorine-based biocides were evaluated for the control of biological growth in cooling systems using tertiary treated wastewater as makeup, based on their biocidal efficiency and cost-effectiveness. Optimal chemical regimens for achieving successful biological growth control were elucidated based on batch-, bench-, and pilot-scale experiments. Biocide usage and biological activity in planktonic and sessile phases were carefully monitored to understand biological growth potential and biocidal efficiency of the three disinfectants in this particular environment. Water parameters, such as temperature, cycles of concentration, and ammonia concentration in recirculating water, critically affected the biocide performance in recirculating cooling systems. Bench-scale recirculating tests were shown to adequately predict the biocide residual required for a pilot-scale cooling system. Optimal residuals needed for proper biological growth control were 1, 2-3, and 0.5-1 mg/L as Cl 2 for NaOCl, preformed NH 2 Cl, and ClO 2 , respectively. Pilot-scale tests also revealed that Legionella pneumophila was absent from these cooling systems when using the disinfectants evaluated in this study. Cost analysis showed that NaOCl is the most cost-effective for controlling biological growth in power plant recirculating cooling systems using tertiary-treated wastewater as makeup.

Evaluation of a teflon based ultraviolet light system on the disinfection of water in a textile air washer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, J.E.; Whisnant, R.B.

The report provides an in-depth evaluation of an ultraviolet (UV) disinfection unit as applied to the treatment of cooling water in a textile air washer system. The UV unit tests used a teflon tube to transport the aquatic phase. The unit reduced microbial populations and maintained an average level of 10,000 Colony formed unites/mL for the 6-month testing period, without the addition of biocides. No cleaning or other maintenance was required of the wetted surfaces during the testing period. Slime deposits observed on walls of the air washer during chemical treatment were also eliminated. The UV unit can be utilizedmore » on both cooling towers and air washers without extensive installation.« less

Evaluation of sessile microorganisms in pipelines and cooling towers of some Iranian industries

NASA Astrophysics Data System (ADS)

Setareh, M.; Javaherdashti, R.

2006-02-01

Microbiologically influenced corrosion (MIC) is a kind of electrochemical corrosion that is enhanced by the effect of certain microorganisms including sessile bacteria. In this investigation, more than 200 samples collected from different systems of Iranian refineries have been examined (by culturing methods and observations) for corrosion-enhancing, biofilm-producing microorganisms such as sulfate-reducing bacteria (SRB), iron-oxidizing bacteria (IOB), heterotrophic biofilm-forming bacteria (HBB), and some eukaryotes such as fungi. This study showed the presence of microorganisms, such as SRB, HBB, thermophillic HBB, and yeasts, except for IOB. It was also revealed that biocides are used to reduce the number of planktonic (floating) bacteria, instead of the number of sessile bacteria, that form biofilms. Using surfactants, or washing with chemicals like chlorine or organic acids in overhauls, may destroy the biofilm and free the residential bacteria into the bulk solution, thus exposing them to the biocide. For thick biofilms, a chlorine or acid wash may also yield the same results.

Unravelling the core microbiome of biofilms in cooling tower systems.

PubMed

Di Gregorio, L; Tandoi, V; Congestri, R; Rossetti, S; Di Pippo, F

2017-11-01

In this study, next generation sequencing and catalyzed reporter deposition fluorescence in situ hybridization, combined with confocal microscopy, were used to provide insights into the biodiversity and structure of biofilms collected from four full-scale European cooling systems. Water samples were also analyzed to evaluate the impact of suspended microbes on biofilm formation. A common core microbiome, containing members of the families Sphingomonadaceae, Comamonadaceae and Hyphomicrobiaceae, was found in all four biofilms, despite the water of each coming from different sources (river and groundwater). This suggests that selection of the pioneer community was influenced by abiotic factors (temperature, pH) and tolerances to biocides. Members of the Sphingomonadaceae were assumed to play a key role in initial biofilm formation. Subsequent biofilm development was driven primarily by light availability, since biofilms were dominated by phototrophs in the two studied 'open' systems. Their interactions with other microbial populations then shaped the structure of the mature biofilm communities analyzed.

The influence and analysis of natural crosswind on cooling characteristics of the high level water collecting natural draft wet cooling tower

NASA Astrophysics Data System (ADS)

Ma, Libin; Ren, Jianxing

2018-01-01

Large capacity and super large capacity thermal power is becoming the main force of energy and power industry in our country. The performance of cooling tower is related to the water temperature of circulating water, which has an important influence on the efficiency of power plant. The natural draft counter flow wet cooling tower is the most widely used cooling tower type at present, and the high cooling tower is a new cooling tower based on the natural ventilation counter flow wet cooling tower. In this paper, for high cooling tower, the application background of high cooling tower is briefly explained, and then the structure principle of conventional cooling tower and high cooling tower are introduced, and the difference between them is simply compared. Then, the influence of crosswind on cooling performance of high cooling tower under different wind speeds is introduced in detail. Through analysis and research, wind speed, wind cooling had little impact on the performance of high cooling tower; wind velocity, wind will destroy the tower inside and outside air flow, reducing the cooling performance of high cooling tower; Wind speed, high cooling performance of cooling tower has increased, but still lower than the wind speed.

In Situ Biomineralization and Particle Deposition Distinctively Mediate Biofilm Susceptibility to Chlorine

PubMed Central

Li, Xiaobao; Chopp, David L.; Russin, William A.; Brannon, Paul T.; Parsek, Matthew R.

2016-01-01

Microbial biofilms and mineral precipitation commonly co-occur in engineered water systems, such as cooling towers and water purification systems, and both decrease process performance. Microbial biofilms are extremely challenging to control and eradicate. We previously showed that in situ biomineralization and the precipitation and deposition of abiotic particles occur simultaneously in biofilms under oversaturated conditions. Both processes could potentially alter the essential properties of biofilms, including susceptibility to biocides. However, the specific interactions between mineral formation and biofilm processes remain poorly understood. Here we show that the susceptibility of biofilms to chlorination depends specifically on internal transport processes mediated by biomineralization and the accumulation of abiotic mineral deposits. Using injections of the fluorescent tracer Cy5, we show that Pseudomonas aeruginosa biofilms are more permeable to solutes after in situ calcite biomineralization and are less permeable after the deposition of abiotically precipitated calcite particles. We further show that biofilms are more susceptible to chlorine killing after biomineralization and less susceptible after particle deposition. Based on these observations, we found a strong correlation between enhanced solute transport and chlorine killing in biofilms, indicating that biomineralization and particle deposition regulate biofilm susceptibility by altering biocide penetration into the biofilm. The distinct effects of in situ biomineralization and particle deposition on biocide killing highlight the importance of understanding the mechanisms and patterns of biomineralization and scale formation to achieve successful biofilm control. PMID:26944848

Corrosion control when using secondary treated municipal wastewater as alternative makeup water for cooling tower systems.

PubMed

Hsieh, Ming-Kai; Li, Heng; Chien, Shih-Hsiang; Monnell, Jason D; Chowdhury, Indranil; Dzombak, David A; Vidic, Radisav D

2010-12-01

Secondary treated municipal wastewater is a promising alternative to fresh water as power plant cooling water system makeup water, especially in arid regions. Laboratory and field testing was conducted in this study to evaluate the corrosiveness of secondary treated municipal wastewater for various metals and metal alloys in cooling systems. Different corrosion control strategies were evaluated based on varied chemical treatment. Orthophosphate, which is abundant in secondary treated municipal wastewater, contributed to more than 80% precipitative removal of phosphorous-based corrosion inhibitors. Tolyltriazole worked effectively to reduce corrosion of copper (greater than 95% inhibition effectiveness). The corrosion rate of mild steel in the presence of free chlorine 1 mg/L (as Cl2) was approximately 50% higher than in the presence of monochloramine 1 mg/L (as Cl2), indicating that monochloramine is a less corrosive biocide than free chlorine. The scaling layers observed on the metal alloys contributed to corrosion inhibition, which could be seen by comparing the mild steel 21-day average corrosion rate with the last 5-day average corrosion rate, the latter being approximately 50% lower than the former.

Biocidal additives for lubricating/cooling fluids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morozova, L.P.; Klyavlina, E.A.; Lebedev, E.V.

1984-03-01

This article reports on the synthesis of new biocidal products for the protection of water emulsions of lubricating/cooling fluids (LCFs) against microbiological damage. The new biocides are based on compounds belonging to the classes of oxazolidines and oxazines, and also compounds of these classes but activated by nitro derivatives of aromatic hydrocarbons. Results are presented from evaluations of the biocidal activity of the new products with respect to aerobes, anaerobes, and fungi growing in a 3% emulsion of the widely used LCF Ukrinol-1. The comparative evaluation was based on the optimal biocidal concentration corresponding to the smallest quantity of addedmore » biocide to give maximum suppression of the microorganisms in a minimum time, and with the longest period of effectiveness. The lubricating properties of the biocides were evaluated in an emulsion of the Ukrinol-1 LCF is a four-ball tester. It is concluded that the developed biocides are homogeneous, transparent liquids with a specific odor and can be considered as nontoxic to man; they mix readily with components used in formulating LCFs and detergents (sulfonates, oxyethylated alcohols, phenols, polyglycols, fatty acid soaps, etc.). They are readily soluble in water and in oils. Includes 3 tables.« less

2004 Savannah River Cooling Tower Collection (U)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garrett, Alfred; Parker, Matthew J.; Villa-Aleman, E.

2005-05-01

The Savannah River National Laboratory (SRNL) collected ground truth in and around the Savannah River Site (SRS) F-Area cooling tower during the spring and summer of 2004. The ground truth data consisted of air temperatures and humidity inside and around the cooling tower, wind speed and direction, cooling water temperatures entering; inside adn leaving the cooling tower, cooling tower fan exhaust velocities and thermal images taken from helicopters. The F-Area cooling tower had six cells, some of which were operated with fans off during long periods of the collection. The operating status (fan on or off) for each of themore » six cells was derived from operations logbooks and added to the collection database. SRNL collected the F-Area cooling tower data to produce a database suitable for validation of a cooling tower model used by one of SRNL's customer agencies. SRNL considers the data to be accurate enough for use in a model validation effort. Also, the thermal images of the cooling tower decks and throats combined with the temperature measurements inside the tower provide valuable information about the appearance of cooling towers as a function of fan operating status and time of day.« less

Wet cooling towers: rule-of-thumb design and simulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leeper, Stephen A.

1981-07-01

A survey of wet cooling tower literature was performed to develop a simplified method of cooling tower design and simulation for use in power plant cycle optimization. The theory of heat exchange in wet cooling towers is briefly summarized. The Merkel equation (the fundamental equation of heat transfer in wet cooling towers) is presented and discussed. The cooling tower fill constant (Ka) is defined and values derived. A rule-of-thumb method for the optimized design of cooling towers is presented. The rule-of-thumb design method provides information useful in power plant cycle optimization, including tower dimensions, water consumption rate, exit air temperature,more » power requirements and construction cost. In addition, a method for simulation of cooling tower performance at various operating conditions is presented. This information is also useful in power plant cycle evaluation. Using the information presented, it will be possible to incorporate wet cooling tower design and simulation into a procedure to evaluate and optimize power plant cycles.« less

[Genotypic variability and persistence of Legionella pulsed-field gel electrophoresis patterns in 16 cooling towers in Shanghai, China].

PubMed

Chen, Ming-liang; Wang, Gang-yi; Chen, Min; Zhou, Hai-jian; Shao, Zhu-jun; Zhang, Xi; Wu, Fan

2010-07-01

To investigate the genotypic characteristics and persistence of Legionella pulsed-field gel electrophoresis (PFGE) patterns in 16 air-conditioner cooling towers in six different public sites of Shanghai. From May to October, continuous sampling was operated once per month in 2007. Legionella strains isolated from the 16 cooling towers were confirmed by serological and latex agglutination. PFGE was applied for the fingerprinting of the isolates, while the cluster results of PFGE were analyzed by BioNumerics software. 131 strains of Legionella were isolated, including L. pneumophila, L. bozemanae, L. micdadei and L. anisa. 52 distinguishable PFGE patterns were differentiated among the 16 cooling towers, with 37 patterns were owned by just one cooling tower, which was not shared with other cooling towers, while 15 patterns were shared by more than 2 cooling towers. All the cooling towers had ≥ 2 PFGE patterns, while in 13 cooling towers the same PFGE patterns were recovered during the six months. From June to October of 2007, 18 strains of Legionella belonging to the PFGE pattern of LPAs.SH0078 were isolated continuously from 6 cooling towers. This study demonstrated great genotypic diversity and complexity of Legionella in cooling towers. Persistence of the PFGE patterns was observed in 81.25% of the cooling towers. The PFGE pattern of LPAs. SH0078 was distributed widely, suggesting it might be the dominate strain in Shanghai.

A Holistic Look at Minimizing Adverse Environmental Impact Under Section 316(b) of the Clean Water Act

DOE PAGES

Veil, John A.; Puder, Markus G.; Littleton, Debra J.; ...

2002-01-01

Section 316(b) of the Clean Water Act (CWA) requires that “the location, design, construction, and capacity of cooling water intake structures reflect the best technology available for minimizing adverse environmental impact.” As the U.S. Environmental Protection Agency (EPA) develops new regulations to implement Section 316(b), much of the debate has centered on adverse impingement and entrainment impacts of cooling-water intake structures. Depending on the specific location and intake layout, once-through cooling systems withdrawing many millions of gallons of water per day can, to a varying degree, harm fish and other aquatic organisms in the water bodies from which the coolingmore » water is withdrawn. Therefore, opponents of once-through cooling systems have encouraged the EPA to require wet or dry cooling tower systems as the best technology available (BTA), without considering site-specific conditions. However, within the context of the broader scope of the CWA mandate, this focus seems too narrow. Therefore, this article examines the phrase “minimizing adverse environmental impact” in a holistic light. Emphasis is placed on the analysis of the terms “environmental” and “minimizing.” Congress chose “environmental” in lieu of other more narrowly focused terms like “impingement and entrainment,” “water quality,” or “aquatic life.” In this light, BTA for cooling-water intake structures must minimize the entire suite of environmental impacts, as opposed to just those associated with impingement and entrainment. Wet and dry cooling tower systems work well to minimize entrainment and impingement, but they introduce other equally important impacts because they impose an energy penalty on the power output of the generating unit. The energy penalty results from a reduction in plant operating efficiency and an increase in internal power consumption. As a consequence of the energy penalty, power companies must generate additional electricity to achieve the same net output. This added production leads to additional environmental impacts associated with extraction and processing of the fuel, air emissions from burning the fuel, and additional evaporation of freshwater supplies during the cooling process. Wet towers also require the use of toxic biocides that are subsequently discharged or disposed. The other term under consideration, “minimizing,” does not equal “eliminating.” Technologies may be available to minimize but not totally eliminate adverse environmental impacts.« less

Method and system for simulating heat and mass transfer in cooling towers

DOEpatents

Bharathan, Desikan; Hassani, A. Vahab

1997-01-01

The present invention is a system and method for simulating the performance of a cooling tower. More precisely, the simulator of the present invention predicts values related to the heat and mass transfer from a liquid (e.g., water) to a gas (e.g., air) when provided with input data related to a cooling tower design. In particular, the simulator accepts input data regarding: (a) cooling tower site environmental characteristics; (b) cooling tower operational characteristics; and (c) geometric characteristics of the packing used to increase the surface area within the cooling tower upon which the heat and mass transfer interactions occur. In providing such performance predictions, the simulator performs computations related to the physics of heat and mass transfer within the packing. Thus, instead of relying solely on trial and error wherein various packing geometries are tested during construction of the cooling tower, the packing geometries for a proposed cooling tower can be simulated for use in selecting a desired packing geometry for the cooling tower.

COOLING TOWER PUMP HOUSE, TRA606. THREE OF SIX SECTIONS OF ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

COOLING TOWER PUMP HOUSE, TRA-606. THREE OF SIX SECTIONS OF COOLING TOWER ARE VISIBLE ABOVE RAILING. PUMP HOUSE IN FOREGROUND IS ON SOUTH SIDE OF COOLING TOWER. NOTE THREE PIPES TAKING WATER FROM PUMP HOUSE TO HOT DECK OF COOLING TOWER. EMERGENCY WATER SUPPLY TOWER IS ALSO IN VIEW. INL NEGATIVE NO. 6197. Unknown Photographer, 6/27/1952 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Genotypic variability and persistence of Legionella pneumophila PFGE patterns in 34 cooling towers from two different areas.

PubMed

Sanchez, Inma; Garcia-Nuñez, Marian; Ragull, Sonia; Sopena, Nieves; Pedro-Botet, Maria Luisa; Estere, Maria; Rey-Joly, Celestino; Sabria, Miquel; Esteve, Maria

2008-02-01

Genotypic variability and clonal persistence are important concepts in molecular epidemiology as they facilitate the search for the source of sporadic cases or outbreaks of legionellosis. We studied the genotypic variability and persistence of Legionella pulsed-field gel electrophoresis (PFGE) patterns over time (period > 6 months) in 34 positive cooling towers from two different areas. In area A, radius of 70 km, 52 indistinguishable PFGE patterns were differentiated among the 27 cooling towers. In 13 cooling towers we observed >or= 2 PFGE patterns. Each cooling tower had its own indistinguishable Legionella PFGE pattern which was not shared with any other cooling tower. In area B, radius of 1 km, 10 indistinguishable PFGE patterns were obtained from the seven cooling towers. In four, we observed >or= 2 PFGE patterns. Three of these 10 indistinguishable PFGE patterns were shared by more than one cooling tower. In 27 of 34 cooling towers the same PFGE pattern was recovered after 6 months to up to 5 years of follow-up. The large genotypic diversity of Legionella observed in the cooling towers aids in the investigation of community outbreaks of Legionnaires' disease. However, shared patterns in small areas may confound the epidemiological investigation. The persistence of some PFGE patterns in cooling towers makes the recovery of the Legionella isolate causing the outbreak possible over time.

Effect of solar radiation on the performance of cross flow wet cooling tower in hot climate of Iran

NASA Astrophysics Data System (ADS)

Banooni, Salem; Chitsazan, Ali

2016-11-01

In some cities such as Ahvaz-Iran, the solar radiation is very high and the annual-mean-daily of the global solar radiation is about 17.33 MJ m2 d-1. Solar radiation as an external heat source seems to affect the thermal performance of the cooling towers. Usually, in modeling cooling tower, the effects of solar radiation are ignored. To investigate the effect of sunshade on the performance and modeling of the cooling tower, the experiments were conducted in two different states, cooling towers with and without sunshade. In this study, the Merkel's approach and finite difference technique are used to predict the thermal behavior of cross flow wet cooling tower without sunshade and the results are compared with the data obtained from the cooling towers with and without sunshade. Results showed that the sunshade is very efficient and it reduced the outlet water temperature, the approach and the water exergy of the cooling tower up to 1.2 °C, 15 and 1.1 %, respectively and increased the range and the efficiency of the cooling tower up to 29 and 37 %, respectively. Also, the sunshade decreased the error between the experimental data of the cooling tower with sunshade and the modeling results of the cooling tower without sunshade 1.85 % in average.

Role of bacterial adhesion in the microbial ecology of biofilms in cooling tower systems.

PubMed

Liu, Yang; Zhang, Wei; Sileika, Tadas; Warta, Richard; Cianciotto, Nicholas P; Packman, Aaron

2009-01-01

The fate of the three heterotrophic biofilm forming bacteria, Pseudomonas aeruginosa, Klebsiella pneumoniae and Flavobacterium sp. in pilot scale cooling towers was evaluated both by observing the persistence of each species in the recirculating water and the formation of biofilms on steel coupons placed in each cooling tower water reservoir. Two different cooling tower experiments were performed: a short-term study (6 days) to observe the initial bacterial colonization of the cooling tower, and a long-term study (3 months) to observe the ecological dynamics with repeated introduction of the test strains. An additional set of batch experiments (6 days) was carried out to evaluate the adhesion of each strain to steel surfaces under similar conditions to those found in the cooling tower experiments. Substantial differences were observed in the microbial communities that developed in the batch systems and cooling towers. P. aeruginosa showed a low degree of adherence to steel surfaces both in batch and in the cooling towers, but grew much faster than K. pneumoniae and Flavobacterium in mixed-species biofilms and ultimately became the dominant organism in the closed batch systems. However, the low degree of adherence caused P. aeruginosa to be rapidly washed out of the open cooling tower systems, and Flavobacterium became the dominant microorganism in the cooling towers in both the short-term and long-term experiments. These results indicate that adhesion, retention and growth on solid surfaces play important roles in the bacterial community that develops in cooling tower systems.

Role of bacterial adhesion in the microbial ecology of biofilms in cooling tower systems

PubMed Central

Liu, Yang; Zhang, Wei; Sileika, Tadas; Warta, Richard; Cianciotto, Nicholas P.; Packman, Aaron

2009-01-01

The fate of the three heterotrophic biofilm forming bacteria, Pseudomonas aeruginosa, Klebsiella pneumoniae and Flavobacterium sp. in pilot scale cooling towers was evaluated both by observing the persistence of each species in the recirculating water and the formation of biofilms on steel coupons placed in each cooling tower water reservoir. Two different cooling tower experiments were performed: a short-term study (6 days) to observe the initial bacterial colonization of the cooling tower, and a long-term study (3 months) to observe the ecological dynamics with repeated introduction of the test strains. An additional set of batch experiments (6 days) was carried out to evaluate the adhesion of each strain to steel surfaces under similar conditions to those found in the cooling tower experiments. Substantial differences were observed in the microbial communities that developed in the batch systems and cooling towers. P. aeruginosa showed a low degree of adherence to steel surfaces both in batch and in the cooling towers, but grew much faster than K. pneumoniae and Flavobacterium in mixed-species biofilms and ultimately became the dominant organism in the closed batch systems. However, the low degree of adherence caused P. aeruginosa to be rapidly washed out of the open cooling tower systems, and Flavobacterium became the dominant microorganism in the cooling towers in both the short-term and long-term experiments. These results indicate that adhesion, retention and growth on solid surfaces play important roles in the bacterial community that develops in cooling tower systems. PMID:19177226

Control of corrosive bacterial community by bronopol in industrial water system.

PubMed

Narenkumar, Jayaraman; Ramesh, Nachimuthu; Rajasekar, Aruliah

2018-01-01

Ten aerobic corrosive bacterial strains were isolated from a cooling tower water system (CWS) which were identified based on the biochemical characterization and 16S rRNA gene sequencing. Out of them, dominant corrosion-causing bacteria, namely, Bacillus thuringiensis EN2, Terribacillus aidingensis EN3, and Bacillus oleronius EN9, were selected for biocorrosion studies on mild steel 1010 (MS) in a CWS. The biocorrosion behaviour of EN2, EN3, and EN9 strains was studied using immersion test (weight loss method), electrochemical analysis, and surface analysis. To address the corrosion problems, an anti-corrosive study using a biocide, bronopol was also demonstrated. Scanning electron microscopy and Fourier-transform infrared spectroscopy analyses of the MS coupons with biofilm developed after exposure to CWS confirmed the accumulation of extracellular polymeric substances and revealed that biofilms was formed as microcolonies, which subsequently cause pitting corrosion. In contrast, the biocide system, no pitting type of corrosion, was observed and weight loss was reduced about 32 ± 2 mg over biotic system (286 ± 2 mg). FTIR results confirmed the adsorption of bronopol on the MS metal surface as protective layer (co-ordination of NH 2 -Fe 3+ ) to prevent the biofilm formation and inhibit the corrosive chemical compounds and thus led to reduction of corrosion rate (10 ± 1 mm/year). Overall, the results from WL, EIS, SEM, XRD, and FTIR concluded that bronopol was identified as effective biocide and corrosion inhibitor which controls the both chemical and biocorrosion of MS in CWS.

The influence of liquid-gas velocity ratio on the noise of the cooling tower

NASA Astrophysics Data System (ADS)

Yang, Bin; Liu, Xuanzuo; Chen, Chi; Zhao, Zhouli; Song, Jinchun

2018-05-01

The noise from the cooling tower has a great influence on psychological performance of human beings. The cooling tower noise mainly consists of fan noise, falling water noise and mechanical noise. This thesis used DES turbulence model with FH-W model to simulate the flow and sound pressure field in cooling tower based on CFD software FLUENT and analyzed the influence of different kinds noise, which affected by diverse factors, on the cooling tower noise. It can be concluded that the addition of cooling water can reduce the turbulence and vortex noise of the rotor fluid field in the cooling tower at some extent, but increase the impact noise of the liquid-gas two phase. In general, the cooling tower noise decreases with the velocity ratio of liquid to gas increasing, and reaches the lowest when the velocity ratio of liquid to gas is close to l.

The optimal operation of cooling tower systems with variable-frequency control

NASA Astrophysics Data System (ADS)

Cao, Yong; Huang, Liqing; Cui, Zhiguo; Liu, Jing

2018-02-01

This study investigates the energy performance of chiller and cooling tower systems integrated with variable-frequency control for cooling tower fans and condenser water pumps. With regard to an example chiller system serving an office building, Chiller and cooling towers models were developed to assess how different variable-frequency control methods of cooling towers fans and condenser water pumps influence the trade-off between the chiller power, pump power and fan power under various operating conditions. The matching relationship between the cooling tower fans frequency and condenser water pumps frequency at optimal energy consumption of the system is introduced to achieve optimum system performance.

2-(Decylthio)ethanamine hydrochloride: A new multifunctional biocide which enhances corrosion inhibition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walter, R.W.; Cooke, L.M.

1997-12-01

2-(Decylthio)ethanamine hydrochloride is a new multifunctional biocide that is registered for use in a variety of recirculating cooling water systems. This biocide has broad spectrum activity against bacteria, fungi and algae. It also has biofilm and corrosion inhibition properties. Data on these various activities will be presented for both laboratory and field evaluations.

Occurrence of infected amoebae in cooling towers compared with natural aquatic environments: implications for emerging pathogens.

PubMed

Berk, S G; Gunderson, J H; Newsome, A L; Farone, A L; Hayes, B J; Redding, K S; Uddin, N; Williams, E L; Johnson, R A; Farsian, M; Reid, A; Skimmyhorn, J; Farone, M B

2006-12-01

Many species of bacteria pathogenic to humans, such as Legionella, are thought to have evolved in association with amoebal hosts. Several novel unculturable bacteria related to Legionella have also been found in amoebae, a few of which have been thought to be causes of nosocomial infections in humans. Because amoebae can be found in cooling towers, we wanted to know whether cooling tower environments might enhance the association between amoebae and bacterial pathogens of amoebae in order to identify potential "hot spots" for emerging human pathogens. To compare occurrence of infected amoebae in natural environments with those in cooling towers, 40 natural aquatic environments and 40 cooling tower samples were examined. Logistic regression analysis determined variables that were significant predictors of the occurrence of infected amoebae, which were found in 22 of 40 cooling tower samples but in only 3 of the 40 natural samples. An odds ratio showed that it is over 16 times more likely to encounter infected amoebae in cooling towers than in natural environments. Environmental data from cooling towers and natural habitats combined revealed dissolved organic carbon (DOC) and pH were predictors of the occurrence of the pathogens, however, when cooling tower data alone were analyzed, no variables accounted for the occurrence. Several bacteria have novel rRNA sequences, and most strains were not culturable outside of amoebae. Such pathogens of amoebae may spread to the environment via aerosols from cooling towers. Studies of emerging infectious diseases should strongly consider cooling towers as a source of amoeba-associated pathogens.

Performance Evaluation of a Mechanical Draft Cross Flow Cooling Towers Employed in a Subtropical Region

NASA Astrophysics Data System (ADS)

Muthukumar, Palanisamy; Naik, Bukke Kiran; Goswami, Amarendra

2018-02-01

Mechanical draft cross flow cooling towers are generally used in a large-scale water cooled condenser based air-conditioning plants for removing heat from warm water which comes out from the condensing unit. During this process considerable amount of water in the form of drift (droplets) and evaporation is carried away along with the circulated air. In this paper, the performance evaluation of a standard cross flow induced draft cooling tower in terms of water loss, range, approach and cooling tower efficiency are presented. Extensive experimental studies have been carried out in three cooling towers employed in a water cooled condenser based 1200 TR A/C plant over a period of time. Daily variation of average water loss and cooling tower performance parameters have been reported for some selected days. The reported average water loss from three cooling towers is 4080 l/h and the estimated average water loss per TR per h is about 3.1 l at an average relative humidity (RH) of 83%. The water loss during peak hours (2 pm) is about 3.4 l/h-TR corresponding to 88% of RH and the corresponding efficiency of cooling towers varied between 25% and 45%.

Investigation of flow characteristics of a single and two-adjacent natural draft dry cooling towers under cross wind condition

NASA Astrophysics Data System (ADS)

Mekanik, Abolghasem; Soleimani, Mohsen

2007-11-01

Wind effect on natural draught cooling towers has a very complex physics. The fluid flow and temperature distribution around and in a single and two adjacent (tandem and side by side) dry-cooling towers under cross wind are studied numerically in the present work. Cross-wind can significantly reduce cooling efficiency of natural-draft dry-cooling towers, and the adjacent towers can affect the cooling efficiency of both. In this paper we will present a complex computational model involving more than 750,000 finite volume cells under precisely defined boundary condition. Since the flow is turbulent, the standard k-ɛ turbulence model is used. The numerical results are used to estimate the heat transfer between radiators of the tower and air surrounding it. The numerical simulation explained the main reason for decline of the thermo-dynamical performance of dry-cooling tower under cross wind. In this paper, the incompressible fluid flow is simulated, and the flow is assumed steady and three-dimensional.

PBF Cooling Tower. Hot deck of Cooling Tower with fan ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Cooling Tower. Hot deck of Cooling Tower with fan motors in place. Fan's propeller blades (not in view) rotate within lower portion of vents. Inlet pipe is a left of view. Contractor's construction buildings in view to right. Photographer: Larry Page. Date: June 30, 1969. INEEL negative no. 69-3781 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

The Damaging Effects of Earthquake Excitation on Concrete Cooling Towers

NASA Astrophysics Data System (ADS)

Abedi-Nik, Farhad; Sabouri-Ghomi, Saeid

2008-07-01

Reinforced concrete cooling towers of hyperbolic shell configuration find widespread application in utilities engaged in the production of electric power. In design of critical civil infrastructure of this type, it is imperative to consider all the possible loading conditions that the cooling tower may experience, an important loading condition in many countries is that of the earthquake excitation, whose influence on the integrity and stability of cooling towers is profound. Previous researches have shown that the columns supporting a cooling tower are sensitive to earthquake forces, as they are heavily loaded elements that do not possess high ductility, and understanding the behavior of columns under earthquake excitation is vital in structural design because they provide the load path for the self weight of the tower shell. This paper presents the results of a finite element investigation of a representative "dry" cooling tower, using realistic horizontal and vertical acceleration data obtained from the recent and widely-reported Tabas, Naghan and Bam earthquakes in Iran. The results of both linear and nonlinear analyses are reported in the paper, the locations of plastic hinges within the supporting columns are identified and the ramifications of the plastic hinges on the stability of the cooling tower are assessed. It is concluded that for the (typical) cooling tower configuration analyzed, the columns that are instrumental in providing a load path are influenced greatly by earthquake loading, and for the earthquake data used in this study the representative cooling tower would be rendered unstable and would collapse under the earthquake forces considered.

The Damaging Effects of Earthquake Excitation on Concrete Cooling Towers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abedi-Nik, Farhad; Sabouri-Ghomi, Saeid

2008-07-08

Reinforced concrete cooling towers of hyperbolic shell configuration find widespread application in utilities engaged in the production of electric power. In design of critical civil infrastructure of this type, it is imperative to consider all the possible loading conditions that the cooling tower may experience, an important loading condition in many countries is that of the earthquake excitation, whose influence on the integrity and stability of cooling towers is profound. Previous researches have shown that the columns supporting a cooling tower are sensitive to earthquake forces, as they are heavily loaded elements that do not possess high ductility, and understandingmore » the behavior of columns under earthquake excitation is vital in structural design because they provide the load path for the self weight of the tower shell. This paper presents the results of a finite element investigation of a representative 'dry' cooling tower, using realistic horizontal and vertical acceleration data obtained from the recent and widely-reported Tabas, Naghan and Bam earthquakes in Iran. The results of both linear and nonlinear analyses are reported in the paper, the locations of plastic hinges within the supporting columns are identified and the ramifications of the plastic hinges on the stability of the cooling tower are assessed. It is concluded that for the (typical) cooling tower configuration analyzed, the columns that are instrumental in providing a load path are influenced greatly by earthquake loading, and for the earthquake data used in this study the representative cooling tower would be rendered unstable and would collapse under the earthquake forces considered.« less

Potentially pathogenic amoeba-associated microorganisms in cooling towers and their control.

PubMed

Pagnier, Isabelle; Merchat, Michèle; La Scola, Bernard

2009-06-01

Cooling towers provide a favorable environment for the proliferation of microorganisms. Cooling towers generate a biofilm and often aerosolize contaminated water, thereby increasing the risk of microorganism dissemination by human inhalation. This pathogen dissemination was first revealed by the epidemics of Legionnaires' disease that were directly related to the presence of cooling towers, and since then, the ecology of Legionella pneumophila has been well studied. Each country has specific standards regarding the acceptable amount of microorganisms in cooling tower systems. However, those standards typically only concern L. pneumophila, even though many other microorganisms can also be isolated from cooling towers, including protozoa, bacteria and viruses. Microbiological control of the cooling tower system can be principally achieved by chemical treatments and also by improving the system's construction. Several new treatments are being studied to improve the efficiency of disinfection. However, as most of these treatments continue to focus solely on L. pneumophila, reports of other types of pathogens continue to increase. Therefore, how their dissemination affects the human populous health should be addressed now.

Hospital-acquired legionellosis originating from a cooling tower during a period of thermal inversion.

PubMed

Engelhart, Steffen; Pleischl, Stefan; Lück, Christian; Marklein, Günter; Fischnaller, Edith; Martin, Sybille; Simon, Arne; Exner, Martin

2008-07-01

A case of hospital-acquired legionellosis occurred in a 75-year-old male patient who underwent surgery due to malignant melanoma. Legionellosis was proven by culture of Legionella pneumophila serogroup 1 from bronchoalveolar lavage (BAL) fluid. Being a chronic smoker the patient used to visit the sickroom balcony that was located about 90 m to the west of a hospital cooling tower. Routine cooling tower water samples drawn during the presumed incubation period revealed 1.0x10(4) CFU/100 ml (L. pneumophila serogroup 1). One of three isolates from the cooling tower water matched the patient's isolate by monoclonal antibody (mab)- and genotyping (sequence-based typing). Horizontal transport of cooling tower aerosols probably was favoured by meteorological conditions with thermal inversion. The case report stresses the importance of routine maintenance and microbiological control of hospital cooling towers.

Enumeration of Legionella pneumophila in cooling tower water systems.

PubMed

Türetgen, Irfan; Sungur, Esra Ilhan; Cotuk, Aysin

2005-01-01

Legionella pneumophila, the causative agent of Legionnaires' disease, is known to colonise and frequently grow in cooling tower waters. Disease is acquired by inhaling aerosol contaminated by legionellae. Determination of the count of Legionella pneumophila in cooling tower waters may, therefore, be useful for risk assessment. In our survey, 103 water samples from 50 cooling towers were examined over a five-year period to indicate the seasonal distribution and the ecology of L. pneumophila, as regards temperature and pH. L. pneumophila serogroup 1 was found in 44% of the isolated strains, which is primarily responsible for the majority of Legionnaires' disease. The large majority of examined towers had levels of L. pneumophila in the high-risk category. These cooling towers have been linked to many outbreaks of Legionnaires' disease.

The effect of ozonated cooling water on the corrosion behavior of stainless steel, titanium and copper alloys. Ozone biocidal action on sessile and planktonic bacteria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Videla, H.A.; Guiamet, P.S.; Mele, M.F.L. de

1999-11-01

Two aspects of ozone utilization as sole chemical treatment for cooling water demand a better understanding: (a) the effect of dissolved ozone on the corrosion behavior of heat exchanger structural materials and (b) the biocidal action of ozone on bacterial biofilms. To assess the effect of ozone dissolved in synthetic cooling water on the corrosion behavior of different structural materials (stainless steel; 70:30 copper-nickel; aluminum brass and titanium), voltamperometric experiments and corrosion potential vs. time measurements were made at ozone concentrations between 0.1 and 1.2 ppm. Present results show that the passive behavior of stainless steel and titanium is notmore » affected by dissolved ozone whereas copper alloys are susceptible to corrosion in the presence of ozone. To study the biocidal action of various concentrations of dissolved ozone against planktonic and sessile bacteria, liquid cultures and biofilms of Pseudomonas fluorescense, formed on different structural materials, were used at different contact times. The results show that dissolved ozone is an effective biocide for controlling planktonic cells but its effectiveness decreases in the presence of sessile bacteria and the extracellular polymeric matrix of the biofilm. It is suggested that the penetration of ozone through the biofilm depends on the simultaneous diffusion and reaction of the biocide with the biofilm matrix which may exhibit local differences in biomass distribution and hydrodynamic conditions.« less

Crosswinds Effect on the Thermal Performance of Wet Cooling Towers Under Variable Operating Conditions

NASA Astrophysics Data System (ADS)

Chen, You Liang; Shi, Yong Feng; Hao, Jian Gang; Chang, Hao; Sun, Feng Zhong

2018-01-01

In order to quantitatively analyze the influence of the variable operating parameters on the cooling performance of natural draft wet cooling towers (NDWCTs), a hot model test system was set up with adjustable ambient temperature and humidity, circulating water flowrate and temperature. In order to apply the hot model test results to the real tower, the crosswind Froude number is defined. The results show that the crosswind has a negative effect on the thermal performance of the cooling tower, and there is a critical crosswind velocity corresponding to the lowest cooling efficiency. According to the crosswind Froude number similarity, when the ambient temperature decreases, or the circulating water flowrate and temperature increase, the cooling tower draft force will increase, and the critical crosswind velocity will increase correspondingly.

50. NORTHERN VIEW OF NONEVAPORATIVE WASTE WATER TREATMENT COOLING TOWERS ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

50. NORTHERN VIEW OF NON-EVAPORATIVE WASTE WATER TREATMENT COOLING TOWERS IN CENTER, AND EVAPORATIVE WASTE WATER COOLING TOWERS ON RIGHT. (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

Energy conservation strategies, the ignored cooling towers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burger, R.

1997-06-01

Because of their apparent lack of sophistication, cooling towers are usually considered orphans of the facilities operation. Historically, cooling towers have been neglected in refrigeration air conditioning systems, electric power generating stations, manufacturing plants, and chemical process plants. Operators are aware of the importance of their sophisticated equipment but, they take the apparently simple cooling towers and cold water returning for granted, Since the box looks sturdy and the fans are rotating, the operators think all is well and ignore the quality of water coming off the tower. A cooling tower is purchased for Design Conditions of performance which aremore » specified. Design Conditions relate to the volume of circulating water (GPM), hot water temperature (HWT), cold water temperature (CWT) discharge, and wet bulb temperature (WBT). The WBT consisting of ambient temperature and relative humidity. After the tower is on line and the CWT becomes inadequate, many engineers look to solutions other than the obvious. All cooling towers are purchased to function at 100% of capability in accordance with Design Condition. In the real world of on-stream utilization, the level of operation is lower. It can be deficient as much as 30% due to a variety of reasons which are not necessarily due to the failure of the performance of the tower.« less

Mycobacteria in Finnish cooling tower waters.

PubMed

Torvinen, Eila; Suomalainen, Sini; Paulin, Lars; Kusnetsov, Jaana

2014-04-01

Evaporative cooling towers are water systems used in, e.g., industry and telecommunication to remove excess heat by evaporation of water. Temperatures of cooling waters are usually optimal for mesophilic microbial growth and cooling towers may liberate massive amounts of bacterial aerosols. Outbreaks of legionellosis associated with cooling towers have been known since the 1980's, but occurrences of other potentially pathogenic bacteria in cooling waters are mostly unknown. We examined the occurrence of mycobacteria, which are common bacteria in different water systems and may cause pulmonary and other soft tissue infections, in cooling waters containing different numbers of legionellae. Mycobacteria were isolated from all twelve cooling systems and from 92% of the 24 samples studied. Their numbers in the positive samples varied from 10 to 7.3 × 10(4) cfu/L. The isolated species included M. chelonae/abscessus, M. fortuitum, M. mucogenicum, M. peregrinum, M. intracellulare, M. lentiflavum, M. avium/nebraskense/scrofulaceum and many non-pathogenic species. The numbers of mycobacteria correlated negatively with the numbers of legionellae and the concentration of copper. The results show that cooling towers are suitable environments for potentially pathogenic mycobacteria. Further transmission of mycobacteria from the towers to the environment needs examination. © 2013 APMIS. Published by John Wiley & Sons Ltd.

Use of cooling tower blow down in ethanol fermentation.

PubMed

Rajagopalan, N; Singh, V; Panno, B; Wilcoxon, M

2010-01-01

Reducing water consumption in bioethanol production conserves an increasingly scarce natural resource, lowers production costs, and minimizes effluent management issues. The suitability of cooling tower blow down water for reuse in fermentation was investigated as a means to lower water consumption. Extensive chemical characterization of the blow down water revealed low concentrations of toxic elements and total dissolved solids. Fermentation carried out with cooling tower blow down water resulted in similar levels of ethanol and residual glucose as a control study using deionized water. The study noted good tolerance by yeast to the specific scale and corrosion inhibitors found in the cooling tower blow down water. This research indicates that, under appropriate conditions, reuse of blow down water from cooling towers in fermentation is feasible.

36. EASTERN VIEW OF BOTTOM CONE OF GAS COOLING TOWER ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

36. EASTERN VIEW OF BOTTOM CONE OF GAS COOLING TOWER No. 1 AND TWO GAS COOLING TOWER SERVICE WATER PUMPS IN THE GAS WASHER PUMP HOUSE. - U.S. Steel Duquesne Works, Basic Oxygen Steelmaking Plant, Along Monongahela River, Duquesne, Allegheny County, PA

Sampling and detection of Legionella pneumophila aerosols generated from an industrial cooling tower.

PubMed

Ishimatsu, S; Miyamoto, H; Hori, H; Tanaka, I; Yoshida, S

2001-08-01

Cooling tower water has frequently been cited as a source of infection in outbreaks of Legionnaires' disease. However, there have been few reports on the presence of legionellae in aerosols from cooling towers. This paper describes our use of an impinger or a six-stage microbial impactor for detecting legionellae in air around a cooling tower contaminated with L. pneumophila (1.2+/-0.3x10(5) CFU/100 ml). Phosphate-buffered saline, Page's saline, 2% yeast extract solution and buffered yeast extract (BYE) broth were tested to evaluate their collection efficiency. These solutions were compared in laboratory experiments using an aerosol of L. pneumophila serogroup (SG) 1. Because BYE broth was the most efficient and storable collecting fluid among them, it was used for outdoor air sampling. In the outdoor air sampling, aerosolized L. pneumophila SG 6 was detected in the air around the cooling tower by the impinger (0.09 CFU/l. air). No legionellae were detected by the impactor with Legionella-selective agar plates (WYOalpha) because the plates were overgrown with fungi. Repetitive element PCR (rep-PCR) and arbitrarily primed PCR (AP-PCR) were employed to assess the epidemiological relationship among Legionella isolates from the air sample and the cooling tower water samples. L. pneumophila SG 6 isolated from the aerosols produced rep-PCR and AP-PCR fingerprints identical to those of L. pneumophila SG 6 strains from the cooling tower water, suggesting that the bacterium was aerosolized from the cooling tower.

Legionella species colonization in cooling towers: risk factors and assessment of control measures.

PubMed

Mouchtouri, Varvara A; Goutziana, Georgia; Kremastinou, Jenny; Hadjichristodoulou, Christos

2010-02-01

Cooling towers can be colonized by Legionella spp, and inhalation of aerosols generated by their operation may cause Legionnaires' disease in susceptible hosts. Environmental investigations of Legionnaires' disease outbreaks linked with cooling towers have revealed poorly maintained systems, lack of control measures, and failure of system equipment. The purpose of this study was to identify Legionella-contaminated cooling towers, identify risk factors for contamination, and assess the effectiveness of control measures. A total of 96 cooling towers of public buildings were registered and inspected, and 130 samples were collected and microbiologically tested. Microbiological test results were associated with characteristics of cooling towers, water samples, inspection results, and maintenance practices. Of the total 96 cooling towers examined, 47 (48.9%) were colonized by Legionella spp, and 22 (22.9%) required remedial action. A total of 65 samples (50.0%) were positive (> or = 500 cfu L(-1)), and 30 (23%) were heavily contaminated (> or = 10(4) cfu L(-1)). Of the 69 isolates identified, 55 strains (79.7.%) were L pneumophila. Legionella colonization was positively associated with the absence of training on Legionella control (relative risk [RR] = 1.66; P = .02), absence of regular Legionella testing (RR = 2.07: P = .002), absence of sunlight protection (RR = 1.63: P = .02), with samples in which the free residual chlorine level in the water sample was < 0.5 mg/L (RR = 2.23; P = .01), and with total plate count (P =.001). Colonization was negatively associated with chemical disinfection (RR = 0.2; P = .0003) and with the presence of a risk assessment and management plan (RR = 0.12; P = .0005). A statistically significant higher age (P =.01) was found in legionellae-positive cooling towers (median, 17 years; interquartile range [IQR] =5.0 to 26.0 years) compared with noncolonized cooling towers (median age, 6 years; IQR =1.0 to 13.5 years). After the 22 legionellae-positive cooling towers were disinfected with chlorine, 2 (9%) of them remained positive for Legionella spp with a concentration > or = 1000 cfu L(-1). Cooling towers can be heavily colonized by Legionella spp and thus present a potential risk for infection. This study demonstrates the importance of a risk assessment and management plan. Water chlorination effectively reduces legionellae contamination. Proper training of cooling tower operators is paramount. Copyright 2010 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Emergency Cooling of Nuclear Power Plant Reactors With Heat Removal By a Forced-Draft Cooling Tower

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murav’ev, V. P., E-mail: murval1@mail.ru

The feasibility of heat removal during emergency cooling of a reactor by a forced-draft cooling tower with accumulation of the peak heat release in a volume of precooled water is evaluated. The advantages of a cooling tower over a spray cooling pond are demonstrated: it requires less space, consumes less material, employs shorter lines in the heat removal system, and provides considerably better protection of the environment from wetting by entrained moisture.

How to control bio-slime in condenser cooling system water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Freymark, S.

1979-08-01

A number of oxidizing and non-oxidizing biocides are currently used for biocontrol. However, yesterday's solution to slime-fouling problems may not apply today in view of tightening effluent restrictions on chlorine. Thus, selection of biocontrol compounds can not be made indiscriminately. In selecting alternative biocontrol compounds, consideration should be given not only to costs but to effectiveness of the biocide in each particular application, taking into consideration cooling water quality, type of microbiological fouling and discharge restrictions. Thoughtful selection of the biocontrol compound(s), alone or in combination with surface-active agents, is essential for maintaining maximum microbiological control in condenser cooling watermore » systems.« less

PBF Cooling Tower Auxiliary Building (PER624) interior. Camera facing north. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Cooling Tower Auxiliary Building (PER-624) interior. Camera facing north. Deluge valves and automatic fire protection piping for Cooling Tower. Photographer: Holmes. Date: May 20, 1970. INEEL negative no. 70-2323 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

40 CFR 63.1329 - Process contact cooling towers provisions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... DDD, shall maintain an ethylene glycol concentration in the process contact cooling tower at or below... to the process contact cooling tower. (1) To determine the ethylene glycol concentration, owners or... procedures specified in 40 CFR 60.564(j)(1)(i). An average ethylene glycol concentration by weight shall be...

Comparison of the efficacy of free residual chlorine and monochloramine against biofilms in model and full scale cooling towers.

PubMed

Türetgen, Irfan

2004-04-01

The presence of microbial cells on surfaces results in the formation of biofilms, which may also give rise to microbiologically influenced corrosion. Biofilms accumulate on all submerged industrial and environmental surfaces. The efficacy of disinfectants is usually evaluated using planktonic cultures, which often leads to an underestimate of the concentration required to control a biofilm. The aim of this study was to investigate the efficacy of monochloramine on biofilms developed in a cooling tower. The disinfectants selected for the study were commercial formulations recommended for controlling microbial growth in cooling towers. A cooling tower and a laboratory model recirculating water system were used as biofilm reactors. Although previous studies have evaluated the efficacy of free chlorine and monochloramine for controlling biofilm growth, there is a lack of published data concerning the use monochloramine in cooling towers. Stainless steel coupons were inserted in each tower basin for a period of 30 d before removal. Monochloramine and free chlorine were tested under identical conditions on mixed biofilms which had been allowed to grow on coupons. Monochloramine was found to be significantly more effective than free chlorine against cooling tower biofilms.

Analysis of Radiant Cooling System Configurations Integrated with Cooling Tower for Different Indian Climatic Zones

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mathur, Jyotirmay; Bhandari, Mahabir S; Jain, Robin

Radiant cooling system has proven to be a low energy consumption system for building cooling needs. This study describes the use of cooling tower in radiant cooling system to improve the overall system efficiency. A comprehensive simulation feasibility study of the application of cooling tower in radiant cooling system was performed for the fifteen cities in different climatic zones of India. It was found that in summer, the wet bulb temperature (WBT) of the different climatic zones except warm-humid is suitable for the integration of cooling tower with radiant cooling system. In these climates, cooling tower can provide on averagemore » 24 C to 27 C water In order to achieve the energy saving potential, three different configurations of radiant cooling system have been compared in terms of energy consumption. The different configurations of the radiant cooling system integrated with cooling tower are: (1) provide chilled water to the floor, wall and ceiling mounted tubular installation. (2) provide chilled water to the wall and ceiling mounted tabular installation. In this arrangement a separate chiller has also been used to provide chilled water at 16 C to the floor mounted tubular installation. (3) provide chilled water to the wall mounted tabular installation and a separate chiller is used to provide chilled water at 16 C to the floor and ceiling mounted tabular installation. A dedicated outdoor air system is also coupled for dehumidification and ventilation in all three configurations. A conventional all-air system was simulated as a baseline to compare these configurations for assessing the energy saving potential.« less

PBF Cooling Tower. View of stairway to fan deck. Vents ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Cooling Tower. View of stairway to fan deck. Vents are made of redwood. Camera facing southwest toward north side of Cooling Tower. Siding is corrugated asbestos concrete. Photographer: Kirsh. Date: June 6, 1969. INEEL negative no. 69-3463 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

PBF. Oblique and contextual view of PBF Cooling Tower, PER720. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF. Oblique and contextual view of PBF Cooling Tower, PER-720. Camera facing northeast. Auxiliary Building (PER-624) abuts Cooling Tower. Demolition equipment has arrived. Date: August 2003. INEEL negative no. HD-35-11-2 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

PBF Cooling Tower contextual view. Camera facing southwest. West wing ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Cooling Tower contextual view. Camera facing southwest. West wing and north facade (rear) of Reactor Building (PER-620) is at left; Cooling Tower to right. Photographer: Kirsh. Date: November 2, 1970. INEEL negative no. 70-4913 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

Disinfection of bacterial biofilms in pilot-scale cooling tower systems

PubMed Central

Liu, Yang; Zhang, Wei; Sileika, Tadas; Warta, Richard; Cianciotto, Nicholas P.; Packman, Aaron I.

2015-01-01

The impact of continuous chlorination and periodic glutaraldehyde treatment on planktonic and biofilm microbial communities was evaluated in pilot-scale cooling towers operated continuously for 3 months. The system was operated at a flow rate of 10,080 l day−1. Experiments were performed with a well-defined microbial consortium containing three heterotrophic bacteria: Pseudomonas aeruginosa, Klebsiella pneumoniae and Flavobacterium sp. The persistence of each species was monitored in the recirculating cooling water loop and in biofilms on steel and PVC coupons in the cooling tower basin. The observed bacterial colonization in cooling towers did not follow trends in growth rates observed under batch conditions and, instead, reflected differences in the ability of each organism to remain attached and form biofilms under the high-through flow conditions in cooling towers. Flavobacterium was the dominant organism in the community, while P. aeruginosa and K. pneumoniae did not attach well to either PVC or steel coupons in cooling towers and were not able to persist in biofilms. As a result, the much greater ability of Flavobacterium to adhere to surfaces protected it from disinfection, whereas P. aeruginosa and K. pneumoniae were subject to rapid disinfection in the planktonic state. PMID:21547755

Disinfection of bacterial biofilms in pilot-scale cooling tower systems.

PubMed

Liu, Yang; Zhang, Wei; Sileika, Tadas; Warta, Richard; Cianciotto, Nicholas P; Packman, Aaron I

2011-04-01

The impact of continuous chlorination and periodic glutaraldehyde treatment on planktonic and biofilm microbial communities was evaluated in pilot-scale cooling towers operated continuously for 3 months. The system was operated at a flow rate of 10,080 l day(-1). Experiments were performed with a well-defined microbial consortium containing three heterotrophic bacteria: Pseudomonas aeruginosa, Klebsiella pneumoniae and Flavobacterium sp. The persistence of each species was monitored in the recirculating cooling water loop and in biofilms on steel and PVC coupons in the cooling tower basin. The observed bacterial colonization in cooling towers did not follow trends in growth rates observed under batch conditions and, instead, reflected differences in the ability of each organism to remain attached and form biofilms under the high-through flow conditions in cooling towers. Flavobacterium was the dominant organism in the community, while P. aeruginosa and K. pneumoniae did not attach well to either PVC or steel coupons in cooling towers and were not able to persist in biofilms. As a result, the much greater ability of Flavobacterium to adhere to surfaces protected it from disinfection, whereas P. aeruginosa and K. pneumoniae were subject to rapid disinfection in the planktonic state.

Cooling towers, the neglected energy conservations and money making machine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burger, R.

1996-12-31

The heat Rejection Industry defines a nominal cooling tower as circulating three gallons of water per minute (GPM) per ton of refrigeration from entering the tower at 95 {degrees}F, Hot Water temperature (HWT), Leaving at 85{degrees}F Cold Water Temperature (CWT) at a Design Wet Bulb of 70{degrees}F (WBT). Manufacturers then provide a selection chart based on various wet bulb temperatures and HWTs. The wet bulb fluctuates and varies throughout the world since it is the combination ambient temperature, relative humidity, and/or dew point. Different HWT and CWT requirements are usually charted as they change, so that the user can selectmore » the nominal cooling tower model recommended by the manufacturer. In the specification of cooling towers it is necessary to clearly understand the definition of nominal cooling tower, and to make sure the specification you need addressed can be met by the system you purchase. This should be tested prior to final acceptance.« less

Distinct difference of flaA genotypes of Legionella pneumophila between isolates from bath water and cooling tower water.

PubMed

Amemura-Maekawa, Junko; Kura, Fumiaki; Chang, Bin; Suzuki-Hashimoto, Atsuko; Ichinose, Masayuki; Endo, Takuro; Watanabe, Haruo

2008-09-01

To investigate the genetic difference of Legionella pneumophila in human-made environments, we collected isolates of L. pneumophila from bath water (n = 167) and cooling tower water (n = 128) primarily in the Kanto region in 2001 and 2005. The environmental isolates were serogrouped and sequenced for a target region of flaA. A total of 14 types of flaA genotypes were found: 10 from cooling tower water and nine from bath water. The flaA genotypes of isolates from cooling tower water were quite different from those of bath water.

Vortex-augmented cooling tower-windmill combination

DOEpatents

McAllister, Jr., John E.

1985-01-01

A cooling tower for cooling large quantities of effluent water from a production facility by utilizing natural wind forces includes the use of a series of helically directed air inlet passages extending outwardly from the base of the tower to introduce air from any direction in a swirling vortical pattern while the force of the draft created in the tower makes it possible to place conventional power generating windmills in the air passages to provide power as a by-product.

Vortex-augmented cooling tower - windmill combination

DOEpatents

McAllister, J.E. Jr.

1982-09-02

A cooling tower for cooling large quantities of effluent water from a production facility by utilizing natural wind forces includes the use of a series of helically directed air inlet passages extending outwardly from the base of the tower to introduce air from any direction in a swirling vortical pattern while the force of the draft created in the tower makes it possible to place conventional power generating windmills in the air passage to provide power as a by-product.

A simplified model of a mechanical cooling tower with both a fill pack and a coil

NASA Astrophysics Data System (ADS)

Van Riet, Freek; Steenackers, Gunther; Verhaert, Ivan

2017-11-01

Cooling accounts for a large amount of the global primary energy consumption in buildings and industrial processes. A substantial part of this cooling demand is produced by mechanical cooling towers. Simulations benefit the sizing and integration of cooling towers in overall cooling networks. However, for these simulations fast-to-calculate and easy-to-parametrize models are required. In this paper, a new model is developed for a mechanical draught cooling tower with both a cooling coil and a fill pack. The model needs manufacturers' performance data at only three operational states (at varying air and water flow rates) to be parametrized. The model predicts the cooled, outgoing water temperature. These predictions were compared with experimental data for a wide range of operational states. The model was able to predict the temperature with a maximum absolute error of 0.59°C. The relative error of cooling capacity was mostly between ±5%.

Engineering evaluation of magma cooling-tower demonstration at Nevada Power Company's Sunrise Station

NASA Astrophysics Data System (ADS)

1980-11-01

The Magma Cooling Tower (MCT) process utilizes a falling film heat exchanger integrated into an induced draft cooling tower to evaporate waste water. A hot water source such as return cooling water provides the energy for evaporation. Water quality control is maintained by removing potential scaling constituents to make concentrations of the waste water possible without scaling heat transfer surfaces. A pilot-scale demonstration test of the MCT process was performed from March 1979 through June 1979 at Nevada Power Company's Sunrise Station in Las Vegas, Nevada. The pilot unit extracted heat from the powerplant cooling system to evaporate cooling tower blowdown. Two water quality control methods were employed: makeup/sidestream softening and fluidized bed crystallization. The 11 week softening mode test was successful.

Legionnaires' disease from a cooling tower in a community outbreak in Lidköping, Sweden- epidemiological, environmental and microbiological investigation supported by meteorological modelling.

PubMed

Ulleryd, Peter; Hugosson, Anna; Allestam, Görel; Bernander, Sverker; Claesson, Berndt E B; Eilertz, Ingrid; Hagaeus, Anne-Christine; Hjorth, Martin; Johansson, Agneta; de Jong, Birgitta; Lindqvist, Anna; Nolskog, Peter; Svensson, Nils

2012-11-21

An outbreak of Legionnaires' Disease took place in the Swedish town Lidköping on Lake Vänern in August 2004 and the number of pneumonia cases at the local hospital increased markedly. As soon as the first patients were diagnosed, health care providers were informed and an outbreak investigation was launched. Classical epidemiological investigation, diagnostic tests, environmental analyses, epidemiological typing and meteorological methods. Thirty-two cases were found. The median age was 62 years (range 36 - 88) and 22 (69%) were males. No common indoor exposure was found. Legionella pneumophila serogroup 1 was found at two industries, each with two cooling towers. In one cooling tower exceptionally high concentrations, 1.2 × 109 cfu/L, were found. Smaller amounts were also found in the other tower of the first industry and in one tower of the second plant. Sero- and genotyping of isolated L. pneumophila serogroup 1 from three patients and epidemiologically suspected environmental strains supported the cooling tower with the high concentration as the source. In all, two L. pneumophila strains were isolated from three culture confirmed cases and both these strains were detected in the cooling tower, but one strain in another cooling tower as well. Meteorological modelling demonstrated probable spread from the most suspected cooling tower towards the town centre and the precise location of four cases that were stray visitors to Lidköping. Classical epidemiological, environmental and microbiological investigation of an LD outbreak can be supported by meteorological modelling methods.The broad competence and cooperation capabilities in the investigation team from different authorities were of paramount importance in stopping this outbreak.

Legionnaires’ disease from a cooling tower in a community outbreak in Lidköping, Sweden- epidemiological, environmental and microbiological investigation supported by meteorological modelling

PubMed Central

2012-01-01

Background An outbreak of Legionnaires’ Disease took place in the Swedish town Lidköping on Lake Vänern in August 2004 and the number of pneumonia cases at the local hospital increased markedly. As soon as the first patients were diagnosed, health care providers were informed and an outbreak investigation was launched. Methods Classical epidemiological investigation, diagnostic tests, environmental analyses, epidemiological typing and meteorological methods. Results Thirty-two cases were found. The median age was 62 years (range 36 – 88) and 22 (69%) were males. No common indoor exposure was found. Legionella pneumophila serogroup 1 was found at two industries, each with two cooling towers. In one cooling tower exceptionally high concentrations, 1.2 × 109 cfu/L, were found. Smaller amounts were also found in the other tower of the first industry and in one tower of the second plant. Sero- and genotyping of isolated L. pneumophila serogroup 1 from three patients and epidemiologically suspected environmental strains supported the cooling tower with the high concentration as the source. In all, two L. pneumophila strains were isolated from three culture confirmed cases and both these strains were detected in the cooling tower, but one strain in another cooling tower as well. Meteorological modelling demonstrated probable spread from the most suspected cooling tower towards the town centre and the precise location of four cases that were stray visitors to Lidköping. Conclusions Classical epidemiological, environmental and microbiological investigation of an LD outbreak can be supported by meteorological modelling methods. The broad competence and cooperation capabilities in the investigation team from different authorities were of paramount importance in stopping this outbreak. PMID:23171054

Legionella longbeachae detected in an industrial cooling tower linked to a legionellosis outbreak, New Zealand, 2015; possible waterborne transmission?

PubMed

Thornley, C N; Harte, D J; Weir, R P; Allen, L J; Knightbridge, K J; Wood, P R T

2017-08-01

A legionellosis outbreak at an industrial site was investigated to identify and control the source. Cases were identified from disease notifications, workplace illness records, and from clinicians. Cases were interviewed for symptoms and risk factors and tested for legionellosis. Implicated environmental sources were sampled and tested for legionella. We identified six cases with Legionnaires' disease and seven with Pontiac fever; all had been exposed to aerosols from the cooling towers on the site. Nine cases had evidence of infection with either Legionella pneumophila serogroup (sg) 1 or Legionella longbeachae sg1; these organisms were also isolated from the cooling towers. There was 100% DNA sequence homology between cooling tower and clinical isolates of L. pneumophila sg1 using sequence-based typing analysis; no clinical L. longbeachae isolates were available to compare with environmental isolates. Routine monitoring of the towers prior to the outbreak failed to detect any legionella. Data from this outbreak indicate that L. pneumophila sg1 transmission occurred from the cooling towers; in addition, L. longbeachae transmission was suggested but remains unproven. L. longbeachae detection in cooling towers has not been previously reported in association with legionellosis outbreaks. Waterborne transmission should not be discounted in investigations for the source of L. longbeachae infection.

Legionnaires' Disease Outbreaks and Cooling Towers, New York City, New York, USA.

PubMed

Fitzhenry, Robert; Weiss, Don; Cimini, Dan; Balter, Sharon; Boyd, Christopher; Alleyne, Lisa; Stewart, Renee; McIntosh, Natasha; Econome, Andrea; Lin, Ying; Rubinstein, Inessa; Passaretti, Teresa; Kidney, Anna; Lapierre, Pascal; Kass, Daniel; Varma, Jay K

2017-11-01

The incidence of Legionnaires' disease in the United States has been increasing since 2000. Outbreaks and clusters are associated with decorative, recreational, domestic, and industrial water systems, with the largest outbreaks being caused by cooling towers. Since 2006, 6 community-associated Legionnaires' disease outbreaks have occurred in New York City, resulting in 213 cases and 18 deaths. Three outbreaks occurred in 2015, including the largest on record (138 cases). Three outbreaks were linked to cooling towers by molecular comparison of human and environmental Legionella isolates, and the sources for the other 3 outbreaks were undetermined. The evolution of investigation methods and lessons learned from these outbreaks prompted enactment of a new comprehensive law governing the operation and maintenance of New York City cooling towers. Ongoing surveillance and program evaluation will determine if enforcement of the new cooling tower law reduces Legionnaires' disease incidence in New York City.

Legionnaires’ Disease Outbreaks and Cooling Towers, New York City, New York, USA

PubMed Central

Fitzhenry, Robert; Cimini, Dan; Balter, Sharon; Boyd, Christopher; Alleyne, Lisa; Stewart, Renee; McIntosh, Natasha; Econome, Andrea; Lin, Ying; Rubinstein, Inessa; Passaretti, Teresa; Kidney, Anna; Lapierre, Pascal; Kass, Daniel; Varma, Jay K.

2017-01-01

The incidence of Legionnaires’ disease in the United States has been increasing since 2000. Outbreaks and clusters are associated with decorative, recreational, domestic, and industrial water systems, with the largest outbreaks being caused by cooling towers. Since 2006, 6 community-associated Legionnaires’ disease outbreaks have occurred in New York City, resulting in 213 cases and 18 deaths. Three outbreaks occurred in 2015, including the largest on record (138 cases). Three outbreaks were linked to cooling towers by molecular comparison of human and environmental Legionella isolates, and the sources for the other 3 outbreaks were undetermined. The evolution of investigation methods and lessons learned from these outbreaks prompted enactment of a new comprehensive law governing the operation and maintenance of New York City cooling towers. Ongoing surveillance and program evaluation will determine if enforcement of the new cooling tower law reduces Legionnaires’ disease incidence in New York City. PMID:29049017

Main photoautotrophic components of biofilms in natural draft cooling towers.

PubMed

Hauer, Tomáš; Čapek, Petr; Böhmová, Petra

2016-05-01

While photoautotrophic organisms are an important component of biofilms that live in certain regions of natural draft cooling towers, little is known about these communities. We therefore examined 18 towers at nine sites to identify the general patterns of community assembly in three distinct tower parts, and we examined how community structures differ depending on geography. We also compared the newly acquired data with previously published data. The bottom sections of draft cooling towers are mainly settled by large filamentous algae, primarily Cladophora glomerata. The central portions of towers host a small amount of planktic algae biomass originating in the cooling water. The upper fourths of towers are colonized by biofilms primarily dominated by cyanobacteria, e.g., members of the genera Gloeocapsa and Scytonema. A total of 41 taxa of phototrophic microorganisms were identified. Species composition of the upper fourth of all towers was significantly affected by cardinal position. There was different species composition at positions facing north compared to positions facing south. West- and east-facing positions were transitory and highly similar to each other in terms of species composition. Biofilms contribute to the degradation of paint coatings inside towers.

Influence of detergents on water drift in cooling towers

NASA Astrophysics Data System (ADS)

Vitkovicova, Rut

An influence of detergents on the water drift from the cooling tower was experimentally investigated. For this experimental measurements was used a model cooling tower, especially an experimental aerodynamic line, which is specially designed for the measurement and monitoring of processes taking place around the eliminators of the liquid phase. The effect of different concentrations of detergent in the cooling water on the drift of water droplets from a commonly used type eliminator was observed with visualization methods.

PBF Cooling Tower (PER720). Camera faces east to show west ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Cooling Tower (PER-720). Camera faces east to show west facade. Sloped (louvered) panels in this and opposite facade allow air to enter tower and cool water falling on splash bars within. Date: August 2003. INEEL negative no. HD-35-10-2 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

Parametric study of closed wet cooling tower thermal performance

NASA Astrophysics Data System (ADS)

Qasim, S. M.; Hayder, M. J.

2017-08-01

The present study involves experimental and theoretical analysis to evaluate the thermal performance of modified Closed Wet Cooling Tower (CWCT). The experimental study includes: design, manufacture and testing prototype of a modified counter flow forced draft CWCT. The modification based on addition packing to the conventional CWCT. A series of experiments was carried out at different operational parameters. In view of energy analysis, the thermal performance parameters of the tower are: cooling range, tower approach, cooling capacity, thermal efficiency, heat and mass transfer coefficients. The theoretical study included develops Artificial Neural Network (ANN) models to predicting various thermal performance parameters of the tower. Utilizing experimental data for training and testing, the models simulated by multi-layer back propagation algorithm for varying all operational parameters stated in experimental test.

New Directions for Evaporative Cooling Systems.

ERIC Educational Resources Information Center

Robison, Rita

1981-01-01

New energy saving technology can be applied to older cooling towers; in addition, evaporative chilling, a process that links a cooling tower to the chilling equipment, can reduce energy use by 80 percent. (Author/MLF)

The nominal cooling tower

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burger, R.

1995-12-31

The heat Rejection Industry defines a nominal cooling tower as circulating three gallons of water per minute (GPM) per ton of refrigeration from entering the tower at 95{degrees}F. Hot Water temperature (HWT) Leaving at 85{degrees}F Cold Water Temperature (CWT) at a Design Wet Bulb of 70{degrees}F (WBT). Manufacturers then provide a selection chart based on various wet bulb temperatures and HWTs. The wet bulb fluctuates and varies through out the world since it is the combination ambient temperature, relative humidity, and/or dew point. Different HWT and CWT requirements are usually charted as they change, so that the user can selectmore » the nominal cooling tower model recommended by the manufacturer. Ask any HVAC operator, refinery manager, power generating station operator what happens when the Wet Bulb reaches or exceeds the design WBT of the area. He probably will tell you, {open_quotes}My cooling tower works quite well, but in the summer time, I usually have trouble with it.{close_quotes} This occurs because he is operating a nominal cooling tower.« less

PBF Cooling Tower and it Auxiliary Building (PER624) to left ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Cooling Tower and it Auxiliary Building (PER-624) to left of tower. Camera facing west and the east louvered face of the tower. Details include secondary coolant water riser piping and flow control valves (butterfly valves) to distribute water evenly to all sections of tower. Photographer: Holmes. Date: May, 20, 1970. INEEL negative no. 70-2322 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

Cooling towers--a potential environmental source of slow-growing mycobacterial species.

PubMed

Black, Walter C; Berk, Sharon G

2003-01-01

Over the last decade a rise in the frequency of disease caused by nontuberculous mycobacteria (NTM) has occurred, especially among AIDS patients. The lack of evidence for person-to-person transmission indicates the environment is a source of infection. The ecology and environmental sources of NTMs are poorly understood, and many pathogenic strains have not been observed outside of clinical cases. Several species of NTMs have been reported from treated water distribution systems; however, one type of manmade environment that has not been examined for mycobacteria is that of cooling towers of air-conditioning systems. Such environments not only harbor a variety of microbial species, they also disseminate them in aerosols. The present investigation examined nine cooling towers from various locations in the United States. Cooling tower water was concentrated, treated with cetylpyridinium chloride, and plated onto Middlebrook 7H10 agar supplemented with OADC and cycloheximide. Colonies presumed to be mycobacterial species were isolated and acid-fast stained. Identification was made by amplifying and sequencing 1450 bp fragments of the 16S rRNA gene in both directions, and comparing resulting sequences with those in GenBank. Results showed that at least 75% of tower samples contained NTMs, and most of the isolates closely matched known mycobacterial pathogens. Isolates most closely matched the following GenBank sequences: Mycobacterium intracellulare, M. szulgai, M. bohemicum, M. gordonae, M. nonchromogenicum, and M. n. sp. "Fuerth 1999." This is the first report of specific NTMs in cooling tower water, and the first report of M. n. sp. "Fuerth 1999" from any environmental sample. Although cooling towers have a relatively high pH, they may favor the growth and dissemination of such potential pathogens, and future epidemiologic investigations should consider cooling towers as possible environmental sources of mycobacteria.

Long alkyl-chain imidazolium ionic liquids: Antibiofilm activity against phototrophic biofilms.

PubMed

Reddy, G Kiran Kumar; Nancharaiah, Y V; Venugopalan, V P

2017-07-01

Biofilm formation is problematic and hence undesirable in medical and industrial settings. In addition to bacteria, phototrophic organisms are an integral component of biofilms that develop on surfaces immersed in natural waters. 1-Alkyl-3-methyl imidazolium ionic liquids (IL) with varying alkyl chain length were evaluated for their influence on the formation of monospecies (Navicula sp.) and multispecies biofilms under phototrophic conditions. An IL with a long alkyl side chain, 1-hexadecyl-3-methylimidaazolium chloride ([C 16 (MIM)][Cl]) retarded growth, adhesion and biofilm formation of Navicula sp. at concentrations as low as 5μM. Interestingly, [C 16 (MIM)][Cl] was very effective in preventing multispecies phototrophic biofilms on fibre reinforced plastic surfaces immersed in natural waters (fresh and seawater). SYTOX ® Green staining and chlorophyll leakage assay confirmed that the biocidal activity of the IL was exerted through cell membrane disruption. The data show that [C 16 (MIM)][Cl] is a potent inhibitor of phototrophic biofilms at micromolar concentrations and a promising agent for biofilm control in re-circulating cooling water systems. This is the first report that ionic liquids inhibit biofilm formation by phototrophic organisms which are important members of biofilms in streams and cooling towers. Copyright © 2017 Elsevier B.V. All rights reserved.

Rapid Identification of a Cooling Tower-Associated Legionnaires' Disease Outbreak Supported by Polymerase Chain Reaction Testing of Environmental Samples, New York City, 2014-2015.

PubMed

Benowitz, Isaac; Fitzhenry, Robert; Boyd, Christopher; Dickinson, Michelle; Levy, Michael; Lin, Ying; Nazarian, Elizabeth; Ostrowsky, Belinda; Passaretti, Teresa; Rakeman, Jennifer; Saylors, Amy; Shamoonian, Elena; Smith, Terry-Ann; Balter, Sharon

2018-04-01

We investigated an outbreak of eight Legionnaires' disease cases among persons living in an urban residential community of 60,000 people. Possible environmental sources included two active cooling towers (air-conditioning units for large buildings) <1 km from patient residences, a market misting system, a community-wide water system used for heating and cooling, and potable water. To support a timely public health response, we used real-time polymerase chain reaction (PCR) to identify Legionella DNA in environmental samples within hours of specimen collection. We detected L. pneumophila serogroup 1 DNA only at a power plant cooling tower, supporting the decision to order remediation before culture results were available. An isolate from a power plant cooling tower sample was indistinguishable from a patient isolate by pulsed-field gel electrophoresis, suggesting the cooling tower was the outbreak source. PCR results were available <1 day after sample collection, and culture results were available as early as 5 days after plating. PCR is a valuable tool for identifying Legionella DNA in environmental samples in outbreak settings.

Ozone inhibits corrosion in cooling towers

NASA Technical Reports Server (NTRS)

French, K. R.; Howe, R. D.; Humphrey, M. F.

1980-01-01

Commercially available corona discharge ozone generator, fitted onto industrial cooling tower, significantly reduces formation of scales (calcium carbonate) and corrosion. System also controls growth of algae and other microorganisms. Modification lowers cost and improves life of cooling system.

[Studies on Legionella-contamination to the air-conditioning cooling towers in big hotels and on its seroprevalence in the related populations in Beijing].

PubMed

Peng, X; Pei, H; Li, X; He, X; Yang, A; Tang, Y; Cao, R

2000-08-01

To understand the situation of Legionella-contamination at cooling towers of big hotel and the level of Legionella-infection among related populations in Beijing. Thirty-eight cooling towers of hotels were chosen for detection of Legionella. Four hundred and fourteen staff members from the hotels were selected as exposure group, with another 414 from general population as controls, for the detection of Legionella antibodies. Sixteen strains of Legionella pneumophila (Lp) were isolated from 21 of the 38 cooling towers, and the predominant strain was Lp serum group 1 (50%, 8/16). The seroprevalence of Lp antibodies for the exposure group was 9.9% (41/414), comparing to 3.5% (14/414) from the control group. The difference was statistically significant (chi(2) = 14.2, P < 0.01). Legionella was discovered in air-conditioning cooling tower of the hotels, which threatened the health to the population exposed to it.

Bacterial community dynamics in a cooling tower with emphasis on pathogenic bacteria and Legionella species using universal and genus-specific deep sequencing.

PubMed

Pereira, Rui P A; Peplies, Jörg; Höfle, Manfred G; Brettar, Ingrid

2017-10-01

Cooling towers are the major source of outbreaks of legionellosis in Europe and worldwide. These outbreaks are mostly associated with Legionella species, primarily L. pneumophila, and its surveillance in cooling tower environments is of high relevance to public health. In this study, a combined NGS-based approach was used to study the whole bacterial community, specific waterborne and water-based bacterial pathogens, especially Legionella species, targeting the 16S rRNA gene. This approach was applied to water from a cooling tower obtained by monthly sampling during two years. The studied cooling tower was an open circuit cooling tower with lamellar cooling situated in Braunschweig, Germany. A highly diverse bacterial community was observed with 808 genera including 25 potentially pathogenic taxa using universal 16S rRNA primers. Sphingomonas and Legionella were the most abundant pathogenic genera. By applying genus-specific primers for Legionella, a diverse community with 85 phylotypes, and a representative core community with substantial temporal heterogeneity was observed. A high percentage of sequences (65%) could not be affiliated to an acknowledged species. L. pneumophila was part of the core community and the most abundant Legionella species reinforcing the importance of cooling towers as its environmental reservoir. Major temperature shifts (>10 °C) were the key environmental factor triggering the reduction or dominance of the Legionella species in the Legionella community dynamics. In addition, interventions by chlorine dioxide had a strong impact on the Legionella community composition but not on the whole bacterial community. Overall, the presented results demonstrated the value of a combined NGS approach for the molecular monitoring and surveillance of health related pathogens in man-made freshwater systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

Contrastive analysis of cooling performance between a high-level water collecting cooling tower and a typical cooling tower

NASA Astrophysics Data System (ADS)

Wang, Miao; Wang, Jin; Wang, Jiajin; Shi, Cheng

2018-02-01

A three-dimensional (3D) numerical model is established and validated for cooling performance optimization between a high-level water collecting natural draft wet cooling tower (HNDWCT) and a usual natural draft wet cooling tower (UNDWCT) under the actual operation condition at Wanzhou power plant, Chongqing, China. User defined functions (UDFs) of source terms are composed and loaded into the spray, fill and rain zones. Considering the conditions of impact on three kinds of corrugated fills (Double-oblique wave, Two-way wave and S wave) and four kinds of fill height (1.25 m, 1.5 m, 1.75 m and 2 m), numerical simulation of cooling performance are analysed. The results demonstrate that the S wave has the highest cooling efficiency in three fills for both towers, indicating that fill characteristics are crucial to cooling performance. Moreover, the cooling performance of the HNDWCT is far superior to that of the UNDWCT with fill height increases of 1.75 m and above, because the air mass flow rate in the fill zone of the HNDWCT improves more than that in the UNDWCT, as a result of the rain zone resistance declining sharply for the HNDWCT. In addition, the mass and heat transfer capacity of the HNDWCT is better in the tower centre zone than in the outer zone near the tower wall under a uniform fill layout. This behaviour is inverted for the UNDWCT, perhaps because the high-level collection devices play the role of flow guiding in the inner zone. Therefore, when non-uniform fill layout optimization is applied to the HNDWCT, the inner zone increases in height from 1.75 m to 2 m, the outer zone reduces in height from 1.75 m to 1.5 m, and the outlet water temperature declines approximately 0.4 K compared to that of the uniform layout.

Alkaline approach to treating cooling towers for control of Legionella pneumophila

DOE Office of Scientific and Technical Information (OSTI.GOV)

States, S.J.; Conley, L.F.; Towner, S.G.

1987-08-01

Earlier field and laboratory studies have shown that Legionella species survive and multiply in the pH range 5.5 to 9.2. Additionally, the technical feasibility of operating cooling towers at elevated alkalinities and pH has previously been documented by published guidelines. The guidelines indicate that these conditions facilitate corrosion control and favor chlorine persistence which enhances the effectiveness of continuous chlorination in biofouling control. This information suggest that control of Legionella species in cooling towers can be accomplished by operating the towers under alkaline conditions. To test this possibility, we collected water samples over a period of months from a hospitalmore » cooling tower. The samples were analyzed for a variety of chemical parameters. Subsamples were pasteurized and inoculated with non-agar-passaged Legionella pneumophila which had been maintained in tap water. Correlation of subsequent Legionella growth with corresponding pH and alkalinity values revealed statistically significant inverse associations. These data support the hypothesis that operating cooling towers outside of the optimal conditions for Legionella growth (e.g., at elevated alkalinities and a pH greater than 9) may be a useful approach to controlling growth in this habitat.« less

Combination film/splash fill for overcoming film fouling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Phelps, P.M.; Minett, T.O.

1995-02-01

In summary, this large cooling tower user has found the Phelps film/splash Stack-Pack fill design to attain a substantial improvement in capability of their existing crossflow cooling towers, without increasing fan power or tower size. The lack of fouling in the film fill component of this fill design is due to the use of film fill with large (1 inch) spacing between sheets, coupled with effective water treatment as provided by Nalco. This combination of factors provides a proven method for significantly increasing crossflow or counterflow cooling tower capability while minimizing chances of serious fill fouling.

Removal of dissolved and colloidal silica

DOEpatents

Midkiff, William S.

2002-01-01

Small amorphous silica particles are used to provide a relatively large surface area upon which silica will preferentially adsorb, thereby preventing or substantially reducing scaling caused by deposition of silica on evaporative cooling tower components, especially heat exchange surfaces. The silica spheres are contacted by the cooling tower water in a sidestream reactor, then separated using gravity separation, microfiltration, vacuum filtration, or other suitable separation technology. Cooling tower modifications for implementing the invention process have been designed.

Rapid Identification of a Cooling Tower-Associated Legionnaires’ Disease Outbreak Supported by Polymerase Chain Reaction Testing of Environmental Samples, New York City, 2014–2015

PubMed Central

Benowitz, Isaac; Fitzhenry, Robert; Boyd, Christopher; Dickinson, Michelle; Levy, Michael; Lin, Ying; Nazarian, Elizabeth; Ostrowsky, Belinda; Passaretti, Teresa; Rakeman, Jennifer; Saylors, Amy; Shamoonian, Elena; Smith, Terry-Ann; Balter, Sharon

2018-01-01

We investigated an outbreak of eight Legionnaires’ disease cases among persons living in an urban residential community of 60,000 people. Possible environmental sources included two active cooling towers (air-conditioning units for large buildings) <1 km from patient residences, a market misting system, a community-wide water system used for heating and cooling, and potable water. To support a timely public health response, we used real-time polymerase chain reaction (PCR) to identify Legionella DNA in environmental samples within hours of specimen collection. We detected L. pneumophila serogroup 1 DNA only at a power plant cooling tower, supporting the decision to order remediation before culture results were available. An isolate from a power plant cooling tower sample was indistinguishable from a patient isolate by pulsed-field gel electrophoresis, suggesting the cooling tower was the outbreak source. PCR results were available <1 day after sample collection, and culture results were available as early as 5 days after plating. PCR is a valuable tool for identifying Legionella DNA in environmental samples in outbreak settings. PMID:29780175

Experimental determination of drift and PM10 cooling tower emissions: Influence of components and operating conditions.

PubMed

Ruiz, J; Kaiser, A S; Lucas, M

2017-11-01

Cooling tower emissions have become an increasingly common hazard to the environment (air polluting, ice formation and salts deposition) and to the health (Legionella disease) in the last decades. Several environmental policies have emerged in recent years limiting cooling tower emissions but they have not prevented an increasing intensity of outbreaks. Since the level of emissions depends mainly on cooling tower component design and the operating conditions, this paper deals with an experimental investigation of the amount of emissions, drift and PM 10 , emitted by a cooling tower with different configurations (drift eliminators and distribution systems) and working under several operating conditions. This objective is met by the measurement of cooling tower source emission parameters by means of the sensitive paper technique. Secondary objectives were to contextualize the observed emission rates according to international regulations. Our measurements showed that the drift rates included in the relevant international standards are significantly higher than the obtained results (an average of 100 times higher) and hence, the environmental problems may occur. Therefore, a revision of the standards is recommended with the aim of reducing the environmental and human health impact. By changing the operating conditions and the distribution system, emissions can be reduced by 52.03% and 82% on average. In the case of drift eliminators, the difference ranges from 18.18% to 98.43% on average. As the emissions level is clearly influenced by operating conditions and components, regulation tests should be referred to default conditions. Finally, guidelines to perform emission tests and a selection criterion of components and conditions for the tested cooling tower are proposed. Copyright © 2017 Elsevier Ltd. All rights reserved.

A community outbreak of Legionnaires' disease: evidence of a cooling tower as the source.

PubMed

Sabria, M; Alvarez, J; Dominguez, A; Pedrol, A; Sauca, G; Salleras, L; Lopez, A; Garcia-Nuñez, M A; Parron, I; Barrufet, M P

2006-07-01

A community outbreak of Legionella pneumonia in the district of Cerdanyola, Mataró (Catalonia, Spain) was investigated in an epidemiological, environmental and molecular study. Each patient was interviewed to ascertain personal risk-factors and the clinical and epidemiological data. Isolates of Legionella from patients and water samples were subtyped by pulsed-field gel electrophoresis. Between 7 August and 25 August 2002, 113 cases of Legionella pneumonia fulfilling the outbreak case definition criteria were reported, with 84 (74%) cases being located within a 500-m radius of the suspected cooling tower source. In this area, the relative risk of being infected was 54.6 (95% CI 25.3-118.1) compared with individuals living far from the cooling tower. Considering the population residing in the Cerdanyola district (28,256 inhabitants) as a reference population, the attack rate for the outbreak was 399.9 cases/100,000 inhabitants, and the case fatality rate was 1.8%. A single DNA subtype was observed among the ten clinical isolates, and one of the subtypes from the cooling tower matched exactly with the clinical subtype. Nine days after closing the cooling tower, new cases of pneumonia caused by Legionella ceased to appear. The epidemiological features of the outbreak, and the microbiological and molecular investigations, implicated the cooling tower as the source of infection.

Occurrence of Infected Free-Living Amoebae in Cooling Towers of Southern Brazil.

PubMed

Soares, Scheila S; Souza, Thamires K; Berté, Francisco K; Cantarelli, Vlademir V; Rott, Marilise B

2017-12-01

This study determined the occurrence of potentially pathogenic free-living amoebae (FLA) and bacteria associated with amoebae in air-conditioning cooling towers in southern Brazil. Water samples were collected from 36 cooling systems from air-conditioning in the state of Rio Grande do Sul, Brazil. The organisms were identified using polymerase chain reaction (PCR) and sequencing automated. The results showed that these aquatic environments, with variable temperature, are potential "hot spots" for emerging human pathogens like free-living amoebae and bacteria associated. In total, 92% of the cooling-tower samples analyzed were positive for FLA, and Acanthamoeba was the dominant genus by culture and PCR. Amoebal isolates revealed intracellular bacteria in 39.3% of them and all were confirmed as members of the genus Pseudomonas. The results obtained show the important role of cooling towers as a source of amoebae-associated pathogens.

Routine sampling and the control of Legionella spp. in cooling tower water systems.

PubMed

Bentham, R H

2000-10-01

Cooling water samples from 31 cooling tower systems were cultured for Legionella over a 16-week summer period. The selected systems were known to be colonized by Legionella. Mean Legionella counts and standard deviations were calculated and time series correlograms prepared for each system. The standard deviations of Legionella counts in all the systems were very large, indicating great variability in the systems over the time period. Time series analyses demonstrated that in the majority of cases there was no significant relationship between the Legionella counts in the cooling tower at time of collection and the culture result once it was available. In the majority of systems (25/28), culture results from Legionella samples taken from the same systems 2 weeks apart were not statistically related. The data suggest that determinations of health risks from cooling towers cannot be reliably based upon single or infrequent Legionella tests.

Chalk point cooling tower project: effects of simulated saline cooling tower drift on woody species. Master's thesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Francis, B.A.

1977-07-01

Cooling towers of power plants are used to dissipate waste heat into the atmosphere. If saline water is used for cooling, a saline aerosol known as drift is released into the atmosphere. Drift effects on vegetation are not well known. To simulate drift for a field study, cooling tower basin water was sprayed thirty separate times during a 46-day period in 1975 on Virginia pine (Pinus virginiana), flowering dogwood (Cornus florida), tulip tree (Liriodendron tulipfera), and California privet (Ligustrum ovalifolium), Norway spruce (Picea abies), and white ash (Fraxinus americana) were added in 1976 and all trees were sprayed 43 timesmore » during a 59-day period. Only dogwood leaves showed significant injury. Absence of injury on other species was probably due to the ability of their leaves to exclude, or reduce absorption of, toxic concentrations of the ions supplied.« less

PBF Cooling Tower. Camera facing southwest. Round piers will support ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Cooling Tower. Camera facing southwest. Round piers will support Tower's wood "fill" or "packing." Black-topped stack in far distance is at Idaho Chemical Processing Plant. Photographer: John Capek. Date: October 16, 1968. INEEL negative no. 68-4097 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

In Hot Water: A Cooling Tower Case Study

ERIC Educational Resources Information Center

Cochran, Justin; Raju, P. K.; Sankar, Chetan

2005-01-01

Problem Statement: Vogtle Electric Generating Plant operated by Southern Nuclear Operating Company, a subsidiary of Southern Company, has found itself at a decision point. Vogtle depends on their natural draft cooling towers to remove heat from the power cycle. Depending on the efficiency of the towers, the cycle can realize more or less power…

Industrial Process Cooling Towers: National Emission Standards for Hazardous Air Pollutants

EPA Pesticide Factsheets

Standards limiting discharge of chromium compound air emissions from industrial process cooling towers (IPCT's). Includes rule history, Federal Registry citations, implementation information and additional resources.

PBF Cooling Tower detail. Camera facing southwest into north side ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Cooling Tower detail. Camera facing southwest into north side of Tower. Five horizontal layers of splash bars constitute fill decks, which will break up falling water into droplets, promoting evaporative cooling. Louvered faces, through which air enters tower, are on east and west sides. Louvers have been installed. Support framework for one of two venturi-shaped fan stacks (or "vents") is in center top. Orifices in hot basins (not in view) will distribute water over fill. Photographer: Kirsh. Date: May 15, 1969. INEEL negative no. 69-3032 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

ETR COOLING TOWER. PUMP HOUSE (TRA645) IN SHADOW OF TOWER ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

ETR COOLING TOWER. PUMP HOUSE (TRA-645) IN SHADOW OF TOWER ON LEFT. AT LEFT OF VIEW, HIGH-BAY BUILDING IS ETR. ONE STORY ATTACHMENT IS ETR ELECTRICAL BUILDING. STACK AT RIGHT IS ETR STACK; MTR STACK IS TOWARD LEFT. CAMERA FACING NORTHEAST. INL NEGATIVE NO. 56-3799. Jack L. Anderson, 11/26/1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

40 CFR 63.400 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Hazardous Air Pollutants for Industrial Process Cooling Towers § 63.400 Applicability. (a) The provisions of this subpart apply to all new and existing industrial process cooling towers that are operated with...

Technology for Water Treatment

NASA Technical Reports Server (NTRS)

1992-01-01

There are approximately 500,000 water cooling towers in the United States, all of which must be kept clear of "scale" and corrosion and free of pollutants and bacteria. Electron Pure, Ltd. manufactures a hydro cooling tower conditioner as well as an automatic pool sanitizer. The pool sanitizer consists of two copper/silver electrodes placed in a chamber mounted in the pool's recirculation system. The tower conditioner combines the ionization system with a water conditioner, pump, centrifugal solids separator and timer. The system saves water, eliminates algae and operates maintenance and chemical free. The company has over 100 distributors in the U.S. as well as others in 20 foreign countries. The buildup of scale and corrosion is the most costly maintenance problem in cooling tower operation. Jet Propulsion Laboratory successfully developed a non-chemical system that not only curbed scale and corrosion, but also offered advantages in water conservation, cost savings and the elimination of toxic chemical discharge. In the system, ozone is produced by an on-site generator and introduced to the cooling tower water. Organic impurities are oxidized, and the dissolved ozone removes bacteria and scale. National Water Management, a NASA licensee, has installed its ozone advantage systems at some 200 cooling towers. Customers have saved money and eliminated chemical storage and discharge.

Assessing the environmental health relevance of cooling towers--a systematic review of legionellosis outbreaks.

PubMed

Walser, Sandra M; Gerstner, Doris G; Brenner, Bernhard; Höller, Christiane; Liebl, Bernhard; Herr, Caroline E W

2014-03-01

Bioaerosols from cooling towers are often suspected to cause community-acquired legionellosis outbreaks. Although Legionella infections can mostly be assigned to the emission sources, uncertainty exists about the release and distribution into the air, the occurrence of the respirable virulent form and the level of the infective concentration. Our study aimed to evaluate studies on legionellosis outbreaks attributed to cooling towers published within the last 11 years by means of a systematic review of the literature. 19 legionellosis outbreaks were identified affecting 12 countries. Recurring events were observed in Spain and Great Britain. In total, 1609 confirmed cases of legionellosis and a case-fatality rate of approximately 6% were reported. Duration of outbreaks was 65 days on average. For diagnosis the urinary antigen test was mainly used. Age, smoking, male sex and underlying diseases (diabetes, immunodeficiency) could be confirmed as risk factors. Smoking and underlying diseases were the most frequent risk factors associated with legionellosis in 11 and 10 of the 19 studies, respectively. The meteorological conditions varied strongly. Several studies reported a temporal association of outbreaks with inadequate maintenance of the cooling systems. A match of clinical and environmental isolates by serotyping and/or molecular subtyping could be confirmed in 84% of outbreaks. Legionella-contaminated cooling towers as environmental trigger, in particular in the neighbourhood of susceptible individuals, can cause severe health problems and even death. To prevent and control Legionella contamination of cooling towers, maintenance actions should focus on low-emission cleaning procedures of cooling towers combined with control measurements of water and air samples. Procedures allowing rapid detection and risk assessment in the case of outbreaks are essential for adequate public health measures. Systematic registration of cooling towers will facilitate the identification of the source of outbreaks and help to shorten their duration. Copyright © 2013 Elsevier GmbH. All rights reserved.

Wet/dry cooling tower and method

DOEpatents

Glicksman, Leon R.; Rohsenow, Warren R.

1981-01-01

A wet/dry cooling tower wherein a liquid to-be-cooled is flowed along channels of a corrugated open surface or the like, which surface is swept by cooling air. The amount of the surface covered by the liquid is kept small compared to the dry part thereof so that said dry part acts as a fin for the wet part for heat dissipation.

User's manual for the BNW-I optimization code for dry-cooled power plants. Volume III. [PLCIRI

DOE Office of Scientific and Technical Information (OSTI.GOV)

Braun, D.J.; Daniel, D.J.; De Mier, W.V.

1977-01-01

This appendix to User's Manual for the BNW-1 Optimization Code for Dry-Cooled Power Plants provides a listing of the BNW-I optimization code for determining, for a particular size power plant, the optimum dry cooling tower design using a plastic tube cooling surface and circular tower arrangement of the tube bundles. (LCL)

Startup of Pumping Units in Process Water Supplies with Cooling Towers at Thermal and Nuclear Power Plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berlin, V. V., E-mail: vberlin@rinet.ru; Murav’ev, O. A., E-mail: muraviov1954@mail.ru; Golubev, A. V., E-mail: electronik@inbox.ru

Aspects of the startup of pumping units in the cooling and process water supply systems for thermal and nuclear power plants with cooling towers, the startup stages, and the limits imposed on the extreme parameters during transients are discussed.

In Hot Water: A Cooling Tower Case Study. Instructor's Manual

ERIC Educational Resources Information Center

Cochran, Justin; Raju, P. K.; Sankar, Chetan

2005-01-01

Vogtle Electric Generating Plant operated by Southern Nuclear Operating Company, a subsidiary of Southern Company, has found itself at a decision point. Vogtle depends on their natural draft cooling towers to remove heat from the power cycle. Depending on the efficiency of the towers, the cycle can realize more or less power output. The efficiency…

72. Joe Moore, Photographer. September, 1996. BEVATRON COOLING TOWERS (3 ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

72. Joe Moore, Photographer. September, 1996. BEVATRON COOLING TOWERS (3 SHOWN) AND MOTOR GENERATOR ON RIGHT - University of California Radiation Laboratory, Bevatron, 1 Cyclotron Road, Berkeley, Alameda County, CA

Ozonation of cooling tower waters

NASA Technical Reports Server (NTRS)

Humphrey, M. F.; French, K. R.; Howe, R. D. (Inventor)

1979-01-01

Continuous ozone injection into water circulating between a cooling tower and heat exchanger with heavy scale deposits inhibits formation of further deposits, promotes flaking of existing deposits, inhibits chemical corrosion and controls algae and bacteria.

7. COOLING TOWER FROM ROOF. Hot Springs National Park, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. COOLING TOWER FROM ROOF. - Hot Springs National Park, Bathhouse Row, Quapaw Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

14. ENGINE TEST CELL BUILDING ROOF. VENTILATION AND COOLING TOWERS. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

14. ENGINE TEST CELL BUILDING ROOF. VENTILATION AND COOLING TOWERS. LOOKING EAST. - Fairchild Air Force Base, Engine Test Cell Building, Near intersection of Arnold Street & George Avenue, Spokane, Spokane County, WA

Final Rule for Industrial Process Cooling Towers: Fact Sheet

EPA Pesticide Factsheets

Fact sheet concerning a final rule to reduce air toxics emissions from industrial process cooling towers. Air toxics are those pollutants known or suspected of causing cancer or other serious health effects.

A Large Community Outbreak of Legionnaires' Disease Associated With a Cooling Tower in New York City, 2015.

PubMed

Weiss, Don; Boyd, Christopher; Rakeman, Jennifer L; Greene, Sharon K; Fitzhenry, Robert; McProud, Trevor; Musser, Kimberlee; Huang, Li; Kornblum, John; Nazarian, Elizabeth J; Fine, Annie D; Braunstein, Sarah L; Kass, Daniel; Landman, Keren; Lapierre, Pascal; Hughes, Scott; Tran, Anthony; Taylor, Jill; Baker, Deborah; Jones, Lucretia; Kornstein, Laura; Liu, Boning; Perez, Rodolfo; Lucero, David E; Peterson, Eric; Benowitz, Isaac; Lee, Kristen F; Ngai, Stephanie; Stripling, Mitch; Varma, Jay K

Infections caused by Legionella are the leading cause of waterborne disease outbreaks in the United States. We investigated a large outbreak of Legionnaires' disease in New York City in summer 2015 to characterize patients, risk factors for mortality, and environmental exposures. We defined cases as patients with pneumonia and laboratory evidence of Legionella infection from July 2 through August 3, 2015, and with a history of residing in or visiting 1 of several South Bronx neighborhoods of New York City. We describe the epidemiologic, environmental, and laboratory investigation that identified the source of the outbreak. We identified 138 patients with outbreak-related Legionnaires' disease, 16 of whom died. The median age of patients was 55. A total of 107 patients had a chronic health condition, including 43 with diabetes, 40 with alcoholism, and 24 with HIV infection. We tested 55 cooling towers for Legionella, and 2 had a strain indistinguishable by pulsed-field gel electrophoresis from 26 patient isolates. Whole-genome sequencing and epidemiologic evidence implicated 1 cooling tower as the source of the outbreak. A large outbreak of Legionnaires' disease caused by a cooling tower occurred in a medically vulnerable community. The outbreak prompted enactment of a new city law on the operation and maintenance of cooling towers. Ongoing surveillance and evaluation of cooling tower process controls will determine if the new law reduces the incidence of Legionnaires' disease in New York City.

The analysis of the process in the cooling tower with the low efficiency

NASA Astrophysics Data System (ADS)

Badriev, A. I.; Sharifullin, V. N.

2017-11-01

We put quite a difficult task maintaining a temperature drop to 11-12 degrees at thermal power plants to ensure the required depth of cooling of vacuum in the condenser, cooling towers. This requirement is achieved with the reducing of the hydraulic load with the low efficiency of the apparatus. The task analysis process in this unit and identify the causes of his poor performance was put in the work. One of the possible reasons may be the heterogeneity of the process in the volume of the apparatus. Therefore, it was decided to investigate experimentally the distribution of the irrigation water and the air flow in the cross section of industrial cooling towers. As a result, we found a significant uneven distribution of flows of water and air in the volume of the apparatus. We have shown theoretically that the uneven distribution of irrigation leads to a significant decrease in the efficiency of evaporation in the cooling tower. The velocity distribution of the air as the tower sections, and inside sections are interesting. The obtained experimental data allowed to establish the internal communication: the effects of the distributions of the density of irrigation in sections of the apparatus for the distribution of changes of the temperature and the air velocity. The obtained results allowed to formulate a methodology for determining process problems and to develop actions on increase of the efficiency of the cooling tower.

A case of nosocomial Legionella pneumonia associated with a contaminated hospital cooling tower.

PubMed

Osawa, Kayo; Shigemura, Katsumi; Abe, Yasuhisa; Jikimoto, Takumi; Yoshida, Hiroyuki; Fujisawa, Masato; Arakawa, Soichi

2014-01-01

We report the epidemiological investigation of a nosocomial pneumonia case due to Legionella pneumophila linked to a contaminated hospital cooling tower in an immune-compromised patient. A 73-year-old female patient was diagnosed with nosocomial Legionella pneumonia proven by a culture of L. pneumophila serogroup 1 from bronchoalveolar lavage fluid. Two strains isolated from the patient and two strains isolated from two cooling towers were found to be identical using repetitive-sequence-based-PCR with a 95% probability. This Legionella pneumonia case might be caused by aerosol from cooling towers on the roof of the hospital building which was contaminated by L. pneumophila. We increased up the temperature of hot water supply appropriately for prevention of Legionella breeding in an environment of patients' living. On the other hand, as the maintenance of cooling tower, we increased the frequency of Legionella culture tests from twice a year to three times a year. In addition, we introduced an automated disinfectants insertion machine and added one antiseptic reagent (BALSTER ST-40 N, Tohzai Chemical Industry Co., Ltd., Kawasaki, Japan) after this Legionella disease, and thereafter, we have no additional cases of Legionella disease or detection of Legionella spp. from the cooling tower or hot water supply. This case demonstrates the importance of detecting the infection source and carrying out environmental maintenance in cooperation with the infection control team. Copyright © 2013 Japanese Society of Chemotherapy and the Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

A Large Community Outbreak of Legionnaires’ Disease Associated With a Cooling Tower in New York City, 2015

PubMed Central

Boyd, Christopher; Rakeman, Jennifer L.; Greene, Sharon K.; Fitzhenry, Robert; McProud, Trevor; Musser, Kimberlee; Huang, Li; Kornblum, John; Nazarian, Elizabeth J.; Fine, Annie D.; Braunstein, Sarah L.; Kass, Daniel; Landman, Keren; Lapierre, Pascal; Hughes, Scott; Tran, Anthony; Taylor, Jill; Baker, Deborah; Jones, Lucretia; Kornstein, Laura; Liu, Boning; Perez, Rodolfo; Lucero, David E.; Peterson, Eric; Benowitz, Isaac; Lee, Kristen F.; Ngai, Stephanie; Stripling, Mitch; Varma, Jay K.

2017-01-01

Objectives: Infections caused by Legionella are the leading cause of waterborne disease outbreaks in the United States. We investigated a large outbreak of Legionnaires’ disease in New York City in summer 2015 to characterize patients, risk factors for mortality, and environmental exposures. Methods: We defined cases as patients with pneumonia and laboratory evidence of Legionella infection from July 2 through August 3, 2015, and with a history of residing in or visiting 1 of several South Bronx neighborhoods of New York City. We describe the epidemiologic, environmental, and laboratory investigation that identified the source of the outbreak. Results: We identified 138 patients with outbreak-related Legionnaires’ disease, 16 of whom died. The median age of patients was 55. A total of 107 patients had a chronic health condition, including 43 with diabetes, 40 with alcoholism, and 24 with HIV infection. We tested 55 cooling towers for Legionella, and 2 had a strain indistinguishable by pulsed-field gel electrophoresis from 26 patient isolates. Whole-genome sequencing and epidemiologic evidence implicated 1 cooling tower as the source of the outbreak. Conclusions: A large outbreak of Legionnaires’ disease caused by a cooling tower occurred in a medically vulnerable community. The outbreak prompted enactment of a new city law on the operation and maintenance of cooling towers. Ongoing surveillance and evaluation of cooling tower process controls will determine if the new law reduces the incidence of Legionnaires’ disease in New York City. PMID:28141970

Nonhazardous Chemical Treatments and Smart Monitoring and Control System for Heating and Cooling Systems

DTIC Science & Technology

2007-06-01

box with the dip slides provides application instructions and illustrates acceptable bacteria levels. Both dip slide and Biotrace ATP Luminometer...Control Good Control Poor Control Biotrace ATP Planktonic 100 to 300 RLU 300 to 1000 RLU >1000 RLU Dip Tube Anaerobic Bacteria 0 organism/mL ɝ...completed monthly to record biocide levels and bacteria tests. Another biocide test method, the Biotrace ATP Luminometer, measures planktonic

Legionella species and serogroups in Malaysian water cooling towers: identification by latex agglutination and PCR-DNA sequencing of isolates.

PubMed

Yong, Stacey Foong Yee; Goh, Fen-Ning; Ngeow, Yun Fong

2010-03-01

In this study, we investigated the distribution of Legionella species in water cooling towers located in different parts of Malaysia to obtain information that may inform public health policies for the prevention of legionellosis. A total of 20 water samples were collected from 11 cooling towers located in three different states in east, west and south Malaysia. The samples were concentrated by filtration and treated with an acid buffer before plating on to BCYE agar. Legionella viable counts in these samples ranged from 100 to 2,000 CFU ml(-1); 28 isolates from the 24 samples were examined by latex agglutination as well as 16S rRNA and rpoB PCR-DNA sequencing. These isolates were identified as Legionella pneumophila serogroup 1 (35.7%), L. pneumophila serogroup 2-14 (39%), L. pneumophila non-groupable (10.7%), L. busanensis, L. gormanii, L. anisa and L. gresilensis. L. pneumophila was clearly the predominant species at all sampling sites. Repeat sampling from the same cooling tower and testing different colonies from the same water sample showed concurrent colonization by different serogroups and different species of Legionella in some of the cooling towers.

Prevalence of Legionella strains in cooling towers and legionellosis cases in New Zealand.

PubMed

Lau, Robert; Maqsood, Saadia; Harte, David; Caughley, Brian; Deacon, Rob

2013-01-01

Over 3,900 water samples from 688 cooling towers were tested for Legionella in 2008 in New Zealand. Of 80 (2.05% isolation rate) Legionella isolates, 10 (12.5%) were L. pneumophila serogroup 1; 10 (12.5%) were L. anisa; nine (11.2%) were L. pneumophila serogroup 8; and one (1.2%) was L. longbeachae serogroup 2. Forty-one (51.2%) Legionella isolates were L. pneumophila serogroups. Over 3,990 water samples from 606 cooling towers were tested for Legionella in 2009 in New Zealand. Of 51 (1.28% isolation rate) Legionella isolates, 18 (35.3%) were L. pneumophila serogroup 1, and 39 (76.4%) were other L. pneumophila serogroups. L. pneumophila serogroups were significantly associated with legionellosis cases in 2008 and 2009. L. longbeachae serogroups were equally significantly associated with legionellosis cases. This significant association of L. longbeachae with legionellosis particularly of L. longbeachae serogroup 1 is unique in that part of the world. The authors' study also showed that the aqueous environment of the cooling tower is not a natural habitat for pathogenic L. longbeachae. Regular monitoring and maintenance of cooling towers have prevented outbreaks of legionellosis.

High-Performance Computing Data Center Efficiency Dashboard | Computational

Science.gov Websites

recovery water (ERW) loop Heat exchanger for energy recovery Thermosyphon Heat exchanger between ERW loop and cooling tower loop Evaporative cooling towers Learn more about our energy-efficient facility

40 CFR 63.1329 - Process contact cooling towers provisions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... viscosity multiple end finisher process that utilizes a process contact cooling tower shall comply with... high viscosity multiple end finisher process and who is subject or becomes subject to 40 CFR part 60...

40 CFR 63.1329 - Process contact cooling towers provisions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... viscosity multiple end finisher process that utilizes a process contact cooling tower shall comply with... high viscosity multiple end finisher process, and who is subject or becomes subject to 40 CFR part 60...

Solar tower enhanced natural draft dry cooling tower

NASA Astrophysics Data System (ADS)

Yang, Huiqiang; Xu, Yan; Acosta-Iborra, Alberto; Santana, Domingo

2017-06-01

Concentrating Solar Power (CSP) plants are located in desert areas where the Direct Normal Irradiance (DNI) value is very high. Since water resource is scarcely available, mechanical draft cooing technology is commonly used, with power consumption of mechanical fans being approximately 2% of the total power generated. Today, there is only one solar power plant (Khi Solar One in South Africa) uses a condenser installed in a Natural Draft Cooling (NDC) tower that avoids the windage loss of water occurring in wet cooling towers. Although, Khi Solar One is a cavity receiver power tower, the receivers can be hung onto the NDC tower. This paper looks at a novel integration of a NDC tower into an external molten salt receiver of a solar power plant, which is one of a largest commercial molten salt tower in China, with 100MWe power capacity. In this configuration study, the NDC tower surrounds the concrete tower of the receiver concentrically. In this way, the receiver concrete tower is the central support of the NDC tower, which consists of cable networks that are fixed to the concrete tower and suspended at a certain height over the floor. The cable networks support the shell of the NDC tower. To perform a preliminary analysis of the behavior of this novel configuration, two cases of numerical simulation in three dimensional (3D) models have been solved using the commercial Computational Fluid Dynamics (CFD) code, ANSYS Fluent 6.3. The results show that the integration of the NDC tower into an external central receiver tower is feasible. Additionally, the total heat transfer rate is not reduced but slightly increases when the molten salt receiver is in operation because of the additional natural draft induced by the high temperature of the receiver.

Study of the activity of quaternary ammonium compounds in the mitigation of biofouling in heat exchangers-condensers cooled by seawater.

PubMed

Trueba, Alfredo; Otero, Félix M; González, José A; Vega, Luis M; García, Sergio

2013-01-01

The effectiveness of two quaternary ammonium compounds (QACs) (non-oxidising biocides) to reduce the growth of biofilm adhering to the tubes of a heat exchanger-condenser cooled by seawater was evaluated. Their effectiveness was compared to that of a conventional oxidising biocide (sodium hypochlorite [NaOCl]) under the same testing conditions. Each biocide was applied intermittently (6 h on, 6 h off) in a first shock stage (1.5 ppm over 8 days) and a second stabilising stage (0.5 ppm over 20 days). The results showed that the antifouling effectiveness of the first of the QACs (fifth generation) was comparable to that shown by the oxidising power of NaOCl. Although the reaction time was longer than that of NaOCl, both the compounds removed the biofilm, and the tube was practically restored to its clean condition. Treatment with the second of the QACs (fourth generation) allowed for the stabilisation of biofilm growth, but not for its removal. Ecotoxicology studies classified the QACs as environmentally harmless under the testing conditions.

40 CFR 61.134 - Standard: Naphthalene processing, final coolers, and final-cooler cooling towers.

Code of Federal Regulations, 2012 CFR

2012-07-01

... POLLUTANTS National Emission Standard for Benzene Emissions from Coke By-Product Recovery Plants § 61.134... are allowed from naphthalene processing, final coolers and final-cooler cooling towers at coke by...

40 CFR 61.134 - Standard: Naphthalene processing, final coolers, and final-cooler cooling towers.

Code of Federal Regulations, 2014 CFR

2014-07-01

... POLLUTANTS National Emission Standard for Benzene Emissions from Coke By-Product Recovery Plants § 61.134... are allowed from naphthalene processing, final coolers and final-cooler cooling towers at coke by...

40 CFR 61.134 - Standard: Naphthalene processing, final coolers, and final-cooler cooling towers.

Code of Federal Regulations, 2013 CFR

2013-07-01

... POLLUTANTS National Emission Standard for Benzene Emissions from Coke By-Product Recovery Plants § 61.134... are allowed from naphthalene processing, final coolers and final-cooler cooling towers at coke by...

40 CFR 61.134 - Standard: Naphthalene processing, final coolers, and final-cooler cooling towers.

Code of Federal Regulations, 2011 CFR

2011-07-01

... POLLUTANTS National Emission Standard for Benzene Emissions from Coke By-Product Recovery Plants § 61.134... are allowed from naphthalene processing, final coolers and final-cooler cooling towers at coke by...

40. LOOKING SOUTHWEST AT GAS COOLING TOWERS No. 1 AND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

40. LOOKING SOUTHWEST AT GAS COOLING TOWERS No. 1 AND No. 2, WITH DORR-OLIVER THICKENER IN FOREGROUND. - U.S. Steel Duquesne Works, Basic Oxygen Steelmaking Plant, Along Monongahela River, Duquesne, Allegheny County, PA

39. LOOKING SOUTH AT GAS COOLING TOWERS No. 1 (ON ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

39. LOOKING SOUTH AT GAS COOLING TOWERS No. 1 (ON RIGHT) AND No. 2, WITH DORR-OLIVER THICKENER IN FOREGROUND. - U.S. Steel Duquesne Works, Basic Oxygen Steelmaking Plant, Along Monongahela River, Duquesne, Allegheny County, PA

2. Left side of Zinc Plant, from packless Cooling Tower ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. Left side of Zinc Plant, from packless Cooling Tower to midpoint of Cell Room, with majority of Upper Plant in view. View is to the east. - Sullivan Electrolytic Zinc Plant, Government Gulch, Kellogg, Shoshone County, ID

5. STEAM PLANT COOLING TOWER LOCATED WEST OF STEAM PLANT ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. STEAM PLANT COOLING TOWER LOCATED WEST OF STEAM PLANT BUILDING, FROM SOUTH. SHOWS CURRENT LEVEL OF DISREPAIR. December 4, 1990 - Crosscut Steam Plant, North side Salt River near Mill Avenue & Washington Street, Tempe, Maricopa County, AZ

An outbreak of Legionella pneumonia originating from a cooling tower.

PubMed

Isozumi, Rie; Ito, Yutaka; Ito, Isao; Osawa, Makoto; Hirai, Toyohiro; Takakura, Syunji; Iinuma, Yoshitsugu; Ichiyama, Satoshi; Tateda, Kazuhiro; Yamaguchi, Keizo; Mishima, Michiaki

2005-01-01

We report 2 cases of Legionella pneumonia in individuals who were exposed to aerosols during maintenance of a cooling tower at a waste processing plant. This report documents the first known occupation-related outbreak of Legionella pneumonia in Japan.

Experimental assessment of heat and mass transfer of modular nozzles of cooling towers

NASA Astrophysics Data System (ADS)

Merentsov, N. A.; Lebedev, V. N.; Golovanchikov, A. B.; Balashov, V. A.; Nefed'eva, E. E.

2018-01-01

Data of experimental study of hydrodynamics, heat and mass transfer of modular nozzles of cooling towers and some comparative characteristics of the packed device with nozzles, which have wide industrial application, are given in the article.

40 CFR 61.134 - Standard: Naphthalene processing, final coolers, and final-cooler cooling towers.

Code of Federal Regulations, 2010 CFR

2010-07-01

... POLLUTANTS National Emission Standard for Benzene Emissions from Coke By-Product Recovery Plants § 61.134... are allowed from naphthalene processing, final coolers and final-cooler cooling towers at coke by-product recovery plants. ...

Legionella confirmation in cooling tower water. Comparison of culture, real-time PCR and next generation sequencing.

PubMed

Farhat, Maha; Shaheed, Raja A; Al-Ali, Haider H; Al-Ghamdi, Abdullah S; Al-Hamaqi, Ghadeer M; Maan, Hawraa S; Al-Mahfoodh, Zainab A; Al-Seba, Hussain Z

2018-02-01

To investigate the presence of Legionella spp in cooling tower water. Legionella proliferation in cooling tower water has serious public health implications as it can be transmitted to humans via aerosols and cause Legionnaires' disease. Samples of cooling tower water were collected from King Fahd Hospital of the University (KFHU) (Imam Abdulrahman Bin Faisal University, 2015/2016). The water samples were analyzed by a standard Legionella culture method, real-time polymerase chain reaction (RT-PCR), and 16S rRNA next-generation sequencing. In addition, the bacterial community composition was evaluated. All samples were negative by conventional Legionella culture. In contrast, all water samples yielded positive results by real-time PCR (105 to 106 GU/L). The results of 16S rRNA next generation sequencing showed high similarity and reproducibility among the water samples. The majority of sequences were Alpha-, Beta-, and Gamma-proteobacteria, and Legionella was the predominant genus. The hydrogen-oxidizing gram-negative bacterium Hydrogenophaga was present at high abundance, indicating high metabolic activity. Sphingopyxis, which is known for its resistance to antimicrobials and as a pioneer in biofilm formation, was also detected. Our findings indicate that monitoring of Legionella in cooling tower water would be enhanced by use of both conventional culturing and molecular methods.

Legionella confirmation in cooling tower water

PubMed Central

Farhat, Maha; Shaheed, Raja A.; Al-Ali, Haidar H.; Al-Ghamdi, Abdullah S.; Al-Hamaqi, Ghadeer M.; Maan, Hawraa S.; Al-Mahfoodh, Zainab A.; Al-Seba, Hussain Z.

2018-01-01

Objectives: To investigate the presence of Legionella spp in cooling tower water. Legionella proliferation in cooling tower water has serious public health implications as it can be transmitted to humans via aerosols and cause Legionnaires’ disease. Methods: Samples of cooling tower water were collected from King Fahd Hospital of the University (KFHU) (Imam Abdulrahman Bin Faisal University, 2015/2016). The water samples were analyzed by a standard Legionella culture method, real-time polymerase chain reaction (RT-PCR), and 16S rRNA next-generation sequencing. In addition, the bacterial community composition was evaluated. Results: All samples were negative by conventional Legionella culture. In contrast, all water samples yielded positive results by real-time PCR (105 to 106 GU/L). The results of 16S rRNA next generation sequencing showed high similarity and reproducibility among the water samples. The majority of sequences were Alpha-, Beta-, and Gamma-proteobacteria, and Legionella was the predominant genus. The hydrogen-oxidizing gram-negative bacterium Hydrogenophaga was present at high abundance, indicating high metabolic activity. Sphingopyxis, which is known for its resistance to antimicrobials and as a pioneer in biofilm formation, was also detected. Conclusion: Our findings indicate that monitoring of Legionella in cooling tower water would be enhanced by use of both conventional culturing and molecular methods. PMID:29436561

Free-living amoebae and their associated bacteria in Austrian cooling towers: a 1-year routine screening.

PubMed

Scheikl, Ute; Tsao, Han-Fei; Horn, Matthias; Indra, Alexander; Walochnik, Julia

2016-09-01

Free-living amoebae (FLA) are widely spread in the environment and known to cause rare but often serious infections. Besides this, FLA may serve as vehicles for bacterial pathogens. In particular, Legionella pneumophila is known to replicate within FLA thereby also gaining enhanced infectivity. Cooling towers have been the source of outbreaks of Legionnaires' disease in the past and are thus usually screened for legionellae on a routine basis, not considering, however, FLA and their vehicle function. The aim of this study was to incorporate a screening system for host amoebae into a Legionella routine screening. A new real-time PCR-based screening system for various groups of FLA was established. Three cooling towers were screened every 2 weeks over the period of 1 year for FLA and Legionella spp., by culture and molecular methods in parallel. Altogether, 83.3 % of the cooling tower samples were positive for FLA, Acanthamoeba being the dominating genus. Interestingly, 69.7 % of the cooling tower samples were not suitable for the standard Legionella screening due to their high organic burden. In the remaining samples, positivity for Legionella spp. was 25 % by culture, but overall positivity was 50 % by molecular methods. Several amoebal isolates revealed intracellular bacteria.

40 CFR 419.47 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... forth in § 419.46 (a) and (b). (b) The following standard is applied to the cooling tower discharge part... flow to the POTW; and (3) by the ratio of the cooling tower discharge flow to the total refinery flow...

40 CFR 419.17 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... forth in § 419.16 (a) and (b). (b) The following standard is applied to the cooling tower discharge part... flow to the POTW; and (3) by the ratio of the cooling tower discharge flow to the total refinery flow...

40 CFR 419.57 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... forth in § 419.56 (a) and (b). (b) The following standard is applied to the cooling tower discharge part... flow to the POTW; and (3) by the ratio of the cooling tower discharge flow to the total refinery flow...

40 CFR 419.37 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... ammonia set forth in § 419.36 (a) and (b). (b) The following standard is applied to the cooling tower... refinery flow to the POTW; and (3) by the ratio of the cooling tower discharge flow to the total refinery...

PBF Cooling Tower (PER720). Camera faces south to show north ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Cooling Tower (PER-720). Camera faces south to show north facade. Note enclosed stairway. Date: August 2003. INEEL negative no. HD-35-10-3 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

PBF Cooling Tower (PER720). Closeup detail of louvered wall panels ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Cooling Tower (PER-720). Close-up detail of louvered wall panels on south facade. Date: August 2003. INEEL negative no. HD-35-11-1 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

49. LOOKING NORTH AT EVAPORATIVE WASTE WATER TREATMENT COOLING TOWERS, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

49. LOOKING NORTH AT EVAPORATIVE WASTE WATER TREATMENT COOLING TOWERS, WITH BLOW ENGINE HOUSE No. 3 ON RIGHT, AND FILTER CAKE HOUSE IN FOREGROUND. (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

Combined Wastewater Characterization and Hazardous Waste Survey, Davis-Monthan AFB, Arizona

DTIC Science & Technology

1990-04-01

drain to the sanitary sewer. The chemical additives contained in the cooling discharge are inhibitor (NSN 6850 0059 2537 and 6850 0059 2937) and Cooling...Vacuucleaner 480 DD 836 CES Heating Plant Phosphate 2400 DD 836 CES Refrigeration Inhibitor NQ DD 836 CES Refrigeration Cooling Tower Treat NQ DD 836 CES...BLDG PRODUCT QTY (GAL/YR) 836 CES Refrigeration 5309 Inhibitor NQ 836 CES Refrigeration 5309 Cooling Tower Treat NQ 836 CES Heating Plant 5309 Sodium

PBF Cooling Tower under construction. Cold water basin is five ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Cooling Tower under construction. Cold water basin is five feet deep. Foundation and basin walls are reinforced concrete. Camera facing west. Pipe openings through wall in front are outlets for return flow of cool water to reactor building. Photographer: John Capek. Date: September 4, 1968. INEEL negative no. 68-3473 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

PBF Cooling Tower detail. Camera facing southwest. Wood fill rises ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Cooling Tower detail. Camera facing southwest. Wood fill rises from foundation piers of cold water basin. Photographer: Kirsh. Date: May 1, 1969. INEEL negative no. 69-2826 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

Review on Water Distribution of Cooling Tower in Power Station

NASA Astrophysics Data System (ADS)

Huichao, Zhang; Lei, Fang; Hao, Guang; Ying, Niu

2018-04-01

As the energy sources situation is becoming more and more severe, the importance of energy conservation and emissions reduction gets clearer. Since the optimization of water distribution system of cooling tower in power station can save a great amount of energy, the research of water distribution system gets more attention nowadays. This paper summarizes the development process of counter-flow type natural draft wet cooling tower and the water distribution system, and introduces the related domestic and international research situation. Combining the current situation, we come to the conclusion about the advantages and disadvantages of the several major water distribution modes, and analyze the problems of the existing water distribution ways in engineering application, furthermore, we put forward the direction of water distribution mode development on the basis knowledge of water distribution of cooling tower. Due to the water system can hardly be optimized again when it’s built, choosing an appropriate water distribution mode according to actual condition seems to be more significant.

Molecular characterization of viable Legionella spp. in cooling tower water samples by combined use of ethidium monoazide and PCR.

PubMed

Inoue, Hiroaki; Fujimura, Reiko; Agata, Kunio; Ohta, Hiroyuki

2015-01-01

Viable Legionella spp. in environmental water samples were characterized phylogenetically by a clone library analysis combining the use of ethidium monoazide and quantitative PCR. To examine the diversity of Legionella spp., six cooling tower water samples and three bath water samples were collected and analyzed. A total of 617 clones were analyzed for their 16S rRNA gene sequences and classified into 99 operational taxonomic units (OTUs). The majority of OTUs were not clustered with currently described Legionella spp., suggesting the wide diversity of not-yet-cultured Legionella groups harbored in cooling tower water environments.

Molecular Characterization of Viable Legionella spp. in Cooling Tower Water Samples by Combined Use of Ethidium Monoazide and PCR

PubMed Central

Inoue, Hiroaki; Fujimura, Reiko; Agata, Kunio; Ohta, Hiroyuki

2015-01-01

Viable Legionella spp. in environmental water samples were characterized phylogenetically by a clone library analysis combining the use of ethidium monoazide and quantitative PCR. To examine the diversity of Legionella spp., six cooling tower water samples and three bath water samples were collected and analyzed. A total of 617 clones were analyzed for their 16S rRNA gene sequences and classified into 99 operational taxonomic units (OTUs). The majority of OTUs were not clustered with currently described Legionella spp., suggesting the wide diversity of not-yet-cultured Legionella groups harbored in cooling tower water environments. PMID:25736979

Technology for Water Treatment (National Water Management)

NASA Technical Reports Server (NTRS)

1992-01-01

The buildup of scale and corrosion is the most costly maintenance problem in cooling tower operation. Jet Propulsion Laboratory successfully developed a non-chemical system that not only curbed scale and corrosion, but also offered advantages in water conservation, cost savings and the elimination of toxic chemical discharge. In the system, ozone is produced by an on-site generator and introduced to the cooling tower water. Organic impurities are oxidized, and the dissolved ozone removes bacteria and scale. National Water Management, a NASA licensee, has installed its ozone advantage systems at some 200 cooling towers. Customers have saved money and eliminated chemical storage and discharge.

An investigation of the accuracy of the Merkel equation for evaporative cooling tower calculations. Waste heat management

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yadigaroglu, G.; Pastor, E.J.

1974-01-01

The exact differential equations governing heat and mass transfer and air flow in an evaporative, natural-draft cooling tower are presented. The Merkel equation is then derived starting from this exact formulation and showing all the approximations involved. The Merkel formulation lumps the sensible and the latent heat transfer together and considers a single enthalpy-difference driving force for the total heat transfer. The effect of the approximations inherent in the Merkel equation is investigated and analyzed by a series of parametric numerical calculations of cooling tower performance under various ambient conditions and load conditions.

Drop tower with no aerodynamic drag

NASA Technical Reports Server (NTRS)

Kendall, J. M., Jr.

1981-01-01

Cooling air accelerated to match velocity of falling object eliminates drag. 3 meter drop tower with suction fan and specific geometry causes air to accelerate downward at 1 g. Although cooling of molten material released from top is slow because surrounding air moves with it, drop remains nearly spherical.

Influence of Chlorine Emissions on Ozone Levels in the Troposphere

EPA Science Inventory

Chlorine emissions from cooling towers are emitted mainly as hypochlous acid, not as molecular chlorine. Chlorine emissions from cooling towers in electric utilities in the U.S. are estimated to be 4,400 tons per year. Molecular chlorine increases more tropospheric ozone than hyp...

User's manual for the BNW-I optimization code for dry-cooled power plants. [AMCIRC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Braun, D.J.; Daniel, D.J.; De Mier, W.V.

1977-01-01

This appendix provides a listing, called Program AMCIRC, of the BNW-1 optimization code for determining, for a particular size power plant, the optimum dry cooling tower design using ammonia flow in the heat exchanger tubes. The optimum design is determined by repeating the design of the cooling system over a range of design conditions in order to find the cooling system with the smallest incremental cost. This is accomplished by varying five parameters of the plant and cooling system over ranges of values. These parameters are varied systematically according to techniques that perform pattern and gradient searches. The dry coolingmore » system optimized by program AMCIRC is composed of a condenser/reboiler (condensation of steam and boiling of ammonia), piping system (transports ammonia vapor out and ammonia liquid from the dry cooling towers), and circular tower system (vertical one-pass heat exchangers situated in circular configurations with cocurrent ammonia flow in the tubes of the heat exchanger). (LCL)« less

Evaporation Tower With Prill Nozzles

NASA Technical Reports Server (NTRS)

Du Fresne, E. R.

1984-01-01

Tower more efficient than conventional evaporation equipment. Liquids such as milk and fruit juice concentrated by passing them through tiny nozzle to form droplets, then allowing droplets to fall through evacuated tower with cooled walls.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boegh, P.; Hopkirk, R.; Junod, A.

From international nuclear industries fair; Basel, Switzerland (16 Oct 1972). The extensive environmental studies performed in Switzerland for the cooling towers of the Kaiseraugst and Leibstadt Nuclear Power Plants are presented. The computer program SAUNA for the calculation of the cooling tower plume behavior is briefly described. The main results of the environmental studies are summarized. (8 references) (auth)

Mathematical model and calculation of water-cooling efficiency in a film-filled cooling tower

NASA Astrophysics Data System (ADS)

Laptev, A. G.; Lapteva, E. A.

2016-10-01

Different approaches to simulation of momentum, mass, and energy transfer in packed beds are considered. The mathematical model of heat and mass transfer in a wetted packed bed for turbulent gas flow and laminar wave counter flow of the fluid film in sprinkler units of a water-cooling tower is presented. The packed bed is represented as the set of equivalent channels with correction to twisting. The idea put forward by P. Kapitsa on representation of waves on the interphase film surface as elements of the surface roughness in interaction with the gas flow is used. The temperature and moisture content profiles are found from the solution of differential equations of heat and mass transfer written for the equivalent channel with the volume heat and mass source. The equations for calculation of the average coefficients of heat emission and mass exchange in regular and irregular beds with different contact elements, as well as the expression for calculation of the average turbulent exchange coefficient are presented. The given formulas determine these coefficients for the known hydraulic resistance of the packed bed element. The results of solution of the system of equations are presented, and the water temperature profiles are shown for different sprinkler units in industrial water-cooling towers. The comparison with experimental data on thermal efficiency of the cooling tower is made; this allows one to determine the temperature of the cooled water at the output. The technical solutions on increasing the cooling tower performance by equalization of the air velocity profile at the input and creation of an additional phase contact region using irregular elements "Inzhekhim" are considered.

Cooling tower water conditioning study. [using ozone

NASA Technical Reports Server (NTRS)

Humphrey, M. F.; French, K. R.

1979-01-01

Successful elimination of cooling tower treatment chemicals was demonstrated. Three towers functioned for long periods of time with ozone as the only treatment for the water. The water in the systems was reused as much as 30 times (cycles of concentration) without deleterious effects to the heat exchangers. Actual system blow-down was eliminated and the only makeup water added was that required to replace the evaporation and mist entrainment losses. Minimum water savings alone are approximately 75.1 1/kg/year. Cost estimates indicate that a savings of 55 percent was obtained on the systems using ozone. A major problem experienced in the use of ozone for cooling tower applications was the difficulty of accurate concentration measurements. The ability to control the operational characteristics relies on easily and accurately determined concentration levels. Present methods of detection are subject to inaccuracies because of interfering materials and the rapid destruction of the ozone.

Monitoring of biofilm-associated Legionella pneumophila on different substrata in model cooling tower system.

PubMed

Türetgen, Irfan; Cotuk, Aysin

2007-02-01

Cooling towers have the potential to develop infectious concentrations of Legionella pneumophila. Legionella counts increases where biofilm and warm water temperatures are present. In this study, biofilm associated L. pneumophila and heterotrophic bacteria were compared in terms of material dependence. Model cooling tower system was experimentally infected by L. pneumophila standard strain and monthly monitored. Different materials were tested for a period of 180 days. The lowest L. pneumophila and heterotrophic plate counts were measured on plastic polymers, whereas L. pneumophila and heterotrophic bacteria were accumulated rapidly on galvanized steel surfaces. It can be concluded that selection of plastic polymers, as a manufacturing material, are suitable for recirculating water systems.

Hypotheses of calculation of the water flow rate evaporated in a wet cooling tower

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bourillot, C.

1983-08-01

The method developed by Poppe at the University of Hannover to calculate the thermal performance of a wet cooling tower fill is presented. The formulation of Poppe is then validated using full-scale test data from a wet cooling tower at the power station at Neurath, Federal Republic of Germany. It is shown that the Poppe method predicts the evaporated water flow rate almost perfectly and the condensate content of the warm air with good accuracy over a wide range of ambient conditions. The simplifying assumptions of the Merkel theory are discussed, and the errors linked to these assumptions are systematicallymore » described, then illustrated with the test data.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hutton, D.

The reasons for preservative treatment of cooling tower wood are reviewed along with a summary of which types of treatment are available, how they are applied, and a comparison of materials and processes. Industries often specify minimum quality preservatives for their cooling towers without understanding the loss of strength caused by decay and the economic losses due to a cooling tower failure and lost production. Wood is subject to both chemical (surface delignification and iron rot) and biological (soft rot) attack. A successful preservative treatment that protects against both must have retention and penetration qualities. Research efforts are examining themore » toxicity and environmental impacts of preservatives and exploring the possibility of chemically modifying wood. (DCK)« less

Lung cancer mortality and exposure to synthetic metalworking fluid and biocides: controlling for the healthy worker survivor effect.

PubMed

Garcia, Erika; Picciotto, Sally; Neophytou, Andreas M; Bradshaw, Patrick T; Balmes, John R; Eisen, Ellen A

2018-05-09

Synthetic metalworking fluids (MWFs), widely used to cool and lubricate industrial machining and grinding operations, have been linked with increased risk of several cancers. Estimates of their relation with lung cancer, however, are inconsistent. Controlling for the healthy worker survivor effect, we examined the relations between lung cancer mortality and exposure to synthetic MWF, as well as to biocides added to water-based fluids to control microbial growth, in a cohort of autoworkers. Biocides served as a marker for endotoxin, which has reported antitumour effects, and were hypothesised to be the reason prior studies found reduced lung cancer risk associated with exposure to synthetic fluids. Using the parametric g-formula, we estimated risk ratios (RRs) comparing cumulative lung cancer mortality under no intervention with what would have occurred under hypothetical interventions reducing exposure to zero (ie, a ban) separately for two exposures: synthetic fluids and biocides. We also specified an intervention on synthetic MWF and biocides simultaneously to estimate joint effects. Under a synthetic MWF ban, we observed decreased lung cancer mortality risk at age 86, RR=0.96 (0.91-1.01), but when we also intervened to ban biocides, the RR increased to 1.03 (0.95-1.11). A biocide-only ban increased lung cancer mortality (RR=1.07 (1.00-1.16)), with slightly larger RR in younger ages. Findings suggest a modest positive association for synthetic MWF with lung cancer mortality, contrary to the negative associations reported in earlier studies. Biocide exposure, however, was inversely associated with risk of lung cancer mortality. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

[Community outbreak of pneumonia due to Legionella pneumophila: importance of monitoring hospital cooling towers].

PubMed

de Olalla, Patricia García; Gracia, José; Rius, Cristina; Caylà, Joan A; Pañella, Helena; Villabí, Joan R; Guix, Joan; Pellicer, Teresa; Ferrer, Dolors; Cusi, Meritxell; Pelaz, Carmen; Sabrià, Miquel

2008-01-01

Description of an outbreak of legionnaires' disease originating in one of the cooling towers of a hospital. This study included patients with confirmed pneumonia caused by Legionella pneumophila serogroup 1 and related to the Vallcarca neighborhood of Barcelona (Spain) in August 2004. Exposure was determined by a standardized questionnaire. An environmental investigation was carried out to identify the source of the outbreak. A descriptive analysis including incidence rates estimation was performed, as well as molecular study to document the genetic identity among human and environmental strains. Thirty-three cases of L. pneumophila pneumonia were detected. Median age was 68 years and 70% of the affected patients were men. Incidence rate among residents in less than 200 meters of the source and older than 65 was 888.9 cases/100,000 inhabitants. Lethality rate was 6%. Four seasonal cooling towers that were not registered with the authorities were identified in a health care center. L. pneumophila was isolated from all four and at least one colony in each tower had the same genetic profile as the strains isolated from patients. An association was demonstrated between a community outbreak of legionellosis and unregistered seasonal cooling towers located in a hospital. All risk facilities should be registered and inspected to ensure that they fulfill current legislation requirements.

Indiana State University Graduates to Advanced Plastic Cooling Towers

ERIC Educational Resources Information Center

Sullivan, Ed

2012-01-01

Perhaps more than many other industries, today's universities and colleges are beset by dramatically rising costs on every front. One of the areas where overhead can be contained or reduced is in the operation of the chilled water systems that support air conditioning throughout college campuses, specifically the cooling towers. Like many…

A community outbreak of Legionnaires' disease associated with a cooling tower in Vic and Gurb, Catalonia (Spain) in 2005.

PubMed

Ferré, M R Sala; Arias, C; Oliva, J M; Pedrol, A; García, M; Pellicer, T; Roura, P; Domínguez, A

2009-02-01

We report the investigation of a community-acquired outbreak of Legionnaires' disease. An epidemiological, environmental, and meteorological investigation was undertaken. Fifty-five cases were reported in October and November 2005. The exposure occurred in a large area, with 12 cases (21.8%) located between 1,800 and 3,400 metres from the source. Water sample cultures showed that Legionella pneumophila serogroup 1 (Lp-1) was present in five cooling towers in two industrial locations in Gurb (plants A and B). Two Lp-1 strains were recovered from plants A and B, but only Lp-1 strains from plant A showed a pulsed-field gel electrophoresis (PFGE) profile identical to those obtained from three of the cases. Inspection of the cooling towers in plant A revealed inadequate maintenance. Weather conditions in October 2005, with mostly high temperatures and high humidity, together with the flat terrain could have been favouring factors. This study showed a community outbreak from a cooling tower as a common source in a large area. Climate and terrain could explain the dissemination of contaminated aerosols.

Development of Modified Incompressible Ideal Gas Model for Natural Draft Cooling Tower Flow Simulation

NASA Astrophysics Data System (ADS)

Hyhlík, Tomáš

2018-06-01

The article deals with the development of incompressible ideal gas like model, which can be used as a part of mathematical model describing natural draft wet-cooling tower flow, heat and mass transfer. It is shown, based on the results of a complex mathematical model of natural draft wet-cooling tower flow, that behaviour of pressure, temperature and density is very similar to the case of hydrostatics of moist air, where heat and mass transfer in the fill zone must be taken into account. The behaviour inside the cooling tower is documented using density, pressure and temperature distributions. The proposed equation for the density is based on the same idea like the incompressible ideal gas model, which is only dependent on temperature, specific humidity and in this case on elevation. It is shown that normalized density difference of the density based on proposed model and density based on the nonsimplified model is in the order of 10-4. The classical incompressible ideal gas model, Boussinesq model and generalised Boussinesq model are also tested. These models show deviation in percentages.

Molecular epidemiology of an outbreak of Legionnaires' disease associated with a cooling tower in Genova-Sestri Ponente, Italy.

PubMed

Castellani Pastoris, M; Ciceroni, L; Lo Monaco, R; Goldoni, P; Mentore, B; Flego, G; Cattani, L; Ciarrocchi, S; Pinto, A; Visca, P

1997-12-01

Fatty acid profile analysis, monoclonal antibody (MAb) subtyping, pulsed-field gel electrophoresis (PFGE), arbitrarily primed polymerase chain reaction (AP-PCR), and ribotyping were used to compare clinical and environmental Legionella pneumophila serogroup 1 isolates from an outbreak of Legionnaires' disease presumptively associated with cooling towers. According to the Oxford subtyping scheme, the MAb subtype of patients' isolates and of two strains originating from a cooling tower was Pontiac, whereas the other isolates were subtype Olda. The strains showed no intrinsic strain-to-strain difference in fatty acid profiles, and ribotyping and length polymorphism of the 16S-23S rDNA intervening regions failed to reveal any differences between the isolates. Conversely, PFGE and AP-PCR appeared to be more discriminatory, as the same genomic profile was found for the clinical and some environmental strains. Meteorologic and epidemiological data and the results of molecular analysis of the Legionella pneumophila serogroup 1 isolates support the hypothesis that the infection was transmitted from one of the cooling towers to the indoor environment of the same building, to homes in proximity that had open windows, and to the streets. In fact, the outbreak diminished and later ended after a part in the tower was replaced. This investigation demonstrates the utility of combined molecular methods (i.e., phenotypic and genomic typing) in comparing epidemiologically linked clinical and environmental isolates. Finally, the outbreak confirms the risk of Legionnaires' disease posed by cooling towers, mainly when atmospheric thermal and humidity inversions occur. This finding emphasizes the need to determine whether the source of infection is in the living or working environment or somewhere else.

Artificial neural network analysis based on genetic algorithm to predict the performance characteristics of a cross flow cooling tower

NASA Astrophysics Data System (ADS)

Wu, Jiasheng; Cao, Lin; Zhang, Guoqiang

2018-02-01

Cooling tower of air conditioning has been widely used as cooling equipment, and there will be broad application prospect if it can be reversibly used as heat source under heat pump heating operation condition. In view of the complex non-linear relationship of each parameter in the process of heat and mass transfer inside tower, In this paper, the BP neural network model based on genetic algorithm optimization (GABP neural network model) is established for the reverse use of cross flow cooling tower. The model adopts the structure of 6 inputs, 13 hidden nodes and 8 outputs. With this model, the outlet air dry bulb temperature, wet bulb temperature, water temperature, heat, sensible heat ratio and heat absorbing efficiency, Lewis number, a total of 8 the proportion of main performance parameters were predicted. Furthermore, the established network model is used to predict the water temperature and heat absorption of the tower at different inlet temperatures. The mean relative error MRE between BP predicted value and experimental value are 4.47%, 3.63%, 2.38%, 3.71%, 6.35%,3.14%, 13.95% and 6.80% respectively; the mean relative error MRE between GABP predicted value and experimental value are 2.66%, 3.04%, 2.27%, 3.02%, 6.89%, 3.17%, 11.50% and 6.57% respectively. The results show that the prediction results of GABP network model are better than that of BP network model; the simulation results are basically consistent with the actual situation. The GABP network model can well predict the heat and mass transfer performance of the cross flow cooling tower.

[Diversity of Legionella pneumophila in cooling towers: coculture kinetics and virulence studies].

PubMed

Ragull, Sonia; García-Núñez, Marian; Pedro-Botet, María Luisa; Rey-Joly, Celestino; Sabria, Miquel

2011-05-01

Legionella pneumophila (L. pneumophila) was isolated from three cooling towers involved in three community outbreaks of Legionnaireś disease. Each cooling tower had two different chromosomal DNA subtypes. However, only one matched identically to the clinical strains. To try to understand why only one of the environmental strains caused clinical cases we investigated the intrinsic virulence of these strains. We selected six strains of L. pneumophila sg.1: two strains (A1 and B1) from cooling tower 1, two strains (A2 and B2) from tower 2 and two strains (A3 and B3) from tower 3. One of the two subtypes (A) exhibited the same chromosomal DNA subtype as the strains isolated from the patients in each outbreak and the other exhibited a different subtype. The replication within macrophages, the presence of lipopolysaccharide epitope recognized by MAb 3/1 and the growth kinetics in BCYE broth were investigated. Isolates were typed by pulsed field electrophoresis. The A strains did not have a higher virulence level, but were able to grow and survive better than strains B in BCYE broth. These results suggest that the strains better adapted to the environment will manage to displace the others and will be able to spread and infect humans. The adaptation to the environmental conditions could play an important role in the pathogenesis of the strains. Copyright © 2010 Elsevier España, S.L. All rights reserved.

Distribution of sequence-based types of legionella pneumophila serogroup 1 strains isolated from cooling towers, hot springs, and potable water systems in China.

PubMed

Qin, Tian; Zhou, Haijian; Ren, Hongyu; Guan, Hong; Li, Machao; Zhu, Bingqing; Shao, Zhujun

2014-04-01

Legionella pneumophila serogroup 1 causes Legionnaires' disease. Water systems contaminated with Legionella are the implicated sources of Legionnaires' disease. This study analyzed L. pneumophila serogroup 1 strains in China using sequence-based typing. Strains were isolated from cooling towers (n = 96), hot springs (n = 42), and potable water systems (n = 26). Isolates from cooling towers, hot springs, and potable water systems were divided into 25 sequence types (STs; index of discrimination [IOD], 0.711), 19 STs (IOD, 0.934), and 3 STs (IOD, 0.151), respectively. The genetic variation among the potable water isolates was lower than that among cooling tower and hot spring isolates. ST1 was the predominant type, accounting for 49.4% of analyzed strains (n = 81), followed by ST154. With the exception of two strains, all potable water isolates (92.3%) belonged to ST1. In contrast, 53.1% (51/96) and only 14.3% (6/42) of cooling tower and hot spring, respectively, isolates belonged to ST1. There were differences in the distributions of clone groups among the water sources. The comparisons among L. pneumophila strains isolated in China, Japan, and South Korea revealed that similar clones (ST1 complex and ST154 complex) exist in these countries. In conclusion, in China, STs had several unique allelic profiles, and ST1 was the most prevalent sequence type of environmental L. pneumophila serogroup 1 isolates, similar to its prevalence in Japan and South Korea.

Controls on Water Use for Thermoelectric Generation: Case Study Texas, U.S.

PubMed Central

2013-01-01

Large-scale U.S. dependence on thermoelectric (steam electric) generation requiring water for cooling underscores the need to understand controls on this water use. The study objective was to quantify water consumption and withdrawal for thermoelectric generation, identifying controls, using Texas as a case study. Water consumption for thermoelectricity in Texas in 2010 totaled ∼0.43 million acre feet (maf; 0.53 km3), accounting for ∼4% of total state water consumption. High water withdrawals (26.2 maf, 32.3 km3) mostly reflect circulation between ponds and power plants, with only two-thirds of this water required for cooling. Controls on water consumption include (1) generator technology/thermal efficiency and (2) cooling system, resulting in statewide consumption intensity for natural gas combined cycle generators with mostly cooling towers (0.19 gal/kWh) being 63% lower than that of traditional coal, nuclear, or natural gas steam turbine generators with mostly cooling ponds (0.52 gal/kWh). The primary control on water withdrawals is cooling system, with ∼2 orders of magnitude lower withdrawals for cooling towers relative to once-through ponds statewide. Increases in natural gas combined cycle plants with cooling towers in response to high production of low-cost natural gas has greatly reduced water demand for thermoelectric cooling since 2000. PMID:23937226

Controls on water use for thermoelectric generation: case study Texas, US.

PubMed

Scanlon, Bridget R; Reedy, Robert C; Duncan, Ian; Mullican, William F; Young, Michael

2013-10-01

Large-scale U.S. dependence on thermoelectric (steam electric) generation requiring water for cooling underscores the need to understand controls on this water use. The study objective was to quantify water consumption and withdrawal for thermoelectric generation, identifying controls, using Texas as a case study. Water consumption for thermoelectricity in Texas in 2010 totaled ∼0.43 million acre feet (maf; 0.53 km(3)), accounting for ∼4% of total state water consumption. High water withdrawals (26.2 maf, 32.3 km(3)) mostly reflect circulation between ponds and power plants, with only two-thirds of this water required for cooling. Controls on water consumption include (1) generator technology/thermal efficiency and (2) cooling system, resulting in statewide consumption intensity for natural gas combined cycle generators with mostly cooling towers (0.19 gal/kWh) being 63% lower than that of traditional coal, nuclear, or natural gas steam turbine generators with mostly cooling ponds (0.52 gal/kWh). The primary control on water withdrawals is cooling system, with ∼2 orders of magnitude lower withdrawals for cooling towers relative to once-through ponds statewide. Increases in natural gas combined cycle plants with cooling towers in response to high production of low-cost natural gas has greatly reduced water demand for thermoelectric cooling since 2000.

PBF Cooling Tower (PER720) and its Auxiliary Building (PER625). Camera ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Cooling Tower (PER-720) and its Auxiliary Building (PER-625). Camera facing west shows east facades. Center pipe carried secondary coolant water from reactor. Building to distributor basin. Date: August 2003. INEEL negative no. HD-35-10-1 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

PBF Cooling Tower (PER720), and Auxiliary Building (PER624). Camera faces ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Cooling Tower (PER-720), and Auxiliary Building (PER-624). Camera faces north to show south facades. Oblong vertical structure at left of center is weather shield for stairway. Date: August 2003. INEEL negative no. HD-35-10-4 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

ETR AND MTR COMPLEXES IN CONTEXT. CAMERA FACING NORTHERLY. FROM ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

ETR AND MTR COMPLEXES IN CONTEXT. CAMERA FACING NORTHERLY. FROM BOTTOM TO TOP: ETR COOLING TOWER, ELECTRICAL BUILDING AND LOW-BAY SECTION OF ETR BUILDING, HEAT EXCHANGER BUILDING (WITH U SHAPED YARD), COMPRESSOR BUILDING. MTR REACTOR SERVICES BUILDING IS ATTACHED TO SOUTH WALL OF MTR. WING A IS ATTACHED TO BALCONY FLOOR OF MTR. NEAR UPPER RIGHT CORNER OF VIEW IS MTR PROCESS WATER BUILDING. WING B IS AT FAR WEST END OF COMPLEX. NEAR MAIN GATE IS GAMMA FACILITY, WITH "COLD" BUILDINGS BEYOND: RAW WATER STORAGE TANKS, STEAM PLANT, MTR COOLING TOWER PUMP HOUSE AND COOLING TOWER. INL NEGATIVE NO. 56-4101. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Concentrating Solar Power Projects - Olivenza 1 | Concentrating Solar Power

Science.gov Websites

Manufacturer: Siemens Turbine Description: 5 extractions Output Type: Steam Rankine Power Cycle Pressure: 100.0 bar Cooling Method: Wet cooling Cooling Method Description: Cooling Towers

Cooling Tower (Evaporative Cooling System) Measurement and Verification Protocol

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kurnik, Charles W.; Boyd, Brian; Stoughton, Kate M.

This measurement and verification (M and V) protocol provides procedures for energy service companies (ESCOs) and water efficiency service companies (WESCOs) to determine water savings resulting from water conservation measures (WCMs) in energy performance contracts associated with cooling tower efficiency projects. The water savings are determined by comparing the baseline water use to the water use after the WCM has been implemented. This protocol outlines the basic structure of the M and V plan, and details the procedures to use to determine water savings.

Demonstration of a Mixed Oxide Process for Control of Corrosion and Microbiological Growth in Cooling Towers

DTIC Science & Technology

2009-08-01

fouling due to the buildup of algae and other microbiological growth, which can cause corrosion, reduce energy efficiency, and spread disease. A new...cooling of DoD facilities is critical to mission ex- ecution. Cooling tower systems are susceptible to fouling due to the buil- dup of algae and other...microbiological growth. The biofilm can harbor disease-causing bacteria. The development of a biofilm can increase corro- sion rates, and decrease the

AUTOMATED DEAD-END ULTRAFILTRATION FOR ENHANCED SURVEILLANCE OF LEGIONELLA 2 PNEUMOPHILA AND LEGIONELLA SPP. IN COOLING TOWER WATERS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brigmon, R.; Leskinen, S.; Kearns, E.

2011-10-10

Detection of Legionella pneumophila in cooling towers and domestic hot water systems involves concentration by centrifugation or membrane filtration prior to inoculation onto growth media or analysis using techniques such as PCR or immunoassays. The Portable Multi-use Automated Concentration System (PMACS) was designed for concentrating microorganisms from large volumes of water in the field and was assessed for enhancing surveillance of L. pneumophila at the Savannah River Site, SC. PMACS samples (100 L; n = 28) were collected from six towers between August 2010 and April 2011 with grab samples (500 ml; n = 56) being collected before and aftermore » each PMACS sample. All samples were analyzed for the presence of L. pneumophila by direct fluorescence immunoassay (DFA) using FITC-labeled monoclonal antibodies targeting serogroups 1, 2, 4 and 6. QPCR was utilized for detection of Legionella spp. in the same samples. Counts of L. pneumophila from DFA and of Legionella spp. from qPCR were normalized to cells/L tower water. Concentrations were similar between grab and PMACS samples collected throughout the study by DFA analysis (P = 0.4461; repeated measures ANOVA). The same trend was observed with qPCR. However, PMACS concentration proved advantageous over membrane filtration by providing larger volume, more representative samples of the cooling tower environment, which led to reduced variability among sampling events and increasing the probability of detection of low level targets. These data highlight the utility of the PMACS for enhanced surveillance of L. pneumophila by providing improved sampling of the cooling tower environment.« less

Prevalence and Molecular Characteristics of Waterborne Pathogen Legionella in Industrial Cooling Tower Environments

PubMed Central

Li, Lijie; Qin, Tian; Li, Yun; Zhou, Haijian; Song, Hongmei; Ren, Hongyu; Li, Liping; Li, Yongguang; Zhao, Dong

2015-01-01

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. PMID:26473896

Prevalence and Molecular Characteristics of Waterborne Pathogen Legionella in Industrial Cooling Tower Environments.

PubMed

Li, Lijie; Qin, Tian; Li, Yun; Zhou, Haijian; Song, Hongmei; Ren, Hongyu; Li, Liping; Li, Yongguang; Zhao, Dong

2015-10-12

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.

Comparative toxicological effects of two antifouling biocides on the marine diatom Chaetoceros lorenzianus: Damage and post-exposure recovery.

PubMed

Chavan, Pooja; Kumar, Rajesh; Kirubagaran, Ramalingam; Venugopalan, Vayalam P

2017-10-01

Antifouling biocides are commonly used in coastal electric power stations to prevent biofouling in their condenser cooling systems. However, the environmental impact of the chemical biocides is less understood than the thermal stress effects caused by the condenser effluents. In this study, Chaetoceros lorenzianus, a representative marine diatom, was used to analyse the toxicity of two antifouling biocides, chlorine and chlorine dioxide. The diatom cells were subjected to a range of concentrations of the biocides (from 0.05 to 2mg/L, as total residual oxidants, TRO) for contact time of 30min. They were analysed for viability, genotoxicity, chlorophyll a and cell density endpoints. The cells were affected at all concentrations of the biocides (0.05-2mg/L), showing dose-dependent decrease in viability and increase in DNA damage. The treated cells were later incubated in filtered seawater devoid of biocide to check for recovery. The cells were able to recover in terms of overall viability and DNA damage, when they had been initially treated with low concentrations of the biocides (0.5mg/L of Cl 2 or 0.2mg/L of ClO 2 ). Chlorophyll a analysis showed irreparable damage at all concentrations, while cell density showed increasing trend of reduction, if treated above 0.5mg/L of Cl 2 and 0.2mg/L of ClO 2 . The data indicated that in C. lorenzianus, cumulative toxic effects and recovery potential of ClO 2 up to 0.2mg/L were comparable with those of Cl 2 , up to 0.5mg/L concentration in terms of the studied endpoints. The results indicate that at the biocide levels currently being used at power stations, recovery of the organism is feasible upon return to ambient environment. Similar studies should be carried out on other planktonic and benthic organisms, which will be helpful in the formulation of future guidelines for discharge of upcoming antifouling biocides such as chlorine dioxide. Copyright © 2017 Elsevier Inc. All rights reserved.

An international trial of quantitative PCR for monitoring Legionella in artificial water systems.

PubMed

Lee, J V; Lai, S; Exner, M; Lenz, J; Gaia, V; Casati, S; Hartemann, P; Lück, C; Pangon, B; Ricci, M L; Scaturro, M; Fontana, S; Sabria, M; Sánchez, I; Assaf, S; Surman-Lee, S

2011-04-01

  To perform an international trial to derive alert and action levels for the use of quantitative PCR (qPCR) in the monitoring of Legionella to determine the effectiveness of control measures against legionellae.   Laboratories (7) participated from six countries. Legionellae were determined by culture and qPCR methods with comparable detection limits. Systems were monitored over ≥10 weeks. For cooling towers (232 samples), there was a significant difference between the log mean difference between qPCR (GU l(-1) ) and culture (CFU l(-1) ) for Legionella pneumophila (0·71) and for Legionella spp. (2·03). In hot and cold water (506 samples), the differences were less, 0·62 for Leg. pneumophila and 1·05 for Legionella spp. Results for individual systems depended on the nature of the system and its treatment. In cooling towers, Legionella spp. GU l(-1) always exceeded CFU l(-1) , and usually Legionella spp. were detected by qPCR when absent by culture. The pattern of results by qPCR for Leg. pneumophila followed the culture trend. In hot and cold water, culture and qPCR gave similar results, particularly for Leg. pneumophila. There were some marked exceptions with temperatures ≥50°C, or in the presence of supplementary biocides. Action and alert levels for qPCR were derived that gave results comparable to the application of the European Guidelines based on culture. Algorithms are proposed for the use of qPCR for routine monitoring.   Action and alert levels for qPCR can be adjusted to ensure public health is protected with the benefit that remedial actions can be validated earlier with only a small increase in the frequency of action being required.   This study confirms it is possible to derive guidelines on the use of qPCR for monitoring the control of legionellae with consequent improvement to response and public health protection. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

77 FR 27804 - Entergy Operations, Inc.; Grand Gulf Nuclear Station, Unit 1

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-11

... modification to the auxiliary cooling tower and the addition of two 60-gallon lube oil tanks associated with... modification of the auxiliary cooling tower and the addition of two 60-gallon lube oil tanks for the new radial... Mississippi River water is the Southeast Wood Fiber company located at the Claiborne County Port facility, 0.8...

Marginal costs of water savings from cooling system retrofits: a case study for Texas power plants

NASA Astrophysics Data System (ADS)

Loew, Aviva; Jaramillo, Paulina; Zhai, Haibo

2016-10-01

The water demands of power plant cooling systems may strain water supply and make power generation vulnerable to water scarcity. Cooling systems range in their rates of water use, capital investment, and annual costs. Using Texas as a case study, we examined the cost of retrofitting existing coal and natural gas combined-cycle (NGCC) power plants with alternative cooling systems, either wet recirculating towers or air-cooled condensers for dry cooling. We applied a power plant assessment tool to model existing power plants in terms of their key plant attributes and site-specific meteorological conditions and then estimated operation characteristics of retrofitted plants and retrofit costs. We determined the anticipated annual reductions in water withdrawals and the cost-per-gallon of water saved by retrofits in both deterministic and probabilistic forms. The results demonstrate that replacing once-through cooling at coal-fired power plants with wet recirculating towers has the lowest cost per reduced water withdrawals, on average. The average marginal cost of water withdrawal savings for dry-cooling retrofits at coal-fired plants is approximately 0.68 cents per gallon, while the marginal recirculating retrofit cost is 0.008 cents per gallon. For NGCC plants, the average marginal costs of water withdrawal savings for dry-cooling and recirculating towers are 1.78 and 0.037 cents per gallon, respectively.

34. SITE BUILDING 002 SCANNER BUILDING ROOM 105 ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

34. SITE BUILDING 002 - SCANNER BUILDING - ROOM 105 - CHILLER ROOM, SHOWING SINGLE COMPRESSOR, LIQUID CHILLERS AND "CHILLED WATER RETURN", COOLING TOWER 'TOWER WATER RETURN" AND 'TOWER WATER SUPPLY" LINES. - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

Army Net Zero Prove Out. Net Zero Waster Best Practices

DTIC Science & Technology

2014-11-18

harvested for non-potable uses such as toilet flushing in buildings, cooling towers and irrigation. Implementation of these solutions should not...potable uses such as toilet flushing in buildings, cooling towers and irrigation. Implementation of these solutions should not increase overall...collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources

The National Shipbuilding Research Program. Environmental Training Modules. Module 2 Shipyard Craft Specific Training

DTIC Science & Technology

1999-05-01

environmental liability. 4) Insecticides and Hazardous Metals Many antifouling coatings contain insecticides such as Tributyltin ( TBT ), and...of potentially toxic substances from shipyard welding operations. ASBESTOS OPERATIONS IN THE SHIPYARD (10ASBTOS.DOC) OBJECTIVE To ensure that...distillation operations. COOLING TOWERS (6-COOLIN.DOC) OBJECTIVE To minimize the potential for toxic emissions from cooling towers. VARNISH DIP TANKS (7

Energy Savings and Persistence from an Energy Services Performance Contract at an Army Base

DTIC Science & Technology

2011-10-01

control system upgrades, lighting retrofits, vending machine controls, and cooling tower variable frequency drivers (VFDs). To accomplish the...controls were installed in the vending machines , and for the 87018 thermal plant, cooling tower VFDs were implemented. To develop baseline models...identify the reasons of improved or deteriorated energy performance of the buildings. For example, periodic submetering of the vending machines

Ozone Treatment For Cooling Towers

NASA Technical Reports Server (NTRS)

Blackwelder, Rick; Baldwin, Leroy V.; Feeney, Ellen S.

1990-01-01

Report presents results of study of cooling tower in which water treated with ozone instead of usual chemical agents. Bacteria and scale reduced without pollution and at low cost. Operating and maintenance costs with treatment about 30 percent of those of treatment by other chemicals. Corrosion rates no greater than with other chemicals. Advantage of ozone, even though poisonous, quickly detected by smell in very low concentrations.

Cooled Water Production System,

DTIC Science & Technology

The invention refers to the field of air conditioning and regards an apparatus for obtaining cooled water . The purpose of the invention is to develop...such a system for obtaining cooled water which would permit the maximum use of the cooling effect of the water -cooling tower.

Implementation of a Legionella Ordinance for Multifamily Housing, Garland, Texas.

PubMed

Whitney, Ellen A; Blake, Sarah; Berkelman, Ruth L

The incidence of legionellosis has sharply increased in the United States as a result of contaminated water systems. Jurisdictions across the country are considering whether to develop and implement regulations to protect individuals against Legionnaires' disease with its associated high morbidity and mortality. This article sheds light on the implementation and effectiveness of a 2005 citywide Legionella testing mandate of multifamily housing cooling towers in Garland, Texas. This ordinance has been in place for more than 10 years and represents the first of its kind in the United States to mandate routine testing of cooling towers for Legionella in multifamily housing. We utilized a mix of both qualitative and quantitative methods to explore the development, adoption, and implementation of the ordinance. Phone interviews were conducted with individuals from the City of Garland Health Department and apartment managers. Quantitative data included public health surveillance data on legionellosis. Barriers and facilitators of implementation, number and percentage of cooling towers from multifamily housing units that tested positive for Legionella by year, and number of legionellosis cases by year in Garland, Texas. Study outcomes highlight key themes that facilitated the successful implementation of the Legionella testing mandate, including the importance of timing, leadership support, stakeholder engagement, and education and outreach. The number of contaminated cooling towers was reduced over time. Mandatory monitoring for legionella in a local jurisdiction may result in reduced risk of legionellosis from cooling towers through raising awareness and education of building owners and managers about the need to prevent, detect, and remediate legionella contamination in their building water systems. Garland, Texas, broke new ground in the United States in moving toward primary prevention of legionellosis. The ordinance may be useful both in serving to educate and increase awareness about the need for Legionella prevention and to monitor effectiveness of maintenance procedures.

Prevalence study of Simkania negevensis in cooling towers in Spain.

PubMed

Pérez, Leonardo Martín; Codony, Francesc; Ríos, Karina; Adrados, Bárbara; Fittipaldi, Mariana; De Dios, Gregori; Peñuela, Gustavo; Morató, Jordi

2011-06-01

Simkania negevensis is an obligate intracellular bacterium grouped into the order Chlamydiales. This new amoeba-resistant intracellular bacterium might represent a novel etiologic agent of bronchiolitis and community-acquired pneumonia and occurs in aquatic habitats such as drinking water and reclaimed wastewater. Another amoeba-related bacterium, Legionella pneumophila, is an etiologic agent of pneumonia transmitted by environmental aerosols or contaminated water/air cooling systems. These transmission pathways are important in the natural history of Legionellae infections and possibly other intracellular microorganisms such as Parachlamydiaceae; thus, understanding the feasibility of Simkania infection by these routes is relevant. In the present work, we investigated the prevalence of this newly identified pathogenic bacterium in cooling towers by quantitative PCR (qPCR) and its possible relationship with Legionella pneumophila co-infection. Our results show Simkania detection in 2 of 70 cooling towers analyzed. To our knowledge, this report is the first describing Simkania negevensis detection in this category of environmental water samples.

Experimental Research on Optimizing Inlet Airflow of Wet Cooling Towers under Crosswind Conditions

NASA Astrophysics Data System (ADS)

Chen, You Liang; Shi, Yong Feng; Hao, Jian Gang; Chang, Hao; Sun, Feng Zhong

2018-01-01

A new approach of installing air deflectors around tower inlet circumferentially was proposed to optimize the inlet airflow and reduce the adverse effect of crosswinds on the thermal performance of natural draft wet cooling towers (NDWCT). And inlet airflow uniformity coefficient was defined to analyze the uniformity of circumferential inlet airflow quantitatively. Then the effect of air deflectors on the NDWCT performance was investigated experimentally. By contrast between inlet air flow rate and cooling efficiency, it has been found that crosswinds not only decrease the inlet air flow rate, but also reduce the uniformity of inlet airflow, which reduce NDWCT performance jointly. After installing air deflectors, the inlet air flow rate and uniformity coefficient increase, the uniformity of heat and mass transfer increases correspondingly, which improve the cooling performance. In addition, analysis on Lewis factor demonstrates that the inlet airflow optimization has more enhancement of heat transfer than mass transfer, but leads to more water evaporation loss.

Reduction of Fire Hazard in Materials for Irrigators and Water Collectors in Cooling Towers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smirnov, N. V.; Konstantinova, N. I., E-mail: konstantinova-n@inbox.ru; Gordon, E. P.

A way of reducing the fire hazard of PVC film used to make cooling-tower irrigators and water collectors is examined. A new generation of fire retardant, nanostructured magnesium hydroxide, is used to impart fire retardant properties. The fabrication technology is optimized with a roller-calendering manufacturing technique, and the permissible ranges of fire hazard indicators for materials in irrigators and water collectors are determined.

Genome Sequence of Legionella massiliensis, Isolated from a Cooling Tower Water Sample.

PubMed

Pagnier, Isabelle; Croce, Olivier; Robert, Catherine; Raoult, Didier; La Scola, Bernard

2014-10-16

We present the draft genome sequence of Legionella massiliensis strain LegA(T), recovered from a cooling tower water sample, using an amoebal coculture procedure. The strain described here is composed of 4,387,007 bp, with a G+C content of 41.19%, and its genome has 3,767 protein-coding genes and 60 predicted RNA genes. Copyright © 2014 Pagnier et al.

CALCULATION OF COOLING TOWERS AND INJECTION COOLERS BY MEANS OF AN EVAPORATION METHOD (in German)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spangemacher, K.

1958-05-01

Calculation and evaluation of cooling towers, as recommended by Merkel, are critically examined. The usual methods of practical calculation are explained as well as a new procedure which combines great accuracy with brevity. Merkel's method is extended to injection coolers for gas and compressed air. It was discussed whether the dimensionless ''evaporation coefficient'' should be called the''Merkel coefficient.'' (tr-auth)

Presence of pathogenic microorganisms in power-plant cooling waters. Final report, October 1, 1981-June 30, 1983

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tyndall, R.L.

1983-07-01

Air was sampled at the point of discharge and at short distances downwind and upwind from industrial and power-plant cooling towers. Both high-volume electrostatic and impinger type samplers were used. Concentrates of the air samples were analyzed for Legionnaires' Disease Bacteria (LDB). In some cases, the samples were also tested for the presence of free-living amoebae. The concentrations of LDB in the air samples were well below the minimal infectious dose for guinea pigs and precluded testing of the samples for infectious LDB. Results of LDB analysis were related to the meteorological conditions at the time of sampling. Generally, themore » concentrations of LDB in the air at the discharge of the cooling towers were 1 x 10/sup -6/ to 1 x 10/sup -7/ of that found in comparable volumes of tower basin water. During periods of high humidity and wind speed, LDB was detected in a few downwind samples and one upwind sample. One site with extensive construction and excavation activity had higher LDB concentrations in air samples relative to other sites. Nonpathogenic Naegleria were present in one of two air samples taken in the mist at the base of a natural-draft cooling tower.« less

European dry cooling tower operating experience

DOE Office of Scientific and Technical Information (OSTI.GOV)

DeSteese, J.G.; Simhan, K.

1976-03-01

Interviews were held with representatives of major plants and equipment manufacturers to obtain current information on operating experience with dry cooling towers in Europe. The report documents the objectives, background, and organizational details of the study, and presents an itemized account of contacts made to obtain information. Plant selection was based on a merit index involving thermal capacity and length of service. A questionnaire was used to organize operational data, when available, into nine major categories of experience. Information was also solicited concerning the use of codes and standards to ensure the achievement of cooling tower performance. Several plant operatorsmore » provided finned-tube samples for metallographic analysis. Additionally, information on both operating experience and developing technology was supplied by European technical societies and research establishments. Information obtained from these contacts provides an updated and representative sample of European experience with dry cooling towers, which supplements some of the detailed reviews already available in the literature. In addition, the study presents categorized operating experience with installations which have not been reviewed so extensively, but nevertheless, have significant operational histories when ranked by the merit index. The contacts and interviews reported in the survey occurred between late March and October 1975. The study was motivated by the expressed interest of U.S. utility industry representatives who expect European experience to provide a basis of confidence that dry cooling is a reliable technology, applicable when necessary, to U.S. operating requirements.« less

Water Purification

NASA Technical Reports Server (NTRS)

1992-01-01

Silver ionization water purification technology was originally developed for Apollo spacecraft. It was later used to cleanse swimming pools and has now been applied to industrial cooling towers and process coolers. Sensible Technologies, Inc. has added two other technologies to the system, which occupies only six square feet. It is manufactured in three capacities, and larger models are custom built on request. The system eliminates scale, corrosion, algae, bacteria and debris, and because of the NASA technology, viruses and waterborne bacteria are also destroyed. Applications include a General Motors cooling tower, amusement parks, ice manufacture and a closed-loop process cooling system.

Demonstration and Validation of Corrosion-Mitigation Technologies for Mechanical Room Utility Piping and Cooling-Tower Pumps

DTIC Science & Technology

2015-05-01

Infrastructure, Task 2.1” ERDC/CERL TR-15-5 ii Abstract Two critical infrastructure corrosion issues at Fort Bragg, NC, are the cor- rosion of steel utility...piping union joints in mechanical rooms and the cor- rosion of steel pump housings in cooling tower systems. Reliable operation of these components...pump 5 incorporating 316 stainless steel housing. .................................... 19 Figure 13. New pump 5 being installed

Review of numerical models to predict cooling tower performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, B.M.; Nomura, K.K.; Bartz, J.A.

1987-01-01

Four state-of-the-art computer models developed to predict the thermal performance of evaporative cooling towers are summarized. The formulation of these models, STAR and TEFERI (developed in Europe) and FACTS and VERA2D (developed in the U.S.), is summarized. A fifth code, based on Merkel analysis, is also discussed. Principal features of the codes, computation time and storage requirements are described. A discussion of model validation is also provided.

Chalk Point cooling tower project native vegetation study. Final report 1979

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patterson, G.W.; Galloway, R.A.; Francis, B.A.

1979-06-01

The Potomac Electric Power Company generating station at Chalk Point, MD, utilizes brackish water in its natural draft cooling tower and, consequently, releases saline aerosol into the atmosphere. A research and monitoring project was established in 1974 to evaluate the effects of this drift on native perennial vegetation. Leaf samples have been collected form dogwood, Cornys florida, Virginia pine, Pinus virginiana, black locust, Robinia pseudoacacia, and sassafras, Sassafras albidum, located at 12 different sites in the vicinity of the power plant. Sampling was begun prior to the operation of the cooling tower, 1974, and continued through 1978. Complete results frommore » monthly monitoring of foliar chloride in the four native tree species is documented for May through September 1978. Results from salt spray experiments indicate chloride and sodium concentrations in the wood of dogwood trees increases with increased spraying levels.« less

Implications of Transitioning from De Facto to Engineered Water Reuse for Power Plant Cooling.

PubMed

Barker, Zachary A; Stillwell, Ashlynn S

2016-05-17

Thermoelectric power plants demand large quantities of cooling water, and can use alternative sources like treated wastewater (reclaimed water); however, such alternatives generate many uncertainties. De facto water reuse, or the incidental presence of wastewater effluent in a water source, is common at power plants, representing baseline conditions. In many cases, power plants would retrofit open-loop systems to cooling towers to use reclaimed water. To evaluate the feasibility of reclaimed water use, we compared hydrologic and economic conditions at power plants under three scenarios: quantified de facto reuse, de facto reuse with cooling tower retrofits, and modeled engineered reuse conditions. We created a genetic algorithm to estimate costs and model optimal conditions. To assess power plant performance, we evaluated reliability metrics for thermal variances and generation capacity loss as a function of water temperature. Applying our analysis to the greater Chicago area, we observed high de facto reuse for some power plants and substantial costs for retrofitting to use reclaimed water. Conversely, the gains in reliability and performance through engineered reuse with cooling towers outweighed the energy investment in reclaimed water pumping. Our analysis yields quantitative results of reclaimed water feasibility and can inform sustainable management of water and energy.

A case study on Simulation and Design optimization to improve Productivity in cooling tower manufacturing industry

NASA Astrophysics Data System (ADS)

Pranav Nithin, R.; Gopikrishnan, S.; Sumesh, A.

2018-02-01

Cooling towers are the heat transfer devices commonly found in industries which are used to extract the high temperature from the coolants and make it reusable in various plants. Basically, the cooling towers has Fills made of PVC sheets stacked together to increase the surface area exposure of the cooling liquid flowing through it. This paper focuses on the study in such a manufacturing plant where fills are being manufactured. The productivity using the current manufacturing method was only 6 to 8 fills per day, where the ideal capacity was of 14 fills per day. In this plant manual labor was employed in the manufacturing process. A change in the process modification designed and implemented will help the industry to increase the productivity to 14. In this paper, initially the simulation study was done using ARENA the simulation package and later the new design was done using CAD Package and validated using Ansys Mechanical APDL. It’s found that, by the implementation of the safe design the productivity can be increased to 196 Units.

PBF Cooling Tower. View from highbay roof of Reactor Building ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Cooling Tower. View from high-bay roof of Reactor Building (PER-620). Camera faces northwest. East louvered face has been installed. Inlet pipes protrude from fan deck. Two redwood vents under construction at top. Note piping, control, and power lines at sub-grade level in trench leading to Reactor Building. Photographer: Kirsh. Date: June 6, 1969. INEEL negative no. 69-3466 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

Rapid on-site monitoring of Legionella pneumophila in cooling tower water using a portable microfluidic system.

PubMed

Yamaguchi, Nobuyasu; Tokunaga, Yusuke; Goto, Satoko; Fujii, Yudai; Banno, Fumiya; Edagawa, Akiko

2017-06-08

Legionnaires' disease, predominantly caused by the bacterium Legionella pneumophila, has increased in prevalence worldwide. The most common mode of transmission of Legionella is inhalation of contaminated aerosols, such as those generated by cooling towers. Simple, rapid and accurate methods to enumerate L. pneumophila are required to prevent the spread of this organism. Here, we applied a microfluidic device for on-chip fluorescent staining and semi-automated counting of L. pneumophila in cooling tower water. We also constructed a portable system for rapid on-site monitoring and used it to enumerate target bacterial cells rapidly flowing in the microchannel. A fluorescently-labelled polyclonal antibody was used for the selective detection of L. pneumophila serogroup 1 in the samples. The counts of L. pneumophila in cooling tower water obtained using the system and fluorescence microscopy were similar. The detection limit of the system was 10 4  cells/ml, but lower numbers of L. pneumophila cells (10 1 to 10 3  cells/ml) could be detected following concentration of 0.5-3 L of the water sample by filtration. Our technique is rapid to perform (1.5 h), semi-automated (on-chip staining and counting), and portable for on-site measurement, and it may therefore be effective in the initial screening of Legionella contamination in freshwater.

Evaluation of the potential of ozone as a power plant biocide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mattice, J.S.; Trabalka, J.R.; Adams, S.M.

1978-09-01

A review of the literature on the chemistry and biological effects of ozone was conducted to evaluate the potential of ozone to function as a power plant biocide. Evaluation of this potential is dependent upon determining the ability of ozone to maintain the integrity of both the condenser cooling system and the associated ecosystem. The well-known bactericidal capacity of ozone and the limited biofouling control studies conducted thus far suggest that ozone can control both slime and macroinvertebrate fouling at power plants. However, full-scale demonstrations of the minimum levels of ozone required and of solution of the practical aspects ofmore » application have not been performed.« less

Health risks from exposure to Legionella in reclaimed water aerosols: Toilet flushing, spray irrigation, and cooling towers.

PubMed

Hamilton, Kerry A; Hamilton, Mark T; Johnson, William; Jjemba, Patrick; Bukhari, Zia; LeChevallier, Mark; Haas, Charles N

2018-05-01

The use of reclaimed water brings new challenges for the water industry in terms of maintaining water quality while increasing sustainability. Increased attention has been devoted to opportunistic pathogens, especially Legionella pneumophila, due to its growing importance as a portion of the waterborne disease burden in the United States. Infection occurs when a person inhales a mist containing Legionella bacteria. The top three uses for reclaimed water (cooling towers, spray irrigation, and toilet flushing) that generate aerosols were evaluated for Legionella health risks in reclaimed water using quantitative microbial risk assessment (QMRA). Risks are compared using data from nineteen United States reclaimed water utilities measured with culture-based methods, quantitative PCR (qPCR), and ethidium-monoazide-qPCR. Median toilet flushing annual infection risks exceeded 10 -4 considering multiple toilet types, while median clinical severity infection risks did not exceed this value. Sprinkler and cooling tower risks varied depending on meteorological conditions and operational characteristics such as drift eliminator performance. However, the greatest differences between risk scenarios were due to 1) the dose response model used (infection or clinical severity infection) 2) population at risk considered (residential or occupational) and 3) differences in laboratory analytical method. Theoretical setback distances necessary to achieve a median annual infection risk level of 10 -4 are proposed for spray irrigation and cooling towers. In both cooling tower and sprinkler cases, Legionella infection risks were non-trivial at potentially large setback distances, and indicate other simultaneous management practices could be needed to manage risks. The sensitivity analysis indicated that the most influential factors for variability in risks were the concentration of Legionella and aerosol partitioning and/or efficiency across all models, highlighting the importance of strategies to manage Legionella occurrence in reclaimed water. Copyright © 2018 Elsevier Ltd. All rights reserved.

Implementation of a Legionella Ordinance for Multifamily Housing, Garland, Texas

PubMed Central

Whitney, Ellen A.; Blake, Sarah

2017-01-01

Context: The incidence of legionellosis has sharply increased in the United States as a result of contaminated water systems. Jurisdictions across the country are considering whether to develop and implement regulations to protect individuals against Legionnaires' disease with its associated high morbidity and mortality. Objective: This article sheds light on the implementation and effectiveness of a 2005 citywide Legionella testing mandate of multifamily housing cooling towers in Garland, Texas. This ordinance has been in place for more than 10 years and represents the first of its kind in the United States to mandate routine testing of cooling towers for Legionella in multifamily housing. Design, Setting, and Population: We utilized a mix of both qualitative and quantitative methods to explore the development, adoption, and implementation of the ordinance. Phone interviews were conducted with individuals from the City of Garland Health Department and apartment managers. Quantitative data included public health surveillance data on legionellosis. Main Outcome Measures: Barriers and facilitators of implementation, number and percentage of cooling towers from multifamily housing units that tested positive for Legionella by year, and number of legionellosis cases by year in Garland, Texas. Results: Study outcomes highlight key themes that facilitated the successful implementation of the Legionella testing mandate, including the importance of timing, leadership support, stakeholder engagement, and education and outreach. The number of contaminated cooling towers was reduced over time. Conclusion: Mandatory monitoring for legionella in a local jurisdiction may result in reduced risk of legionellosis from cooling towers through raising awareness and education of building owners and managers about the need to prevent, detect, and remediate legionella contamination in their building water systems. Garland, Texas, broke new ground in the United States in moving toward primary prevention of legionellosis. The ordinance may be useful both in serving to educate and increase awareness about the need for Legionella prevention and to monitor effectiveness of maintenance procedures. PMID:28141673

ETR COMPLEX. CAMERA FACING SOUTH. FROM BOTTOM OF VIEW TO ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

ETR COMPLEX. CAMERA FACING SOUTH. FROM BOTTOM OF VIEW TO TOP: MTR, MTR SERVICE BUILDING, ETR CRITICAL FACILITY, ETR CONTROL BUILDING (ATTACHED TO ETR), ETR BUILDING (HIGH-BAY), COMPRESSOR BUILDING (ATTACHED AT LEFT OF ETR), HEAT EXCHANGER BUILDING (JUST BEYOND COMPRESSOR BUILDING), COOLING TOWER PUMP HOUSE, COOLING TOWER. OTHER BUILDINGS ARE CONTRACTORS' CONSTRUCTION BUILDINGS. INL NEGATIVE NO. 56-4105. Unknown Photographer, ca. 1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Formation of secondary inorganic aerosols by power plant emissions exhausted through cooling towers in Saxony.

PubMed

Hinneburg, Detlef; Renner, Eberhard; Wolke, Ralf

2009-01-01

The fraction of ambient PM10 that is due to the formation of secondary inorganic particulate sulfate and nitrate from the emissions of two large, brown-coal-fired power stations in Saxony (East Germany) is examined. The power stations are equipped with natural-draft cooling towers. The flue gases are directly piped into the cooling towers, thereby receiving an additionally intensified uplift. The exhausted gas-steam mixture contains the gases CO, CO2, NO, NO2, and SO2, the directly emitted primary particles, and additionally, an excess of 'free' sulfate ions in water solution, which, after the desulfurization steps, remain non-neutralized by cations. The precursor gases NO2 and SO2 are capable of forming nitric and sulfuric acid by several pathways. The acids can be neutralized by ammonia and generate secondary particulate matter by heterogeneous condensation on preexisting particles. The simulations are performed by a nested and multi-scale application of the online-coupled model system LM-MUSCAT. The Local Model (LM; recently renamed as COSMO) of the German Weather Service performs the meteorological processes, while the Multi-scale Atmospheric Transport Model (MUSCAT) includes the transport, the gas phase chemistry, as well as the aerosol chemistry (thermodynamic ammonium-sulfate-nitrate-water system). The highest horizontal resolution in the inner region of Saxony is 0.7 km. One summer and one winter episode, each realizing 5 weeks of the year 2002, are simulated twice, with the cooling tower emissions switched on and off, respectively. This procedure serves to identify the direct and indirect influences of the single plumes on the formation and distribution of the secondary inorganic aerosols. Surface traces of the individual tower plumes can be located and distinguished, especially in the well-mixed boundary layer in daytime. At night, the plumes are decoupled from the surface. In no case does the resulting contribution of the cooling tower emissions to PM10 significantly exceed 15 microg m(-3) at the surface. These extreme values are obtained in narrow plumes on intensive summer conditions, whereas different situations with lower turbulence (night, winter) remain below this value. About 90% of the PM10 concentrations in the plumes are secondarily formed sulfate, mainly ammonium sulfate, and about 10% originate from the primarily emitted particles. Under the assumptions made, ammonium nitrate plays a rather marginal role. The analyzed results depend on the specific emission data of power plants with flue gas emissions piped through the cooling towers. The emitted fraction of 'free' sulfate ions remaining in excess after the desulfurization steps plays an important role at the formation of secondary aerosols and therefore has to be measured carefully.

Atmospheric considerations regarding the impact of heat dissipation from a nuclear energy center

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rotty, R.M.; Bauman, H.; Bennett, L.L.

1976-05-01

Potential changes in climate resulting from a large nuclear energy center are discussed. On a global scale, no noticeable changes are likely, but on both a regional and a local scale, changes can be expected. Depending on the cooling system employed, the amount of fog may increase, the amount and distribution of precipitation will change, and the frequency or location of severe storms may change. Very large heat releases over small surface areas can result in greater atmospheric instability; a large number of closely spaced natural-draft cooling towers have this disadvantage. On the other hand, employment of natural-draft towers makesmore » an increase in the occurrence of ground fog unlikely. The analysis suggests that the cooling towers for a large nuclear energy center should be located in clusters of four with at least 2.5-mile spacing between the clusters. This is equivalent to the requirement of one acre of land surface per each two megawatts of heat being rejected.« less

Isolation of Legionella pneumophila from cooling towers, public baths, hospitals, and fountains in Seoul, Korea, from 2010 to 2012.

PubMed

Kim, Changkyu; Jeon, Sujin; Jung, Jihun; Oh, Younghee; Kim, Yeonsun; Lee, Jaein; Choi, Sungmin; Chae, Youngzoo; Lee, Young-Ki

2015-01-01

Legionnaire's disease is associated with a high mortality rate. The authors collected 3,495 water samples in Seoul, Korea, between 2010 and 2012 from public facilities (cooling towers, public baths, hospitals, and decorative fountains), which are considered the major habitats of Legionella pneumophila. In all, 527 (15.1%) isolates of L. pneumophila were obtained by microbial culture and polymerase chain reaction. Serological diagnosis and pulsed-field gel electrophoresis (PFGE) analysis were performed for the samples. The authors categorized the samples into four groups (A-D) on the basis of PFGE results. The analysis revealed that cooling towers containing the most samples with L. pneumophila serogroup 1 constituted the highest proportion of isolate. Samples from public facilities and serogroups could be distinctively classified by PFGE patterns. Thus, it is expected that source-specific features revealed through PFGE and serological analyses could serve as the basis for effectively coping with future outbreaks of L. pneumophila.

Numerical modelling of series-parallel cooling systems in power plant

NASA Astrophysics Data System (ADS)

Regucki, Paweł; Lewkowicz, Marek; Kucięba, Małgorzata

2017-11-01

The paper presents a mathematical model allowing one to study series-parallel hydraulic systems like, e.g., the cooling system of a power boiler's auxiliary devices or a closed cooling system including condensers and cooling towers. The analytical approach is based on a set of non-linear algebraic equations solved using numerical techniques. As a result of the iterative process, a set of volumetric flow rates of water through all the branches of the investigated hydraulic system is obtained. The calculations indicate the influence of changes in the pipeline's geometrical parameters on the total cooling water flow rate in the analysed installation. Such an approach makes it possible to analyse different variants of the modernization of the studied systems, as well as allowing for the indication of its critical elements. Basing on these results, an investor can choose the optimal variant of the reconstruction of the installation from the economic point of view. As examples of such a calculation, two hydraulic installations are described. One is a boiler auxiliary cooling installation including two screw ash coolers. The other is a closed cooling system consisting of cooling towers and condensers.

11. SITE BUILDING 002 SCANNER BUILDING EVAPORATIVE COOLING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

11. SITE BUILDING 002 - SCANNER BUILDING - EVAPORATIVE COOLING TOWER SYSTEM IN FOREGROUND. - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

Legionnaires' disease bacteria in power plant cooling systems: downtime report. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tyndall, R.L.; Solomon, J.A.; Christensen, S.W.

1985-11-01

Legionnaires' disease bacteria (Legionella) are a normal part of the aquatic community that, when aerosolized, can be pathogenic to man. The downtime study was designed to determine the degree to which Legionella populations are aerosolized during cleaning and maintenance operations in a closed-cycle steam-electric power plant. Both high-volume and impinger air samples were collected prior to and during downtime operations. Emphasis was placed on sampling inside or adjacent to water boxes, condensers, and cooling towers. Control air samples were taken upwind from the plant site. Water and sludge samples were also collected at various locations. In the laboratory, the concentrationsmore » of Legionella were determined using the direct fluorescent antibody method. All positive air samples, and other selected air samples, were injected into guinea pigs to detect infectious Legionella. Legionella could be detected in only 12 of the 127 air samples collected. These were predominantly L. pneumophila, serogroups 1-6. In contrast to the air samples, most of the water and sludge samples were positive for Legionella, again predominantly L. pneumophila, serogroups 1-6. The highest Legionella concentrations were found in sludge samples associated with condenser tube cleaning. Among the water samples, the highest Legionella concentrations were found in cooling towers, immediately after the tower basins were cleaned and refilled, and in condenser tubes. Two of the three cooling tower water samples collected prior to downtime operations were infectious for guinea pigs. 16 refs., 4 figs., 11 tabs.« less

Strengths and limitations of molecular subtyping in a community outbreak of Legionnaires' disease.

PubMed

Kool, J L; Buchholz, U; Peterson, C; Brown, E W; Benson, R F; Pruckler, J M; Fields, B S; Sturgeon, J; Lehnkering, E; Cordova, R; Mascola, L M; Butler, J C

2000-12-01

An epidemiological and microbiological investigation of a cluster of eight cases of Legionnaires' disease in Los Angeles County in November 1997 yielded conflicting results. The epidemiological part of the investigation implicated one of several mobile cooling towers used by a film studio in the centre of the outbreak area. However, water sampled from these cooling towers contained L. pneumophila serogroup 1 of another subtype than the strain that was recovered from case-patients in the outbreak. Samples from two cooling towers located downwind from all of the case-patients contained a Legionella strain that was indistinguishable from the outbreak strain by four subtyping techniques (AP-PCR, PFGE, MAb, and MLEE). It is unlikely that these cooling towers were the source of infection for all the case-patients, and they were not associated with risk of disease in the case-control study. The outbreak strain also was not distinguishable, by three subtyping techniques (AP-PCR, PFGE, and MAb), from a L. pneumophila strain that had caused an outbreak in Providence, RI, in 1993. Laboratory cross-contamination was unlikely because the initial subtyping was done in different laboratories. In this investigation, microbiology was helpful for distinguishing the outbreak cluster from unrelated cases of Legionnaires' disease occurring elsewhere. However, multiple subtyping techniques failed to distinguish environmental sources that were probably not associated with the outbreak. Persons investigating Legionnaires' disease outbreaks should be aware that microbiological subtyping does not always identify a source with absolute certainty.

Investigation of N-acyl homoserine lactone (AHL) molecule production in Gram-negative bacteria isolated from cooling tower water and biofilm samples.

PubMed

Haslan, Ezgi; Kimiran-Erdem, Ayten

2013-09-01

In this study, 99 Gram-negative rod bacteria were isolated from cooling tower water, and biofilm samples were examined for cell-to-cell signaling systems, N-acyl homoserine lactone (AHL) signal molecule types, and biofilm formation capacity. Four of 39 (10 %) strains isolated from water samples and 14 of 60 (23 %) strains isolated from biofilm samples were found to be producing a variety of AHL signal molecules. It was determined that the AHL signal molecule production ability and the biofilm formation capacity of sessile bacteria is higher than planktonic bacteria, and there was a statistically significant difference between the AHL signal molecule production of these two groups (p < 0.05). In addition, it was found that bacteria belonging to the same species isolated from cooling tower water and biofilm samples produced different types of AHL signal molecules and that there were different types of AHL signal molecules in an AHL extract of bacteria. In the present study, it was observed that different isolates of the same strains did not produce the same AHLs or did not produce AHL molecules, and bacteria known as AHL producers did not produce AHL. These findings suggest that detection of signal molecules in bacteria isolated from cooling towers may contribute to prevention of biofilm formation, elimination of communication among bacteria in water systems, and blockage of quorum-sensing controlled virulence of these bacteria.

Extracellular polysaccharides produced by cooling water tower biofilm bacteria and their possible degradation.

PubMed

Ceyhan, Nur; Ozdemir, Guven

2008-01-01

The extracellular polymers (EPS) of biofilm bacteria that can cause heat and mass transfer problems in cooling water towers in the petrochemical industry were investigated. In addition, these microorganisms were screened for their ability to grow and degrade their own EPS and the EPS of other species. Twelve bacteria producing the most EPS were isolated from cooling water towers and characterized biochemically by classic and commercial systems. These were species of Pseudomonas, Burkholderia, Aeromonas, Pasteurella, Pantoea, Alcaligenes and Sphingomonas. EPS of these species were obtained by propan-2-ol precipitation and centrifugation from bacterial cultures in media enriched with glucose, sucrose or galactose. EPS yields were of 1.68-4.95 g l(-1). These EPS materials were characterized for total sugar and protein contents. Their total sugar content ranged from 24 to 56% (g sugar g(-1) EPS), and their total protein content ranged from 10 to 28% (g protein g(-1) EPS). The monosaccharide compositions of EPS were determined by HPLC. Generally, these compositions were enriched in galactose and glucose, with lesser amounts of mannose, rhamnose, fructose and arabinose. All bacteria were investigated in terms of EPS degradation. Eight of the bacteria were able to utilize EPS from Burkholderia cepacia, seven of the bacteria were able to utilize EPS from Pseudomonas sp. and Sphingomonas paucimobilis. The greatest viscosity reduction of B. cepacia was obtained with Pseudomonas sp. The results show that the bacteria in this study are able to degrade EPS from biofilms in cooling towers.

Rapid quantification of viable Legionella in nuclear cooling tower waters using filter cultivation, fluorescent in situ hybridization and solid-phase cytometry.

PubMed

Baudart, J; Guillaume, C; Mercier, A; Lebaron, P; Binet, M

2015-05-01

To develop a rapid and sensitive method to quantify viable Legionella spp. in cooling tower water samples. A rapid, culture-based method capable of quantifying as few as 600 Legionella microcolonies per litre within 2 days in industrial waters was developed. The method combines a short cultivation step of microcolonies on GVPC agar plate, specific detection of Legionella cells by a fluorescent in situ hybridization (FISH) approach, and a sensitive enumeration using a solid-phase cytometer. Following optimization of the cultivation conditions, the qualitative and quantitative performance of the method was assessed and the method was applied to 262 nuclear power plant cooling water samples. The performance of this method was in accordance with the culture method (NF-T 90-431) for Legionella enumeration. The rapid detection of viable Legionella in water is a major concern to the effective monitoring of this pathogenic bacterium in the main water sources involved in the transmission of legionellosis infection (Legionnaires' disease). The new method proposed here appears to be a robust, efficient and innovative means for rapidly quantifying cultivable Legionella in cooling tower water samples within 48 h. © 2015 The Society for Applied Microbiology.

Numerical analysis of heat and mass transfer for water recovery in an evaporative cooling tower

NASA Astrophysics Data System (ADS)

Lee, Hyunsub; Son, Gihun

2017-11-01

Numerical analysis is performed for water recovery in an evaporative cooling tower using a condensing heat exchanger, which consists of a humid air channel and an ambient dry air channel. The humid air including water vapor produced in an evaporative cooling tower is cooled by the ambient dry air so that the water vapor is condensed and recovered to the liquid water. The conservation equations of mass, momentum, energy and vapor concentration in each fluid region and the energy equation in a solid region are simultaneously solved with the heat and mass transfer boundary conditions coupled to the effect of condensation on the channel surface of humid air. The present computation demonstrates the condensed water film distribution on the humid air channel, which is caused by the vapor mass transfer between the humid air and the colder water film surface, which is coupled to the indirect heat exchange with the ambient air. Computations are carried out to predict water recovery rate in parallel, counter and cross-flow type heat exchangers. The effects of air flow rate and channel interval on the water recovery rate are quantified.

Outbreak of legionnaires' disease from a cooling water system in a power station.

PubMed

Morton, S; Bartlett, C L; Bibby, L F; Hutchinson, D N; Dyer, J V; Dennis, P J

1986-09-01

In September and October 1981 six cases of pneumonia occurred among men working in a power station under construction. Three were identified as cases of legionella pneumonia and two others had serology suggestive of legionella infection. In a sample of 92 men from the site 10 had low levels of antibodies to legionella; a similar sample of men working on an adjacent site showed none with positive serology. In a case control study it was found that cases of pneumonia were more likely than controls to have worked on a part of the site where four small capacity cooling towers were located. Legionella pneumophila serogroup 1 was isolated from the water systems of these four towers but was not found in samples from any other cooling towers or hot or cold water outlets on the site. It would appear that there was airborne spread of the organism from these cooling water systems which had not received conventional treatment to inhibit corrosion and organic growth. This is the first outbreak of legionnaires' disease to be recorded in an industrial setting in the United Kingdom. No cases of legionella infection have occurred on the site since the introduction of control measures.

Reuse of refinery's tertiary-treated wastewater in cooling towers: microbiological monitoring.

PubMed

Dos Santos, Vera Lúcia; Veiga, Andréa Azevedo; Mendonça, Rafael Silva; Alves, Andrea Lima; Pagnin, Sérgio; Santiago, Vânia M J

2015-02-01

The study was planned to quantify the distribution of bacteria between bulk water and biofilm formed on different materials in an industrial scale cooling tower system of an oil refinery operating with clarified and chlorinated freshwater (CCW) or chlorinated tertiary effluent (TRW) as makeup water. The sessile and planktonic heterotrophic bacteria and Pseudomonas aeruginosa densities were significantly higher in the cooling tower supplied with clarified and chlorinated freshwater (CTCW) (p < 0.05). In the two towers, the biofilm density was higher on the surface of glass slides and stainless steel coupons than on the surface of carbon steel coupons. The average corrosion rates of carbon steel coupons (0.4-0.8 millimeters per year (mpy)) and densities of sessile (12-1.47 × 10(3) colony-forming unit (CFU) cm(-1)) and planktonic (0-2.36 × 10(3) CFU mL(-1)) microbiota remained below of the maximum values of reference used by water treatment companies as indicative of efficient microbial control. These data indicate that the strategies of the water treatment station (WTS) (free chlorine) and industrial wastewater treatment station (IWTS) followed by reverse electrodialysis system (RES) (free chlorine plus chloramine) were effective for the microbiological control of the two makeup water sources.

40 CFR 63.404 - Compliance demonstrations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Standards for Hazardous Air Pollutants for Industrial Process Cooling Towers § 63.404 Compliance... Act, the Administrator or delegated authority can require cooling water sample analysis of an IPCT if... accordance with paragraph (c) of this section in lieu of a water sample analysis. If cooling water sample...

Desalination of Impaired Water Using Geothermal Energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turchi, Craig S; Akar, Sertac; Cath, Tzahi

Membrane distillation (MD) and nanofiltration (NF) are explored as a means to provide high quality water for on-site use at the Tuscarora geothermal power plant in northern Nevada. The plant uses a wet cooling tower, but decreasing flow from the wells providing makeup water necessitates exploration for alternative water or alternative cooling sources. Scenarios are explored to extend cooling water by (1) extracting fresh water from the geothermal brine, (2) upgrading the makeup-water quality to allow for increased cycles of concentration in the cooling tower, or (3) recovering water from the cooling tower blowdown. The preliminary cost analysis indicates thatmore » applying NF to extract water from the injection brine is the most attractive option of the scenarios examined. This approach may be useful for other plants as well. The estimated cost for the NF treatment of the injection brine ranges from $0.63/m3 to $0.45/m3 and provides a reduction in the current makeup well flows of 35% to 71%. Savings from the reduction in makeup well pumping and chemical treatment do not fully offset the estimated cost of the proposed treatment systems; the site will have to weigh the cost of these water treatment options versus alternatives in light of the diminishing flows from the existing cooling-water wells. Testing is planned to quantify the performance of the proposed NF and MD technologies and help refine the estimated system costs.« less

PBF Reactor Building (PER620). Plot plan shows layout, including auxiliary ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Reactor Building (PER-620). Plot plan shows layout, including auxiliary buildings: Emergency Generator (621), Hose House (622), Cooling Tower Auxiliary (624), Maintenance and Storage Warehouse (625), Gas Cylinder Storage (627), Hose House (628), Cooling Tower (720), Substation (719), and other features. Road connections between PBF Reactor, its control building, and SPERT-I site. Note cable trenches along road to control building. Date: July 1965. Ebasco Services, PER-U-101. INEEL index no. 761-0100-00-205-123005 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

The 'fine line' of heat rejection.

PubMed

Carruthers, Phillip

2010-09-01

Selection of heat rejection equipment has traditionally entailed a choice between the higher energy consumption of an air-cooled solution, and the high water consumption of a water-cooled solution. This paper examines advancement in heat rejection technology and the way it can be applied to air conditioning and refrigeration plant in healthcare and other facilities. It also examines field difficulties encountered in pipework design as the knowledge and experience levels of engineers designing systems with remote condensers diminish. With plant larger than 1,000 kW, the only option previously has been water-cooled solutions using an array of cooling towers, or perhaps an evaporative condenser, since air-cooled plant involved massive volumes of chemical refrigerant, which posed a problem ecologically. An additional hurdle was problems associated with limitations on pipe lengths for refrigeration plant. The advent of adiabatically pre-cooled closed circuit coolers and air-cooled condensers has introduced an alternative to cooling towers that offers the potential for "water-cooled performance" from an air-cooled solution with no serious threat of Legionella contamination. However, each application needs to be considered on a case-by-case basis. The paper examines, in detail, the impact of adiabatic pre-cooling, with recent examples of its application in sub-tropical Brisbane providing evidence of the potential performance achievable.

Temporal Evolution of Water Use for Thermoelectric Generation

NASA Astrophysics Data System (ADS)

Reedy, R. C.; Scanlon, B. R.

2013-12-01

The long lifespan of power plants (30 - 50 yr) results in the current power plant fleet representing a legacy of past variations in fuel availability and costs, water availability and water rights, and advances in technologies, such as combined cycle plants, which impact trends in water consumption. The objective of this study was to reconstruct past water consumption and withdrawal of thermoelectric generation based on data on controls, including fuel types, generator technologies, and cooling systems, using Texas as a case study and comparing with the US. Fuel sources in Texas varied over time, from predominantly natural gas in the 1960s and early 1970s to coal and nuclear sources following the 1973 oil embargo and more recently to large increases in natural gas generation (85% increase 1998 - 2004) in response to hydraulic fracturing and low natural gas prices. The dominant generator technology in Texas was steam turbines until the early 1990s; however, combined cycle plants markedly increased in the late 1990s (400% increase 1998 - 2004). Proliferation of cooling ponds in Texas, mostly in the 1970s and 1980s (340% increase) reflects availability of large quantities of unappropriated surface water and increases in water rights permitting during this time and lower cost and higher cooling efficiency of ponds relative to wet cooling towers. Water consumption for thermoelectricity in Texas in 2010 totaled ~0.53 km3 (0.43 million acre feet, maf), accounting for ~4% of total state water consumption. High water withdrawals (32.3 km3, 26.2 maf) mostly reflect circulation between cooling ponds and power plants. About a third of the water withdrawals is not required for cooling and reflects circulation by idling plants being used as peaking plants. Controls on water consumption include (1) generator technology/thermal efficiency and (2) cooling system resulting in statewide consumption for natural gas combined cycle generators with mostly cooling towers being 60% lower than that of traditional coal, nuclear, or natural gas steam turbine generators with mostly cooling ponds. The primary control on water withdrawals is cooling system, with ~ two orders of magnitude lower withdrawals for cooling towers relative to once-through ponds statewide. Increases in natural gas combined cycle plants with cooling towers in response to high production of low-cost natural gas has greatly reduced water demand for thermoelectric cooling since 2000. A similar approach will be applied to thermoelectric generation throughout the US using information on fuel sources, generator technologies and cooling systems to better understand current water use for thermoelectric generation based on the legacy of past drivers and long lifespans of power plants. Understanding the historical evolution of water needs for thermoelectricity should allow us to better project future water needs.

Energy Systems Integration Partnerships: NREL + Sandia + Johnson Controls

DOE Office of Scientific and Technical Information (OSTI.GOV)

NREL and Sandia National Laboratories partnered with Johnson Controls to deploy the company's BlueStream Hybrid Cooling System at ESIF's high-performance computing data center to reduce water consumption seen in evaporative cooling towers.

Calder Hall Cooling Tower Demolition: Landmark Milestone for Decommissioning at Sellafield

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williamson, E.J.

2008-07-01

September 2007 saw a very visible change to the Sellafield site following the culmination of a major decommissioning project; the demolition of the four Calder Hall cooling towers. A key part of the UK's nuclear industrial heritage, Calder Hall, the world's first commercial nuclear power station, was opened by Her Majesty Queen Elizabeth II in October 1953 and continued to generate electricity until its closure in 2003. Following the decision to decommission the Calder Hall site, explosive demolition was identified as the safest and most cost effective route for the removal of the towers. The technique, involving the placement ofmore » explosive in 60% of the circumference of both shell and legs, is a tried and tested method which had already been used successfully in more than 200 cooling towers in the UK in the last 30 years. The location and composition of the four 88 metre high towers also created additional challenges. Situated only 40 metres away from the UK's only nuclear Fuel Handling Plant, as well as other sensitive structures on the Sellafield site, the project had to address the impact of a number of key areas, including dust, ground vibration and air over pressure, to ensure that the demolition could be carried out safely and without significant impact on other operational areas on the site. At the same time, the towers had to be prepared for demolition in a way that minimised the amounts of radioactive or hazardous waste materials arising. This paper follows the four year journey from the initial decision to demolish the towers right through to the demolition itself as well as the clean up of the site post demolition. It will also consider the massive programme of work necessary not only to carry out the physical work safely but also to gain regulatory confidence and stakeholder support to carry out the project successfully. In summary: The demolition of the four Calder Hall cooling towers was a highly visible symbol of the changes that are occurring on the Sellafield site as it moves forward towards a decommissioning future. Although in itself the demolition was both straightforward and standard, the various complexities posed by the towers situation at Sellafield introduced an entirely new element to the project, with a number of complex challenges which had to be overcome or resolved before the demolition could take place. It is a testament to the skill and dedication of the project team and its associated contractors that the project was delivered safely and successfully without a single accident, injury or event throughout the entire four years, and with minimal impact on both site operations and the local community. (authors)« less

Removal of Dissolved Silica using Calcinated Hydrotalcite in Real-life Applications.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sasan, Koroush; Brady, Patrick Vane.; Krumhansl, James L.

Water shortages are a growing global problem. Reclamation of industrial and municipal wastewater will be necessary in order to mitigate water scarcity. However, many operational challenges, such as silica scaling, prevent large scale water reuse. Previously, our team at Sandia has demonstrated the use of selective ion exchange materials, such as calcinated hydrotalcite (HTC, (Mg 6 Al 2 (OH) 16 (CO 3 )*4H 2 O)), for the low cost removal of silica from synthetic cooling tower water. However, it is not currently know if calcinated HTC has similar capabilities in realistic applications. The purpose of this study was to investigatemore » the ability of calcinated HTC to remove silica from real cooling tower water. This was investigated under both batch and continuous conditions, and in the presence of competing ions. It was determined that calcinated HTC behaved similarly in real and synthetic cooling tower water; the HTC is highly selective for the silica even in the presence of competing cations. Therefore, the data concludes that calcinated HTC is a viable anti-scaling pretreatment for the reuse of industrial wastewaters.« less

Effectiveness of disinfectants used in cooling towers against Legionella pneumophila.

PubMed

García, M T; Pelaz, C

2008-01-01

Legionella persists in man-made aquatic installations despite preventive treatments. More information about disinfectants could improve the effectiveness of treatments. This study tests the susceptibility of Legionella pneumophila serogroup (sg) 1 against 8 disinfectants used in cooling tower treatments. We determined the minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC) and bactericidal effect of sodium hypochlorite (A), hydrogen peroxide with silver nitrate (B), didecyldimethylammonium chloride (C), benzalkonium chloride (D), tributyltetradecylphosphonium chloride (E), tetrahydroxymethylphosphonium sulfide (F), 2,2-dibromonitropropionamide (G) and chloromethylisothiazolone (H) against 28 L. pneumophila sg 1 isolates. MIC and MBC values were equivalent. Bacteria are less susceptible to disinfectants F, B, D and A than to H, E, C and G. All disinfectants induced a bactericidal effect. The effect rate is dose dependent for G, H, F and B; the effect is fast for the rest of disinfectants at any concentration. The bactericidal activity of disinfectants A, G and F depends on the susceptibility test used. All disinfectants have bactericidal activity against L. pneumophila sg 1 at concentrations used in cooling tower treatments. Results depend on the assay for some products.

Study of using microfiltration and reverse osmosis membrane technologies for reclaiming cooling water in the power industry.

PubMed

Li, J; Xu, Z Y; An, H G; Liu, L Q

2007-07-01

A study of using dual membrane technologies, microfiltration (MF) and reverse osmosis (RO), for reclaiming blowdown of the cooling tower was conducted at ZJK power plant, Hebei province, China. The study shows that the combined MF-RO system can effectively reduce water consumption in the power industry. The results indicate that MF process is capable of producing a filtrate suitable for RO treatment and achieving a silt density index (SDI) less than 2, turbidity of 0.2 NTU. The water quality of RO effluent is very good with an average conductivity of about 40 micros/cm and rejection of 98%. The product water is suitable for injection into the cooling tower to counteract with cooling water intrusion. After adopting this system, water-saving effectiveness as expressed in terms of cycles of concentration could be increased from 2.5-2.8 times to 5 times.

[Legionella outbreak in Amsterdam: a cooling tower as the source].

PubMed

van den Hoek, J A R; IJzerman, E P F; Coutinho, R A

2006-08-19

During the period 6-28 July 2006, 30 confirmed cases of Legionella infection were identified in Amsterdam, 2 of which were fatal. All had a positive urinary antigen test, by which Legionella pneumophila serogroup I could be demonstrated. Consultations between the parties involved in the control of infectious diseases started on July 7th, as soon as it became clear that there was an outbreak. On July 10th it was established that relatively many of these patients lived in the eastern part of the city centre. After a study of the prevailing winds during the past 3 weeks, the search for installations containing water was started. A cooling tower in the town centre was closed on July 11th by way of precaution. During the following week, this tower was proven to be the source of the outbreak.

Heat rejection system

DOEpatents

Smith, Gregory C.; Tokarz, Richard D.; Parry, Jr., Harvey L.; Braun, Daniel J.

1980-01-01

A cooling system for rejecting waste heat consists of a cooling tower incorporating a plurality of coolant tubes provided with cooling fins and each having a plurality of cooling channels therein, means for directing a heat exchange fluid from the power plant through less than the total number of cooling channels to cool the heat exchange fluid under normal ambient temperature conditions, means for directing water through the remaining cooling channels whenever the ambient temperature rises above the temperature at which dry cooling of the heat exchange fluid is sufficient and means for cooling the water.

Evaluation of Side Stream Filtration Technology at Oak Ridge National Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boyd, Brian K.

2014-08-01

This technology evaluation was performed by Pacific Northwest National Laboratory and Oak Ridge National Laboratory on behalf of the Federal Energy Management Program. The objective was to quantify the benefits side stream filtration provides to a cooling tower system. The evaluation assessed the performance of an existing side stream filtration system at a cooling tower system at Oak Ridge National Laboratory’s Spallation Neutron Source research facility. This location was selected because it offered the opportunity for a side-by-side comparison of a system featuring side stream filtration and an unfiltered system.

Biofouling reduction in recirculating cooling systems through biofiltration of process water.

PubMed

Meesters, K P H; Van Groenestijn, J W; Gerritse, J

2003-02-01

Biofouling is a serious problem in industrial recirculating cooling systems. It damages equipment, through biocorrosion, and causes clogging and increased energy consumption, through decreased heat transfer. In this research a fixed-bed biofilter was developed which removed assimilable organic carbon (AOC) from process water, thus limiting the major substrate for the growth of biofouling. The biofilter was tested in a laboratory model recirculating cooling water system, including a heat exchanger and a cooling tower. A second identical model system without a biofilter served as a reference. Both installations were challenged with organic carbon (sucrose and yeast extract) to provoke biofouling. The biofilter improved the quality of the recirculating cooling water by reducing the AOC content, the ATP concentration, bacterial numbers (30-40 fold) and the turbidity (OD660). The process of biofouling in the heat exchangers, the process water pipelines and the cooling towers, was monitored by protein increase, heat transfer resistance, and chlorine demanded for maintenance. This revealed that biofouling was lower in the system with the biofilter compared to the reference installation. It was concluded that AOC removal through biofiltration provides an attractive, environmental-friendly means to reduce biofouling in industrial cooling systems.

Hydraulic design of a re-circulating water cooling system of a combined cycle power plant in Thailand

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sarkar, C.K.; Pandit, D.R.; Kwon, S.G.

The paper describes the hydraulic design and hydraulic transient analysis of the re-circulating water cooling system of the combined cyclo Sipco power cogeneration plant in Thailand. The power plant of 450 MW total capacity is proposed to be built in two stages. Stage one will produce 300 MW of power and will consist of two gas turbine generators (GTG) and one steam turbine generator (STG). Stage two will produce 150 MW of power and will consist of one GTG and one STG. The cooling system will consist of one GTG and one STG. The cooling system will consist of coolingmore » towers, a combined collecting basin and pump intake sump, pumps and motors, and separate conveyance systems and condensers for the generator units in the two stages. In a re-circulating water cooling system, cold water is pumped from the pump intake sump to the condensers through the conveyance system and hot water from the condensers is carried through the returning pipeline system to the cooling towers, whence the water after cooling is drained into the sump at the base of the towers. Total cooling water requirement for the system in stage one is estimated to be 112,000 gallons per minute (GPM), and that in stage two, 56,000 GPM. The sump is designed using the computer program HEC-2, developed by the US Army Corps of Engineers (COE) and the pump intake basin, following the recommendations of the Hydraulic Institute. The pumps were sized by computing the head loss in the system, and, the steady state and transient performances (during pump start-up and shut-down procedures and due to possible power or mechanical failure of one or all pumps) of the system were analyzed by mathematically modeling the system using the computer program WHAMO (Water Hammer nd Mass Oscillations), also developed by the COE.« less

Effect of diesel leakage in circulating cooling water system on preponderant bacteria diversity and bactericidal effect of biocides.

PubMed

Zhong, Huiyun; Liu, Fang; Lu, Jinjin; Yang, Wei; Zhao, Chaocheng

2015-01-01

Petroleum products leakage results in adverse effect on the normal operation of a circulating cooling water system. However, relatively little research has been done to explore the effect of petroleum products leakage on circulating cooling water quality and biofilm preponderant bacteria diversity. Also, normal biocides application modes cannot fulfil the need for biofilm control. In this study, diesel oil was used as the experimental subject representing leaking petroleum products; the effect of diesel addition on biofilm preponderant bacteria diversity and the bactericidal effect of chlorine dioxide and tetradecyl dimethyl benzyl ammonium chloride (1427) was investigated. Bacterial community structures were examined by PCR-denaturing gradient gel electrophoresis and PCR cloning of 16S rDNA genes. Except for 100 mg/L diesel, increasing diesel concentration enhanced the biofilm detachment ratio compared with the control test. The microstructure of biofilm samples with 0, 300 and 900 mg/L diesel addition was observed. The species of preponderant bacteria in the biofilm sample with 300 mg/L diesel addition were more and the bacterial distribution was more uniform than those in the biofilm sample with 900 mg/L diesel addition. With ClO2 and 1427 addition, chemical oxygen demand increased, lipid phosphorus and bacterial count first decreased and then remained stable, and the bactericidal ratio first increased and then remained stable. Diesel addition variation has more obvious effect on ClO2 than 1427.

On the geological origin of Devils Tower (WY, USA)

NASA Astrophysics Data System (ADS)

Zavada, P.; Dedecek, P.; Holloway, S. D.; Chang, J. C.; Crain, K.; Keller, G. R.

2011-12-01

The Devils Tower is an exceptional igneous rock formation and a dominating landmark of the northern plains in Wyoming (USA). It rises 250 m above the surrounding sedimentary formations. Previous hypotheses suggested that the Devils Tower was originally part of a magmatic intrusion; volcanic conduit, magmatic stock or a laccolith. Our review of the geological evidence suggests that the Devils Tower is a remnant of an eroded lava lake that filled a broad phreatomagmatic volcano crater. Our hypothesis is based on a detailed study of a similar phonolite landmark in Czech Republic, called Boren, and analogue modeling, finite element numerical modeling of cooling for various shapes of volcanic bodies, and results of field and gravity surveys of the area. The Devils Tower together with a group of five phonolite bodies called Missouri Buttes, located 6 km NW from the Devils Tower, represent the easternmost products of the Tertiary tectonomagmatic events related to the lithospheric-scale uplift of the Black hills monocline. The phreatomagmatic deposits in the surroundings of the Missouri Buttes and the Devils Tower suggest that these phonolite bodies were originally emplaced into phreatomagmatic maar-diatreme volcanoes. To reveal the original shape of the Devils Tower, we employed the analogue modeling using plaster of Paris as analogue for phonolite magma to study internal fabrics and shapes of extrusive/intrusive magmatic bodies emplaced into the maar-diatreme volcanoes. Then, the resulting shapes of analogue magmatic bodies were used for the Finite Element thermal numerical models of their cooling using the thermophysical parameters of the phonolite magma and the rock units surrounding the Devils Tower and Missouri Buttes. Because the columnar joints grow perpendicular to the isotherms in cooling igneous and volcanic bodies, we analyzed the match between the thermal structure of the FE models and the columnar jointing pattern on the Devils Tower. The best fit of the thermal structure and the inverted fan columnar jointing pattern on Devils Tower was found for one of the models that produced a lava lake filling the entire maar crater of the phreatomagmatic volcano. The Devils Tower represents the central part of the lake just above the feeding conduit. After emplacement and solidification of the lava lake, erosion first removed the weakly consolidated phreatomagmatic deposits in the tuff ring around the lake. Then the lava body eroded laterally due to the formation of ice in the columnar joints, pushing columns away from the neighboring columns into the open space. The remnant of the solidified lake (Devils Tower) represents a structure, which is resistant to this kind of erosion, because its base is formed by columns that lean against each other and towards the center of the Tower. In contrast, the Missouri Buttes most probably represent a remnant of a branched intrusion producing several extrusive domes on the maar-crater periphery that can form by subsequent emplacement of different magma batches (e.g. from a stratified magma chamber), each with relatively lower yield strength owing to decreasing crystal content.

ETR COMPLEX. CAMERA FACING EAST. FROM LEFT TO RIGHT: ETRCRITICAL ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

ETR COMPLEX. CAMERA FACING EAST. FROM LEFT TO RIGHT: ETR-CRITICAL FACILITY BUILDING, ETR CONTROL BUILDING (ATTACHED TO HIGH-BAY ETR), ETR, ONE-STORY SECTION OF ETR BUILDING, ELECTRICAL BUILDING, COOLING TOWER PUMP HOUSE, COOLING TOWER. COMPRESSOR AND HEAT EXCHANGER BUILDING ARE PARTLY IN VIEW ABOVE ETR. DARK-COLORED DUCTS PROCEED FROM GROUND CONNECTION TO ETR WASTE GAS STACK. OTHER STACK IS MTR STACK WITH FAN HOUSE IN FRONT OF IT. RECTANGULAR STRUCTURE NEAR TOP OF VIEW IS SETTLING BASIN. INL NEGATIVE NO. 56-4102. Unknown Photographer, ca. 1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

ETR, TRA642. ETR COMPLEX NEARLY COMPLETE. CAMERA FACES NORTHWEST, PROBABLY ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

ETR, TRA-642. ETR COMPLEX NEARLY COMPLETE. CAMERA FACES NORTHWEST, PROBABLY FROM TOP DECK OF COOLING TOWER. SHADOW IS CAST BY COOLING TOWER UNITS OFF LEFT OF VIEW. HIGH-BAY REACTOR BUILDING IS SURROUNDED BY ITS ATTACHED SERVICES: ELECTRICAL (TRA-648), HEAT EXCHANGER (TRA-644 WITH U-SHAPED YARD), AND COMPRESSOR (TRA-643). THE CONTROL BUILDING (TRA-647) ON THE NORTH SIDE IS HIDDEN FROM VIEW. AT UPPER RIGHT IS MTR BUILDING, TRA-603. INL NEGATIVE NO. 56-3798. Jack L. Anderson, Photographer, 11/26/1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Thermal modeling of a secondary concentrator integrated with an open direct-absorption molten-salt volumetric receiver in a beam-down tower system

NASA Astrophysics Data System (ADS)

Lahlou, Radia; Armstrong, Peter; Grange, Benjamin; Almheiri, Saif; Calvet, Nicolas; Slocum, Alexander; Shamim, Tariq

2016-05-01

An upward-facing three-dimensional secondary concentrator, herein termed Final Optical Element (FOE), is designed to be used in a beam-down tower in combination with an open volumetric direct-absorption molten-salt receiver tank acting simultaneously as a thermal energy storage system. It allows reducing thermal losses from the open receiver by decreasing its aperture area while keeping minimal spillage losses. The FOE is exposed to high solar fluxes, a part of which is absorbed by its reflector material, leading to material degradation by overheating. Consequently, the FOE may require active cooling. A thermal model of the FOE under passive cooling mechanism is proposed as a first step to evaluate its sensitivity to some design parameters. Then, it will be used to evaluate the requirements for the active cooling system. The model provides insights on the FOE thermal behavior and highlights the effectiveness of a design modification on passive cooling enhancement. First prototype tests under reduced flux and with no active cooling will be used for model adjustment.

Counter-Flow Cooling Tower Test Cell

NASA Astrophysics Data System (ADS)

Dvořák, Lukáš; Nožička, Jiří

2014-03-01

The article contains a design of a functional experimental model of a cross-flow mechanical draft cooling tower and the results and outcomes of measurements. This device is primarily used for measuring performance characteristics of cooling fills, but with a simple rebuild, it can be used for measuring other thermodynamic processes that take part in so-called wet cooling. The main advantages of the particular test cell lie in the accuracy, size, and the possibility of changing the water distribution level. This feature is very useful for measurements of fills of different heights without the influence of the spray and rain zone. The functionality of this test cell has been verified experimentally during assembly, and data from the measurement of common film cooling fills have been compared against the results taken from another experimental line. For the purpose of evaluating the data gathered, computational scripts were created in the MATLAB numerical computing environment. The first script is for exact calculation of the thermal balance of the model, and the second is for determining Merkel's number via Chebyshev's method.

Method and apparatus for generating microshells of refractory materials

NASA Technical Reports Server (NTRS)

Lee, Mark C. (Inventor); Schilling, Christopher (Inventor); Ladner, Jr., George O. (Inventor); Wang, Taylor G. (Inventor)

1987-01-01

A system is described for forming accurately spherical and centered fluid-filled shells, especially of high melting temperature material. Material which is to form the shells is placed in a solid form in a container, and the material is rapidly heated to a molten temperature to avoid recrystallization and the possible generation of unwanted microbubbles in the melt. Immediately after the molten shells are formed, they drop through a drop tower whose upper end is heated along a distance of at least one foot to provide time for dissipation of surface waves on the shells while they cool to a highly viscous, or just above melting temperature so that the bubble within the shell will not rise and become off centered. The rest of the tower is cryogenically cooled to cool the shell to a solid state.

ECOLOGICAL EFFECTS OF AEROSOL DRIFT FROM A SALTWATER COOLING SYSTEM

EPA Science Inventory

The local terrestrial effects of salt aerosol drift from powered spray modules and a mechanical draft cooling tower at Turkey Point, Florida were evaluated through field and controlled exposure studies. Indigenous vegetation, soil and fresh water were sampled over a year long per...

Operational cooling tower model (CTTOOL V1.0)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aleman, S.; LocalDomainServers, L.; Garrett, A.

2015-01-01

Mechanical draft cooling towers (MDCT’s) are widely used to remove waste heat from industrial processes, including suspected proliferators of weapons of mass destruction (WMD). The temperature of the air being exhausted from the MDCT is proportional to the amount of thermal energy being removed from the process cooling water, although ambient weather conditions and cooling water flow rate must be known or estimated to calculate the rate of thermal energy dissipation (Q). It is theoretically possible to derive MDCT air exhaust temperatures from thermal images taken from a remote sensor. A numerical model of a MDCT is required to translatemore » the air exhaust temperature to a Q. This report describes the MDCT model developed by the Problem Centered Integrated Analysis (PCIA) program that was designed to perform those computational tasks. The PCIA program is a collaborative effort between the Savannah River National Laboratory (SRNL), the Northrop-Grumman Corporation (NG) and the Aerospace Corporation (AERO).« less

Biocidal efficacy of monochloramine against planktonic and biofilm-associated Naegleria fowleri cells.

PubMed

Goudot, S; Herbelin, P; Mathieu, L; Soreau, S; Banas, S; Jorand, F P A

2014-04-01

Free-living amoebae (FLA) in aqueous systems are a problem for water network managers and health authorities because some are pathogenic, such as Naegleria fowleri, and they have also been reported to operate as reservoirs and vectors of several pathogenic bacteria. Therefore, to better control the occurrence of such amoebae, we evaluate the efficacy of monochloramine against planktonic forms (trophozoites and cysts) and also biofilm-associated cells of N. fowleri as FLA are often associated with biofilms. From a freshwater biofilm growing in a pilot reactor and inoculated with N. fowleri, we obtained Ct values ranging from 4 to 17 mg Cl2 min l(-1) at 25°C and pH 8·2 on both planktonic and biofilm associated cells. In addition, the inactivation pattern of biofilm associated was intermediate between those of trophozoïtes and cysts. The monochloramine efficiency varies with the life stage of N. fowleri (trophozoïte, cyst, and biofilm-associated). The sensitivity to disinfectant of amoeba, that is, trophozoïtes and cysts, in the biofilm life stage is as high as that of their planktonic cyst form. This study gives Ct values for cysts and biofilm-associated N. fowleri. This may impact on water treatment strategies against amoebae and should be considered when controlling N. fowleri in man-made water systems such as cooling towers or hot water systems. © 2014 The Society for Applied Microbiology.

40 CFR 749.68 - Hexavalent chromium-based water treatment chemicals in cooling systems.

Code of Federal Regulations, 2011 CFR

2011-07-01

... tower used to remove heat from industrial processes, chemical reactions, or plants producing electrical... treatment chemicals in cooling systems. 749.68 Section 749.68 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT WATER TREATMENT CHEMICALS Air Conditioning and...

40 CFR 749.68 - Hexavalent chromium-based water treatment chemicals in cooling systems.

Code of Federal Regulations, 2012 CFR

2012-07-01

... tower used to remove heat from industrial processes, chemical reactions, or plants producing electrical... treatment chemicals in cooling systems. 749.68 Section 749.68 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT WATER TREATMENT CHEMICALS Air Conditioning and...

40 CFR 749.68 - Hexavalent chromium-based water treatment chemicals in cooling systems.

Code of Federal Regulations, 2013 CFR

2013-07-01

... tower used to remove heat from industrial processes, chemical reactions, or plants producing electrical... treatment chemicals in cooling systems. 749.68 Section 749.68 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT WATER TREATMENT CHEMICALS Air Conditioning and...

40 CFR 749.68 - Hexavalent chromium-based water treatment chemicals in cooling systems.

Code of Federal Regulations, 2014 CFR

2014-07-01

... tower used to remove heat from industrial processes, chemical reactions, or plants producing electrical... treatment chemicals in cooling systems. 749.68 Section 749.68 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT WATER TREATMENT CHEMICALS Air Conditioning and...

Preliminary design package for solar heating and cooling systems

NASA Technical Reports Server (NTRS)

1978-01-01

Summarized preliminary design information on activities associated with the development, delivery and support of solar heating and cooling systems is given. These systems are for single family dwellings and commercial applications. The heating/cooling system use a reversible vapor compression heat pump that is driven in the cooling mode by a Rankine power loop, and in the heating mode by a variable speed electric motor. The heating/cooling systems differ from the heating-only systems in the arrangement of the heat pump subsystem and the addition of a cooling tower to provide the heat sink for cooling mode operation.

78 FR 3458 - Florida Power Corporation, Crystal River Unit 3, Draft Environmental Assessment Related to the...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-16

... design intake volume of 680,000 gpm [gallons per minute] (42,840 L/s), with a combined condenser flow... licensee in 2007 and the cooling tower design was subsequently modified to meet PM emission thresholds by reducing the flow rate through the tower. The predicted emissions from the modified design are 91.2 tons PM...

Solar Heating and Cooling for a Controls Manufacturing Plant Lumberton, New Jersey

NASA Technical Reports Server (NTRS)

1982-01-01

Comprehensive report documents computer-controlled system which has separate solar-collector and cooling-tower areas located away from building and is completely computer controlled. System description, test data, major problems and resolution, performance, operation and maintenance, manufacturer's literature and drawing comprise part of 257-page report.

Evaporatively cooled chiller for solar air conditioning systems design and field test

NASA Astrophysics Data System (ADS)

Merrick, R. H.; Murray, J. G.

1984-06-01

Design changes to improve reliability, part load performance, and manufacturability characteristics of the chiller are focused upon. Low heat flux was achieved by large transfer area allows scale formation without being a thermal barrier: 80 mils = 1 deg. The scaling rate is minimized by keeping surface temperatures below 100 F and a generous water recirculation flow rate. By integrating the cooling tower function into the chiller itself parasitic power consumption was reduced 35%. This system also provided the winter freeze protection without the specific manual shut down procedures required by separate water cooled units and their towers. The severe reduction in cumulative coefficient of performance (COP) due to cycling conditions has been substantially reduced using the spin down control scheme. The major disappointment was the failure to develop a satisfactory inexpensive protective coating. Hot dip galvanizing was demonstrated to be effective but costly, partially due to transportation expense.

Quantitative Real-Time Legionella PCR for Environmental Water Samples: Data Interpretation

PubMed Central

Joly, Philippe; Falconnet, Pierre-Alain; André, Janine; Weill, Nicole; Reyrolle, Monique; Vandenesch, François; Maurin, Max; Etienne, Jerome; Jarraud, Sophie

2006-01-01

Quantitative Legionella PCRs targeting the 16S rRNA gene (specific for the genus Legionella) and the mip gene (specific for the species Legionella pneumophila) were applied to a total of 223 hot water system samples (131 in one laboratory and 92 in another laboratory) and 37 cooling tower samples (all in the same laboratory). The PCR results were compared with those of conventional culture. 16S rRNA gene PCR results were nonquantifiable for 2.8% of cooling tower samples and up to 39.1% of hot water system samples, and this was highly predictive of Legionella CFU counts below 250/liter. PCR cutoff values for identifying hot water system samples containing >103 CFU/liter legionellae were determined separately in each laboratory. The cutoffs differed widely between the laboratories and had sensitivities from 87.7 to 92.9% and specificities from 77.3 to 96.5%. The best specificity was obtained with mip PCR. PCR cutoffs could not be determined for cooling tower samples, as the results were highly variable and often high for culture-negative samples. Thus, quantitative Legionella PCR appears to be applicable to samples from hot water systems, but the positivity cutoff has to be determined in each laboratory. PMID:16597985

Optimum dry-cooling sub-systems for a solar air conditioner

NASA Technical Reports Server (NTRS)

Chen, J. L. S.; Namkoong, D.

1978-01-01

Dry-cooling sub-systems for residential solar powered Rankine compression air conditioners were economically optimized and compared with the cost of a wet cooling tower. Results in terms of yearly incremental busbar cost due to the use of dry-cooling were presented for Philadelphia and Miami. With input data corresponding to local weather, energy rate and capital costs, condenser surface designs and performance, the computerized optimization program yields design specifications of the sub-system which has the lowest annual incremental cost.

Costs and description of a solar-energy system--Austin, Texas

NASA Technical Reports Server (NTRS)

1981-01-01

Heating and cooling system uses Fresnel lens concentrating collectors. Major system components are 36 collectors, 1,500 gallon thermal storage tank, absorption cooler, cooling tower, heating coil, pumps, heat exchanger, and backup heating and air conditioning. Final report includes detailed breakdown of component and installation costs for seven project subsystems.

Splash bar for cooling tower fill assembly

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stackhouse, D.W.; Heidl, S.C.

1987-11-10

A crossflow cooling tower fill assembly for allowing liquid to fall down through the fill assembly and for allowing cooling air to flow through the fill assembly transverse to the flow of the liquid in order to cool the liquid is described. The assembly comprises: longitudinal splash bars; and means for supporting the splash bars so that the splash bars are substantially horizontal and parallel to one another and arranged in vertically spaced, substantially horizontal planes. The splash bars in each plane are horizontally spaced from one another to allow the liquid to fall down between the splash bars tomore » the planes of splash bars below. Each splash bar includes a substantially horizontal, longitudinally extending top web member having (1) longitudinally extending, downwardly projecting vertical side web members, both of the side web members having a lower longitudinal edge with a longitudinally extending, inwardly projecting flange, and (2) at least one longitudinally extending, downardly projecting rib web member between the side web members. Each rib web member has a lower longitudinal edge with a longitudinally extending, laterally projecting flange.« less

Occurrence and pathogenicity of Naegleria fowleri in artificially heated waters.

PubMed Central

Sykora, J L; Keleti, G; Martinez, A J

1983-01-01

The occurrence of pathogenic Naegleria fowleri in thermal discharges, recipient waters, and cooling towers of eight power plants located in western Pennsylvania was investigated for 2 years in conjunction with several environmental measurements. Pathogenic N. fowleri was detected in one cooling tower and in the discharge, receiving waters, or both of five of eight localities. The occurrence of this organism was related to elevated temperatures, but no significant correlation was found for other biological and chemical parameters. Laboratory experiments on the effect of pH on pathogenic N. fowleri documented 100% survival at a range from 2.1 to 8.15. Higher pH reduced or killed the amoebae. No case of human primary amoebic meningoencephalitis occurred during the study. PMID:6847189

Occurrence and pathogenicity of Naegleria fowleri in artificially heated waters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sykora, J.L.; Keleti, G.; Martinez, A.J.

1983-03-01

The occurrence of pathogenic Naegleria fowleri in thermal discharges, recipient waters, and cooling towers of eight power plants located in western Pennsylvania was investigated for 2 years in conjunction with several environmental measurements. Pathogenic N. fowleri was detected in one cooling tower and in the discharge, receiving waters, or both of five of eight localities. The occurrence of this organism was related to elevated temperatures, but no significant correlation was found for other biological and chemical parameters. Laboratory experiments on the effect of pH on pathogenic N. fowleri documented 100% survival at a range from 2.1 to 8.15. Higher pHmore » reduced or killed the amoebae. No case of human primary amoebic meningoencephalitis occurred during the study.« less

Ice Thermal Storage Systems for LWR Supplemental Cooling and Peak Power Shifting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haihua Zhao; Hongbin Zhang; Phil Sharpe

2010-06-01

Availability of enough cooling water has been one of the major issues for the nuclear power plant site selection. Cooling water issues have frequently disrupted the normal operation at some nuclear power plants during heat waves and long draught. The issues become more severe due to the new round of nuclear power expansion and global warming. During hot summer days, cooling water leaving a power plant may become too hot to threaten aquatic life so that environmental regulations may force the plant to reduce power output or even temporarily to be shutdown. For new nuclear power plants to be builtmore » at areas without enough cooling water, dry cooling can be used to remove waste heat directly into the atmosphere. However, dry cooling will result in much lower thermal efficiency when the weather is hot. One potential solution for the above mentioned issues is to use ice thermal storage systems (ITS) that reduce cooling water requirements and boost the plant’s thermal efficiency in hot hours. ITS uses cheap off-peak electricity to make ice and uses those ice for supplemental cooling during peak demand time. ITS is suitable for supplemental cooling storage due to its very high energy storage density. ITS also provides a way to shift large amount of electricity from off peak time to peak time. Some gas turbine plants already use ITS to increase thermal efficiency during peak hours in summer. ITSs have also been widely used for building cooling to save energy cost. Among three cooling methods for LWR applications: once-through, wet cooling tower, and dry cooling tower, once-through cooling plants near a large water body like an ocean or a large lake and wet cooling plants can maintain the designed turbine backpressure (or condensation temperature) during 99% of the time; therefore, adding ITS to those plants will not generate large benefits. For once-through cooling plants near a limited water body like a river or a small lake, adding ITS can bring significant economic benefits and avoid forced derating and shutdown during extremely hot weather. For the new plants using dry cooling towers, adding the ice thermal storage systems can effectively reduce the efficiency loss and water consumption during hot weather so that new LWRs could be considered in regions without enough cooling water. \\ This paper presents the feasibility study of using ice thermal storage systems for LWR supplemental cooling and peak power shifting. LWR cooling issues and ITS application status will be reviewed. Two ITS application case studies will be presented and compared with alternative options: one for once-through cooling without enough cooling for short time, and the other with dry cooling. Because capital cost, especially the ice storage structure/building cost, is the major cost for ITS, two different cost estimation models are developed: one based on scaling method, and the other based on a preliminary design using Building Information Modeling (BIM), an emerging technology in Architecture/Engineering/Construction, which enables design options, performance analysis and cost estimating in the early design stage.« less

Effective Disposal of Fuel Cell Polyurethane Foam

DTIC Science & Technology

1987-01-01

devices. There are several types of Air Pollution Control Devices (APCD). Venturi scrubbers , wet scrubbers , packed towers, and cyclonic flow units all...emission gases to be subjected to high temperatures for a longer period of time or by scrubbing the gases with venturi or wet scrubbers . Packed towers...could be lowered if a chamber equipped with a water spray to cool the gases were used. Venturi or wet scrubbers could accomplish this effecti vely. Acid

Use of saline water in energy development. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Israelsen, C.E.; Adams, V.D.; Batty, J.C.

1980-06-01

Information was assembled relative to future energy-related projects in the upper basin, and estimates were made of their anticipated water needs. Using computer models, various options were tested for using saline water for coal-fired power plant cooling. Both cooling towers and brine evaporation ponds were included. Information is presented of several proven water treatment technologies, and comparisons are made of their cost effectiveness when placed in various combinations in the power plant makeup and blowdown water systems. A relative value scale was developed which compares graphically the relative values of waters of different salinities based on three different water treatmentmore » options and predetermined upper limits of cooling tower circulating salinities. Coal from several different mines was slurried in waters of different salinities. Samples were analyzed in the laboratory to determine which constituents had been leached from or absorbed by the coal, and what possible deleterious effects this might have on the burning properties of the coal, or on the water for culinary use or irrigation.« less

Industrial Cooling Tower Disinfection Treatment to Prevent Legionella spp.

PubMed

Iervolino, Matteo; Mancini, Benedetta; Cristino, Sandra

2017-09-26

The contamination of industrial cooling towers has been identified as one cause of legionellosis, but the real risk has been underestimated. Two different disinfection treatments were tested on Legionella colonization in an industrial Cooling Tower System (CTS). Environmental monitoring of Legionella , P. aeruginosa , and a heterotrophic plate count (HPC) at 36 °C was performed from June to October 2016. The disinfection procedures adopted were based on hydrogen peroxide (H₂O₂) and silver salts (Ag⁺), in addition to an anti-algal treatment, then using hyperclorination as a shock, and then continuous treatment by sodium hypochlorite (NaClO). L . pneumophila serogroup 8 was found at a concentration of 5.06 Log cfu/L after the CTS filling; a shock treatment performed by H₂O₂/Ag⁺ produced a rapid increase in contamination up to 6.14 Log cfu/L. The CTS activity was stopped and two subsequent shock treatments were performed using NaClO, followed by continuous hyperclorination. These procedures showed a significant decrease ( p < 0.05) in Legionella concentration (1.77 Log cfu/L). The same trend was observed for P . aeruginosa (0.55 Log cfu/100 mL) and HPC (1.95 Log cfu/mL) at 36 °C. Environmental monitoring and the adoption of maintenance procedures, including anti-scale treatment, and physical, chemical, and microbiological control, ensure the good performance of a CTS, reducing the Legionella risk for public health.

Flotation process for removal of precipitates from electrochemical chromate reduction unit

DOEpatents

DeMonbrun, James R.; Schmitt, Charles R.; Williams, Everett H.

1976-01-01

This invention is an improved form of a conventional electrochemical process for removing hexavalent chromium or other metal-ion contaminants from cooling-tower blowdown water. In the conventional process, the contaminant is reduced and precipitated at an iron anode, thus forming a mixed precipitate of iron and chromium hydroxides, while hydrogen being evolved copiously at a cathode is vented from the electrochemical cell. In the conventional process, subsequent separation of the fine precipitate has proved to be difficult and inefficient. In accordance with this invention, the electrochemical operation is conducted in a novel manner permitting a much more efficient and less expensive precipitate-recovery operation. That is, the electrochemical operation is conducted under an evolved-hydrogen partial pressure exceeding atmospheric pressure. As a result, most of the evolved hydrogen is entrained as bubbles in the blowdown in the cell. The resulting hydrogen-rich blowdown is introduced to a vented chamber, where the entrained hydrogen combines with the precipitate to form a froth which can be separated by conventional techniques. In addition to the hydrogen, two materials present in most blowdown act as flotation promoters for the precipitate. These are (1) air, with which the blowdown water becomes saturated in the course of normal cooling-tower operation, and (2) surfactants which commonly are added to cooling-tower recirculating-water systems to inhibit the growth of certain organisms or prevent the deposition of insoluble particulates.

Epidemiological investigation and case-control study: a Legionnaires' disease outbreak associated with cooling towers in Warstein, Germany, August-September 2013.

PubMed

Maisa, Anna; Brockmann, Ansgar; Renken, Frank; Lück, Christian; Pleischl, Stefan; Exner, Martin; Daniels-Haardt, Inka; Jurke, Annette

2015-01-01

Between 1 August and 6 September 2013, an outbreak of Legionnaires' disease (LD) with 159 suspected cases occurred in Warstein, North Rhine-Westphalia, Germany. The outbreak consisted of 78 laboratory-confirmed cases of LD, including one fatality, with a case fatality rate of 1%. Legionella pneumophila, serogroup 1, subtype Knoxville, sequence type 345, was identified as the epidemic strain. A case-control study was conducted to identify possible sources of infection. In univariable analysis, cases were almost five times more likely to smoke than controls (odds ratio (OR): 4.81; 95% confidence interval (CI): 2.33-9.93; p < 0.0001). Furthermore, cases were twice as likely to live within a 3 km distance from one identified infection source as controls (OR: 2.14; 95% CI: 1.09-4.20; p < 0.027). This is the largest outbreak of LD in Germany to date. Due to a series of uncommon events, this outbreak was most likely caused by multiple sources involving industrial cooling towers. Quick epidemiological assessment, source tracing and shutting down of potential sources as well as rapid laboratory testing and early treatment are necessary to reduce morbidity and mortality. Maintenance of cooling towers must be carried out according to specification to prevent similar LD outbreaks in the future.

Acidity of vapor plume from cooling tower mixed with flue gases emitted from coal-fired power plant.

PubMed

Hlawiczka, Stanislaw; Korszun, Katarzyna; Fudala, Janina

2016-06-01

Acidity of products resulting from the reaction of flue gas components emitted from a coal-fired power plant with water contained in a vapor plume from a wet cooling tower was analyzed in a close vicinity of a power plant (710 m from the stack and 315 m from the cooling tower). Samples of this mixture were collected using a precipitation funnel where components of the mixed plumes were discharged from the atmosphere with the rainfall. To identify situations when the precipitation occurred at the same time as the wind directed the mixed vapor and flue gas plumes above the precipitation funnel, an ultrasound anemometer designed for 3D measurements of the wind field located near the funnel was used. Precipitation samples of extremely high acidity were identified - about 5% of samples collected during 12 months showed the acidity below pH=3 and the lowest recorded pH was 1.4. During the measurement period the value of pH characterizing the background acidity of the precipitation was about 6. The main outcome of this study was to demonstrate a very high, and so far completely underestimated, potential of occurrence of episodes of extremely acid depositions in the immediate vicinity of a coal-fired power plant. Copyright © 2016 Elsevier B.V. All rights reserved.

Dynamics of Legionella spp. and bacterial populations during the proliferation of L. pneumophila in a cooling tower facility.

PubMed

Wéry, Nathalie; Bru-Adan, Valérie; Minervini, Céline; Delgénes, Jean-Philippe; Garrelly, Laurent; Godon, Jean-Jacques

2008-05-01

The dynamics of Legionella spp. and of dominant bacteria were investigated in water from a cooling tower plant over a 9-month period which included several weeks when Legionella pneumophila proliferated. The structural diversity of both the bacteria and the Legionella spp. was monitored by a fingerprint technique, single-strand conformation polymorphism, and Legionella spp. and L. pneumophila were quantified by real-time quantitative PCR. The structure of the bacterial community did not change over time, but it was perturbed periodically by chemical treatment or biofilm detachment. In contrast, the structure of the Legionella sp. population changed in different periods, its dynamics at times showing stability but also a rapid major shift during the proliferation of L. pneumophila in July. The dynamics of the Legionella spp. and of dominant bacteria were not correlated. In particular, no change in the bacterial community structure was observed during the proliferation of L. pneumophila. Legionella spp. present in the cooling tower system were identified by cloning and sequencing of 16S rRNA genes. A high diversity of Legionella spp. was observed before proliferation, including L. lytica, L. fallonii, and other Legionella-like amoebal pathogen types, along with as-yet-undescribed species. During the proliferation of L. pneumophila, Legionella sp. diversity decreased significantly, L. fallonii and L. pneumophila being the main species recovered.

Dynamics of Legionella spp. and Bacterial Populations during the Proliferation of L. pneumophila in a Cooling Tower Facility▿

PubMed Central

Wéry, Nathalie; Bru-Adan, Valérie; Minervini, Céline; Delgénes, Jean-Philippe; Garrelly, Laurent; Godon, Jean-Jacques

2008-01-01

The dynamics of Legionella spp. and of dominant bacteria were investigated in water from a cooling tower plant over a 9-month period which included several weeks when Legionella pneumophila proliferated. The structural diversity of both the bacteria and the Legionella spp. was monitored by a fingerprint technique, single-strand conformation polymorphism, and Legionella spp. and L. pneumophila were quantified by real-time quantitative PCR. The structure of the bacterial community did not change over time, but it was perturbed periodically by chemical treatment or biofilm detachment. In contrast, the structure of the Legionella sp. population changed in different periods, its dynamics at times showing stability but also a rapid major shift during the proliferation of L. pneumophila in July. The dynamics of the Legionella spp. and of dominant bacteria were not correlated. In particular, no change in the bacterial community structure was observed during the proliferation of L. pneumophila. Legionella spp. present in the cooling tower system were identified by cloning and sequencing of 16S rRNA genes. A high diversity of Legionella spp. was observed before proliferation, including L. lytica, L. fallonii, and other Legionella-like amoebal pathogen types, along with as-yet-undescribed species. During the proliferation of L. pneumophila, Legionella sp. diversity decreased significantly, L. fallonii and L. pneumophila being the main species recovered. PMID:18390683

[Legionnaire's disease outbreak].

PubMed

Barrufet-Barqué, M Pilar; Sauca-Subias, Goretti; Force-Sanmartín, Lluís; Felip-Benach, Angela; Martínez-Pérez, Encarna; Capdevila-Morell, Josep A

2006-02-11

To describe an outbreak of Legionella pneumophila serogroup 1 in Mataró, Catalunya, Spain, in August 2002. The source of the microorganism was a cooling tower. Prospective and observational study with analysis of epidemiological, clinical, and microbiological data. 151 patients were affected (62% male), with a mean age of 58.4 years old. Seven patients were classified as Pontiac Fever and 144 suffered from pneumonia. The diagnosis of pneumonia was confirmed in 79% of cases, was considered suspicious in 14% and probable in 7%. Forty per cent of patients were smokers and 53.5% had comorbidities, mainly diabetes mellitus (22%). Chief symptoms were fever (97%), chills and muscular pain (63% respectively), headache (54%) and cough (53%). Pulmonary condensation was the more frequent radiological feature (71%). Normal pulmonary exploration was observed in 38%. Forty-three per cent of cases were severely ill, and 16% of patients belonged to Fine's IV and V class. Antigenuria was the most important test for diagnosis, which confirmed 76% of cases. Legionella spp. was obtained in respiratory secretions of 10 patients. Molecular analysis confirmed clonality between respiratory microorganisms and that obtained in the cooling tower. The outbreak involved an important number of subjects in a short period of time. Antigenuria was the most useful test. However, the isolation of L. pneumophila from patients permitted the prompt identification of microorganism's source in a cooling tower. The low mortality observed probably relates to a rapid diagnosis and its target treatment.

User's manual for the BNW-I optimization code for dry-cooled power plants. Volume I

DOE Office of Scientific and Technical Information (OSTI.GOV)

Braun, D.J.; Daniel, D.J.; De Mier, W.V.

1977-01-01

This User's Manual provides information on the use and operation of three versions of BNW-I, a computer code developed by Battelle, Pacific Northwest Laboratory (PNL) as a part of its activities under the ERDA Dry Cooling Tower Program. These three versions of BNW-I were used as reported elsewhere to obtain comparative incremental costs of electrical power production by two advanced concepts (one using plastic heat exchangers and one using ammonia as an intermediate heat transfer fluid) and a state-of-the-art system. The computer program offers a comprehensive method of evaluating the cost savings potential of dry-cooled heat rejection systems and componentsmore » for power plants. This method goes beyond simple ''figure-of-merit'' optimization of the cooling tower and includes such items as the cost of replacement capacity needed on an annual basis and the optimum split between plant scale-up and replacement capacity, as well as the purchase and operating costs of all major heat rejection components. Hence, the BNW-I code is a useful tool for determining potential cost savings of new heat transfer surfaces, new piping or other components as part of an optimized system for a dry-cooled power plant.« less

Moist air state above counterflow wet-cooling tower fill based on Merkel, generalised Merkel and Klimanek & Białecky models

NASA Astrophysics Data System (ADS)

Hyhlík, Tomáš

2017-09-01

The article deals with an evaluation of moist air state above counterflow wet-cooling tower fill. The results based on Klimanek & Białecky model are compared with results of Merkel model and generalised Merkel model. Based on the numerical simulation it is shown that temperature is predicted correctly by using generalised Merkel model in the case of saturated or super-saturated air above the fill, but the temperature is underpredicted in the case of unsaturated moist air above the fill. The classical Merkel model always under predicts temperature above the fill. The density of moist air above the fill, which is calculated using generalised Merkel model, is strongly over predicted in the case of unsaturated moist air above the fill.

75 FR 17970 - Nine Mile Point Nuclear Station, LLC; Nine Mile Point Nuclear Station, Unit No. 2; Draft...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-08

... industrial use. Potable water in the area is supplied to residents either through the Scriba Water District... and drift losses from the cooling tower. NMP2 has its own cooling water intake and discharge... service water system and makeup to the circulating water system to replace evaporation and drift losses...

10 CFR Appendix B to Subpart A of... - Environmental Effect of Renewing the Operating License of a Nuclear Power Plant

Code of Federal Regulations, 2011 CFR

2011-01-01

...). Aquatic Ecology (for all plants) Refurbishment 1 SMALL. During plant shutdown and refurbishment there will... cooling ponds and is not expected to be a problem during the license renewal term. Aquatic Ecology (for...)(ii)(B). Aquatic Ecology (for plants with cooling-tower-based heat dissipation systems) Entrainment of...

Feasibility of Rectangular Concrete Pressure Vessels for Human Occupancy

DTIC Science & Technology

1990-07-01

incorporated: into the s 1.71 ! -1 rule-. 20 DISTRIBUTION/ AVAILABILIT ’- ,"r ABSTRACT 2’ ABSTRACT SECURITY CLASSIFICATION 7 JUNCLASSIFIED/UNLIMITED 0 SAME AS RPT...carried the end loads. Gas cooled reactors were never very popular in the US. Domestic utilities preferred boiling water reactors that operated at...Point Tower); 1975 - 9,000 psi in Chicago ( Water Tower Place); 1984 - 10,000 psi in Seattle (Century Square Bldg.); 1987 - 10,000 psi in Toronto

NASA Marshall Space Flight Center Improves Cooling System Performance: Best Management Practice Case Study #10: Cooling Towers (Fact Sheet)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC) has a longstanding sustainability program that revolves around energy and water efficiency as well as environmental protection. MSFC identified a problematic cooling loop with six separate compressor heat exchangers and a history of poor efficiency. The facility engineering team at MSFC partnered with Flozone Services, Incorporated to implement a comprehensive water treatment platform to improve the overall efficiency of the system.

Legionnaires' Disease

MedlinePlus

... and Treatment Cooling Towers, Evaporative Condensers, and Fluid Coolers Humidifiers and Misters Domestic Water Systems Domestic Hot- ... 105° F, or 39° to 41° C) Cough (dry at first, later producing phlegm) Difficulty in breathing ...

Water use at pulverized coal power plants with postcombustion carbon capture and storage.

PubMed

Zhai, Haibo; Rubin, Edward S; Versteeg, Peter L

2011-03-15

Coal-fired power plants account for nearly 50% of U.S. electricity supply and about a third of U.S. emissions of CO(2), the major greenhouse gas (GHG) associated with global climate change. Thermal power plants also account for 39% of all freshwater withdrawals in the U.S. To reduce GHG emissions from coal-fired plants, postcombustion carbon capture and storage (CCS) systems are receiving considerable attention. Current commercial amine-based capture systems require water for cooling and other operations that add to power plant water requirements. This paper characterizes and quantifies water use at coal-burning power plants with and without CCS and investigates key parameters that influence water consumption. Analytical models are presented to quantify water use for major unit operations. Case study results show that, for power plants with conventional wet cooling towers, approximately 80% of total plant water withdrawals and 86% of plant water consumption is for cooling. The addition of an amine-based CCS system would approximately double the consumptive water use of the plant. Replacing wet towers with air-cooled condensers for dry cooling would reduce plant water use by about 80% (without CCS) to about 40% (with CCS). However, the cooling system capital cost would approximately triple, although costs are highly dependent on site-specific characteristics. The potential for water use reductions with CCS is explored via sensitivity analyses of plant efficiency and other key design parameters that affect water resource management for the electric power industry.

10 CFR Appendix B to Subpart A of... - Environmental Effect of Renewing the Operating License of a Nuclear Power Plant

Code of Federal Regulations, 2010 CFR

2010-01-01

... environmental impacts of renewing the operating license for a nuclear power plant as required by section 102(2... cooling ponds and is not expected to be a problem during the license renewal term. Aquatic Ecology (for... depression beyond the site boundary. Impacts of large ground-water withdrawal for cooling tower makeup at...

90. VIEW OF OXIDIZER APRON AND SOUTH SIDE OF SKID ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

90. VIEW OF OXIDIZER APRON AND SOUTH SIDE OF SKID 9, SKID 7, AND SKID 9A. COOLING TOWER ON NORTH SIDE OF OXIDIZER APRON. LEFT TO RIGHT IN BACKGROUND: METEOROLOGICAL TOWER, SLC-3W MST, SURPLUS ATLAS E/F LAUNCHER, PYROTECHNIC SHED (BLDG. 757), STORAGE SHED (BLDG. 776), CABLE TRAYS, AND TOP OF LAUNCH OPERATIONS BUILDING (BLDG. 763). - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Optimizing Performance of a Thermal Energy Storage System

NASA Astrophysics Data System (ADS)

Subirats Soler, Monica

In this thesis, the problem of electricity demand shifting for the cooling needs of a large institution using a thermal energy storage (TES) tank is considered. The system is formed by electric chillers, cooling towers and a TES tank that can store energy for the cooling demand of most days, but not for the hottest ones. The goal is to supply all the cooling needed while minimizing the cost. This is done by shifting the cooling demand to night and early morning hours, when electricity is cheaper and due to lower temperatures, the chillers work more efficiently. This is all done with the help of the TES tank, that acts as a buffer storing chilled water. After a series of assumptions and simplifications, the cost function becomes convex and thus a minimum solution exists. However, from previous work only the chillers were considered, omitting the negative effect that other components of the system, such as cooling towers, had on the overall cost of operation. Using data from the operation of the power plant under real conditions, a method to model the whole system is presented in this thesis. In addition, the algorithm relied on the knowledge of an accurate prediction of the cooling demand, which obviously is not known in advance. A method to predict it starting from a forecasting of the temperature is presented. Finally, the algorithm can be easily modified to allow the imposition constraints that limit the maximum power use of chillers, during specific periods, in response to the overall needs of the micro-grid.

40 CFR 63.1329 - Process contact cooling towers provisions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... existing affected source that manufactures PET using a continuous terephthalic acid high viscosity multiple... viscosity multiple end finisher process, and who is subject or becomes subject to 40 CFR part 60, subpart...

40 CFR 63.1329 - Process contact cooling towers provisions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... existing affected source that manufactures PET using a continuous terephthalic acid high viscosity multiple... viscosity multiple end finisher process, and who is subject or becomes subject to 40 CFR part 60, subpart...

Mathematical Model of Two Phase Flow in Natural Draft Wet-Cooling Tower Including Flue Gas Injection

NASA Astrophysics Data System (ADS)

Hyhlík, Tomáš

2016-03-01

The previously developed model of natural draft wet-cooling tower flow, heat and mass transfer is extended to be able to take into account the flow of supersaturated moist air. The two phase flow model is based on void fraction of gas phase which is included in the governing equations. Homogeneous equilibrium model, where the two phases are well mixed and have the same velocity, is used. The effect of flue gas injection is included into the developed mathematical model by using source terms in governing equations and by using momentum flux coefficient and kinetic energy flux coefficient. Heat and mass transfer in the fill zone is described by the system of ordinary differential equations, where the mass transfer is represented by measured fill Merkel number and heat transfer is calculated using prescribed Lewis factor.

Industrial Cooling Tower Disinfection Treatment to Prevent Legionella spp.

PubMed Central

Iervolino, Matteo; Mancini, Benedetta; Cristino, Sandra

2017-01-01

The contamination of industrial cooling towers has been identified as one cause of legionellosis, but the real risk has been underestimated. Two different disinfection treatments were tested on Legionella colonization in an industrial Cooling Tower System (CTS). Environmental monitoring of Legionella, P. aeruginosa, and a heterotrophic plate count (HPC) at 36 °C was performed from June to October 2016. The disinfection procedures adopted were based on hydrogen peroxide (H2O2) and silver salts (Ag+), in addition to an anti-algal treatment, then using hyperclorination as a shock, and then continuous treatment by sodium hypochlorite (NaClO). L. pneumophila serogroup 8 was found at a concentration of 5.06 Log cfu/L after the CTS filling; a shock treatment performed by H2O2/Ag+ produced a rapid increase in contamination up to 6.14 Log cfu/L. The CTS activity was stopped and two subsequent shock treatments were performed using NaClO, followed by continuous hyperclorination. These procedures showed a significant decrease (p < 0.05) in Legionella concentration (1.77 Log cfu/L). The same trend was observed for P. aeruginosa (0.55 Log cfu/100 mL) and HPC (1.95 Log cfu/mL) at 36 °C. Environmental monitoring and the adoption of maintenance procedures, including anti-scale treatment, and physical, chemical, and microbiological control, ensure the good performance of a CTS, reducing the Legionella risk for public health. PMID:28954435

Biocidal Inactivation of Lactococcus lactis Bacteriophages: Efficacy and Targets of Commonly Used Sanitizers

PubMed Central

Hayes, Stephen; Murphy, James; Mahony, Jennifer; Lugli, Gabriele A.; Ventura, Marco; Noben, Jean-Paul; Franz, Charles M. A. P.; Neve, Horst; Nauta, Arjen; Van Sinderen, Douwe

2017-01-01

Lactococcus lactis strains, being intensely used in the dairy industry, are particularly vulnerable to members of the so-called 936 group of phages. Sanitization and disinfection using purpose-made biocidal solutions is a critical step in controlling phage contamination in such dairy processing plants. The susceptibility of 36 936 group phages to biocidal treatments was examined using 14 biocides and commercially available sanitizers. The targets of a number of these biocides were investigated by means of electron microscopic and proteomic analyses. The results from this study highlight significant variations in phage resistance to biocides among 936 phages. Furthermore, rather than possessing resistance to specific biocides or biocide types, biocide-resistant phages tend to possess a broad tolerance to multiple classes of antimicrobial compounds. PMID:28210242

Solar heating and cooling system installed at RKL Controls Company, Lumberton, New Jersey

NASA Technical Reports Server (NTRS)

1981-01-01

The final results of the design and operation of a computer controlled solar heated and cooled 40,000 square foot manufacturing building, sales office, and computer control center/display room are summarized. The system description, test data, major problems and resolutions, performance, operation and maintenance manual, equipment manufacturers' literature, and as-built drawings are presented. The solar system is composed of 6,000 square feet of flat plate collectors, external above ground storage subsystem, controls, absorption chiller, heat recovery, and a cooling tower.

Real-time Data Center Energy Efficiency At Pacific Northwest National Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sisk, Daniel R.; Khaleel, Mohammad A.; Marquez, Andres

2009-05-26

The escalating consumption of power in data centers worldwide has brought the issue of data center energy efficiency to the forefront. Data center owners and operators now regard detailed knowledge of the energy efficiencies of their data centers as a competitive advantage. With funding from the Department of Energy (NNSA), PNNL has undertaken an in-depth analysis of the real-time energy efficiency for its Energy Smart Data Center Test Bed(ESDC-TB), which is housed in the mixed-use EMSL. The analysis is centered around the real-time display of The Green Grid’s proposed DCiE metric. To calculate this metric, PNNL relies on a varietymore » of sources of data. At the ESDC-TB level, the data center is instrumented to the 100% level (all power consumption, and water temperatures and flow rates are measured). Most of this data is monitored in real-time, but the exception to this is with the CRAHs, which rely on a one-time power consumption measurement for the blowers (these are single speed blowers, so a one-time measurement suffices.). Outside of the data center (EMSL facility level), PNNL relies on the following: • Real-time data from the entire chiller plant (five chillers), six chilled water pumps, and one of four cooling towers (blowers only). • One-time power measurements for a single fixed speed pump that is representative of each grouping of pumps (the other pumps are assumed to possess the same power consumption levels). • One-time power measurements for a single two-speed cooling tower blower. This same blower model is deployed in three of the four cooling towers, so is assumed to be representative for all these blowers. • One-time power measurements for a single fixed speed cooling tower pump. This same pump model is deployed in all four cooling towers, so is assumed to be representative for all these pumps. A software tool named FRED was developed by PNNL to acquire, reduce, display, and archive all the data acquired from the ESDC-TB and EMSL. FRED provides the ability to display various levels of real-time data starting at the ESDC-TB and EMSL levels, then to lower levels as desired. For example, for the ESDC-TB, graphical screens are provided at the data center level, the rack level, the server level, and even the component level. In the near-term, FRED will also display the real-time DCiE. One of the major challenges to doing this in a mixed-use facility has been to quantify the power consumption of each major mechanical or electrical subsystem that is attributable to the IT equipment housed within the ESDC-TB (i.e., NW-ICE). PNNL has tackled this issue for its five chiller plant, and the analysis is presented in the paper. The analysis for all the remaining mechanical and electrical subsystems is now underway and will be presented in future publications.« less

Factors Mediating Environmental Biofilm Formation by Legionella pneumophila.

PubMed

Abu Khweek, Arwa; Amer, Amal O

2018-01-01

Legionella pneumophila ( L. pneumophila ) is an opportunistic waterborne pathogen and the causative agent for Legionnaires' disease, which is transmitted to humans via inhalation of contaminated water droplets. The bacterium is able to colonize a variety of man-made water systems such as cooling towers, spas, and dental lines and is widely distributed in multiple niches, including several species of protozoa In addition to survival in planktonic phase, L. pneumophila is able to survive and persist within multi-species biofilms that cover surfaces within water systems. Biofilm formation by L. pneumophila is advantageous for the pathogen as it leads to persistence, spread, resistance to treatments and an increase in virulence of this bacterium. Furthermore, Legionellosis outbreaks have been associated with the presence of L. pneumophila in biofilms, even after the extensive chemical and physical treatments. In the microbial consortium-containing L. pneumophila among other organisms, several factors either positively or negatively regulate the presence and persistence of L. pneumophila in this bacterial community. Biofilm-forming L. pneumophila is of a major importance to public health and have impact on the medical and industrial sectors. Indeed, prevention and removal protocols of L. pneumophila as well as diagnosis and hospitalization of patients infected with this bacteria cost governments billions of dollars. Therefore, understanding the biological and environmental factors that contribute to persistence and physiological adaptation in biofilms can be detrimental to eradicate and prevent the transmission of L. pneumophila . In this review, we focus on various factors that contribute to persistence of L. pneumophila within the biofilm consortium, the advantages that the bacteria gain from surviving in biofilms, genes and gene regulation during biofilm formation and finally challenges related to biofilm resistance to biocides and anti-Legionella treatments.

78 FR 34405 - Notice of Lodging of Proposed Consent Decree Under the Clean Air Act

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-07

..., particularly fluorides, emanating from its phosphoric acid process equipment. The facility's cooling towers are... has confirmed that PCS's hydrogen fluoride (``HF'') emissions comply with 40 CFR part 63, Subpart A...

Detection of Legionella species in environmental water by the quantitative PCR method in combination with ethidium monoazide treatment.

PubMed

Inoue, Hiroaki; Takama, Tomoko; Yoshizaki, Miwa; Agata, Kunio

2015-01-01

We detected Legionella species in 111 bath water samples and 95 cooling tower water samples by using a combination of conventional plate culture, quantitative polymerase chain reaction (qPCR) and qPCR combined with ethidium monoazide treatment (EMA-qPCR) methods. In the case of bath water samples, Legionella spp. were detected in 30 samples by plate culture, in 85 samples by qPCR, and in 49 samples by EMA-qPCR. Of 81 samples determined to be Legionella-negative by plate culture, 56 and 23 samples were positive by qPCR and EMA-qPCR, respectively. Therefore, EMA treatment decreased the number of Legionella-positive bath water samples detected by qPCR. In contrast, EMA treatment had no effect on cooling tower water samples. We therefore expect that EMA-qPCR is a useful method for the rapid detection of viable Legionella spp. from bath water samples.

Legionella oakridgensis: unusual new species isolated from cooling tower water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Orrison, L.H.; Cherry, W.B.; Tyndall, R.L.

1983-02-01

A new species of Legionella represented by 10 strains isolated from industrial cooling towers is described. Legionella oakridgensis differed genetically from the other seven species of Legionella in DNA hybridization studies and differed serologically in direct fluorescent-antibody tests. The new species, unlike all other species except L. jordanis, did not require added L-cysteine for growth in serial transfer on charcoal-yeast extract agar. L. oakridgensis, as well as three other species tested, required L-cysteine for primary isolation from animal tissues. L. oakridgensis was the only species of Legionella that failed to produce alkaline phosphatase at pH 8.5. In all other respects,more » it resembled other species of Legionella, including having a high content of branched-chain cellular fatty acids and being pathogenic for guinea pigs. These bacteria have not yet been associated with human disease, but they are potential causes of legionellosis.« less

Fungal biodiversity and mycotoxigenic fungi in cooling-tower water systems in Istanbul, Turkey.

PubMed

Kadaifciler, Duygu Göksay; Demirel, Rasime

2017-04-01

This is the first study to assess fungal diversity and mycotoxigenic fungi in open recirculating cooling-tower (CT) water systems (biofilm and water phase). The production capability of mycotoxin from fungal isolates was also examined. The mean fungal count in 21 different water and biofilm samples was determined as 234 CFU/100 mL and 4 CFU/cm 2 . A total of 32 species were identified by internal transcribed spacer (ITS) sequencing. The most common isolated fungi belonged to the genera Aspergillus and Penicillium, of which the most prevalent fungi were Aspergillus versicolor, Aspergillus niger, and Penicillium dipodomyicola. From 42% of the surveyed CTs, aflatoxigenic A. flavus isolates were identified. The detection of opportunistic pathogens and/or allergen species suggests that open recirculating CTs are a possible source of fungal infection for both the public and for occupational workers via the inhalation of aerosols and/or skin contact.

Heat and Mass Transfer in the Over-Shower Zone of a Cooling Tower with Flow Rotation

NASA Astrophysics Data System (ADS)

Kashani, M. M. Hemmasian; Dobrego, K. V.

2013-11-01

The influence of flow rotation in the over-shower zone of a natural draft wet cooling tower (NDCT) on heat and mass transfer in this zone is investigated numerically. The 3D geometry of an actual NDCT and three models of the induced rotation velocity fields are utilized for calculations. Two phases (liquid and gaseous) and three components are taken into consideration. The interphase heat exchange, heat transfer to the walls, condensation-evaporation intensity field, and other parameters are investigated as functions of the induced rotation intensity (the inclination of the velocity vector at the periphery). It is shown that the induced flow rotation intensifies the heat and mass transfer in the over-shower zone of an NDCT. Flow rotation leads to specific redistribution of evaporation-condensation areas in an NDCT and stimulates water condensation near its walls.

Large outbreak of Legionnaires' disease and Pontiac fever at a military base.

PubMed

Ambrose, J; Hampton, L M; Fleming-Dutra, K E; Marten, C; McClusky, C; Perry, C; Clemmons, N A; McCormic, Z; Peik, S; Mancuso, J; Brown, E; Kozak, N; Travis, T; Lucas, C; Fields, B; Hicks, L; Cersovsky, S B

2014-11-01

We investigated a mixed outbreak of Legionnaires' disease (LD) and Pontiac fever (PF) at a military base to identify the outbreak's environmental source as well as known legionellosis risk factors. Base workers with possible legionellosis were interviewed and, if consenting, underwent testing for legionellosis. A retrospective cohort study collected information on occupants of the buildings closest to the outbreak source. We identified 29 confirmed and probable LD and 38 PF cases. All cases were exposed to airborne pathogens from a cooling tower. Occupants of the building closest to the cooling tower were 6·9 [95% confidence interval (CI) 2·2-22·0] and 5·5 (95% CI 2·1-14·5) times more likely to develop LD and PF, respectively, than occupants of the next closest building. Thorough preventive measures and aggressive responses to outbreaks, including searching for PF cases in mixed legionellosis outbreaks, are essential for legionellosis control.

Corrosion control when using passively treated abandoned mine drainage as alternative makeup water for cooling systems.

PubMed

Hsieh, Ming-Kai; Chien, Shih-Hsiang; Li, Heng; Monnell, Jason D; Dzombak, David A; Vidic, Radisav D

2011-09-01

Passively treated abandoned mine drainage (AMD) is a promising alternative to fresh water as power plant cooling water system makeup water in mining regions where such water is abundant. Passive treatment and reuse of AMD can avoid the contamination of surface water caused by discharge of abandoned mine water, which typically is acidic and contains high concentrations of metals, especially iron. The purpose of this study was to evaluate the feasibility of reusing passively treated AMD in cooling systems with respect to corrosion control through laboratory experiments and pilot-scale field testing. The results showed that, with the addition of the inhibitor mixture orthophosphate and tolyltriazole, mild steel and copper corrosion rates were reduced to acceptable levels (< 0.127 mm/y and < 0.0076 mm/y, respectively). Aluminum had pitting corrosion problems in every condition tested, while cupronickel showed that, even in the absence of any inhibitor and in the presence of the biocide monochloramine, its corrosion rate was still very low (0.018 mm/y).

Efficacy of Biocides Used in the Modern Food Industry To Control Salmonella enterica, and Links between Biocide Tolerance and Resistance to Clinically Relevant Antimicrobial Compounds

PubMed Central

Condell, Orla; Iversen, Carol; Cooney, Shane; Power, Karen A.; Walsh, Ciara; Burgess, Catherine

2012-01-01

Biocides play an essential role in limiting the spread of infectious disease. The food industry is dependent on these agents, and their increasing use is a matter for concern. Specifically, the emergence of bacteria demonstrating increased tolerance to biocides, coupled with the potential for the development of a phenotype of cross-resistance to clinically important antimicrobial compounds, needs to be assessed. In this study, we investigated the tolerance of a collection of susceptible and multidrug-resistant (MDR) Salmonella enterica strains to a panel of seven commercially available food-grade biocide formulations. We explored their abilities to adapt to these formulations and their active biocidal agents, i.e., triclosan, chlorhexidine, hydrogen peroxide, and benzalkonium chloride, after sequential rounds of in vitro selection. Finally, cross-tolerance of different categories of biocidal formulations, their active agents, and the potential for coselection of resistance to clinically important antibiotics were investigated. Six of seven food-grade biocide formulations were bactericidal at their recommended working concentrations. All showed a reduced activity against both surface-dried and biofilm cultures. A stable phenotype of tolerance to biocide formulations could not be selected. Upon exposure of Salmonella strains to an active biocidal compound, a high-level of tolerance was selected for a number of Salmonella serotypes. No cross-tolerance to the different biocidal agents or food-grade biocide formulations was observed. Most tolerant isolates displayed changes in their patterns of susceptibility to antimicrobial compounds. Food industry biocides are effective against planktonic Salmonella. When exposed to sublethal concentrations of individual active biocidal agents, tolerant isolates may emerge. This emergence was associated with changes in antimicrobial susceptibilities. PMID:22367085

Efficacy of biocides used in the modern food industry to control salmonella enterica, and links between biocide tolerance and resistance to clinically relevant antimicrobial compounds.

PubMed

Condell, Orla; Iversen, Carol; Cooney, Shane; Power, Karen A; Walsh, Ciara; Burgess, Catherine; Fanning, Séamus

2012-05-01

Biocides play an essential role in limiting the spread of infectious disease. The food industry is dependent on these agents, and their increasing use is a matter for concern. Specifically, the emergence of bacteria demonstrating increased tolerance to biocides, coupled with the potential for the development of a phenotype of cross-resistance to clinically important antimicrobial compounds, needs to be assessed. In this study, we investigated the tolerance of a collection of susceptible and multidrug-resistant (MDR) Salmonella enterica strains to a panel of seven commercially available food-grade biocide formulations. We explored their abilities to adapt to these formulations and their active biocidal agents, i.e., triclosan, chlorhexidine, hydrogen peroxide, and benzalkonium chloride, after sequential rounds of in vitro selection. Finally, cross-tolerance of different categories of biocidal formulations, their active agents, and the potential for coselection of resistance to clinically important antibiotics were investigated. Six of seven food-grade biocide formulations were bactericidal at their recommended working concentrations. All showed a reduced activity against both surface-dried and biofilm cultures. A stable phenotype of tolerance to biocide formulations could not be selected. Upon exposure of Salmonella strains to an active biocidal compound, a high-level of tolerance was selected for a number of Salmonella serotypes. No cross-tolerance to the different biocidal agents or food-grade biocide formulations was observed. Most tolerant isolates displayed changes in their patterns of susceptibility to antimicrobial compounds. Food industry biocides are effective against planktonic Salmonella. When exposed to sublethal concentrations of individual active biocidal agents, tolerant isolates may emerge. This emergence was associated with changes in antimicrobial susceptibilities.

Water cooler towers and other man-made aquatic systems as environmental collection systems for agents of concern

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brigmon, Robin; Kingsley, Mark T.

An apparatus and process of using existing process water sources such as cooling towers, fountains, and waterfalls is provided in which the water sources are utilized as monitoring system for the detection of environmental agents which may be present in the environment. The process water is associated with structures and have an inherent filtering or absorbing capability available in the materials and therefore can be used as a rapid screening tool for quality and quantitative assessment of environmental agents.

Coagulation chemistries for silica removal from cooling tower water.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nyman, May Devan; Altman, Susan Jeanne; Stewart, Tom

2010-02-01

The formation of silica scale is a problem for thermoelectric power generating facilities, and this study investigated the potential for removal of silica by means of chemical coagulation from source water before it is subjected to mineral concentration in cooling towers. In Phase I, a screening of many typical as well as novel coagulants was carried out using concentrated cooling tower water, with and without flocculation aids, at concentrations typical for water purification with limited results. In Phase II, it was decided that treatment of source or make up water was more appropriate, and that higher dosing with coagulants deliveredmore » promising results. In fact, the less exotic coagulants proved to be more efficacious for reasons not yet fully determined. Some analysis was made of the molecular nature of the precipitated floc, which may aid in process improvements. In Phase III, more detailed study of process conditions for aluminum chloride coagulation was undertaken. Lime-soda water softening and the precipitation of magnesium hydroxide were shown to be too limited in terms of effectiveness, speed, and energy consumption to be considered further for the present application. In Phase IV, sodium aluminate emerged as an effective coagulant for silica, and the most attractive of those tested to date because of its availability, ease of use, and low requirement for additional chemicals. Some process optimization was performed for coagulant concentration and operational pH. It is concluded that silica coagulation with simple aluminum-based agents is effective, simple, and compatible with other industrial processes.« less

Modelling biofilm-induced formation damage and biocide treatment in subsurface geosystems

PubMed Central

Ezeuko, C C; Sen, A; Gates, I D

2013-01-01

Biofilm growth in subsurface porous media, and its treatment with biocides (antimicrobial agents), involves a complex interaction of biogeochemical processes which provide non-trivial mathematical modelling challenges. Although there are literature reports of mathematical models to evaluate biofilm tolerance to biocides, none of these models have investigated biocide treatment of biofilms growing in interconnected porous media with flow. In this paper, we present a numerical investigation using a pore network model of biofilm growth, formation damage and biocide treatment. The model includes three phases (aqueous, adsorbed biofilm, and solid matrix), a single growth-limiting nutrient and a single biocide dissolved in the water. Biofilm is assumed to contain a single species of microbe, in which each cell can be a viable persister, a viable non-persister, or non-viable (dead). Persisters describe small subpopulation of cells which are tolerant to biocide treatment. Biofilm tolerance to biocide treatment is regulated by persister cells and includes ‘innate’ and ‘biocide-induced’ factors. Simulations demonstrate that biofilm tolerance to biocides can increase with biofilm maturity, and that biocide treatment alone does not reverse biofilm-induced formation damage. Also, a successful application of biological permeability conformance treatment involving geologic layers with flow communication is more complicated than simply engineering the attachment of biofilm-forming cells at desired sites. PMID:23164434

40 CFR 63.1335 - General recordkeeping and reporting provisions.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., on paper, microfilm, computer, floppy disk, magnetic tape, or microfiche. (2) If an owner or operator... subject to § 63.1316, § 63.1327 for batch process vents, § 63.1329 for process contact cooling towers, and...

40 CFR 63.1335 - General recordkeeping and reporting provisions.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., on paper, microfilm, computer, floppy disk, magnetic tape, or microfiche. (2) If an owner or operator... subject to § 63.1316, § 63.1327 for batch process vents, § 63.1329 for process contact cooling towers, and...

Comparison of plate counts, Petrifilm, dipslides, and adenosine triphosphate bioluminescence for monitoring bacteria in cooling-tower waters.

PubMed

Mueller, Sherry A; Anderson, James E; Kim, Byung R; Ball, James C

2009-04-01

Effective bacterial control in cooling-tower systems requires accurate and timely methods to count bacteria. Plate-count methods are difficult to implement on-site, because they are time- and labor-intensive and require sterile techniques. Several field-applicable methods (dipslides, Petrifilm, and adenosine triphosphate [ATP] bioluminescence) were compared with the plate count for two sample matrices--phosphate-buffered saline solution containing a pure culture of Pseudomonas fluorescens and cooling-tower water containing an undefined mixed bacterial culture. For the pure culture, (1) counts determined on nutrient agar and plate-count agar (PCA) media and expressed as colony-forming units (CFU) per milliliter were equivalent to those on R2A medium (p = 1.0 and p = 1.0, respectively); (2) Petrifilm counts were not significantly different from R2A plate counts (p = 0.99); (3) the dipslide counts were up to 2 log units higher than R2A plate counts, but this discrepancy was not statistically significant (p = 0.06); and (4) a discernable correlation (r2 = 0.67) existed between ATP readings and plate counts. For cooling-tower water samples (n = 62), (1) bacterial counts using R2A medium were higher (but not significant; p = 0.63) than nutrient agar and significantly higher than tryptone-glucose yeast extract (TGE; p = 0.03) and PCA (p < 0.001); (2) Petrifilm counts were significantly lower than nutrient agar or R2A (p = 0.02 and p < 0.001, respectively), but not statistically different from TGE, PCA, and dipslides (p = 0.55, p = 0.69, and p = 0.91, respectively); (3) the dipslide method yielded bacteria counts 1 to 3 log units lower than nutrient agar and R2A (p < 0.001), but was not significantly different from Petrifilm (p = 0.91), PCA (p = 1.00) or TGE (p = 0.07); (4) the differences between dipslides and the other methods became greater with a 6-day incubation time; and (5) the correlation between ATP readings and plate counts varied from system to system, was poor (r2 values ranged from < 0.01 to 0.47), and the ATP method was not sufficiently sensitive to measure counts below approximately 10(4) CFU/mL.

Geology of Devils Tower National Monument, Wyoming

USGS Publications Warehouse

Robinson, Charles Sherwood

1956-01-01

Devils Tower is a steep-sided mass of igneous rock that rises above the surrounding hills and the valley of the Belle Fourche River in Crook County, Wyo. It is composed of a crystalline rock, classified as phonolite porphyry, that when fresh is gray but which weathers to green or brown. Vertical joints divide the rock mass into polygonal columns that extend from just above the base to the top of the Tower. The hills in the vicinity and at the base of the Tower are composed of red, yellow, green, or gray sedimentary rocks that consist of sandstone, shale, or gypsum. These rocks, in aggregate about 400 feet thick, include, from oldest to youngest, the upper part of the Spearfish formation, of Triassic age, the Gypsum Spring formation, of Middle Jurassic age, and the Sundance formation, of Late Jurassic age. The Sundance formation consists of the Stockade Beaver shale member, the Hulett sandstone member, the Lak member, and the Redwater shale member. The formations have been only slightly deformed by faulting and folding. Within 2,000 to 3.000 feet of the Tower, the strata for the most part dip at 3 deg - 5 deg towards the Tower. Beyond this distance, they dip at 2 deg - 5 deg from the Tower. The Tower is believed to have been formed by the intrusion of magma into the sedimentary rocks, and the shape of the igneous mass formed by the cooled magma is believed to have been essentially the same as the Tower today. Devils Tower owes its impressiveness to its resistance to erosion as compared with the surrounding sedimentary rocks, and to the contrast of the somber color of the igneous column to the brightly colored bands of sedimentary rocks.

Modal surveys of very large civil structures using remote measurement of response to naturally occurring excitation

NASA Astrophysics Data System (ADS)

Winney, Peter E.

1989-07-01

A standard 660MW turbo-alternator, operated by the CEGB, runs at an energy conversion efficiency of about 38%. In addition to the 660MW electrical power, 600MW of waste thermal power is generated which has to be dissipated via water cooled heat exchangers. A typical 2000MW station has a requirement of about 1.3 billion gallons of cooling water per day. This is more than the daily throughput of most of our rivers and so inland stations are equipped with cooling towers to dump heat from the coolant.

Loading and release mechanisms of a biocide in polystyrene-block-poly(acrylic acid) block copolymer micelles.

PubMed

Vyhnalkova, Renata; Eisenberg, Adi; van de Ven, Theo G M

2008-07-24

The kinetics of loading of polystyrene197-block-poly(acrylic acid)47 (PS197-b-PAA47) micelles, suspended in water, with thiocyanomethylthiobenzothiazole biocide and its subsequent release were investigated. Loading of the micelles was found to be a two-step process. First, the surface of the PS core of the micelles is saturated with biocide, with a rate determined by the transfer of solid biocide to micelles during transient micelle-biocide contacts. Next, the biocide penetrates as a front into the micelles, lowering the Tg in the process (non-Fickian case II diffusion). The slow rate of release is governed by the height of the energy barrier that a biocide molecule must overcome to pass from PS into water, resulting in a uniform biocide concentration within the micelle, until Tg is increased to the point that diffusion inside the micelles becomes very slow. Maximum loading of biocide into micelles is approximately 30% (w/w) and is achieved in 1 h. From partition experiments, it can be concluded that the biocide has a similar preference for polystyrene as for ethylbenzene over water, implying that the maximum loading is governed by thermodynamics.

Development of an improved PCR-ICT hybrid assay for direct detection of Legionellae and Legionella pneumophila from cooling tower water specimens.

PubMed

Horng, Yu-Tze; Soo, Po-Chi; Shen, Bin-Jon; Hung, Yu-Li; Lo, Kai-Yin; Su, Hsun-Pi; Wei, Jun-Rong; Hsieh, Shang-Chen; Hsueh, Po-Ren; Lai, Hsin-Chih

2006-06-01

A novelly improved polymerase chian reaction and immunochromatography test (PCR-ICT) hybrid assay comprising traditional multiplex-nested PCR and ICT, (a lateral-flow device) was developed for direct detection of Legionella bacteria from environmental cooling tower samples. The partial 16S rDNA (specific for Legionella spp.) and dnaJ (specific for Legionella pneumophila) genes from Legionella chromosome were first specifically amplified by multiplex-nested PCR, respectively, followed by detection using ICT strip. Reading of results was based on presence or absence of the two test lines on the strips. Presence of test line 1 indicated existence of Legionella spp. specific 16S rDNA and identified Legionella spp. Presence of test line 2 further indicated existence of dnaJ and thus specifically identified L. pneumophila. In contrast, for non-Legionellae bacteria no test line formation was observed. Results of direct detection of Legionella bacteria and L. pneumophila from water tower specimens by this assay showed 100% sensitivity, and 96.6% and 100% specificity, respectively compared with traditional culture, biochemical and serological identification methods. The PCR-ICT hybrid assay does not require sophisticated equipment and was proved to be practically useful in rapid and direct Legionellae detection from environmental water samples.

Wastewater reuse in a cascade based system of a petrochemical industry for the replacement of losses in cooling towers.

PubMed

Hansen, Everton; Rodrigues, Marco Antônio Siqueira; Aquim, Patrice Monteiro de

2016-10-01

This article discusses the mapping of opportunities for the water reuse in a cascade based system in a petrochemical industry in southern Brazil. This industrial sector has a large demand for water for its operation. In the studied industry, for example, approximately 24 million cubic meters of water were collected directly from the source in 2014. The objective of this study was to evaluate the implementation of the reuse of water in cascade in a petrochemical industry, focusing on the reuse of aqueous streams to replenish losses in the cooling towers. This is an industrial scale case study with real data collected during the years 2014 and 2015. Water reuse was performed using heuristic approach based on the exploitation of knowledge acquired during the search process. The methodology of work consisted of the construction of a process map identifying the stages of production and water consumption, as well as the characterization of the aqueous streams involved in the process. For the application of the industrial water reuse as cooling water, mass balances were carried out considering the maximum concentration levels of turbidity, pH, conductivity, alkalinity, calcium hardness, chlorides, sulfates, silica, chemical oxygen demand and suspended solids as parameters turbidity, pH, conductivity, alkalinity, calcium hardness, chlorides, sulfates, silica, chemical oxygen demand and suspended solids as parameters. The adopted guideline was the fulfillment of the water quality criteria for each application in the industrial process. The study showed the feasibility for the reuse of internal streams as makeup water in cooling towers, and the implementation of the reuse presented in this paper totaled savings of 385,440 m(3)/year of water, which means a sufficient volume to supply 6350 inhabitants for a period of one year, considering the average water consumption per capita in Brazil; in addition to 201,480 m(3)/year of wastewater that would no longer be generated. Copyright © 2016 Elsevier Ltd. All rights reserved.

Resistance of Bacteria to Biocides.

PubMed

Maillard, Jean-Yves

2018-04-01

Biocides and formulated biocides are used worldwide for an increasing number of applications despite tightening regulations in Europe and in the United States. One concern is that such intense usage of biocides could lead to increased bacterial resistance to a product and cross-resistance to unrelated antimicrobials including chemotherapeutic antibiotics. Evidence to justify such a concern comes mostly from the use of health care-relevant bacterial isolates, although the number of studies of the resistance characteristics of veterinary isolates to biocides have increased the past few years. One problem remains the definition of "resistance" and how to measure resistance to a biocide. This has yet to be addressed globally, although the measurement of resistance is becoming more pressing, with regulators both in Europe and in the United States demanding that manufacturers provide evidence that their biocidal products will not impact on bacterial resistance. Alongside in vitro evidence of potential antimicrobial cross-resistance following biocide exposure, our understanding of the mechanisms of bacterial resistance and, more recently, our understanding of the effect of biocides to induce a mechanism(s) of resistance in bacteria has improved. This article aims to provide an understanding of the development of antimicrobial resistance in bacteria following a biocide exposure. The sections provide evidence of the occurrence of bacterial resistance and its mechanisms of action and debate how to measure bacterial resistance to biocides. Examples pertinent to the veterinary field are used where appropriate.

40 CFR Table 4 to Subpart F of... - Organic Hazardous Air Pollutants Subject to Cooling Tower Monitoring Requirements in § 63.104

Code of Federal Regulations, 2012 CFR

2012-07-01

... glycol dimethyl ether 111966 Diethyl sulfate 64675 Dimethylaniline (N,N-) 121697 Dimethylhydrazine (1,1... 67721 Hexane 110543 Isophorone 78591 Methanol 67561 Methyl bromide (Bromomethane) 74839 Methyl chloride...

Credit BG. View looking northeast down from the tower onto ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Credit BG. View looking northeast down from the tower onto the two horizontal test stations at Test Stand "D." Station Dy is at the far left (Dy vacuum cell out of view), with in-line exhaust gas cooling sections and steam-driven "air ejector" (or evacuator) discharging engine exhausts to the east. The Dd cell is visible at the lower left, and the Dd exhaust train has the same functions as at Dy. The spherical tank is an electrically heated "accumulator" which supplies steam to the ejectors at Dv, Dd, and Dy stations. Other large piping delivered cooling water to the horizontal train cooling sections. The horizontal duct at the "Y" branch in the Dd train connects the Dd ejector to the Dv and Cv vacuum duct system (a blank can be bolted into this duct to isolate the Dd system). The shed roof for the Dpond test station appears at bottom center of this image. The open steel frame to the lower left of the image supports a hoist and crane for installing or removing test engines from the Dd test cell - Jet Propulsion Laboratory Edwards Facility, Test Stand D, Edwards Air Force Base, Boron, Kern County, CA

Experiences in solar cooling systems

NASA Astrophysics Data System (ADS)

Ward, D. S.

The results of performance evaluations for nine solar cooling systems are presented, and reasons fow low or high net energy balances are discussed. Six of the nine systems are noted to have performed unfavorably compared to standard cooling systems due to thermal storage losses, excessive system electrical demands, inappropriate control strategies, poor system-to-load matching, and poor chiller performance. A reduction in heat losses in one residential unit increased the total system efficiency by 2.5%, while eliminating heat losses to the building interior increased the efficiency by 3.3%. The best system incorporated a lithium bromide absorption chiller and a Rankine cycle compression unit for a commercial application. Improvements in the cooling tower and fan configurations to increase the solar cooling system efficiency are indicated. Best performances are expected to occur in climates inducing high annual cooling loads.

New environmentally-benign concepts in wood protection: the combination of organic biocides and non-biocidal additives

Treesearch

Frederick Green; Tor P. Schultz

2003-01-01

The principal wood preservative for residential use is currently a broad-spectrum biocide which contains As, Cr and Cu. However, the use of totally organic wood preservative systems in certain applications or localities may be required in the future. This will greatly increase the price of treated wood. The combination of organic biocides with non-biocidal additives to...

Enhanced Biocide Mitigation of Field Biofilm Consortia by a Mixture of D-Amino Acids

PubMed Central

Li, Yingchao; Jia, Ru; Al-Mahamedh, Hussain H.; Xu, Dake; Gu, Tingyue

2016-01-01

Microbiologically influenced corrosion (MIC) is a major problem in the oil and gas industry as well as in many other industries. Current treatment methods rely mostly on pigging and biocide dosing. Biocide resistance is a growing concern. Thus, it is desirable to use biocide enhancers to improve the efficacy of existing biocides. D-Amino acids are naturally occurring. Our previous work demonstrated that some D-amino acids are biocide enhancers. Under a biocide stress of 50 ppm (w/w) hydroxymethyl phosphonium sulfate (THPS) biocide, 1 ppm D-tyrosine and 100 ppm D-methionine used separately successfully mitigated the Desulfovibrio vulgaris biofilm on carbon steel coupons. The data reported in this work revealed that 50 ppm of an equimolar mixture of D-methionine, D-tyrosine, D-leucine, and D-tryptophan greatly enhanced 50 ppm THPS biocide treatment of two recalcitrant biofilm consortia containing sulfate reducing bacteria (SRB), nitrate reducing bacteria (NRB), and fermentative bacteria, etc., from oil-field operations. The data also indicated that individual D-amino acids were inadequate for the biofilm consortia. PMID:27379039

Synergistic activity of biocides and antibiotics on resistant bacteria from organically produced foods.

PubMed

Fernández Fuentes, Miguel Angel; Abriouel, Hikmate; Gadea, Rebeca; Pérez Pulido, Rubén; Gálvez, Antonio; Ortega, Elena

2014-10-01

Synergism between biocides and antibiotics was investigated in 20 biocide and antibiotic-resistant bacterial strains that were previously isolated from organically produced foods, according to their antimicrobial resistance profiles. Most of the antibiotic/biocide combinations yielded synergistic interactions, reducing the inhibitory concentrations of biocides and antibiotics by 4- to 16-fold. Among enterococci, synergism with biocides was detected for amoxicillin (AM), cefuroxime (CX), erythromycin (EM), ciprofloxacin (CP), and trimethoprim/sulphametoxazol (T/S). Among staphylococci, interactions were synergistic (AM) and either synergistic or indifferent (CX and EM, depending on biocide). Among the three methicillin-resistant Staphylococcus aureus clinical strains included in the study, the combinations of methicillin and triclosan or hexachlorophene acted synergistically in all strains, but interactions were either synergistic or indifferent for the other biocides, depending on the strain. All combinations tested were synergistic for Lactobacillus (AM, CX, EM, and CP) and Micrococcus (AM, EM). In Salmonella, interactions were indifferent (AM, CX, EM, and CP) or synergistic (T/S). Synergism with biocides was also detected in Klebsiella isolates (AM, CX, and T/S), Enterobacter sp. (AM, CX, EM, and T/S), Pantoea (AM, CX, EM, CP, and T/S), and Chryseobacterium sp. (EM). These results suggest that combinations of biocides and antibiotics may open new possibilities to combat antimicrobial resistance.

Startup of air-cooled condensers and dry cooling towers at low temperatures of the cooling air

NASA Astrophysics Data System (ADS)

Milman, O. O.; Ptakhin, A. V.; Kondratev, A. V.; Shifrin, B. A.; Yankov, G. G.

2016-05-01

The problems of startup and performance of air-cooled condensers (ACC) and dry cooling towers (DCT) at low cooling air temperatures are considered. Effects of the startup of the ACC at sub-zero temperatures are described. Different options of the ACC heating up are analyzed, and examples of existing technologies are presented (electric heating, heating up with hot air or steam, and internal and external heating). The use of additional heat exchanging sections, steam tracers, in the DCT design is described. The need for high power in cases of electric heating and heating up with hot air is noted. An experimental stand for research and testing of the ACC startup at low temperatures is described. The design of the three-pass ACC unit is given, and its advantages over classical single-pass design at low temperatures are listed. The formation of ice plugs inside the heat exchanging tubes during the start-up of ACC and DCT at low cooling air temperatures is analyzed. Experimental data on the effect of the steam flow rate, steam nozzle distance from the heat-exchange surface, and their orientation in space on the metal temperature were collected, and test results are analyzed. It is noted that the surface temperature at the end of the heat up is almost independent from its initial temperature. Recommendations for the safe start-up of ACCs and DCTs are given. The heating flow necessary to sufficiently heat up heat-exchange surfaces of ACCs and DCTs for the safe startup is estimated. The technology and the process of the heat up of the ACC with the heating steam external supply are described by the example of the startup of the full-scale section of the ACC at sub-zero temperatures of the cooling air, and the advantages of the proposed start-up technology are confirmed.

Nuclear Power and the Environment.

ERIC Educational Resources Information Center

Dukert, Joseph M.

Described are the major environmental effects resulting from the production of electricity by nuclear power plants. Discussed are effects of waste heat, radioactivity, radioactive waste elimination, costs, and future prospects. Included are diagrams illustrating cooling tower operation, effects of thermal discharge into water systems, radioactive…

Legionella (Legionnaires' Disease and Pontiac Fever): Causes and Transmission

MedlinePlus

... of Infection Legionella is a type of bacterium found naturally in freshwater environments, like lakes and streams. It can become a health concern when it grows and spreads in human-made building water systems like Showerheads and sink faucets Cooling towers ( ...

Bioengineered silver nanoparticles as potent anti-corrosive inhibitor for mild steel in cooling towers.

PubMed

Narenkumar, Jayaraman; Parthipan, Punniyakotti; Madhavan, Jagannathan; Murugan, Kadarkarai; Marpu, Sreekar Babu; Suresh, Anil Kumar; Rajasekar, Aruliah

2018-02-01

Silver nanoparticle-aided enhancement in the anti-corrosion potential and stability of plant extract as ecologically benign alternative for microbially induced corrosion treatment is demonstrated. Bioengineered silver nanoparticles (AgNPs) surface functionalized with plant extract material (proteinacious) was generated in vitro in a test tube by treating ionic AgNO 3 with the leaf extract of Azadirachta indica that acted as dual reducing as well as stabilizing agent. Purity and crystallinity of the AgNPs, along with physical and surface characterizations, were evaluated by performing transmission electron microscopy, Fourier transform infrared spectroscopy, energy dispersive x-ray spectra, single-area electron diffractions, zeta potential, and dynamic light scattering measurements. Anti-corrosion studies against mild steel (MS1010) by corrosion-inducive bacterium, Bacillus thuringiensis EN2 isolated from cooling towers, were evaluated by performing electrochemical impedance spectroscopy (EIS), weight loss analysis, and surface analysis by infrared spectroscopy. Our studies revealed that AgNPs profoundly inhibited the biofilm on MS1010 surface and reduced the corrosion rates with the CR of 0.5 mm/y and an inhibition efficiency of 77% when compared to plant extract alone with a CR of 2.2 mm/y and an inhibition efficiency of 52%. Further surface analysis by infrared spectra revealed that AgNPs formed a protective layer of self-assembled film on the surface of MS1010. Additionally, EIS and surface analysis revealed that the AgNPs have inhibited the bacterial biofilm and reduced the pit on MS1010. This is the first report disclosing the application of bioengineered AgNP formulations as potent anti-corrosive inhibitor upon forming a protective layer over mild steel in cooling water towers. Graphical Abstract ᅟ.

Consumer exposure to biocides--identification of relevant sources and evaluation of possible health effects.

PubMed

Hahn, Stefan; Schneider, Klaus; Gartiser, Stefan; Heger, Wolfgang; Mangelsdorf, Inge

2010-02-03

Products containing biocides are used for a variety of purposes in the home environment. To assess potential health risks, data on products containing biocides were gathered by means of a market survey, exposures were estimated using a worst case scenario approach (screening), the hazard of the active components were evaluated, and a preliminary risk assessment was conducted. Information on biocide-containing products was collected by on-site research, by an internet inquiry as well as research into databases and lists of active substances. Twenty active substances were selected for detailed investigation. The products containing these substances were subsequently classified by range of application; typical concentrations were derived. Potential exposures were then estimated using a worst case scenario approach according to the European Commission's Technical Guidance Document on Risk Assessment. Relevant combinations of scenarios and active substances were identified. The toxicological data for these substances were compiled in substance dossiers. For estimating risks, the margins of exposure (MOEs) were determined. Numerous consumer products were found to contain biocides. However, it appeared that only a limited number of biocidal active substances or groups of biocidal active substances were being used. The lowest MOEs for dermal exposure or exposure by inhalation were obtained for the following scenarios and biocides: indoor pest control using sprays, stickers or evaporators (chlorpyrifos, dichlorvos) and spraying of disinfectants as well as cleaning of surfaces with concentrates (hydrogen peroxide, formaldehyde, glutardialdehyde). The risk from aggregate exposure to individual biocides via different exposure scenarios was higher than the highest single exposure on average by a factor of three. From the 20 biocides assessed 10 had skin-sensitizing properties. The biocides isothiazolinone (mixture of 5-chloro-2-methyl-2H-isothiazolin-3-one and 2-methyl-2H-isothiazolin-3-one, CMI/MI), glutardialdehyde, formaldehyde and chloroacetamide may be present in household products in concentrations which have induced sensitization in experimental studies. Exposure to biocides from household products may contribute to induction of sensitization in the population. The use of biocides in consumer products should be carefully evaluated. Detailed risk assessments will become available within the framework of the EU Biocides Directive.

Consumer exposure to biocides - identification of relevant sources and evaluation of possible health effects

PubMed Central

2010-01-01

Background Products containing biocides are used for a variety of purposes in the home environment. To assess potential health risks, data on products containing biocides were gathered by means of a market survey, exposures were estimated using a worst case scenario approach (screening), the hazard of the active components were evaluated, and a preliminary risk assessment was conducted. Methods Information on biocide-containing products was collected by on-site research, by an internet inquiry as well as research into databases and lists of active substances. Twenty active substances were selected for detailed investigation. The products containing these substances were subsequently classified by range of application; typical concentrations were derived. Potential exposures were then estimated using a worst case scenario approach according to the European Commission's Technical Guidance Document on Risk Assessment. Relevant combinations of scenarios and active substances were identified. The toxicological data for these substances were compiled in substance dossiers. For estimating risks, the margins of exposure (MOEs) were determined. Results Numerous consumer products were found to contain biocides. However, it appeared that only a limited number of biocidal active substances or groups of biocidal active substances were being used. The lowest MOEs for dermal exposure or exposure by inhalation were obtained for the following scenarios and biocides: indoor pest control using sprays, stickers or evaporators (chlorpyrifos, dichlorvos) and spraying of disinfectants as well as cleaning of surfaces with concentrates (hydrogen peroxide, formaldehyde, glutardialdehyde). The risk from aggregate exposure to individual biocides via different exposure scenarios was higher than the highest single exposure on average by a factor of three. From the 20 biocides assessed 10 had skin-sensitizing properties. The biocides isothiazolinone (mixture of 5-chloro-2-methyl-2H-isothiazolin-3-one and 2-methyl-2H-isothiazolin-3-one, CMI/MI), glutardialdehyde, formaldehyde and chloroacetamide may be present in household products in concentrations which have induced sensitization in experimental studies. Conclusions Exposure to biocides from household products may contribute to induction of sensitization in the population. The use of biocides in consumer products should be carefully evaluated. Detailed risk assessments will become available within the framework of the EU Biocides Directive. PMID:20128903

Cooling tower plume - model and experiment

NASA Astrophysics Data System (ADS)

Cizek, Jan; Gemperle, Jiri; Strob, Miroslav; Nozicka, Jiri

The paper discusses the description of the simple model of the, so-called, steam plume, which in many cases forms during the operation of the evaporative cooling systems of the power plants, or large technological units. The model is based on semi-empirical equations that describe the behaviour of a mixture of two gases in case of the free jet stream. In the conclusion of the paper, a simple experiment is presented through which the results of the designed model shall be validated in the subsequent period.

Analysis of economic and environmental benefits of a new heat pump air conditioning system with a heat recovery device

NASA Astrophysics Data System (ADS)

Li, lingxue

2017-08-01

The paper designs a new wind-water cooling and heating water conditioner system, connects cooling tower with heat recovery device, which uses cooling water to completely remove the heat that does not need heat recollection, in order to ensure that the system can work efficiently with higher performance coefficient. After the test actual engineering operation, the system’s maximum cooling coefficient of performance can reach 3.5. Its maximum comprehensive coefficient of performance can reach 6.5. After the analysis of its economic and environmental, we conclude that the new system can save 89822 kw per year. It reflects energy-saving and environmental benefits of the cold and hot water air conditioning system.

42. NORTHEAST VIEW OF BLOW ENGINE HOUSE No. 3, WITH ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

42. NORTHEAST VIEW OF BLOW ENGINE HOUSE No. 3, WITH FILTER CAKE HOSUE IN CENTER FOREGROUND, AND EVAPORATIVE WASTE WATER TREATMENT COOLING TOWER TO THE LEFT. (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

FUGITIVE EMISSION SOURCES AND BATCH OPERATIONS IN SYNTHETIC ORGANIC CHEMICAL PRODUCTION

EPA Science Inventory

This survey report was developed for the EPA for use in assessing the potential magnitude of fugitive volatile organic compound (VOC) emissions from agitator seals, cooling towers and batch operations in the production of 378 designated chemicals. The information presented in thi...

Detection of Legionella pneumophila by PCR-ELISA method in industrial cooling tower water.

PubMed

Soheili, Majid; Nejadmoghaddam, Mohammad Reza; Babashamsi, Mohammad; Ghasemi, Jamileh; Jeddi Tehrani, Mahmood

2007-11-15

Water supply and Cooling Tower Water (CTW) are among the most common sources of Legionella pneumophila (LP) contamination. A nonradio active method is described to detect LP in industrial CTW samples. DNA was purified and amplified by nested -PCR with amplimers specific for the 16s rRNA gene of LP. The 5' end biotinylated oligomer probe was immobilized on sterptavidin B coated microtiter plates. The nested-PCR product was labeled with digoxigenin and then hybridized with 5'-biotinylated probes. The amplification products were detected by using proxidase-labled anti dioxygenin antibody in a colorimetric reaction. The assay detected LP present in 1 L of 5 CTW samples examined. All of the samples were Legionella positive in both culture and PCR-ELISA methods. The PCR-ELISA assay appears to exhibit high specificity and is a more rapid technique in comparison with bacterial culture method. Thus could prove suitable for use in the routine examination of industrial CTW contamination.

Adsorption interactions of humic acids with biocides

NASA Astrophysics Data System (ADS)

Mal'Tseva, E. V.; Ivanov, A. A.; Yudina, N. V.

2009-11-01

The chemical composition of humic acids from brown coal (Aldrich) was determined by element analysis, 13C NMR spectroscopy, and potentiometric titration. The adsorption ability of humic acids with different biocides (cyproconasol, propiconasol, tebuconasol, irgarol 1051, and DCOIT) was studied. The adsorption ability of a mixture of biocides in aqueous solutions was higher than that of the individual components. The limiting concentration of humic acids at which adsorption of biocides was maximum was determined. Adsorption constants were calculated by the Freundlich equation for each biocide in aqueous solution.

Antiseptic resistance: what do we know and what does it mean?

PubMed

Sheldon, Albert T

2005-01-01

Biocides (antiseptics, disinfectants, preservatives, sterilants) are used in clinical medicine as intervention strategies that prevent the dissemination of nosocomial pathogens. Biocides are also used for personal hygiene and to prevent cross-contamination of food-borne pathogens in homes, restaurants, day care centers, and nursing homes. However, laboratory evidence has emerged suggesting that the mechanism of nonsusceptibility to biocides may counter-select for resistance to antibiotics. Nature conserves successful survival strategies. Using existing mechanisms of resistance to antibiotics and their means of dissemination, microorganisms have adopted this same survival strategy for biocide nonsusceptibility. These mechanisms are intrinsic in nature or are acquired. The consequences to biocide efficacy in the clinical setting are probably not significant from the biocide perspective. But, the selective pressure biocides exert on bacterial populations that have mechanisms of resistance similar to those to antibiotics or that are also substrates for antibiotic resistance is of concern.

Characterization of biocide-tolerant bacteria isolated from cheese and dairy small-medium enterprises.

PubMed

Fernández Márquez, Ma Luisa; Grande Burgos, Ma José; López Aguayo, Ma Carmen; Pérez Pulido, Rubén; Gálvez, Antonio; Lucas, Rosario

2017-04-01

A collection of 120 bacterial isolates from small medium enterprises involved in the production of cow milk and the manufacture of goat cheese were screened for sensitivity to biocides benzalkonium chloride (BC), cetrimide (CT), hexadecylpyridinium chloride (HDP), triclosan (TC), hexachlorophene (CF) and poly-(hexamethylen guanidinium) hydrochloride (PHMG). Nineteen isolates were selected according to biocide tolerance and identified by 16S rDNA sequencing as Lactococcus sp. (6) Enterococcus sp. (1), Lactobacillus sp. (4), Bacillus sp. (1) Escherichia sp. (5), Enterobacter sp. (1) and Helicobacter sp. (1). These were further characterised regarding antimicrobial resistance phenotype and genotype. Several isolates were multiply (3 or more) tolerant to biocides or resistant to antibiotics, but only two Escherichia sp. isolates and Enterobacter sp. were multiply resistant to biocides and antibiotics. Statistical analysis of biocide tolerance and antibiotic resistance revealed significant positive correlations between different biocides and between biocides and antibiotics. The biocide tolerance genes most frequently found were qacEΔ1 and qacA/B. The sulfonamide resistance gene sul1 was found in two Escherichia sp. isolates and in Enterobacter sp., all of which also carried qacEΔ1. Beta-lactam (bla CTX-M , bla PSE ) and tetracycline resistance genes [tet(A), tet(C) and tet(D)] were detected. Efflux pump genes acrB and mdfA were found in most Gram-negative isolates. Results from the study suggest that exposure to biocides can indirectly select for antibiotic resistance. Copyright © 2016 Elsevier Ltd. All rights reserved.

Possible underestimations of risks for the environment due to unregulated emissions of biocides from households to wastewater.

PubMed

Wieck, Stefanie; Olsson, Oliver; Kümmerer, Klaus

2016-09-01

The aim of this study was to investigate the role of household products as possible sources of biocidal active substances in municipal wastewater and their regulation under the Biocidal Products Regulation (EU) 528/2012. In 131 households, we investigated the prevalence of products used to control pests, washing and cleaning agents and select personal care products with high release to wastewater. Inventories of these products were established with the help of barcode scanning. All uses of biocidal active substances were evaluated regarding their assessment under the Biocidal Products Regulation. 2963 products were scanned in total, with 48% being washing and cleaning agents, 43% personal care products and 9% products used to control pests. Biocidal active substances were found in each household. These were observed primarily in washing and cleaning agents and personal care products (90%), while only a small percentage of the observations of biocidal active substances was in biocidal products. 64% of the observations of biocidal active substances were in applications that do not fall under the Biocidal Products Regulation and are thus not subject to its environmental risk assessment. This study shows clearly that risks for the environment are underestimated because unregulated emissions to wastewater occur. It demonstrates that there are gaps in the current chemical legislation that lead to a release of substances into wastewater that were not subject to environmental risk assessment under the Biocidal Products Regulation. This is one example of the limitations of scientific risk assessment of chemicals - its complexity is immense. From our point of view, the results underline the importance of a sustainable use of the substances as this is the only way to decrease yet unidentified risks. Copyright © 2016 Elsevier Ltd. All rights reserved.

40 CFR 423.16 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2013 CFR

2013-07-01

... used for transformer fluid. (b) The pollutants discharged in chemical metal cleaning wastes shall not... 126 priority pollutants (Appendix A) contained in chemicals added for cooling tower maintenance... priority pollutants in paragraph (d)(1) of this section may be determined by engineering calculations which...

40 CFR 423.16 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2010 CFR

2010-07-01

... used for transformer fluid. (b) The pollutants discharged in chemical metal cleaning wastes shall not... 126 priority pollutants (Appendix A) contained in chemicals added for cooling tower maintenance... priority pollutants in paragraph (d)(1) of this section may be determined by engineering calculations which...

40 CFR 423.16 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2012 CFR

2012-07-01

... used for transformer fluid. (b) The pollutants discharged in chemical metal cleaning wastes shall not... 126 priority pollutants (Appendix A) contained in chemicals added for cooling tower maintenance... priority pollutants in paragraph (d)(1) of this section may be determined by engineering calculations which...

40 CFR 423.16 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2011 CFR

2011-07-01

... used for transformer fluid. (b) The pollutants discharged in chemical metal cleaning wastes shall not... 126 priority pollutants (Appendix A) contained in chemicals added for cooling tower maintenance... priority pollutants in paragraph (d)(1) of this section may be determined by engineering calculations which...

40 CFR 423.16 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2014 CFR

2014-07-01

... used for transformer fluid. (b) The pollutants discharged in chemical metal cleaning wastes shall not... 126 priority pollutants (Appendix A) contained in chemicals added for cooling tower maintenance... priority pollutants in paragraph (d)(1) of this section may be determined by engineering calculations which...

10. SITE BUILDING 002 SCANNER BUILDING LOOKING AT ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

10. SITE BUILDING 002 - SCANNER BUILDING - LOOKING AT SOUTHWEST CORNER "B" FACE AND "C" FACE ON WEST AND EVAPORATIVE COOLING TOWER AT NORTH. VIEW IS LOOKING NORTH 45° EAST. - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

Consumers' perceptions of biocidal products in households.

PubMed

Wieck, Stefanie; Olsson, Oliver; Kümmerer, Klaus

2018-03-01

Biocidal products are commonly used in households and can pose a risk to human health and the environment. The aim of this study was to evaluate consumers' use and understanding of biocidal products in order to identify starting points for minimising their exposure to these products and reducing possible emissions to the environment. In a case study, standardised questionnaires were used to interview consumers in 133 households in three neighbourhoods in Northern Germany, representing the urban-rural typologies in Europe: predominantly urban, intermediate and predominantly rural regions. The questions focussed on the comprehension of the term 'biocide', pest control habits, sources of information, risk perception of different product groups and possible emission reduction measures. Only 21% of the respondents understood the term 'biocide' correctly, whereas 29% thought of 'something that had to do with organic pest control', and 28% were not able to think of a possible meaning. The risk perception of biocidal products compared to plant protection products varied depending on the living conditions. In the urban neighbourhood, biocidal products were perceived as more dangerous than in the rural area. The main pests to be fought were ants, mould and fruit fly. The results of the study indicate that there is a considerable difference between the types of biocidal products that interviewees claimed to own and those that they actually did have in their households. Most notably, respondents did not realise that they owned surface disinfectants. This result indicates that consumers often seem not to be aware of using specific biocidal products. Also, this shows the limitations of collecting data on products owned with only one method, as the results from products inventories of the households deviate from the data collected in interviews. Our results show that the term 'biocide' is not fully understood by many people. To communicate possible risks of biocidal products, other terms would have to be used. Online information regarding general facts on necessary general hygiene measures and biocidal products against bacteria and insects are likely to be of highest relevance for consumers. However, risk communication for biocidal products in general is difficult because consumers are often not aware of using biocidal products. For this reason, information and awareness raising campaigns should be accompanied by further measures such as sales restrictions for specific user-groups or prohibitions of certain uses for a sustainable use of biocidal products. Copyright © 2017 Elsevier GmbH. All rights reserved.

A large Legionnaires' disease outbreak in Pamplona, Spain: early detection, rapid control and no case fatality

PubMed Central

CASTILLA, J.; BARRICARTE, A.; ALDAZ, J.; GARCÍA CENOZ, M.; FERRER, T.; PELAZ, C.; PINEDA, S.; BALADRÓN, B.; MARTÍN, I.; GOÑI, B.; ARATAJO, P.; CHAMORRO, J.; LAMEIRO, F.; TORROBA, L.; DORRONSORO, I.; MARTÍNEZ-ARTOLA, V.; ESPARZA, M. J.; GASTAMINZA, M. A.; FRAILE, P.; ALDAZ, P.

2008-01-01

SUMMARY An outbreak of Legionnaire's disease was detected in Pamplona, Spain, on 1 June 2006. Patients with pneumonia were tested to detect Legionella pneumophila antigen in urine (Binax Now; Binax Inc., Scarborough, ME, USA), and all 146 confirmed cases were interviewed. The outbreak was related to district 2 (22 012 inhabitants), where 45% of the cases lived and 50% had visited; 5% lived in neighbouring districts. The highest incidence was found in the resident population of district 2 (3/1000 inhabitants), section 2 (14/1000). All 31 cooling towers of district 2 were analysed. L. pneumophila antigen (Binax Now) was detected in four towers, which were closed on 2 June. Only the strain isolated in a tower situated in section 2 of district 2 matched all five clinical isolates, as assessed by mAb and two genotyping methods, AFLP and PFGE. Eight days after closing the towers, new cases ceased appearing. Early detection and rapid coordinated medical and environmental actions permitted immediate control of the outbreak and probably contributed to the null case fatality. PMID:17662166

A large Legionnaires' disease outbreak in Pamplona, Spain: early detection, rapid control and no case fatality.

PubMed

Castilla, J; Barricarte, A; Aldaz, J; García Cenoz, M; Ferrer, T; Pelaz, C; Pineda, S; Baladrón, B; Martín, I; Goñi, B; Aratajo, P; Chamorro, J; Lameiro, F; Torroba, L; Dorronsoro, I; Martínez-Artola, V; Esparza, M J; Gastaminza, M A; Fraile, P; Aldaz, P

2008-06-01

An outbreak of Legionnaire's disease was detected in Pamplona, Spain, on 1 June 2006. Patients with pneumonia were tested to detect Legionella pneumophila antigen in urine (Binax Now; Binax Inc., Scarborough, ME, USA), and all 146 confirmed cases were interviewed. The outbreak was related to district 2 (22 012 inhabitants), where 45% of the cases lived and 50% had visited; 5% lived in neighbouring districts. The highest incidence was found in the resident population of district 2 (3/1000 inhabitants), section 2 (14/1000). All 31 cooling towers of district 2 were analysed. L. pneumophila antigen (Binax Now) was detected in four towers, which were closed on 2 June. Only the strain isolated in a tower situated in section 2 of district 2 matched all five clinical isolates, as assessed by mAb and two genotyping methods, AFLP and PFGE. Eight days after closing the towers, new cases ceased appearing. Early detection and rapid coordinated medical and environmental actions permitted immediate control of the outbreak and probably contributed to the null case fatality.

Prevalence of mip virulence gene and PCR-base sequence typing of Legionella pneumophila from cooling water systems of two cities in Iran.

PubMed

Ahmadrajabi, Roya; Shakibaie, Mohammad Reza; Iranmanesh, Zahra; Mollaei, Hamid Reza; Sobhanipoor, Mohammad Hossein

2016-07-03

Legionella pneumophila is the primary respiratory pathogen and mostly transmitted to human through water cooling systems and cause mild to severe pneumonia with high mortality rate especially in elderly both in hospitals and community. However, current Legionella risk assessments may be compromised by uncertainties in Legionella detection methods. Here, we investigated the presence of L. pneumophila mip gene in water samples collected from different hospitals cooling towers, nursing homes and building/hotels water coolants from two geographical locations of Iran (Kerman and Bam cities) during summer season of 2015 by both nested and real-time PCR methods. Analysis of the 128 water samples for presence of the mip gene by nested-PCR revealed, 18 (23%) positive cases in Kerman and 7(14%) in Bam. However, when samples were tested by real-time PCR, we identified 4 more new cases of L. pneumophila in the hospitals as well as nursing homes water systems that were missed by nested-PCR. The highest rate of contamination was detected in water obtained from hospitals cooling towers in both the cities (p≤0.05). Dendrogram analysis and clonal relationship by PCR-base sequence typing (SBT) of the L. pneumophila genomic DNAs in Kerman water samples showed close clonal similarities among the isolates, in contrast, isolates identified from Bam city demonstrated two fingerprint patterns. The clones from hospital water samples were more related to the L. pneumophila serogroup- 1.

Prevalence of mip virulence gene and PCR-base sequence typing of Legionella pneumophila from cooling water systems of two cities in Iran

PubMed Central

Ahmadrajabi, Roya; Shakibaie, Mohammad Reza; Iranmanesh, Zahra; Mollaei, Hamid Reza; Sobhanipoor, Mohammad Hossein

2016-01-01

ABSTRACT Legionella pneumophila is the primary respiratory pathogen and mostly transmitted to human through water cooling systems and cause mild to severe pneumonia with high mortality rate especially in elderly both in hospitals and community. However, current Legionella risk assessments may be compromised by uncertainties in Legionella detection methods. Here, we investigated the presence of L. pneumophila mip gene in water samples collected from different hospitals cooling towers, nursing homes and building/hotels water coolants from two geographical locations of Iran (Kerman and Bam cities) during summer season of 2015 by both nested and real-time PCR methods. Analysis of the 128 water samples for presence of the mip gene by nested-PCR revealed, 18 (23%) positive cases in Kerman and 7(14%) in Bam. However, when samples were tested by real-time PCR, we identified 4 more new cases of L. pneumophila in the hospitals as well as nursing homes water systems that were missed by nested-PCR. The highest rate of contamination was detected in water obtained from hospitals cooling towers in both the cities (p≤0.05). Dendrogram analysis and clonal relationship by PCR-base sequence typing (SBT) of the L. pneumophila genomic DNAs in Kerman water samples showed close clonal similarities among the isolates, in contrast, isolates identified from Bam city demonstrated two fingerprint patterns. The clones from hospital water samples were more related to the L. pneumophila serogroup- 1. PMID:27028760

Chapter 14: Evaluating the Leaching of Biocides from Preservative-Treated Wood Products

Treesearch

Stan T. Lebow

2014-01-01

Leaching of biocides is an important consideration in the long term durability and any potential for environmental impact of treated wood products. This chapter discusses factors affecting biocide leaching, as well as methods of evaluating rate and quantity of biocide released. The extent of leaching is a function of preservative formulation, treatment methods, wood...

Protecting wood from mould, decay, and termites with multi-component biocide systems

Treesearch

Carol A. Clausen

2007-01-01

Biocides must be developed for controlling mould establishment on cellulose-based building materials. Accordingly, biocides intended for indoor applications must be non- toxic, non-volatile, odourless, hypoallergenic, and able to provide long-term protection under conditions of high humidity. Multi-component biocide systems were tested in American Wood-Preservers’...

Low Gravity Freefall Facilities

NASA Technical Reports Server (NTRS)

1981-01-01

Composite of Marshall Space Flight Center's Low-Gravity Free Fall Facilities.These facilities include a 100-meter drop tower and a 100-meter drop tube. The drop tower simulates in-flight microgravity conditions for up to 4.2 seconds for containerless processing experiments, immiscible fluids and materials research, pre-flight hardware design test and flight experiment simulation. The drop tube simulates in-flight microgravity conditions for up to 4.6 seconds and is used extensively for ground-based microgravity convection research in which extremely small samples are studied. The facility can provide deep undercooling for containerless processing experiments that require materials to remain in a liquid phase when cooled below the normal solidification temperature.

Microgravity

NASA Image and Video Library

1981-03-30

Composite of Marshall Space Flight Center's Low-Gravity Free Fall Facilities.These facilities include a 100-meter drop tower and a 100-meter drop tube. The drop tower simulates in-flight microgravity conditions for up to 4.2 seconds for containerless processing experiments, immiscible fluids and materials research, pre-flight hardware design test and flight experiment simulation. The drop tube simulates in-flight microgravity conditions for up to 4.6 seconds and is used extensively for ground-based microgravity convection research in which extremely small samples are studied. The facility can provide deep undercooling for containerless processing experiments that require materials to remain in a liquid phase when cooled below the normal solidification temperature.

Antimicrobial biocides in the healthcare environment: efficacy, usage, policies, and perceived problems.

PubMed

Maillard, Jean-Yves

2005-12-01

Biocides are heavily used in the healthcare environment, mainly for the disinfection of surfaces, water, equipment, and antisepsis, but also for the sterilization of medical devices and preservation of pharmaceutical and medicinal products. The number of biocidal products for such usage continuously increases along with the number of applications, although some are prone to controversies. There are hundreds of products containing low concentrations of biocides, including various fabrics such as linen, curtains, mattresses, and mops that claim to help control infection, although evidence has not been evaluated in practice. Concurrently, the incidence of hospital-associated infections (HAIs) caused notably by bacterial pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) remains high. The intensive use of biocides is the subject of current debate. Some professionals would like to see an increase in their use throughout hospitals, whereas others call for a restriction in their usage to where the risk of pathogen transmission to patients is high. In addition, the possible linkage between biocide and antibiotic resistance in bacteria and the role of biocides in the emergence of such resistance has provided more controversies in their extensive and indiscriminate usage. When used appropriately, biocidal products have a very important role to play in the control of HAIs. This paper discusses the benefits and problems associated with the use of biocides in the healthcare environment and provides a constructive view on their overall usefulness in the hospital setting.

Risks of Using Antifouling Biocides in Aquaculture

PubMed Central

Guardiola, Francisco Antonio; Cuesta, Alberto; Meseguer, José; Esteban, Maria Angeles

2012-01-01

Biocides are chemical substances that can deter or kill the microorganisms responsible for biofouling. The rapid expansion of the aquaculture industry is having a significant impact on the marine ecosystems. As the industry expands, it requires the use of more drugs, disinfectants and antifoulant compounds (biocides) to eliminate the microorganisms in the aquaculture facilities. The use of biocides in the aquatic environment, however, has proved to be harmful as it has toxic effects on the marine environment. Organic booster biocides were recently introduced as alternatives to the organotin compounds found in antifouling products after restrictions were imposed on the use of tributyltin (TBT). The replacement products are generally based on copper metal oxides and organic biocides. The biocides that are most commonly used in antifouling paints include chlorothalonil, dichlofluanid, DCOIT (4,5-dichloro-2-n-octyl-4-isothiazolin-3-one, Sea-nine 211®), Diuron, Irgarol 1051, TCMS pyridine (2,3,3,6-tetrachloro-4-methylsulfonyl pyridine), zinc pyrithione and Zineb. There are two types of risks associated with the use of biocides in aquaculture: (i) predators and humans may ingest the fish and shellfish that have accumulated in these contaminants and (ii) the development of antibiotic resistance in bacteria. This paper provides an overview of the effects of antifouling (AF) biocides on aquatic organisms. It also provides some insights into the effects and risks of these compounds on non-target organisms. PMID:22408407

Risks of using antifouling biocides in aquaculture.

PubMed

Guardiola, Francisco Antonio; Cuesta, Alberto; Meseguer, José; Esteban, Maria Angeles

2012-01-01

Biocides are chemical substances that can deter or kill the microorganisms responsible for biofouling. The rapid expansion of the aquaculture industry is having a significant impact on the marine ecosystems. As the industry expands, it requires the use of more drugs, disinfectants and antifoulant compounds (biocides) to eliminate the microorganisms in the aquaculture facilities. The use of biocides in the aquatic environment, however, has proved to be harmful as it has toxic effects on the marine environment. Organic booster biocides were recently introduced as alternatives to the organotin compounds found in antifouling products after restrictions were imposed on the use of tributyltin (TBT). The replacement products are generally based on copper metal oxides and organic biocides. The biocides that are most commonly used in antifouling paints include chlorothalonil, dichlofluanid, DCOIT (4,5-dichloro-2-n-octyl-4-isothiazolin-3-one, Sea-nine 211(®)), Diuron, Irgarol 1051, TCMS pyridine (2,3,3,6-tetrachloro-4-methylsulfonyl pyridine), zinc pyrithione and Zineb. There are two types of risks associated with the use of biocides in aquaculture: (i) predators and humans may ingest the fish and shellfish that have accumulated in these contaminants and (ii) the development of antibiotic resistance in bacteria. This paper provides an overview of the effects of antifouling (AF) biocides on aquatic organisms. It also provides some insights into the effects and risks of these compounds on non-target organisms.

METHODOLOGIES FOR ESTIMATING AIR EMISSIONS FROM THREE NON-TRADITIONAL SOURCE CATEGORIES: OIL SPILLS, PETROLEUM VESSEL LOADING & UNLOADING, AND COOLING TOWERS

EPA Science Inventory

The report discusses part of EPA's program to identify and characterize emissions sources not currently accounted for by either the existing Aerometric Information Retrieval System (AIRS) or State Implementation Plan (sip) area source methodologies and to develop appropriate emis...

78 FR 31517 - Notification of Proposed Production Activity; Vestas Nacelles America, Inc.; Subzone 123E (Wind...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-24

... Activity; Vestas Nacelles America, Inc.; Subzone 123E (Wind Turbines); Brighton, Denver, Pueblo, and... during customs entry procedures that apply to wind turbines, nacelles, hubs, blades, and towers (free, 2...; dehumidifiers; cooling units; condensate heaters; heat exchangers; slip rings; filters; kabi sprayers; bearings...

75 FR 54961 - Final Supplemental Environmental Impact Statement, Single Nuclear Unit at the Bellefonte Plant...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-09

... facility, a wind farm, a methane- gas cofiring facility, and several small solar photovoltaic facilities... maintenance of select plant systems and other regulatory compliance activities. Major buildings and plant... the plant cooling towers and the reactor, auxiliary, control, turbine, office, and service buildings...

40 CFR 423.17 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2014 CFR

2014-07-01

... discharged in chemical metal cleaning wastes shall not exceed the concentration listed in the following table... chemicals added for cooling tower maintenance, except: Chromium, total 0.2 Zinc, total 1.0 (2) At the... engineering calculations which demonstrate that the regulated pollutants are not detectable in the final...

40 CFR 423.17 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... discharged in chemical metal cleaning wastes shall not exceed the concentration listed in the following table... chemicals added for cooling tower maintenance, except: Chromium, total 0.2 Zinc, total 1.0 (2) At the... engineering calculations which demonstrate that the regulated pollutants are not detectable in the final...

40 CFR 423.17 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2012 CFR

2012-07-01

... discharged in chemical metal cleaning wastes shall not exceed the concentration listed in the following table... chemicals added for cooling tower maintenance, except: Chromium, total 0.2 Zinc, total 1.0 (2) At the... engineering calculations which demonstrate that the regulated pollutants are not detectable in the final...

40 CFR 423.17 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2011 CFR

2011-07-01

... discharged in chemical metal cleaning wastes shall not exceed the concentration listed in the following table... chemicals added for cooling tower maintenance, except: Chromium, total 0.2 Zinc, total 1.0 (2) At the... engineering calculations which demonstrate that the regulated pollutants are not detectable in the final...

40 CFR 423.17 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... discharged in chemical metal cleaning wastes shall not exceed the concentration listed in the following table... chemicals added for cooling tower maintenance, except: Chromium, total 0.2 Zinc, total 1.0 (2) At the... engineering calculations which demonstrate that the regulated pollutants are not detectable in the final...

17. Photocopy of photograph (original in the Langley Research Center ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

17. Photocopy of photograph (original in the Langley Research Center Archives, Hampton, VA LaRC) (L86-10,257) DETAIL VIEW OF EXTERIOR OF COOLING TOWER FOR 8- FOOT HIGH SPEED WIND TUNNEL. - NASA Langley Research Center, 8-Foot High Speed Wind Tunnel, 641 Thornell Avenue, Hampton, Hampton, VA

13. Photocopy of photograph (original in the Langley Research Center ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

13. Photocopy of photograph (original in the Langley Research Center Archives, Hampton, VA LaRC) AERIAL VIEW OF 8-FOOT HIGH SPEED WIND TUNNEL IN FOREGROUND. NOTE COOLING TOWER AT LEFT CENTER. - NASA Langley Research Center, 8-Foot High Speed Wind Tunnel, 641 Thornell Avenue, Hampton, Hampton, VA

Biocides in the Yangtze River of China: spatiotemporal distribution, mass load and risk assessment.

PubMed

Liu, Wang-Rong; Zhao, Jian-Liang; Liu, You-Sheng; Chen, Zhi-Feng; Yang, Yuan-Yuan; Zhang, Qian-Qian; Ying, Guang-Guo

2015-05-01

Nineteen biocides were investigated in the Yangtze River to understand their spatiotemporal distribution, mass loads and ecological risks. Fourteen biocides were detected, with the highest concentrations up to 166 ng/L for DEET in surface water, and 54.3 ng/g dry weight (dw) for triclocarban in sediment. The dominant biocides were DEET and methylparaben, with their detection frequencies of 100% in both phases. An estimate of 152 t/y of 14 biocides was carried by the Yangtze River to the East China Sea. The distribution of biocides in the aquatic environments was significantly correlated to Gross Domestic Product (GDP), total phosphorus (TP) and total nitrogen (TN), suggesting dominant input sources from domestic wastewater of the cities along the river. Risk assessment showed high ecological risks posed by carbendazim in both phases and by triclosan in sediment. Therefore, proper measures should be taken to reduce the input of biocides into the river systems. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effective delivery of volatile biocides employing mesoporous silicates for treating biofilms

PubMed Central

Chan, Andrea C.; Townley, Helen E.

2017-01-01

Nanoparticulate delivery of biocides has the potential to decrease levels of exposure to non-target organisms, and miminize long-term exposure that can promote the development of resistance. Silica nanoparticles are an ideal vehicle since they are inert, biocompatible, biodegradable, and thermally and chemically stable. Encapsulation of biocides within nanoparticulates can improve their stability and longevity and maximize the biocidal potential of hydrophobic volatile compounds. Herein, we have shown that the plant secondary metabolites allyl isothiocyanate and cinnamaldehyde demonstrated increased antimicrobial activity against Escherichia coli in planktonic form, when packaged into mesoporous silica nanoparticles. Furthermore, the biocide-loaded nanoparticles showed activity against Pseudomonas aeruginosa biofilms that have inherent resistance to antimicrobial agents. The delivery platform can also be expanded to traditional biocides and other non-conventional antimicrobial agents. PMID:28077760

Development of methods for the decrease in instability of recycling water of conjugated closed-circuit cooling system of HPP

NASA Astrophysics Data System (ADS)

Chichirov, A. A.; Chichirova, N. D.; Vlasov, S. M.; Lyapin, A. I.; Misbakhov, R. Sh.; Silov, I. Yu.; Murtazin, A. I.

2016-10-01

On Russian HPPs, conjugated closed-circuit cooling systems, where purge water is used as initial for water-treatment facilities, are widespread. For this reason, it is impossible to use general methods for the stabilization treatment of recycling water in order to prevent scale formation in the units of a system, namely, turbine condensers and cooling towers. In this paper, the methods for the decrease in the instability of recycling water using the methods of chemical engineering, such as stabilization and synchronization of flows and organization of recycles, are suggested. The results of an industrial experiment on the implementation of stabilization treatment of recycling water by the organization of recycle are given. The experiment was carried out on Kazan CHPP-3. The flow scheme involved the recycle of chemically purified water (CPW) for the heat network make-up to the closed-circuit cooling system. The experiment was carried out at three stages with the gradual change of the consumption of the recycle, namely, 0, 50, and 100 t/h. According to the results of experiments, the reliable decrease in the rate of the sedimentation was recorded on the units of the system, namely, turbine condenser and chimney-type cooling tower. This is caused by two reasons. Firstly, this is periodic excessive concentration of recycling water due to the nonstationary character of inlet and outlet flows. Secondly, this is seasonal (particularly, in the summer period) exceeding of the evaporation coefficient. As a result of stabilization and synchronization of flows and organization of recycles, the quality of clarified and chemically purified water for the heat network make-up increases and the corrosion of iron- and copper-containing structural materials decreases. A natural decrease in temperature drop on the operating turbine condensers is mentioned.

Application of Pulse Spark Discharges for Scale Prevention and Continuous Filtration Methods in Coal-Fired Power Plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cho, Young; Fridman, Alexander

2012-06-30

The overall objective of the present work was to develop a new scale-prevention technology by continuously precipitating and removing dissolved mineral ions (such as calcium and magnesium) in cooling water while the COC could be doubled from the present standard value of 3.5. The hypothesis of the present study was that if we could successfully precipitate and remove the excess calcium ions in cooling water, we could prevent condenser-tube fouling and at the same time double the COC. The approach in the study was to utilize pulse spark discharges directly in water to precipitate dissolved mineral ions in recirculating coolingmore » water into relatively large suspended particles, which could be removed by a self-cleaning filter. The present study began with a basic scientific research to better understand the mechanism of pulse spark discharges in water and conducted a series of validation experiments using hard water in a laboratory cooling tower. Task 1 of the present work was to demonstrate if the spark discharge could precipitate the mineral ions in water. Task 2 was to demonstrate if the selfcleaning filter could continuously remove these precipitated calcium particles such that the blowdown could be eliminated or significantly reduced. Task 3 was to demonstrate if the scale could be prevented or minimized at condenser tubes with a COC of 8 or (almost) zero blowdown. In Task 1, we successfully completed the validation study that confirmed the precipitation of dissolved calcium ions in cooling water with the supporting data of calcium hardness over time as measured by a calcium ion probe. In Task 2, we confirmed through experimental tests that the self-cleaning filter could continuously remove precipitated calcium particles in a simulated laboratory cooling tower such that the blowdown could be eliminated or significantly reduced. In addition, chemical water analysis data were obtained which were used to confirm the COC calculation. In Task 3, we conducted a series of heat transfer fouling tests using a condenser heat exchanger in the laboratory cooling tower, from which we confirmed that the plasma water treatment technology could prevent or significantly mitigate mineral foulings in condenser tubes when compared with the no-treatment case. With the completion of the present work, a cooling water treatment technology using pulse spark discharges is currently ready for field-validation tests. The plasma water treatment technology is a true mechanical water softener with almost no maintenance, which continuously converts hard water to soft water spending a relatively small amount of energy. Such a mechanical water softener could find wide-spread applications to solve hard water problems both in industry and at home.« less

Estimation of the residual bromine concentration after disinfection of cooling water by statistical evaluation.

PubMed

Megalopoulos, Fivos A; Ochsenkuehn-Petropoulou, Maria T

2015-01-01

A statistical model based on multiple linear regression is developed, to estimate the bromine residual that can be expected after the bromination of cooling water. Make-up water sampled from a power plant in the Greek territory was used for the creation of the various cooling water matrices under investigation. The amount of bromine fed to the circuit, as well as other important operational parameters such as concentration at the cooling tower, temperature, organic load and contact time are taken as the independent variables. It is found that the highest contribution to the model's predictive ability comes from cooling water's organic load concentration, followed by the amount of bromine fed to the circuit, the water's mean temperature, the duration of the bromination period and finally its conductivity. Comparison of the model results with the experimental data confirms its ability to predict residual bromine given specific bromination conditions.

Dry Air Cooler Modeling for Supercritical Carbon Dioxide Brayton Cycle Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moisseytsev, A.; Sienicki, J. J.; Lv, Q.

Modeling for commercially available and cost effective dry air coolers such as those manufactured by Harsco Industries has been implemented in the Argonne National Laboratory Plant Dynamics Code for system level dynamic analysis of supercritical carbon dioxide (sCO 2) Brayton cycles. The modeling can now be utilized to optimize and simulate sCO 2 Brayton cycles with dry air cooling whereby heat is rejected directly to the atmospheric heat sink without the need for cooling towers that require makeup water for evaporative losses. It has sometimes been stated that a benefit of the sCO 2 Brayton cycle is that it enablesmore » dry air cooling implying that the Rankine steam cycle does not. A preliminary and simple examination of a Rankine superheated steam cycle and an air-cooled condenser indicates that dry air cooling can be utilized with both cycles provided that the cycle conditions are selected appropriately« less

User's manual for the BNW-II optimization code for dry/wet-cooled power plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Braun, D.J.; Bamberger, J.A.; Braun, D.J.

1978-05-01

The User's Manual describes how to operate BNW-II, a computer code developed by the Pacific Northwest Laboratory (PNL) as a part of its activities under the Department of Energy (DOE) Dry Cooling Enhancement Program. The computer program offers a comprehensive method of evaluating the cost savings potential of dry/wet-cooled heat rejection systems. Going beyond simple ''figure-of-merit'' cooling tower optimization, this method includes such items as the cost of annual replacement capacity, and the optimum split between plant scale-up and replacement capacity, as well as the purchase and operating costs of all major heat rejection components. Hence the BNW-II code ismore » a useful tool for determining potential cost savings of new dry/wet surfaces, new piping, or other components as part of an optimized system for a dry/wet-cooled plant.« less

40 CFR 430.17 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... sources (PSNS) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides...

40 CFR 430.47 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... sources (PSNS) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides...

40 CFR 430.17 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2014 CFR

2014-07-01

... sources (PSNS) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides...

40 CFR 430.67 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2014 CFR

2014-07-01

... sources (PSNS) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides...

40 CFR 430.67 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... sources (PSNS) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides...

Biocide Runoff from Building Facades: Degradation Kinetics in Soil.

PubMed

Bollmann, Ulla E; Fernández-Calviño, David; Brandt, Kristian K; Storgaard, Morten S; Sanderson, Hans; Bester, Kai

2017-04-04

Biocides are common additives in building materials. In-can and film preservatives in polymer-resin render and paint, as well as wood preservatives are used to protect facade materials from microbial spoilage. Biocides leach from the facade material with driving rain, leading to highly polluted runoff water (up to several mg L -1 biocides) being infiltrated into the soil surrounding houses. In the present study the degradation rates in soil of 11 biocides used for the protection of building materials were determined in laboratory microcosms. The results show that some biocides are degraded rapidly in soil (e.g., isothiazolinones: T 1/2 < 10 days) while others displayed higher persistence (e.g., terbutryn, triazoles: T 1/2 ≫ 120 days). In addition, mass balances of terbutryn and octylisothiazolinone were determined, including nine (terbutryn) and seven (octylisothiazolinone) degradation products, respectively. The terbutryn mass balance could be closed over the entire study period of 120 days and showed that relative persistent metabolites were formed, while the mass balances for octylisothiazolinone could not be closed. Octylisothiazolinone degradation products did not accumulate over time suggesting that the missing fraction was mineralized. Microtox-tests revealed that degradation products were less toxic toward the bacterium Aliivibrio fischeri than their parent compounds. Rain is mobilizing these biocides from the facades and transports them to the surrounding soils; thus, rainfall events control how often new input to the soil occurs. Time intervals between rainfall events in Northern Europe are shorter than degradation half-lives even for many rapidly degraded biocides. Consequently, residues of some biocides are likely to be continuously present due to repeated input and most biocides can be considered as "pseudo-persistent"-contaminants in this context. This was verified by (sub)urban soil screening, where concentrations of up to 0.1 μg g -1 were detected for parent compounds as well as terbutryn degradation products in soils below biocide treated facades.

Susceptibility of Legionella Strains to the Chlorinated Biocide, Monochloramine

PubMed Central

Jakubek, Delphine; Guillaume, Carole; Binet, Marie; Leblon, Gérard; DuBow, Michael; Le Brun, Matthieu

2013-01-01

Members of the Legionella genus find suitable conditions for their growth and survival in nuclear power plant cooling circuits. To limit the proliferation of Legionella pathogenic bacteria in nuclear power plant cooling circuits, and ensure that levels remain below regulatory thresholds, monochloramine treatment can be used. Although the treatment is highly effective, i.e. it reduces Legionella numbers by over 99%, Legionella bacteria can still be detected at low concentrations and rapid re-colonisation of circuits can occur after the treatment has ceased. The aim of this study was to develop an in vitro methodology for determining the intrinsic susceptibility of L. pneumophila strains, collected from various nuclear power plant cooling circuits subjected to different treatment conditions. The methodology was developed by using an original approach based on response surface methodology (RSM) combined with a multifactorial experimental design. The susceptibility was evaluated by the Ct factor. The susceptibility of environmental strains varies widely and is, for some strains, greater than that of known tolerant species; however, strain susceptibility was not related to treatment conditions. Selection pressure induced by monochloramine use did not result in the selection of more tolerant Legionella strains and did not explain the detection of Legionella during treatment or the rapid re-colonisation of cooling circuits after disinfection has ceased. PMID:24005820

Susceptibility of Legionella strains to the chlorinated biocide, monochloramine.

PubMed

Jakubek, Delphine; Guillaume, Carole; Binet, Marie; Leblon, Gérard; DuBow, Michael; Le Brun, Matthieu

2013-01-01

Members of the Legionella genus find suitable conditions for their growth and survival in nuclear power plant cooling circuits. To limit the proliferation of Legionella pathogenic bacteria in nuclear power plant cooling circuits, and ensure that levels remain below regulatory thresholds, monochloramine treatment can be used. Although the treatment is highly effective, i.e. it reduces Legionella numbers by over 99%, Legionella bacteria can still be detected at low concentrations and rapid re-colonisation of circuits can occur after the treatment has ceased. The aim of this study was to develop an in vitro methodology for determining the intrinsic susceptibility of L. pneumophila strains, collected from various nuclear power plant cooling circuits subjected to different treatment conditions. The methodology was developed by using an original approach based on response surface methodology (RSM) combined with a multifactorial experimental design. The susceptibility was evaluated by the Ct factor. The susceptibility of environmental strains varies widely and is, for some strains, greater than that of known tolerant species; however, strain susceptibility was not related to treatment conditions. Selection pressure induced by monochloramine use did not result in the selection of more tolerant Legionella strains and did not explain the detection of Legionella during treatment or the rapid re-colonisation of cooling circuits after disinfection has ceased.

Effects of Material Choice on Biocide Loss in Orion Water Storage Tanks

NASA Technical Reports Server (NTRS)

Wallace, W. T.; Wallace, S. L.; Gazda, D. B.; Lewis, J. F.

2016-01-01

When preparing for long-duration spaceflight missions, maintaining a safe supply of potable water is of the utmost importance. One major aspect of that is ensuring that microbial growth is minimized. Historically, this challenge has been addressed through the use of biocides. When using biocides, the choice of materials for the storage containers is important, because surface reactions can reduce biocide concentrations below their effective range. In the water storage system baselined for the Orion vehicle, the primary wetted materials are stainless steel (316 L) and a titanium alloy (Ti6Al4V). Previous testing with these materials has shown that the biocide selected for use in the system (ionic silver) will plate out rapidly upon initial wetting of the system. One potential approach for maintaining an adequate biocide concentration is to spike the water supply with high levels of biocide in an attempt to passivate the surface. To evaluate this hypothesis, samples of the wetted materials were tested individually and together to determine the relative loss of biocide under representative surface area-to-volume ratios after 24 hours. Additionally, we have analyzed the efficacy of disinfecting a system containing these materials by measuring reductions in bacterial counts in the same test conditions. Preliminary results indicate that the use of titanium, either individually or in combination with stainless steel, can result in over 95% loss of biocide, while less than 5% is lost when using stainless steel. In bacterial testing, viable organisms were recovered from samples exposed to the titanium coupons after 24 hours. By comparison, no organisms were recovered from the test vessels containing only stainless steel. These results indicate that titanium, while possessing some favorable attributes, may pose additional challenges when used in water storage tanks with ionic silver biocide.

Antimicrobial biocides in the healthcare environment: efficacy, usage, policies, and perceived problems

PubMed Central

Maillard, Jean-Yves

2005-01-01

Biocides are heavily used in the healthcare environment, mainly for the disinfection of surfaces, water, equipment, and antisepsis, but also for the sterilization of medical devices and preservation of pharmaceutical and medicinal products. The number of biocidal products for such usage continuously increases along with the number of applications, although some are prone to controversies. There are hundreds of products containing low concentrations of biocides, including various fabrics such as linen, curtains, mattresses, and mops that claim to help control infection, although evidence has not been evaluated in practice. Concurrently, the incidence of hospital-associated infections (HAIs) caused notably by bacterial pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) remains high. The intensive use of biocides is the subject of current debate. Some professionals would like to see an increase in their use throughout hospitals, whereas others call for a restriction in their usage to where the risk of pathogen transmission to patients is high. In addition, the possible linkage between biocide and antibiotic resistance in bacteria and the role of biocides in the emergence of such resistance has provided more controversies in their extensive and indiscriminate usage. When used appropriately, biocidal products have a very important role to play in the control of HAIs. This paper discusses the benefits and problems associated with the use of biocides in the healthcare environment and provides a constructive view on their overall usefulness in the hospital setting. PMID:18360573

Information technologies in public health management: a database on biocides to improve quality of life.

PubMed

Roman, C; Scripcariu, L; Diaconescu, Rm; Grigoriu, A

2012-01-01

Biocides for prolonging the shelf life of a large variety of materials have been extensively used over the last decades. It has estimated that the worldwide biocide consumption to be about 12.4 billion dollars in 2011, and is expected to increase in 2012. As biocides are substances we get in contact with in our everyday lives, access to this type of information is of paramount importance in order to ensure an appropriate living environment. Consequently, a database where information may be quickly processed, sorted, and easily accessed, according to different search criteria, is the most desirable solution. The main aim of this work was to design and implement a relational database with complete information about biocides used in public health management to improve the quality of life. Design and implementation of a relational database for biocides, by using the software "phpMyAdmin". A database, which allows for an efficient collection, storage, and management of information including chemical properties and applications of a large quantity of biocides, as well as its adequate dissemination into the public health environment. The information contained in the database herein presented promotes an adequate use of biocides, by means of information technologies, which in consequence may help achieve important improvement in our quality of life.

Image Cytometric Analysis of Algal Spores for Evaluation of Antifouling Activities of Biocidal Agents.

PubMed

Il Koo, Bon; Lee, Yun-Soo; Seo, Mintae; Seok Choi, Hyung; Leng Seah, Geok; Nam, Taegu; Nam, Yoon Sung

2017-07-31

Chemical biocides have been widely used as marine antifouling agents, but their environmental toxicity impose regulatory restriction on their use. Although various surrogate antifouling biocides have been introduced, their comparative effectiveness has not been well investigated partly due to the difficulty of quantitative evaluation of their antifouling activity. Here we report an image cytometric method to quantitatively analyze the antifouling activities of seven commercial biocides using Ulva prolifera as a target organism, which is known to be a dominant marine species causing soft fouling. The number of spores settled on a substrate is determined through image analysis using the intrinsic fluorescence of chlorophylls in the spores. Pre-determined sets of size and shape of spores allow for the precise determination of the number of settled spores. The effects of biocide concentration and combination of different biocides on the spore settlement are examined. No significant morphological changes of Ulva spores are observed, but the amount of adhesive pad materials is appreciably decreased in the presence of biocides. It is revealed that the growth rate of Ulva is not directly correlated with the antifouling activities against the settlement of Ulva spores. This work suggests that image cytometric analysis is a very convenient, fast-processable method to directly analyze the antifouling effects of biocides and coating materials.

40 CFR 430.106 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2013 CFR

2013-07-01

... biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides. PSES must be attained on or before July 1, 1984: Subpart J...

Biofilm Surface Density Determines Biocide Effectiveness

PubMed Central

Bas, Sara; Kramer, Mateja; Stopar, David

2017-01-01

High resistance of biofilms for chemical challenges is a serious industrial and medical problem. In this work a gradient of surface covered with biofilm has been produced and correlated to the effectiveness of different commercially available oxidative biocides. The results for thin Escherichia coli biofilms grown in rich media supplemented with glucose or lactose on glass or poly methyl methacrylate surfaces indicate that the effectiveness of hydrogen peroxide or chlorine dioxide and quaternary ammonium compounds is inversely proportional to the fraction of the surface covered with the biofilm. In areas where biofilm covered more than 90% of the available surface the biocide treatment was inefficient after 60 min of incubation. The combined effect of oxidant and surfactant increased the effectiveness of the biocide. On the other hand, the increased biofilm viscoelasticity reduced biocide effectiveness. The results emphasize differential biocide effectiveness depending on the fraction of the attached bacterial cells. The results suggest that biofilm biocide resistance is an acquired property that increases with biofilm maturation. The more dense sessile structures present lower log reductions compared to less dense ones. PMID:29276508

Considerations to Prevent Growth and Spread of Legionella in HVAC Systems.

ERIC Educational Resources Information Center

Coleman, Jeff

1998-01-01

Discusses the threat posed by the Legionnaire's Disease bacterium and the germ's ability to thrive in heating, ventilating, and air conditioning (HVAC) systems, especially in standing water. Describes ways to minimize disease risk through HVAC system design (such as locating cooling towers away from air intakes) and ways to maintain a clean…

40 CFR Table 4 to Subpart F of... - Organic Hazardous Air Pollutants Subject to Cooling Tower Monitoring Requirements in § 63.104

Code of Federal Regulations, 2010 CFR

2010-07-01

... Dichlorobenzidine (3,3″-) 91941 Dichloroethane (1,2-) (Ethylene dichloride) (EDC) 107062 Dichloroethyl ether (Bis(2... Ethyl acrylate 140885 Ethylbenzene 100414 Ethyl chloride (Chloroethane) 75003 Ethylene dibromide (Dibromoethane) 106934 Ethylene glycol dimethyl ether 110714 Ethylene glycol monobutyl ether 111762 Ethylene...

Legionella busanensis sp. nov., isolated from cooling tower water in Korea.

PubMed

Park, Mi-Yeoun; Ko, Kwan Soo; Lee, Hae Kyung; Park, Man-Suk; Kook, Yoon-Hoh

2003-01-01

Three Legionella-like micro-organisms, isolated from cooling tower water of a building in Busan, Korea, were characterized by a variety of biochemical and molecular phylogenetic tests. Analyses of whole-cell fatty acids and results of biochemical tests revealed that these three isolates are distinct from previously described Legionella species. Furthermore, results of comparative analyses of 16S rDNA (1476-1488 bp), mip (408 bp) and rpoB (300 bp) sequences also confirmed that these strains represent a novel species within the genus Legionella. The 16S rDNA sequences of the three Korean isolates had similarities of less than 95.8% to other Legionella species. Phylogenetic trees formed by analysis of the 16S rRNA, rpoB and mip genes revealed that the isolates formed a distinct cluster within the genus Legionella. Based on the evaluated phenotypic and phylogenetic characteristics, it is proposed that these Korean isolates from water be classified as a novel species, Legionella busanensis sp. nov.; the type strain is strain K9951T (=KCTC 12084T =ATCC BAA-518T).

Roseomonas tokyonensis sp. nov. isolated from a biofilm sample obtained from a cooling tower in Tokyo, Japan.

PubMed

Furuhata, Katsunori; Ishizaki, Naoto; Edagawa, Akiko; Fukuyama, Masafumi

2013-01-01

Strain K-20(T), a Gram-negative, nonmotile, nonspore-forming and strictly aerobic coccobacillus, which produces a pale pink pigment (R2A agar medium, 30℃, seven days) was isolated from a sample of biofilm obtained from a cooling tower in Tokyo, Japan. A phylogenetic analysis of the 16S rRNA partial gene sequences (1,439 bp) showed that the strain (accession number: AB297501) was related to Roseomonas frigidaquae CW67(T) and Roseomonas stagni HS-69(T) with 97.4% and 96.9% sequence similarity, respectively. Strain K-20(T) formed a distinct cluster with Roseomonas frigidaquae CW67(T) in the phylogenetic tree at a high bootstrap value (93%); however, distance was recognized between the strains. In addition, the DNA-DNA hybridization level between strain K-20(T) and Roseomonas frigidaquae JCM 15073(T) was 33%. The taxonomic data indicate that K-20(T) (=JCM 14634(T) =KCTC 32152(T)) should be classified in the genus Roseomonas as the type strain of a novel species, Roseomonas tokyonensis sp. nov.

Experimental development of processes to produce homogenized alloys of immiscible metals, phase 3

NASA Technical Reports Server (NTRS)

Reger, J. L.

1976-01-01

An experimental drop tower package was designed and built for use in a drop tower. This effort consisted of a thermal analysis, container/heater fabrication, and assembly of an expulsion device for rapid quenching of heated specimens during low gravity conditions. Six gallium bismuth specimens with compositions in the immiscibility region (50 a/o of each element) were processed in the experimental package: four during low gravity conditions and two under a one gravity environment. One of the one gravity processed specimens did not have telemetry data and was subsequently deleted for analysis since the processing conditions were not known. Metallurgical, Hall effect, resistivity, and superconductivity examinations were performed on the five specimens. Examination of the specimens showed that the gallium was dispersed in the bismuth. The low gravity processed specimens showed a relatively uniform distribution of gallium, with particle sizes of 1 micrometer or less, in contrast to the one gravity control specimen. Comparison of the cooling rates of the dropped specimens versus microstructure indicated that low cooling rates are more desirable.

Exceptional selectivity for dissolved silicas in industrial waters using mixed oxides

DOE PAGES

Sasan, Koroush; Brady, Patrick V.; Krumhansl, James L.; ...

2017-11-07

The removal of silica, ubiquitous in produced and industrial waters, by novel mixed oxides is investigated in this present study. We have combined the advantage of high selectivity hydrotalcite (HTC, (Mg 6Al 2(OH) 16(CO 3)·4H 2O)), with large surface area of active alumina (AA, (Al 2O 3)) for effective removing of the dissolved silica from cooling tower water. The batch test results indicated the combined HTC/AA is a more effective method for removing silica from CTW than using each of HTC or AA separately. The silica uptake was confirmed by Fourier transform infrared (FTIR), and Energy dispersive spectroscopy (EDS). Ourmore » results indicate HTC/AA effectively removes silica from cooling tower water (CTW), even in the presence of large concentrations of competing anions, such as Cl -, NO 3 - HCO 3 -, CO 3 2- and SO 4 2-. The Single Path Flow Through (SPFT) tests confirmed to rapid uptake of silica by combined HTC/AA during column filtration. The experimental data of silica adsorption fit best to Freundlich isotherm model.« less

Study on the Control Strategy of Ground Source Heat Pump of Complex Buildings

NASA Astrophysics Data System (ADS)

Dandan, Zhang; Wei, Li; Siyi, Tang

2018-05-01

The complex building group is a building group which integrates residential, business and office. Study on the operation of buried tube heat exchanger (BHE) with 30%, 50%, 70% and 100% occupancy rate by numerical simulation under the condition of full operation of the business and office, the optimal operation control strategy of a hybrid ground-source heat pump (HGSHP) system with different occupancy rates can be obtained. The results show that: at low occupancy rate the optimal operation control of the heat pump system is to use the cooling tower in the valley load period (June and September) and the heat absorption of the buried tube in winter; While at high occupancy rates, opening the cooling tower when the temperature of the outlet of the BHE is 2 degrees centigrade higher than the temperature of the wet bulb at the corresponding time is the optimal operating strategy. This paper is based on the annual energy consumption and optimization of soil temperature rise, which has an important guideline value for the design and operation of HGSHP system in complex buildings.

Exceptional selectivity for dissolved silicas in industrial waters using mixed oxides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sasan, Koroush; Brady, Patrick V.; Krumhansl, James L.

The removal of silica, ubiquitous in produced and industrial waters, by novel mixed oxides is investigated in this present study. We have combined the advantage of high selectivity hydrotalcite (HTC, (Mg 6Al 2(OH) 16(CO 3)·4H 2O)), with large surface area of active alumina (AA, (Al 2O 3)) for effective removing of the dissolved silica from cooling tower water. The batch test results indicated the combined HTC/AA is a more effective method for removing silica from CTW than using each of HTC or AA separately. The silica uptake was confirmed by Fourier transform infrared (FTIR), and Energy dispersive spectroscopy (EDS). Ourmore » results indicate HTC/AA effectively removes silica from cooling tower water (CTW), even in the presence of large concentrations of competing anions, such as Cl -, NO 3 - HCO 3 -, CO 3 2- and SO 4 2-. The Single Path Flow Through (SPFT) tests confirmed to rapid uptake of silica by combined HTC/AA during column filtration. The experimental data of silica adsorption fit best to Freundlich isotherm model.« less

How we went digital without a strategy.

PubMed

Semler, R

2000-01-01

Once you say what business you're in, you put your employees into a mental straitjacket and hand them a ready-made excuse for ignoring new opportunities. So rather than dictate his company's identity, Ricardo Semler--the majority owner of Semco in São Paulo, Brazil--lets his employees shape it through their individual efforts and interests. "I don't know what Semco is," he writes in this first-person account of his company's expansion from manufacturing to Internet services. "Nor do I want to know." Ten years ago, Semco employees who were selling cooling towers to owners of large commercial buildings heard customers complain about the high cost of maintaining the towers. The salespeople proposed a new business in cooling-tower maintenance, and the venture is now a $30 million property-management business. That initiative led to the creation, with Semco's support, of an on-line exchange to facilitate the management of commercial construction projects. The exchange is revolutionizing the construction process in Brazil and has become a springboard for further Web initiatives such as virtual trade shows. The author shares some of the lessons he has learned along the way: Forget about the top line. Never stop being a start-up. Don't be a nanny (treat your employees like adults). Let talent find its place. Make decisions quickly and openly when it comes to reviewing proposals for new businesses. And partner promiscuously: "Our partners," Semler says, "are as much a part of our company as our employees."

Regulation of sporicides under the European Biocidal Products Directive.

PubMed

Low, A

2011-03-01

Disinfectants (including sporicides) used in the healthcare setting fall within the scope of the European Biocidal Products Directive (98/8/EC). The active substances used in these products will be evaluated as part of an EU wide review programme, to determine whether they can be used in biocidal products without undue risks to humans, animals and the environment, and that these products will be effective. Following the review of an active substance, biocidal products containing the active substance will become subject to regulatory controls in all EU Member States. This paper discusses how the Directive operates, both through the review programme and the authorisation of biocidal products at the Member State level, together with the requirements to provide data on the efficacy of both the active substances and end-use biocidal products. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

Ecotoxicological Assessment of Immersion Samples from Façade Render Containing Free or Encapsulated Biocides.

PubMed

Vermeirssen, Etiënne L M; Campiche, Sophie; Dietschweiler, Conrad; Werner, Inge; Burkhardt, Michael

2018-05-22

To protect house façades from fouling by microorganisms, biocides can be added to a render or paint before it is applied. During driving rain events, these biocides gradually leach out and have the potential to pollute soil or aquatic ecosystems. We studied the leaching behaviour of biocides and toxicity of leachates from renders with either free or encapsulated biocides. Both render types contained equal amounts of terbutryn, 2-octyl-3(2H)-isothiazolinone (OIT) and 4,5-dichloro-2-n-octyl-4-isothiazolino-3-one (DCOIT). Leachate samples were generated over nine immersion cycles according to a European standard and biocides were quantified. The first and ninth samples were tested using bioassays with algae, bacteria and water flea, the first sample with earthworms and springtails. Encapsulation reduced leaching of terbutryn, OIT and DCOIT four-, 17-, and 27-fold. For aquatic organisms, the toxicity of water from render containing encapsulated biocides was always lower than that of render with free biocides. Furthermore, toxicity decreased four- to five-fold over the nine immersion cycles. Inhibition of photosynthesis was the most sensitive endpoint, followed by algal growth rate, bacterial bioluminescence and water flea reproduction. Toxicity to algae was explained by terbutryn and toxicity to bacteria by OIT. None of the samples affected soil organisms. Results demonstrate that combining standardised leaching tests with standardised bioassays is a promising approach to evaluate the ecotoxicity of biocides that leach from façade renders. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

NANOTECHNOLOGY: A NOVEL APPROACH TO PREVENT BIOCIDE LEACHING

EPA Science Inventory

This project will demonstrate the environmental benefits of introducing biocide into wood using hydrophobic nanoparticles as a delivery vehicle and controlled release device for organic and inorganic biocides. The primary benefits expected from use of nanoparticles as controll...

Molten Salt Power Tower Cost Model for the System Advisor Model (SAM)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turchi, C. S.; Heath, G. A.

2013-02-01

This report describes a component-based cost model developed for molten-salt power tower solar power plants. The cost model was developed by the National Renewable Energy Laboratory (NREL), using data from several prior studies, including a contracted analysis from WorleyParsons Group, which is included herein as an Appendix. The WorleyParsons' analysis also estimated material composition and mass for the plant to facilitate a life cycle analysis of the molten salt power tower technology. Details of the life cycle assessment have been published elsewhere. The cost model provides a reference plant that interfaces with NREL's System Advisor Model or SAM. The referencemore » plant assumes a nominal 100-MWe (net) power tower running with a nitrate salt heat transfer fluid (HTF). Thermal energy storage is provided by direct storage of the HTF in a two-tank system. The design assumes dry-cooling. The model includes a spreadsheet that interfaces with SAM via the Excel Exchange option in SAM. The spreadsheet allows users to estimate the costs of different-size plants and to take into account changes in commodity prices. This report and the accompanying Excel spreadsheet can be downloaded at https://sam.nrel.gov/cost.« less

Biocidal Efficacy of Dissolved Ozone, Formaldehyde and Sodium Hypochlorite Against Total Planktonic Microorganisms in Produced Water

NASA Astrophysics Data System (ADS)

Puyate, Y. T.; Rim-Rukeh, A.

The performance of three biocides (dissolved ozone, formaldehyde and sodium hypochlorite) in eliminating the bacteria and fungi in produced water is investigated experimentally. The analysis involves monitoring the microbial population in nine conical flasks each containing the same volume of a mixture of produced water, culture medium that sustains the growth of microorganisms and a known concentration of biocide. The concentrations of each biocide used in the study are 0.1, 0.2 and 0.5 ppm. It is shown that dissolved ozone exhibits the best biocidal characteristics and a concentration of 0.5 ppm eliminated all the microorganisms in the produced water after 150 min contact time.

Experimental measurement of cooling tower emissions using image processing of sensitive papers

NASA Astrophysics Data System (ADS)

Ruiz, J.; Kaiser, A. S.; Ballesta, M.; Gil, A.; Lucas, M.

2013-04-01

Cooling tower emissions are harmful for several reasons such as air polluting, wetting, icing and solid particle deposition, but mainly due to human health hazards (i.e. Legionella). There are several methods for measuring drift drops. This paper is focussed on the sensitive paper technique, which is suitable in low drift scenarios and real conditions. The lack of an automatic classification method motivated the development of a digital image process algorithm for the Sensitive Paper method. This paper presents a detailed description of this method, in which, drop-like elements are identified by means of the Canny edge detector combined with some morphological operations. Afterwards, the application of a J48 decision tree is proposed as one of the most relevant contributions. This classification method allows us to discern between stains whose origin is a drop and stains whose origin is not a drop. The method is applied to a real case and results are presented in terms of drift and PM10 emissions. This involves the calculation of the main features of the droplet distribution at the cooling tower exit surface in terms of drop size distribution data, cumulative mass distribution curve and characteristic drop diameters. The Log-normal and the Rosin-Rammler distribution functions have been fitted to the experimental data collected in the tests and it can been concluded that the first one is the most suitable for experimental data among the functions tested (whereas the second one is less suitable). Realistic PM10 calculations include the measurement of drift emissions and Total Dissolved Solids as well as the size and number of drops. Results are compared to the method proposed by the U.S. Environmental Protection Agency assessing its overestimation. Drift emissions have found to be 0.0517% of the recirculating water, which is over the Spanish standards limit (0.05%).

Leaching of biocides from building facades: Upscaling of a local two-region leaching model to the city scale

NASA Astrophysics Data System (ADS)

Coutu, S.; Rota, C.; Rossi, L.; Barry, D. A.

2011-12-01

Facades are protected by paints that contain biocides as protection against degradation. These biocides are leached by rainfall (albeit at low concentrations). At the city scale, however, the surface area of building facades is significant, and leached biocides are a potential environmental risk to receiving waters. A city-scale biocide-leaching model was developed based on two main steps. In the first step, laboratory experiments on a single facade were used to calibrate and validate a 1D, two-region phenomenological model of biocide leaching. The same data set was analyzed independently by another research group who found empirically that biocide leachate breakthrough curves were well represented by a sum of two exponentials. Interestingly, the two-region model was found analytically to reproduce this functional form as a special case. The second step in the method is site-specific, and involves upscaling the validated single facade model to a particular city. In this step, (i) GIS-based estimates of facade heights and areas are deduced using the city's cadastral data, (ii) facade flow is estimated using local meteorological data (rainfall, wind direction) and (iii) paint application rates are modeled as a stochastic process based on manufacturers' recommendations. The methodology was applied to Lausanne, Switzerland, a city of about 200,000 inhabitants. Approximately 30% of the annually applied mass of biocides was estimated to be released to the environment.

Biocides in hydraulic fracturing fluids: a critical review of their usage, mobility, degradation, and toxicity.

PubMed

Kahrilas, Genevieve A; Blotevogel, Jens; Stewart, Philip S; Borch, Thomas

2015-01-06

Biocides are critical components of hydraulic fracturing ("fracking") fluids used for unconventional shale gas development. Bacteria may cause bioclogging and inhibit gas extraction, produce toxic hydrogen sulfide, and induce corrosion leading to downhole equipment failure. The use of biocides such as glutaraldehyde and quaternary ammonium compounds has spurred a public concern and debate among regulators regarding the impact of inadvertent releases into the environment on ecosystem and human health. This work provides a critical review of the potential fate and toxicity of biocides used in hydraulic fracturing operations. We identified the following physicochemical and toxicological aspects as well as knowledge gaps that should be considered when selecting biocides: (1) uncharged species will dominate in the aqueous phase and be subject to degradation and transport whereas charged species will sorb to soils and be less bioavailable; (2) many biocides are short-lived or degradable through abiotic and biotic processes, but some may transform into more toxic or persistent compounds; (3) understanding of biocides' fate under downhole conditions (high pressure, temperature, and salt and organic matter concentrations) is limited; (4) several biocidal alternatives exist, but high cost, high energy demands, and/or formation of disinfection byproducts limits their use. This review may serve as a guide for environmental risk assessment and identification of microbial control strategies to help develop a sustainable path for managing hydraulic fracturing fluids.

Apparatus for production of ultrapure amorphous metals utilizing acoustic cooling

NASA Technical Reports Server (NTRS)

Lee, M. C. (Inventor)

1985-01-01

Amorphous metals are produced by forming a molten unit of metal and deploying the unit into a bidirectional acoustical levitating field or by dropping the unit through a spheroidizing zone, a slow quenching zone, and a fast quenching zone in which the sphere is rapidly cooled by a bidirectional jet stream created in the standing acoustic wave field produced between a half cylindrical acoustic driver and a focal reflector or a curved driver and a reflector. The cooling rate can be further augmented first by a cryogenic liquid collar and secondly by a cryogenic liquid jacket surrounding a drop tower. The molten unit is quenched to an amorphous solid which can survive impact in a unit collector or is retrieved by a vacuum chuck.

Considerations on Directive 98/8 of the European Commission - the biocide directive.

PubMed

Patryn, Rafał; Jarosz, Mirosław J; Włoszczak-Szubzda, Anna; Sak, Jarosław; Pawlikowski, Jakub

2011-01-01

Nowadays, versatile human activity requires the development of technologies in the chemical and biological industries that ultimately enable an increase in human activity, and help create the living conditions in the domain of human civilization. Increasing this activity very frequently requires the implementation of new technologies concerning the active elimination of numerous threats and obstacles which are found in the human and natural environment. The concept of so-called biocidal products has been introduced into the European legislation as long as ten years ago, defining them as various types of 'chemical substances or microorganisms which can deter, render harmless, or exert a controlling eff ect on any harmful organism, by chemical or biological means'. They can be added to other materials (typically liquids) to protect them against biological infestation and growth. Biocidal products - due to their specificity, toxicity and composition - create a serious risk for human and animal life and health, as well as for the natural environment, it is therefore fully justified to have legal regulations concerning such biocides. Because biocidal products are intended to kill living organisms, and as such, many biocidal products pose a significant risk to human health and welfare, and have significant adverse eff ects on the natural environment. Great care is required when handling biocides and appropriate protective clothing and equipment should be used. Currently, Directive 98/8/EC is a comprehensive set of legal regulations concerning biocidal products, their specificity, principles relating to their placing on the market, and guidelines for their control. It is worth emphasizing that Directive 98/8/EC implements the clampdown on poisoning cases with biocides, the duty of which was passed to the so-called Centres of Consultation and Toxicological Information. These centres provide round-the-clock (24-hour) medical consultation and assistance in cases of poisonings with these products. The presented study constitutes an in-depth presentation and analysis of the European law concerning biocides and the current regulations applying to them.

Bactericidal Specificity and Resistance Profile of Poly(Quaternary Ammonium) Polymers and Protein-Poly(Quaternary Ammonium) Conjugates.

PubMed

Ji, Weihang; Koepsel, Richard R; Murata, Hironobu; Zadan, Sawyer; Campbell, Alan S; Russell, Alan J

2017-08-14

Antibacterial polymers are potentially powerful biocides that can destroy bacteria on contact. Debate in the literature has surrounded the mechanism of action of polymeric biocides and the propensity for bacteria to develop resistance to them. There has been particular interest in whether surfaces with covalently coupled polymeric biocides have the same mechanism of action and resistance profile as similar soluble polymeric biocides. We designed and synthesized a series of poly(quaternary ammonium) polymers, with tailorable molecular structures and architectures, to engineer their antibacterial specificity and their ability to delay the development of bacterial resistance. These linear poly(quaternary ammonium) homopolymers and block copolymers, generated using atom transfer radical polymerization, had structure-dependent antibacterial specificity toward Gram positive and negative bacterial species. When single block copolymers contained two polymer segments of differing antibacterial specificity, the polymer combined the specificities of its two components. Nanoparticulate human serum albumin-poly(quaternary ammonium) conjugates of these same polymers, synthesized via "grafting from" atom transfer radical polymerization, were strongly biocidal and also exhibited a marked decrease in the rate of bacterial resistance development relative to linear polymers. These protein-biocide conjugates mimicked the behavior of surface-presented polycationic biocides rather than their nonproteinaceous counterparts.

40 CFR 430.76 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2014 CFR

2014-07-01

... limitations are only applicable at facilities where chlorophenolic-containing biocides are used. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides. Zinc limitations are only applicable at facilities where zinc...

40 CFR 430.76 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2013 CFR

2013-07-01

... limitations are only applicable at facilities where chlorophenolic-containing biocides are used. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides. Zinc limitations are only applicable at facilities where zinc...

40 CFR 430.65 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

...-continuous dischargers. Only facilities where chlorophenolic-containing biocides are used shall be subject to pentachlorophenol and trichlorophenol limitations. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart F [NSPS] Pollutant...

40 CFR 430.15 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

...-continuous dischargers. Only facilities where chlorophenolic-containing biocides are used shall be subject to pentachlorophenol and trichlorophenol limitations. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart A [NSPS] Pollutant...

40 CFR 430.45 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

...-continuous dischargers. Only facilities where chlorophenolic-containing biocides are used shall be subject to pentachlorophenol and trichlorophenol limitations. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart D [NSPS for...

40 CFR 430.35 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

...-continuous dischargers. Only facilities where chlorophenolic-containing biocides are used shall be subject to pentachlorophenol and trichlorophenol limitations. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart C [NSPS for...

Biocidal packaging for pharmaceuticals, foods, and other perishables.

PubMed

Larson, Alyssa M; Klibanov, Alexander M

2013-01-01

Many consumer goods must be protected from bacterial and fungal colonization to ensure their integrity and safety. By making these items' packaging biocidal, the interior environment can be preserved from microbial spoilage without altering the products themselves. Herein we briefly review this concept, referred to as active packaging, and discuss existing methods for constructing active packaging systems. They are based on either packaging materials that release biocides or those that are themselves intrinsically biocidal (or biostatic), with numerous variations within each category.

Combined treatments of enterocin AS-48 with biocides to improve the inactivation of methicillin-sensitive and methicillin-resistant Staphylococcus aureus planktonic and sessile cells.

PubMed

Caballero Gómez, Natacha; Abriouel, Hikmate; Grande, M José; Pérez Pulido, Rubén; Gálvez, Antonio

2013-05-15

Control of staphylococci during cleaning and disinfection is important to the food industry. Broad-spectrum bacteriocins with proved anti-staphylococcal activity, such as enterocin AS-48, could open new possibilities for disinfection in combination with biocides. In the present study, enterocin AS-48 was tested singly or in combination with biocides against a cocktail of six Staphylococcus aureus strains (including three methicillin-resistant strains) in planktonic state as well as in biofilms formed on polystyrene microtiter plates. Cells were challenged with enterocin, biocides or enterocin/biocide combinations. Inactivation of planktonic cells increased significantly (p<0.05) when enterocin AS-48 (25mg/l) was tested in combination with benzalkonium chloride (BC), cetrimide (CT) and hexadecylpyridinium chloride (HDP), and non-significantly in combination with didecyldimethylammonium bromide (AB), triclosan (TC), hexachlorophene (CF), polyhexamethylen guanidinium chloride (PHMG), chlorhexidine (CH) or P3-oxonia (OX). In the sessile state (24h biofilms), staphylococci required higher biocide concentrations in most cases, except for OX. Inactivation of sessile staphylococci increased remarkably when biocides were applied in combination with enterocin AS-48, especially when the bacteriocin was added at 50mg/l. During storage, the concentrations of sessile as well as planktonic cells in the treated samples decreased remarkably for BC, TC and PHMG, but OX failed to inhibit proliferation of the treated biofilms as well as growth of planktonic cells. The observed inhibitory effects during storage were potentiated when the biocides were combined with 50 mg/l enterocin AS-48. Results from this study suggest that selected combinations of enterocin AS-48 and biocides offer potential use against planktonic and sessile, methicillin-sensitive and methicillin-resistant S. aureus. Copyright © 2013 Elsevier B.V. All rights reserved.

Assessment of Silver Based Disinfection Technology for CEV and Future US Spacecraft

NASA Technical Reports Server (NTRS)

Callahan, Michael R.; Adam, Niklas M.; Roberts, Michael S.; Garland, Jay L.; Sager, John C.; Pickering, Karen D.

2007-01-01

Silver biocide offers a potential advantage over iodine, the current state-of-the-art in US spacecraft disinfection technology, in that silver can be safely consumed by the crew. As such, silver may reduce the overall complexity and mass of future spacecraft potable water systems, particularly those used to support long duration missions. A primary technology gap identified for the use of silver biocide is one of material compatibility. Wetted materials of construction are required to be selected such that silver ion concentrations can be maintained at biocidally effective levels. Preliminary data on silver biocide depletion rates in heritage spacecraft potable water system wetted-materials of construction has been gathered as part of a multi-phase test project aimed at the characterization of silver based biocide technology through: development of preferred materials lists, investigation of silver biocide forms and delivery methods, down-selection of silver biocide technologies, and integrated testing. A 10% - 20% loss in silver ion concentration per day was observed for acid passivated Nitronic 40 tubing with surface area to volume (S/V) ratios of approximately 4.59 cm-1. The Nitronic 40 tubes were tested both with and without biocide pretreatment. Silver biocide depletion was also observed at approximately 0.1% per day for the first 35 days of exposure to acid passivated Inconel 718 coupon, S/V of approximately 0.14 cm-1. Surface analysis by scanning election microscopy (SEM) suggested deposition of silver metal on both test materials. SEM analysis also provided evidence of potential variability in the passivation process for tube configuration of the Nitronic 40 test apparatus. These preliminary results are presented and discussed herein, along with the current project status.

Biocides in hydraulic fracturing: A comparison to agricultural and assessment of hazard and vulnerability with respect to groundwater pollution

NASA Astrophysics Data System (ADS)

Worrall, Fred; Wilson, Miles; Davies, Richard

2017-04-01

Biocides are one possible chemical additive to frack fluids and their role is to control bacterial growth. Since biocides are designed to be toxic to particular organisms, their accidental or deliberate release into the environment has become a growing topic of concern, especially with regards to fracking. The objective of this study was to consider whether biocides proposed for use in fracking, could be a threat to English groundwater based on past groundwater monitoring data. The study considered all groundwater samples analysed for biocides in English groundwater between 2005 and 2014. The monitoring records were compared to: records of application (both amount and area); and chemical and molecular data for the biocides. The study did not use traditional adsorption and degradation data as these parameters are prone to variability and are not pure molecular parameters. The study showed that of the 110 biocides tested for in English groundwaters in the decade 2005 - 2014. The total number of detections was 2234 out of 1475000 observations of 95 compounds, and 38 were compounds that were not applied during the period of record. The detection of these 38 compounds did not decline over the 10 year period implying very long residence times and that once compounds do pollute an aquifer, then they will be a persistent problem. The study was able to develop binomial regression models of the probability of detecting pesticide in groundwater based upon molecular and application variables; and solely upon molecular properties. The solubility of the range of biocides used in frack fluids would imply a potentially higher hazard than for most agricultural biocides, but molecular modelling implied that one compound could be safer than others.

40 CFR 430.105 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... apply to non-continuous dischargers. Only facilities where chlorophenolic-containing biocides are used... chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart J [NSPS for secondary fiber non-deink facilities where paperboard from wastepaper is...

40 CFR 430.115 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

...-containing biocides are used shall be subject to pentachlorophenol and trichlorophenol limitations. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart K [NSPS for non-integrated mills where fine paper is...

Chemistry of Durable and Regenerable Biocidal Textiles

ERIC Educational Resources Information Center

Gang Sun; Worley, S. Dave

2005-01-01

Antimicrobial textiles can be categorized into two groups, biocidal and biostatic materials, according to their functions. Biostatic functions refer to inhibiting growth of microorganisms on textiles and preventing the materials from biodegradation and biocidal materials are able to kill microorganisms, thus eliminating their growth, sterilizing…

Crew Exploration Vehicle Potable Water System Verification Description

NASA Technical Reports Server (NTRS)

Tuan, George; Peterson, Laurie J.; Vega, Leticia M.

2010-01-01

A stored water system on the crew exploration vehicle (CEV) will supply the crew with potable water for: drinking and food rehydration, hygiene, medical needs, sublimation, and various contingency situations. The current baseline biocide for the stored water system is ionic silver, similar in composition to the biocide used to maintain the quality of the water, transferred from the orbiter to the International Space Station, stored in contingency water containers. In the CEV water system, a depletion of the ionic silver biocide is expected due to ionic silver-plating onto the surfaces of materials within the CEV water system, thus negating its effectiveness as a biocide. Because this may be the first time NASA is considering a stored water system for long-term missions that do not maintain a residual biocide, a team of experts in materials compatibility, biofilms and point-of-use filters, surface treatment and coatings, and biocides has been created to pinpoint concerns and perform the testing that will help alleviate concerns related to the CEV water system.

Study of flow around model of cooling tower by means of 2D Particle Image Velocimetry measurement

NASA Astrophysics Data System (ADS)

Barraclough, Veronika; Novotný, Jan; Šafařík, Pavel

This paper deals with flow around a bluff body of hyperboloid shape. It combines results gathered in the course of research by means of Particle Image Velocimetry (PIV). The experiments were carried out by means of low-frequency 2D PIV and the Reynolds number was 43 000.

Determination of the Heat and Mass Transfer Efficiency at the Contact Stage of a Jet-Film Facility

NASA Astrophysics Data System (ADS)

Dmitrieva, O. S.; Madyshev, I. N.; Dmitriev, A. V.

2017-05-01

A contact jet-film facility has been developed for increasing the efficiency of operation of industrial cooling towers. The results of experimental and analytical investigation of the operation of this facility, its hydraulic resistance, and of the heat and mass transfer efficiency of its contact stage are presented.

NREL, Hewlett-Packard Developed Ultra-Efficient, High-Performance Computing

Science.gov Websites

and allows the heat captured from the supercomputer to provide all the heating needs for the Energy Systems Integration Facility. And there's even enough heat left over to melt snow outside on sidewalks during the winter. During the summer, the unused heat can be rejected via cooling towers. R&D

75 FR 16732 - Action Affecting Export Privileges; Aqua-Loop Cooling Towers, Co.

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-02

... Regulations by facilitating or coordinating the export of approximately 174 rolls of hog hair filter media... about September 28, 2004, Aqua-Loop ordered or financed approximately 174 rolls of hog hair filter media... coordinating the export of approximately 185 rolls of hog hair filter media, part number HHB6O 130 and valued...

40 CFR Table 4 to Subpart F of... - Organic Hazardous Air Pollutants Subject to Cooling Tower Monitoring Requirements in § 63.104

Code of Federal Regulations, 2011 CFR

2011-07-01

... STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emission Standards for Organic Hazardous Air Pollutants From the Synthetic Organic Chemical Manufacturing Industry Pt. 63, Subpt. F, Table... 40 Protection of Environment 9 2011-07-01 2011-07-01 false Organic Hazardous Air Pollutants...

40 CFR Table 4 to Subpart F of... - Organic Hazardous Air Pollutants Subject to Cooling Tower Monitoring Requirements in § 63.104

Code of Federal Regulations, 2014 CFR

2014-07-01

... STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emission Standards for Organic Hazardous Air Pollutants From the Synthetic Organic Chemical Manufacturing Industry Pt. 63, Subpt. F, Table... 40 Protection of Environment 10 2014-07-01 2014-07-01 false Organic Hazardous Air Pollutants...

40 CFR Table 4 to Subpart F of... - Organic Hazardous Air Pollutants Subject to Cooling Tower Monitoring Requirements in § 63.104

Code of Federal Regulations, 2013 CFR

2013-07-01

... STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emission Standards for Organic Hazardous Air Pollutants From the Synthetic Organic Chemical Manufacturing Industry Pt. 63, Subpt. F, Table... 40 Protection of Environment 10 2013-07-01 2013-07-01 false Organic Hazardous Air Pollutants...

75 FR 63802 - Action Affecting Export Privileges; Parto Abgardan Cooling Towers Co.

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-18

... to prevent evasion, certain types of orders under [Part 766] may be made applicable not only to the... order to prevent evasion of that denial order, the Assistant Secretary shall issue or amend the order... the Denial Order is justified in order to prevent evasion of that Order. I find that BIS has presented...

Short Shot Tower for Silicon

NASA Technical Reports Server (NTRS)

Bates, H. E.; Hill, D. M.; Jewett, D. N.

1983-01-01

Drop length necessary to convert molten silicon to shot reduced by proposed new process. Conversion of silicon from powder or chunks to shot often simplifies processing. Shot is more easily handled in most processing equipment. Drops of liquid silicon fall through protective cloud of argon, then through rapidly cooling bath of methanol, where they quickly turn into solid shot.

77 FR 11390 - Delegation of National Emission Standards for Hazardous Air Pollutants for Source Categories; Nevada

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-27

... Tanks. O Ethylene Oxide X X X Sterilization Facilities. Q Industrial Process Cooling X X Towers. R... Organic-Water Separators. WW Storage Vessels (Tanks)-- X X Control Level 2. XX Ethylene Manufacturing X X... Refractory Products X X Manufacturing. TTTTT Primary Magnesium Refining. X WWWWW Hospital Ethylene Oxide X X...

Modeling of facade leaching in urban catchments

NASA Astrophysics Data System (ADS)

Coutu, S.; Del Giudice, D.; Rossi, L.; Barry, D. A.

2012-12-01

Building facades are protected from microbial attack by incorporation of biocides within them. Flow over facades leaches these biocides and transports them to the urban environment. A parsimonious water quantity/quality model applicable for engineered urban watersheds was developed to compute biocide release from facades and their transport at the urban basin scale. The model couples two lumped submodels applicable at the basin scale, and a local model of biocide leaching at the facade scale. For the facade leaching, an existing model applicable at the individual wall scale was utilized. The two lumped models describe urban hydrodynamics and leachate transport. The integrated model allows prediction of biocide concentrations in urban rivers. It was applied to a 15 km2urban hydrosystem in western Switzerland, the Vuachère river basin, to study three facade biocides (terbutryn, carbendazim, diuron). The water quality simulated by the model matched well most of the pollutographs at the outlet of the Vuachère watershed. The model was then used to estimate possible ecotoxicological impacts of facade leachates. To this end, exceedance probabilities and cumulative pollutant loads from the catchment were estimated. Results showed that the considered biocides rarely exceeded the relevant predicted no-effect concentrations for the riverine system. Despite the heterogeneities and complexity of (engineered) urban catchments, the model application demonstrated that a computationally "light" model can be employed to simulate the hydrograph and pollutograph response within them. It thus allows catchment-scale assessment of the potential ecotoxicological impact of biocides on receiving waters.

Nanotechnology : implications for the wood preservation industry

Treesearch

Carol A. Clausen

2007-01-01

Nanotechnology has the potential to greatly impact the wood protection industry through the creation of nanomaterials with unique properties. Nanobiocides may find applications as co-biocides, or may alter treatability properties such as penetration and biocide distribution. Nanocarrier delivery systems may increase the applications for organic biocides through...

40 CFR 430.16 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2013 CFR

2013-07-01

... pretreatment standards for existing sources (PSES) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides. PSES must be attained on or before July 1, 1984: Subpart A [PSES...

40 CFR 430.107 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... standards for new sources (PSNS) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart J [PSNS for secondary fiber non-deink facilities where paperboard from wastepaper is...

40 CFR 430.16 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2014 CFR

2014-07-01

... pretreatment standards for existing sources (PSES) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides. PSES must be attained on or before July 1, 1984: Subpart A [PSES...

40 CFR 430.77 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2014 CFR

2014-07-01

... applicable at facilities where chlorophenolic-containing biocides are used. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides. Zinc limitations are only applicable at facilities where zinc hydrosulfite is used as a bleaching...

40 CFR 430.37 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... standards for new sources (PSNS) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart C [PSNS for unbleached kraft facilities where linerboard is produced] Pollutant or...

40 CFR 430.96 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2013 CFR

2013-07-01

... pretreatment standards for existing sources (PSES) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides. PSES must be attained on or before July 1, 1984: Subpart I [Facilities...

40 CFR 430.77 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... applicable at facilities where chlorophenolic-containing biocides are used. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides. Zinc limitations are only applicable at facilities where zinc hydrosulfite is used as a bleaching...

40 CFR 430.97 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... for new sources (PSNS) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart I [Facilities where fine paper is produced] Pollutant or pollutant property PSNS Maximum...

40 CFR 430.95 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... apply to non-continuous dischargers. Only facilities where chlorophenolic-containing biocides are used... chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart I [Facilities where fine paper is produced] [NSPS] Pollutant or pollutant property Kg/kkg...

Biocidal Energetic Materials for the Destruction of Spore Forming Bacteria

DTIC Science & Technology

2015-07-01

Bacteria Spore Gas Antibacterial Thermal Unclassified Unclassified Unclassified SAR 47 Suhithi Peiris...naturally antibacterial and biocidal properties using combustion synthesis of mildly energetic reactants; and, (2) engineering an aerosolized spray...of biocidal gases using unique a deflagration synthesis approach. Accomplishments for all years: Major Activity 1: Creating highly porous

40 CFR 430.66 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2013 CFR

2013-07-01

... standards for existing sources (PSES) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides. PSES must be attained on or before July 1, 1984: Subpart F Pollutant or pollutant property PSES...

40 CFR 430.46 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2013 CFR

2013-07-01

... pretreatment standards for existing sources (PSES) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides. PSES must be attained on or before July 1, 1984: Subpart D [PSES for...

40 CFR 430.36 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2013 CFR

2013-07-01

... pretreatment standards for existing sources (PSES) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using those biocides. PSES must be attained on or before July 1, 1984: Subpart C [PSES for...

40 CFR 430.66 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2014 CFR

2014-07-01

... standards for existing sources (PSES) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides. PSES must be attained on or before July 1, 1984: Subpart F Pollutant or pollutant property PSES...

40 CFR 430.34 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

... biocides are used must achieve the following effluent limitations representing the degree of effluent...-continuous dischargers. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart C [BAT effluent limitations for...

40 CFR 430.104 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

... chlorophenolic-containing biocides are used must achieve the following effluent limitations representing the... applicable to non-continuous dischargers. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart J [BAT effluent...

40 CFR 430.64 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

... biocides are used must achieve the following effluent limitations representing the degree of effluent...-continuous dischargers. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart F Pollutant or pollutant property BAT...

40 CFR 430.14 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

... biocides are used must achieve the following effluent limitations representing the degree of effluent...-continuous dischargers. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart A [BAT effluent limitations] Pollutant...

40 CFR 430.44 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

... biocides are used must achieve the following effluent limitations representing the degree of effluent...-continuous dischargers. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart D [BAT effluent limitations for...

40 CFR 430.94 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

... chlorophenolic-containing biocides are used must achieve the following effluent limitations representing the... applicable to non-continuous dischargers. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart I [Facilities...

Analysis of metal and biocides resistance genes in drug resistance and susceptible Salmonella enterica from food animals

USDA-ARS?s Scientific Manuscript database

Background Generally drug resistant bacteria carry antibiotic resistance genes and heavy metal and biocide resistance genes on large conjugative plasmids. The presence of these metal and biocide resistance genes in susceptible bacteria are not assessed comprehensively. Hence, WGS data of susceptib...

SOLUBILITY OF ORGANIC BIOCIDES IN SUPERCRITICAL CO2 AND CO2+ COSOLVENT MIXTURES

EPA Science Inventory

Solubilities of four organic biocides in supercritical carbon dioxide (Sc-CO2) were measured using a dynamic flowr apparatus over a pressure range of 10 to 30 MPa and temperature of 35-80 degrees C. The biocides studied were: Amical-48 (diiodomethyl p-tolyl sulfone), chlorothalo...

Formulation of Biocides Increases Antimicrobial Potency and Mitigates the Enrichment of Nonsusceptible Bacteria in Multispecies Biofilms

PubMed Central

Forbes, Sarah; Cowley, Nicola; Mistry, Hitesh; Amézquita, Alejandro

2017-01-01

ABSTRACT The current investigation aimed to generate data to inform the development of risk assessments of biocide usage. Stabilized domestic drain biofilm microcosms were exposed daily over 6 months to increasing concentrations (0.01% to 1%) of the biocide benzalkonium chloride (BAC) in a simple aqueous solution (BAC-s) or in a complex formulation (BAC-f) representative of a domestic cleaning agent. Biofilms were analyzed by culture, differentiating by bacterial functional group and by BAC or antibiotic susceptibility. Bacterial isolates were identified by 16S rRNA sequencing, and changes in biofilm composition were assessed by high-throughput sequencing. Exposure to BAC-f resulted in significantly larger reductions in levels of viable bacteria than exposure to BAC-s, while bacterial diversity greatly decreased during exposure to both BAC-s and BAC-f, as evidenced by sequencing and viable counts. Increases in the abundance of bacteria exhibiting reduced antibiotic or BAC susceptibility following exposure to BAC at 0.1% were significantly greater for BAC-s than BAC-f. Bacteria with reduced BAC and antibiotic susceptibility were generally suppressed by higher BAC concentrations, and formulation significantly enhanced this effect. Significant decreases in the antimicrobial susceptibility of bacteria isolated from the systems before and after long-term BAC exposure were not detected. In summary, dose-dependent suppression of bacterial viability by BAC was enhanced by formulation. Biocide exposure decreased bacterial diversity and transiently enriched populations of organisms with lower antimicrobial susceptibility, and the effects were subsequently suppressed by exposure to 1% BAC-f, the concentration most closely reflecting deployment in formulated products. IMPORTANCE Assessment of the risks of biocide use has been based mainly on the exposure of axenic cultures of bacteria to biocides in simple aqueous solutions. The current investigation aimed to assess the effects of formulation on the outcome of biocide exposure in multispecies biofilms. Formulation of the cationic biocide BAC significantly increased antimicrobial potency. Bacteria with lower antimicrobial susceptibility whose populations were enriched after low-level biocide exposure were more effectively suppressed by the biocide at in-use concentrations (1% [wt/vol]) in a formulation than in a simple aqueous solution. These observations underline the importance of simulating normal deployment conditions in considering the risks and benefits of biocide use. PMID:28115386

ICPSU Install onto Mobile Launcher - Preps for Lift

NASA Image and Video Library

2018-03-15

The mobile launcher (ML) tower is lit up before early morning sunrise at NASA's Kennedy Space Center in Florida. Preparations are underway to lift and install the Interim Cryogenic Propulsion Stage Umbilical (ICPSU) at about the 240-foot-level on the tower. The last of the large umbilicals to be installed, the ICPSU will provide super-cooled hydrogen and liquid oxygen to the Space Launch System (SLS) rocket's interim cryogenic propulsion stage, or upper stage, at T-0 for Exploration Mission-1. The umbilical will supply fuel, oxidizer, gaseous helium, hazardous gas leak detection, electrical commodities and environment control systems to the upper stage of the SLS rocket during launch. Exploration Ground Systems is overseeing installation of the umbilicals on the ML.

Direct injection GC method for measuring light hydrocarbon emissions from cooling-tower water.

PubMed

Lee, Max M; Logan, Tim D; Sun, Kefu; Hurley, N Spencer; Swatloski, Robert A; Gluck, Steve J

2003-12-15

A Direct Injection GC method for quantifying low levels of light hydrocarbons (C6 and below) in cooling water has been developed. It is intended to overcome the limitations of the currently available technology. The principle of this method is to use a stripper column in a GC to strip waterfrom the hydrocarbons prior to entering the separation column. No sample preparation is required since the water sample is introduced directly into the GC. Method validation indicates that the Direct Injection GC method offers approximately 15 min analysis time with excellent precision and recovery. The calibration studies with ethylene and propylene show that both liquid and gas standards are suitable for routine calibration and calibration verification. The sampling method using zero headspace traditional VOA (Volatile Organic Analysis) vials and a sample chiller has also been validated. It is apparent that the sampling method is sufficient to minimize the potential for losses of light hydrocarbons, and samples can be held at 4 degrees C for up to 7 days with more than 93% recovery. The Direct Injection GC method also offers <1 ppb (w/v) level method detection limits for ethylene, propylene, and benzene. It is superior to the existing El Paso stripper method. In addition to lower detection limits for ethylene and propylene, the Direct Injection GC method quantifies individual light hydrocarbons in cooling water, provides better recoveries, and requires less maintenance and setup costs. Since the instrumentation and supplies are readily available, this technique could easily be established as a standard or alternative method for routine emission monitoring and leak detection of light hydrocarbons in cooling-tower water.

Correlation between antibiotic and biocide resistance in mesophilic and psychrotrophic Pseudomonas spp. isolated from slaughterhouse surfaces throughout meat chain production.

PubMed

Lavilla Lerma, Leyre; Benomar, Nabil; Casado Muñoz, María del Carmen; Gálvez, Antonio; Abriouel, Hikmate

2015-10-01

The aim of this study was to evaluate biocide susceptibility in mesophilic and psychrotrophic pseudomonads isolated from surfaces of a goat and lamb slaughterhouse, which was representative of the region. To determine biocide resistance in pseudomonads, we determined for the first time the epidemiological cut-off values (ECOFFs) of benzalkonium, cetrimide, chlorhexidine, hexachlorophene, P3 oxonia, polyhexamethylene guanidine hydrochloride (PHMG), topax 66 and triclosan being generally very similar in different Pseudomonas spp. with some exceptions. Thus, resistance of pseudomonads was mainly shown to triclosan, and in lesser extent to cetrimide and benzalkonium chloride depending on the species, however they were highly susceptible to industrial formulations of biocides. By means of statistical analysis, positive correlations between antibiotics, biocides and both antimicrobials in pseudomonads were detected suggesting a co- or cross resistance between different antimicrobials in goat and lamb slaughterhouse environment. Cross-resistance between biocides and antibiotics in pseudomonads were especially detected between PHMG or triclosan and different antibiotics depending on the biocide and the population type. Thus, the use of those biocides as disinfectant in slaughterhouse zones must be carefully evaluated because of the selection pressure effect of antimicrobials on the emergence of resistant bacteria which could be spread to the consumer. It is noteworthy that specific industrial formulations such as topax 66 and oxonia P3 showed few correlations with antibiotics (none or 1-2 antibiotics) which should be taken into consideration for disinfection practices in goat and lamb slaughterhouse. Copyright © 2015 Elsevier Ltd. All rights reserved.

Leaching of biocides used in façade coatings under laboratory test conditions.

PubMed

Schoknecht, Ute; Gruycheva, Jana; Mathies, Helena; Bergmann, Hannelore; Burkhardt, Michael

2009-12-15

The European Biocidal Products Directive 98/8/EC requires a risk assessment concerning possible effects of active ingredients on the environment. Biocides can be leached from treated materials exposed to outdoor use. These emissions have to be estimated and evaluated during the authorization procedure. Different immersion and irrigation tests were performed to investigate leaching of biocides from façade coatings. Several marketed formulations of textured coatings and paints spiked with a mixture of commonly used active ingredients (OIT, DCOIT, IPBC, carbendazim, isoproturon, diuron, terbutryn, and Irgarol 1051) were investigated. The emission process can be described by time-dependent functions that depend on the test conditions. The results of all test procedures confirm that leachability is related to water solubility and n-octanol-water partition coefficient of the active ingredients and that leaching of biocides from façade coatings is mainly a diffusion controlled process. Other factors like the composition of the product, availability and transport of water, concentration of active ingredients in the coatings, as well as UV-exposure of the coatings influence biocide emissions.

40 CFR 63.99 - Delegated Federal authorities.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (stage 1) R X 9 Pulp & Paper I S X 10 Halogenated Solvent Cleaning T X 11 Polymer & Resins 1 U X 12... Sterilization O X 7 Chromium Cooling Towers Q X 8 Gasoline Distribution (stage 1) R X 9 Pulp & Paper I S X 10... R Gasoline Distribution X S Pulp & Paper MACT I X T Halogenated Solvent X U Polymers & Resins/Group...

Gas-Bearing Crucible for Shot Tower

NASA Technical Reports Server (NTRS)

Youngberg, C. L.; Miller, C. G.; Stephens, J. B.; Finnerty, A. A.

1983-01-01

Device protects molten drops from contamination and distortion. Gas flowing through levitator tube levitates small balls while they melt. Gas heated by filament extending through center of tube. Gas bearing crucible on tube has concave configuration to hold single relatively large ball or many recesses to hold many small balls. By time spheres reach foam, they are cooled sufficiently by radiation to retain their shape.

Distribution of monoclonal antibody subgroups and sequence-based types among Legionella pneumophila serogroup 1 isolates derived from cooling tower water, bathwater, and soil in Japan.

PubMed

Amemura-Maekawa, Junko; Kikukawa, Kiyomi; Helbig, Jürgen H; Kaneko, Satoko; Suzuki-Hashimoto, Atsuko; Furuhata, Katsunori; Chang, Bin; Murai, Miyo; Ichinose, Masayuki; Ohnishi, Makoto; Kura, Fumiaki

2012-06-01

Legionella pneumophila serogroup (SG) 1 is the most frequent cause of legionellosis. This study analyzed environmental isolates of L. pneumophila SG 1 in Japan using monoclonal antibody (MAb) typing and sequence-based typing (SBT). Samples were analyzed from bathwater (BW; n = 50), cooling tower water (CT; n = 50), and soil (SO; n = 35). The distribution of MAb types varied by source, with the most prevalent types being Bellingham (42%), Oxford (72%), and OLDA (51%) in BW, CT, and SO, respectively. The ratios of MAb 3/1 positive isolates were 26, 2, and 14% from BW, CT, and SO, respectively. The environmental isolates from BW, CT, and SO were divided into 34 sequence types (STs; index of discrimination [IOD] = 0.973), 8 STs (IOD = 0.448), and 11 STs (IOD = 0.879), respectively. Genetic variation among CT isolates was smaller than seen in BW and SO. ST1 accounted for 74% of the CT isolates. The only common STs between (i) BW and CT, (ii) BW and SO, and (iii) CT and SO were ST1, ST129, and ST48, respectively, suggesting that each environment constitutes an independent habitat.

Treatment of cooling tower blowdown water containing silica, calcium and magnesium by electrocoagulation.

PubMed

Liao, Z; Gu, Z; Schulz, M C; Davis, J R; Baygents, J C; Farrell, J

2009-01-01

This research investigated the effectiveness of electrocoagulation using iron and aluminium electrodes for treating cooling tower blowdown (CTB) waters containing dissolved silica (Si(OH)(4)), Ca(2 + ) and Mg(2 + ). The removal of each target species was measured as a function of the coagulant dose in simulated CTB waters with initial pH values of 5, 7, and 9. Experiments were also performed to investigate the effect of antiscaling compounds and coagulation aids on hardness ion removal. Both iron and aluminum electrodes were effective at removing dissolved silica. For coagulant doses < or =3 mM, silica removal was a linear function of the coagulant dose, with 0.4 to 0.5 moles of silica removed per mole of iron or aluminium. Iron electrodes were only 30% as effective at removing Ca(2 + ) and Mg(2 + ) as compared to silica. There was no measurable removal of hardness ions by aluminium electrodes in the absence of organic additives. Phosphonate based antiscaling compounds were uniformly effective at increasing the removal of Ca(2 + ) and Mg(2 + ) by both iron and aluminium electrodes. Cationic and amphoteric polymers used as coagulation aids were also effective at increasing hardness ion removal.

KENNEDY SPACE CENTER, FLA. - Workers on Launch Complex 17-B, Cape Canaveral Air Force Station, prepare the first stage of a Delta II rocket for its lift up the mobile service tower. The rocket is being erected to launch the Space InfraRed Telescope Facility (SIRTF). Consisting of an 0.85-meter telescope and three cryogenically cooled science instruments, SIRTF is one of NASA's largest infrared telescopes to be launched. SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space. Most of this infrared radiation is blocked by the Earth's atmosphere and cannot be observed from the ground.

NASA Image and Video Library

2003-07-18

KENNEDY SPACE CENTER, FLA. - Workers on Launch Complex 17-B, Cape Canaveral Air Force Station, prepare the first stage of a Delta II rocket for its lift up the mobile service tower. The rocket is being erected to launch the Space InfraRed Telescope Facility (SIRTF). Consisting of an 0.85-meter telescope and three cryogenically cooled science instruments, SIRTF is one of NASA's largest infrared telescopes to be launched. SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space. Most of this infrared radiation is blocked by the Earth's atmosphere and cannot be observed from the ground.

KENNEDY SPACE CENTER, FLA. - On Launch Complex 17-B, Cape Canaveral Air Force Station, the first stage of a Delta II rocket is moved into the mobile service tower. The rocket is being erected to launch the Space InfraRed Telescope Facility (SIRTF). Consisting of an 0.85-meter telescope and three cryogenically cooled science instruments, SIRTF is one of NASA's largest infrared telescopes to be launched. SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space. Most of this infrared radiation is blocked by the Earth's atmosphere and cannot be observed from the ground.

NASA Image and Video Library

2003-07-18

KENNEDY SPACE CENTER, FLA. - On Launch Complex 17-B, Cape Canaveral Air Force Station, the first stage of a Delta II rocket is moved into the mobile service tower. The rocket is being erected to launch the Space InfraRed Telescope Facility (SIRTF). Consisting of an 0.85-meter telescope and three cryogenically cooled science instruments, SIRTF is one of NASA's largest infrared telescopes to be launched. SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space. Most of this infrared radiation is blocked by the Earth's atmosphere and cannot be observed from the ground.

KENNEDY SPACE CENTER, FLA. - On Launch Complex 17-B, Cape Canaveral Air Force Station, the first stage of a Delta II rocket is nearly erect for its move into the mobile service tower. The rocket is being erected to launch the Space InfraRed Telescope Facility (SIRTF). Consisting of an 0.85-meter telescope and three cryogenically cooled science instruments, SIRTF is one of NASA's largest infrared telescopes to be launched. SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space. Most of this infrared radiation is blocked by the Earth's atmosphere and cannot be observed from the ground.

NASA Image and Video Library

2003-07-18

KENNEDY SPACE CENTER, FLA. - On Launch Complex 17-B, Cape Canaveral Air Force Station, the first stage of a Delta II rocket is nearly erect for its move into the mobile service tower. The rocket is being erected to launch the Space InfraRed Telescope Facility (SIRTF). Consisting of an 0.85-meter telescope and three cryogenically cooled science instruments, SIRTF is one of NASA's largest infrared telescopes to be launched. SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space. Most of this infrared radiation is blocked by the Earth's atmosphere and cannot be observed from the ground.

KENNEDY SPACE CENTER, FLA. - On Launch Complex 17-B, Cape Canaveral Air Force Station, the first stage of a Delta II rocket waits to be lifted up into the mobile service tower. The rocket is being erected to launch the Space InfraRed Telescope Facility (SIRTF). Consisting of an 0.85-meter telescope and three cryogenically cooled science instruments, SIRTF is one of NASA's largest infrared telescopes to be launched. SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space. Most of this infrared radiation is blocked by the Earth's atmosphere and cannot be observed from the ground.

NASA Image and Video Library

2003-07-18

KENNEDY SPACE CENTER, FLA. - On Launch Complex 17-B, Cape Canaveral Air Force Station, the first stage of a Delta II rocket waits to be lifted up into the mobile service tower. The rocket is being erected to launch the Space InfraRed Telescope Facility (SIRTF). Consisting of an 0.85-meter telescope and three cryogenically cooled science instruments, SIRTF is one of NASA's largest infrared telescopes to be launched. SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space. Most of this infrared radiation is blocked by the Earth's atmosphere and cannot be observed from the ground.

Legionnaires' Disease Bacteria in power plant cooling systems: downtime report. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tyndall, R.L.; Solomon, J.A.; Christensen, S.W.

1985-04-01

Legionnaires' Disease Bacteria (Legionella) are a normal part of the aquatic community that, when aerosolized, can be pathogenic to man. The downtime study was designed to determine the degree to which Legionella populations are aerosolized during cleaning and maintenance operations in a closed-cycle steam-electric power plant. Both high-volume and impinger air samples were collected prior to and during downtime operations. Emphasis was placed on sampling inside or adjacent to water boxes, condensers, and cooling towers. Control air samples were taken upwind from the plant site. Water and sludge samples were also collected at various locations. In the laboratory, the concentrationsmore » of Groups A, B, and C Legionella were determined using the direct fluorescent antibody method. All positive air samples, and other selected air samples, were injected into guinea pigs to detect infectious Legionella. Legionella could be detected in only 12 of the 126 air samples collected. These were predominantly Group A Legionella (L. pneumophila, serogroups 1 to 6). All 12 positive samples had been collected in the vicinity of water boxes, condensers, detention ponds, and cooling towers during downtime operations where aerosolization of Legionella populations would be expected. None of the air samples yielded infectious Legionella when injected into guinea pigs. Detection of Legionella in air samples taken during downtime was significantly more likely than detection during normal operating conditions (p <0.01). 13 refs., 4 figs., 10 tabs.« less

Silver biocide's real-world success.

PubMed

Pearson, Susan

2015-03-01

Although temperature control has been the UK's longest-serving means of controlling the growth and proliferation of Legionella in hot and cold water systems, there are other factors, including major rises in energy costs, that warrant the use of biocides--including in the healthcare sector. In 2000, the HSE's new 'L8' guidelines took this into account, giving equal weight to both temperature reg~mes and biocides, such as chlorine dioxide, as control methods. Susan Pearson BSc reports on one potentially effective biocide- silver hydrogen peroxide, explains how it 'works' in practice, and highlights the recent 'real-world' evidence of its effectiveness and advantages.

Glass-(nAg, nCu) biocide coatings on ceramic oxide substrates.

PubMed

Esteban-Tejeda, Leticia; Malpartida, Francisco; Díaz, Luis Antonio; Torrecillas, Ramón; Rojo, Fernando; Moya, José Serafín

2012-01-01

The present work was focused on obtaining biocide coatings constituted by a glassy soda-lime matrix containing silver or copper nanoparticles on ceramic (alumina and zirconia based) substrates. Both glassy coatings showed a high biocide activity against Gram-, Gram+ bacteria and yeast, reducing cell numbers more than three logarithms. Silver nanoparticles had a significantly higher biocide activity than copper nanoparticles, since the lixiviation levels required to reduce cell numbers more than 3 logarithms was of almost 1-2 µg/cm(2) in the case of silver nanoparticles, and 10-15 µg/cm(2) for the copper nanoparticles.

The environmental fate and effects of antifouling paint biocides.

PubMed

Thomas, K V; Brooks, S

2010-01-01

Antifouling (AF) biocides are the active ingredients in AF paints that prevent the settlement, adhesion and growth of organisms to a painted surface. A wide range of chemicals are used as AF biocides, which have very different physico-chemical properties and therefore differing environmental fates, behaviour and effects. Copper has been used as an antifoulant for centuries and extensive research has been performed to understand how copper speciation influences bioavailability and toxicity. For biocides that have been widely used over a number of decades, for example Irgarol 1051 and diuron, there are a large amount of environmental data in the public domain, including for their respective metabolites, that allows their environmental safety and potential risk to the environment to be assessed. For other biocides such as dichlofluanid, DCOIT (SeaNine 211) and zinc/copper pyrithione, there is a good understanding of their fate and effects. However, few monitoring studies have been performed and not so much is known about the fate and effects of their metabolites. There are also new or candidate biocides such as triphenylborane pyridine, Econea, capsaicin and medetomidine for which there is very little information in the public domain. This review provides an overview of the environmental fate and occurrence data that are in the public domain for AF biocides and provides some insight into the effects of these compounds on non-target organisms.

Biocides in hydraulic fracturing: hazard and vulnerability with respect to potential groundwater pollution

NASA Astrophysics Data System (ADS)

Worrall, Fred; Wilson, Miles; Davies, Richard

2016-04-01

Biocides are one possible chemical additive to frack fluids and their role is to control bacterial growth. Bacterial growth might lead to biofilm build up; and acid sulfide species and hydrogen sulfide (H2S) production: biofilm build up may reduce formation permeability and hinder gas extraction. Kahrilas et al. (2014) published a review of common biocides used in fracking in the USA. The biocides assessed in the review were the sixteen most commonly used in the USA, based on the hydraulic fracturing chemical registry Frac Focus (Frac Focus, 2015). However, the review of Kahrilas et al. (2014) contained no data or observations and so the objective of this study was to consider whether biocides proposed for use in hydrofacturing could be a threat to English groundwater. The study considered all groundwater samples analysed for biocides in English groundwater between 2005 and 2014. The monitoring records were compared to: records of application (both amount and area); and chemical and molecular data for the biocides. The study did not use traditional adsorption and degradation data as these parameters are to prone to variability and are not pure molecular parameters. The study then used the approach of Worrall and Thomsen (2004) to consider the hazard represented by proposed frack biocides and the approach of Worrall and Kolpin (2003) to consider the vulnerability of the areas of potential shale gas exploitation. The study showed that of the 113 biocides tested for in English groundwaters in the decade 2005 - 2014 that 95 were detected above 0.1 g/l . Of these 95, 41 were compounds that were not recorded as being applied during the period of record and the detection of these 41 compounds did not decline over the 10 year period which implies very long residence times and that once compounds do pollute an aquifer then they will be a persistent problem. Furthermore, the solubility of the range of biocides used in frack fluids would imply a potentially higher hazard than for other compounds. For one proposed area of shale gas exploitation we could show that the for the 15 km radius around the proposed frack site the total average probability of detecting a pesticide above 0.1 μg l-1 was 0.08%, while for the same group of pesticides on the national scale, the probability of detection was 0.18%, i.e. for that area the aquifer was less vulnerable to biocide pollution than would be expected.

Selection of an Alternate Biocide for the ISS Internal Thermal Control System Coolant, Phase 2

NASA Technical Reports Server (NTRS)

Wilson, Mark E.; Cole, Harold; Weir, Natalee; Oehler, Bill; Steele, John; Varsik, Jerry; Lukens, Clark

2004-01-01

The ISS (International Space Station) ITCS (Internal Thermal Control System) includes two internal coolant loops that utilize an aqueous based coolant for heat transfer. A silver salt biocide had previously been utilized as an additive in the coolant formulation to control the growth and proliferation of microorganisms within the coolant loops. Ground-based and in-flight testing demonstrated that the silver salt was rapidly depleted, and did not act as an effective long-term biocide. Efforts to select an optimal alternate biocide for the ITCS coolant application have been underway and are now in the final stages. An extensive evaluation of biocides was conducted to down-select to several candidates for test trials and was reported on previously. Criteria for that down-select included: the need for safe, non-intrusive implementation and operation in a functioning system; the ability to control existing planktonic and biofilm residing microorganisms; a negligible impact on system-wetted materials of construction; and a negligible reactivity with existing coolant additives. Candidate testing to provide data for the selection of an optimal alternate biocide is now in the final stages. That testing has included rapid biocide effectiveness screening using Biolog MT2 plates to determine minimum inhibitory concentration (amount that will inhibit visible growth of microorganisms), time kill studies to determine the exposure time required to completely eliminate organism growth, materials compatibility exposure evaluations, coolant compatibility studies, and bench-top simulated coolant testing. This paper reports the current status of the effort to select an alternate biocide for the ISS ITCS coolant. The results of various test results to select the optimal candidate are presented.

Aspects of tests and assessment of filtering materials used for respiratory protection against bioaerosols. Part I: type of active substance, contact time, microorganism species.

PubMed

Majchrzycka, Katarzyna; Gutarowska, Beata; Brochocka, Agnieszka

2010-01-01

This paper presents the results of a study on antimicrobial activity of polymer filter nonwovens produced by needle-punching or melt-blowing with an addition of disinfecting agents. The first part of the paper discusses how the biocidal activity of nonwovens is a function of the active agent added to the nonwovens, the duration of the contact of microorganisms with nonwovens and the type of microorganisms. The types of fibres and disinfecting agents had a considerable effect on the biocidal activity of nonwovens. The biocidal effect of nonwovens increased with the duration of their contact with microorganisms. Fibre activity differed considerably depending on the species of the microorganism. The microorganisms most sensitive to biocidal activity of the active filter nonwoven were S. aureus, M. flavus and E. coli. There were no biocidal effects on spore-forming bacterium B. subtilis.

Encapsulation of biocides by cyclodextrins: toward synergistic effects against pathogens

PubMed Central

Nardello-Rataj, Véronique

2014-01-01

Summary Host–guest chemistry is useful for the construction of nanosized objects. Some of the widely used hosts are probably the cyclodextrins (CDs). CDs can form water-soluble complexes with numerous hydrophobic compounds. They have been widespread used in medicine, drug delivery and are of interest for the biocides encapsulation. Indeed, this enables the development of more or less complex systems that release antimicrobial agents with time. In this paper, the general features of CDs and their applications in the field of biocides have been reviewed. As the key point is the formation of biocide–CD inclusion complexes, this review deals with this in depth and the advantages of biocide encapsulation are highlighted throughout several examples from the literature. Finally, some future directions of investigation have been proposed. We hope that scientists studying biocide applications receive inspiration from this review to exploit the opportunities offered by CDs in their respective research areas. PMID:25550722

Biocidal properties of maltose reduced silver nanoparticles against American foulbrood diseases pathogens.

PubMed

Çulha, Mustafa; Kalay, Şaban; Sevim, Elif; Pinarbaş, Müberra; Baş, Yıldız; Akpinar, Rahşan; Karaoğlu, Şengül Alpay

2017-12-01

Bee disease caused by spore-forming Paenibacillus larvae and Paenibacillus alvei is a serious problem for honey production. Thus, there is an ongoing effort to find an effective agent that shows broad biocidal activity with minimal environmental hazard. In this study, the biocidal effect of maltose reduced silver nanoparticles (AgNPs) is evaluated against American foulbrood and European foulbrood pathogens. The results demonstrate that the maltose reduced AgNPs are excellent short and long-term biocides against P. larvae isolates. The long-term effect suggests that the Ag + ions are released from the AgNPs with increasing time in a controlled manner.

Effects of single and repeated exposure to biocidal active substances on the barrier function of the skin in vitro.

PubMed

Buist, Harrie E; van de Sandt, Johannes J M; van Burgsteden, Johan A; de Heer, Cees

2005-10-01

The dermal route of exposure is important in worker exposure to biocidal products. Many biocidal active substances which are used on a daily basis may decrease the barrier function of the skin to a larger extent than current risk assessment practice addresses, due to possible skin effects of repeated exposure. The influence of repeated and single exposure to representative biocidal active substances on the skin barrier was investigated in vitro. The biocidal active substances selected were alkyldimethylbenzylammonium chloride (ADBAC), boric acid, deltamethrin, dimethyldidecylammonium chloride (DDAC), formaldehyde, permethrin, piperonyl butoxide, sodium bromide, and tebuconazole. Of these nine compounds, only the quaternary ammonium chlorides ADBAC and DDAC had a clear and consistent influence on skin permeability of the marker compounds tritiated water and [(14)C]propoxur. For these compounds, repeated exposure increased skin permeability more than single exposure. At high concentrations the difference between single and repeated exposure was quantitatively significant: repeated exposure to 300 mg/L ADBAC increased skin permeability two to threefold in comparison to single exposure. Therefore, single and repeated exposure to specific biocidal products may significantly increase skin permeability, especially when used undiluted.

Importance of Porins for Biocide Efficacy against Mycobacterium smegmatis▿

PubMed Central

Frenzel, Elrike; Schmidt, Stefan; Niederweis, Michael; Steinhauer, Katrin

2011-01-01

Mycobacteria are among the microorganisms least susceptible to biocides but cause devastating diseases, such as tuberculosis, and increasingly opportunistic infections. The exceptional resistance of mycobacteria to toxic solutes is due to an unusual outer membrane, which acts as an efficient permeability barrier, in synergy with other resistance mechanisms. Porins are channel-forming proteins in the outer membrane of mycobacteria. In this study we used the alamarBlue assay to show that the deletion of Msp porins in isogenic mutants increased the resistance of Mycobacterium smegmatis to isothiazolinones (methylchloroisothiazolinone [MCI]/methylisothiazolinone [MI] and octylisothiazolinone [2-n-octyl-4-isothiazolin-3-one; OIT]), formaldehyde-releasing biocides {hexahydrotriazine [1,3,5-tris (2-hydroxyethyl)-hexahydrotriazine; HHT] and methylenbisoxazolidine [N,N′-methylene-bis-5-(methyloxazolidine); MBO]}, and the lipophilic biocides polyhexamethylene biguanide and octenidine dihydrochloride 2- to 16-fold. Furthermore, the susceptibility of the porin triple mutant against a complex disinfectant was decreased 8-fold compared to wild-type (wt) M. smegmatis. Efficacy testing in the quantitative suspension test EN 14348 revealed 100-fold improved survival of the porin mutant in the presence of this biocide. These findings underline the importance of porins for the susceptibility of M. smegmatis to biocides. PMID:21398489

Determining the biofilm penetrating ability of various biocides utilizing an artificial biofilm matrix

DOE Office of Scientific and Technical Information (OSTI.GOV)

McIlwaine, D.B.; Diemer, J.; Grab, L.

1997-12-01

The efficacy of many commonly used biocides is often determined by laboratory evaluations against a variety of planktonic microorganisms. While these tests provide some information as to the performance of a biocide against a particular microorganism, they may not predict how well the biocide will perform under actual field conditions against the more problematic sissile form of the organisms. In order to address the issue of how well a biocide penetrates and kills the problematic microorganisms contained within a biofilm, an artificial biofilm system utilizing microorganisms embedded in alginate beads has been used to compare the efficacy of biocide treatmentsmore » against both the planktonic and sessile form of the same organism. Pure cultures of Enterobacter aerogenes, as well as mixed field isolates, were used in the experiments. In addition, the alginate beads were prepared with actual system waters taken from a variety of industrial applications. In that way, all of the scale and corrosion inhibitors and other contaminants which are present in the actual system are also present in the model biofilm system. In all cases, the organisms contained within the artificial biofilm were significantly more difficult to kill than the corresponding planktonic microbes.« less

Design and Certification of the Extravehicular Activity Mobility Unit (EMU) Water Processing Jumper

NASA Technical Reports Server (NTRS)

Peterson, Laurie J.; Neumeyer, Derek J.; Lewis, John F.

2006-01-01

The Extravehicular Mobility Units (EMUs) onboard the International Space Station (ISS) experienced a failure due to cooling water contamination from biomass and corrosion byproducts forming solids around the EMU pump rotor. The coolant had no biocide and a low pH which induced biofilm growth and corrosion precipitates, respectively. NASA JSC was tasked with building hardware to clean the ionic, organic, and particulate load from the EMU coolant loop before and after Extravehicular Activity (EVAs). Based on a return sample of the EMU coolant loop, the chemical load was well understood, but there was not sufficient volume of the returned sample to analyze particulates. Through work with EMU specialists, chemists, (EVA) Mission Operations Directorate (MOD) representation, safety and mission assurance, astronaut crew, and team engineers, requirements were developed for the EMU Water Processing hardware (sometimes referred to as the Airlock Coolant Loop Recovery [A/L CLR] system). Those requirements ranged from the operable level of ionic, organic, and particulate load, interfaces to the EMU, maximum cycle time, operating pressure drop, flow rate, and temperature, leakage rates, and biocide levels for storage. Design work began in February 2005 and certification was completed in April 2005 to support a return to flight launch date of May 12, 2005. This paper will discuss the details of the design and certification of the EMU Water Processing hardware and its components

Study on processing immiscible materials in zero gravity

NASA Technical Reports Server (NTRS)

Reger, J. L.; Mendelson, R. A.

1975-01-01

An experimental investigation was conducted to evaluate mixing immiscible metal combinations under several process conditions. Under one-gravity, these included thermal processing, thermal plus electromagnetic mixing, and thermal plus acoustic mixing. The same process methods were applied during free fall on the MSFC drop tower facility. The design is included of drop tower apparatus to provide the electromagnetic and acoustic mixing equipment, and a thermal model was prepared to design the specimen and cooling procedure. Materials systems studied were Ca-La, Cd-Ga and Al-Bi; evaluation of the processed samples included the morphology and electronic property measurements. The morphology was developed using optical and scanning electron microscopy and microprobe analyses. Electronic property characterization of the superconducting transition temperatures were made using an impedance change-tuned coil method.

Significant Differences Characterise the Correlation Coefficients between Biocide and Antibiotic Susceptibility Profiles in Staphylococcus aureus.

PubMed

Oggioni, Marco R; Coelho, Joana Rosado; Furi, Leonardo; Knight, Daniel R; Viti, Carlo; Orefici, Graziella; Martinez, Jose-Luis; Freitas, Ana Teresa; Coque, Teresa M; Morrissey, Ian

2015-01-01

There is a growing concern by regulatory authorities for the selection of antibiotic resistance caused by the use of biocidal products. We aimed to complete the detailed information on large surveys by investigating the relationship between biocide and antibiotic susceptibility profiles of a large number of Staphylococcus aureus isolates using four biocides and antibiotics commonly used in clinical practice. The minimal inhibitory concentration (MIC) for most clinically-relevant antibiotics was determined according to the standardized methodology for over 1600 clinical S. aureus isolates and compared to susceptibility profiles of benzalkonium chloride, chlorhexidine, triclosan, and sodium hypochlorite. The relationship between antibiotic and biocide susceptibility profiles was evaluated using non-linear correlations. The main outcome evidenced was an absence of any strong or moderate statistically significant correlation when susceptibilities of either triclosan or sodium hypochlorite were compared for any of the tested antibiotics. On the other hand, correlation coefficients for MICs of benzalkonium chloride and chlorhexidine were calculated above 0.4 for susceptibility to quinolones, beta-lactams, and also macrolides. Our data do not support any selective pressure for association between biocides and antibiotics resistance and furthermore do not allow for a defined risk evaluation for some of the compounds. Importantly, our data clearly indicate that there does not involve any risk of selection for antibiotic resistance for the compounds triclosan and sodium hypochlorite. These data hence infer that biocide selection for antibiotic resistance has had so far a less significant impact than feared.

Effects of Antifouling Biocides on Molecular and Biochemical Defense System in the Gill of the Pacific Oyster Crassostrea gigas.

PubMed

Park, Mi Seon; Kim, Young Dae; Kim, Bo-Mi; Kim, Youn-Jung; Kim, Jang Kyun; Rhee, Jae-Sung

2016-01-01

Antifouling biocides such as organotin compounds and their alternatives are potent toxicants in marine ecosystems. In this study, we employed several molecular and biochemical response systems of the Pacific oyster Crassostrea gigas to understand a potential mode of action of antifouling biocides (i.e. tributyltin (TBT), diuron and irgarol) after exposure to different concentrations (0.01, 0.1, and 1 μg L-1) for 96 h. As a result, all the three antifouling biocides strongly induced the antioxidant defense system. TBT reduced both enzymatic activity and mRNA expression of Na+/K+-ATPase and acetylcholinesterase (AChE). Lower levels of both Na+/K+-ATPase activity and AChE mRNA expression were observed in the diuron-exposed oysters compared to the control, while the irgarol treatment reduced only the transcriptional expression of AChE gene. We also analyzed transcript profile of heat shock protein (Hsp) superfamily in same experimental conditions. All antifouling biocides tested in this study significantly modulated mRNA expression of Hsp superfamily with strong induction of Hsp70 family. Taken together, overall results indicate that representative organotin TBT and alternatives have potential hazardous effects on the gill of C. gigas within relatively short time period. Our results also suggest that analyzing a series of molecular and biochemical parameters can be a way of understanding and uncovering the mode of action of emerging antifouling biocides. In particular, it was revealed that Pacific oysters have different sensitivities depend on the antifouling biocides.

ETR HEAT EXCHANGER BUILDING, TRA644. METAL FRAME OF BUILDING GOES ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

ETR HEAT EXCHANGER BUILDING, TRA-644. METAL FRAME OF BUILDING GOES UP IN BACKGROUND AS WORKERS PLACE A SECTION OF WATER LINE THAT WILL CARRY SECONDARY COOLANT BETWEEN HEAT EXCHANGER BUILDING AND THE COOLING TOWER. INL NEGATIVE NO. 56-2205. Jack L. Anderson, Photographer, 6/28/1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Cooling tower influence on the rainwater pH near a major power plant

Treesearch

Ta-Yung Li

1976-01-01

The dense network of 12 rainguages, covering an area of 6 km in diameter, was reinstalled near PEPCO's 710 MW Chalk Point power plant in southern Maryland. The rainwater samples were collected from July to December 1974. This second season's collection of rainwater samples were analyzed and results showed a general shifting of pH toward higher values since...

75 FR 19252 - Delegation of New Source Performance Standards and National Emission Standards for Hazardous Air...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-14

... Industrial Process Cooling X Towers. R Gasoline Distribution X S Pulp & Paper MACT I X T Halogenated Solvent.... IIII Auto & Light Duty Truck (Surface X Coating). JJJJ Paper & Other Webs (Surface X Coating). KKKK... subparts B, H, I, K, Q, R, T, and W. For the part 63 NESHAPs, this includes the NESHAPs set forth in the...