scholarly journals Assessing the Impact of Cyanuric Acid on Bather’s Risk of Gastrointestinal Illness at Swimming Pools

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1314
Author(s):  
Falk ◽  
Blatchley ◽  
Kuechler ◽  
Meyer ◽  
Pickens ◽  
...  
Keyword(s):  
Environmental Protection Agency ◽  
Hypochlorous Acid ◽  
Cyanuric Acid ◽  
Microbial Inactivation ◽  
Water Disinfection ◽  
Gastrointestinal Illness ◽  
Swimming Pools ◽  
Minimum Concentration ◽  
Illness Model ◽  
The Impact

Current regulatory codes for swimming pool disinfection separately regulate free chlorine (FC) and cyanuric acid (CYA). It is well-known that CYA affects disinfection rates by reversibly binding to FC in aqueous solutions. However, limits for these regulated parameters have neither systematically accounted for this chemistry nor been based on the risk of gastrointestinal illness. This study was intended to determine the minimum concentration of FC relative to CYA based on the risk of gastrointestinal illness from normal fecal sloughing of selected pathogens and to find a simple regulatory rule for jointly managing FC and CYA for consistent disinfection. Literature data on CYA’s effect on microbial inactivation rates were reanalyzed based on the equilibria governing hypochlorous acid (HOCl) concentration. A model was developed that considers the rates of pathogen introduction into pool water, disinfection, turbulent diffusive transport, and pathogen uptake by swimmers to calculate the associated risk of illness. Model results were compared to U.S. Environmental Protection Agency (EPA) untreated recreational water acceptable gastrointestinal illness risk. For Cryptosporidium, correlation between log inactivation and Chick–Watson Ct was far better when C refers to HOCl concentration than to FC (r = −0.96 vs. −0.06). The HOCl concentration had a small variation (± 1.8%) at a constant CYA/FC ratio for typical FC and CYA ranges in swimming pools. In 27 U.S. states, the allowed FC and CYA results in HOCl concentrations spanning more than a factor of 500. Using conservative values for a high bather load pool with 2 mg/L FC and 90 mg/L CYA, the model predicted a 0.071 annual probability of infection for Giardia, exceeding the EPA regulatory 0.036 limit for untreated recreational waters. FC and CYA concentrations in swimming pools should be jointly regulated as a ratio. We recommend a maximum CYA/FC ratio of 20.

Development of point-of-use water disinfection technology using ceramic water filter and electrochemical hybrid system

2013 ◽  
Vol 13 (4) ◽  
pp. 1174-1180
Author(s):  
Y. J. Yoon ◽  
M. H. Kwon ◽  
Y. M. Jung ◽  
J. H. Moon ◽  
J. W. Kang
Keyword(s):  
Hybrid System ◽  
Environmental Protection Agency ◽  
Microbial Inactivation ◽  
Water Disinfection ◽  
Escherichia Coli O157 ◽  
Protection Agency ◽  
Water Filter ◽  
Point Of Use ◽  
The Us ◽  
By Products

The efficiency of water disinfection using a ceramic water filter and electrochemical hybrid system was investigated. Escherichia coli O157:H7 was effectively inactivated even when a storage battery, charged using a solar panel device, was used for the electrolysis process. During electrolysis, the rate of microbial inactivation was higher at higher initial Cl− concentrations. This was because of the higher CT value (the disinfectant concentration, C [mg/L], multiplied by the exposure time, T [min]) of free chlorine. Microorganisms were effectively inactivated under low pH and high temperature conditions. Disinfection by-products, such as trihalomethanes (THMs) and haloacetic acids (HAAs), were below the standard concentrations allowed in drinking water by the US Environmental Protection Agency.

scholarly journals Microbial stabilization of grape musts and wines using coiled UV-C reactor

OENO One ◽  
2020 ◽  
Vol 54 (1) ◽  
Author(s):  
Rémy Junqua ◽  
Emmanuel Vinsonneau ◽  
Rémy Ghidossi
Keyword(s):  
Microbial Inactivation ◽  
Operating Conditions ◽  
Water Disinfection ◽  
Industrial Scale ◽  
Hydrodynamic Characteristics ◽  
Dean Number ◽  
Multiple Strains ◽  
Inactivation Efficiency ◽  
The Impact ◽  
Uv C

UV-C light is well known for its germicidal properties and is widely used for water disinfection. However, its low penetration into absorbing liquids, such as wines and musts, reduces drastically the microbial inactivation effectiveness. Additionally, wines require UV-C doses to be as low as possible to avoid any possible light-struck flavors. In order to add to the technologies that allow the reduction of SO2 use, a coiled UV-C reactor was designed to inactivate microorganisms in wines and musts. Due to its unique hydrodynamic characteristics, this design could improve the exposure probabilities of the microorganisms to the UV-C light in absorbing liquids. In a first step, theoretical and measured fluid dynamics parameters such as Dean number were employed to improve the operating conditions of the reactor. The higher the Dean number, the higher the UV-C dose delivery efficiency in this reactor, and thus the lower the dose required to inactivate a given load of microorganisms. The second step investigated the impact of different wines on microbial inactivation efficiency and the UV-C doses required to inactivate microorganisms frequently found in wines. White and rosé wines, with low absorbances at 254 nm, required lower doses (≈ 600 J/L) than red wine (≈ 5000 J/L) because their absorption coefficient is ten times lower. The tolerance of microbial strains to UV-C treatments was variable, with higher resistance observed for yeast than for bacteria. In the third step, treatments conducted at semi-industrial scale showed that physicochemical and sensorial properties of wines and musts were not altered, highlighting the possible relevance of such a reactor on an industrial scale. Highlights: • Design of a coiled UV-C reactor for microbial stabilization of wines and musts• Focus on inactivation efficiency in multiple strains and wine varieties• Chemical and sensorial analyses to ensure treatment does not affect the organoleptic properties of the product

Impact of Particulate Matter on Distribution System Disinfection Efficacy

2008 ◽  
Vol 43 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Linda Wojcicka ◽  
Carole Baxter ◽  
Ron Hofmann
Keyword(s):  
Helicobacter Pylori ◽  
Particulate Matter ◽  
Distribution System ◽  
Contact Time ◽  
Water Disinfection ◽  
Sphingomonas Paucimobilis ◽  
Soil Corrosion ◽  
Log Reduction ◽  
Drinking Water Disinfection ◽  
The Impact

Abstract Microorganisms have been shown to survive drinking water disinfection and remain viable in disinfected waters despite the presence of disinfectant residuals. This may be partially attributed to protection by particulate matter. The aim of this study was to determine the effects of the presence of particulate matter on disinfection kinetics. Sphingomonas paucimobilis ATCC 10829 and Helicobacter pylori ATCC 43504 were used in inactivation experiments in the presence and absence of soil, corrosion, and wastewater particles. The results showed that the presence of such particles tended to inhibit chlorine and monochloramine inactivation, although the magnitude of the impact under the conditions tested was small (e.g., 1-log reduction in inactivation for several minutes of contact time in the presence of less than 1 mg/L of disinfectant).

Practical Guide to Determine the Impact of Radon and Other Radionuclides on Water Treatment Processes

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1255-1264
Author(s):  
K. L. Martins
Keyword(s):  
Activated Carbon ◽  
Water Treatment ◽  
Environmental Protection Agency ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Packed Tower ◽  
Treatment Processes ◽  
Radioactivity Exposure ◽  
The Impact ◽  
Percent Removal

During treatment of groundwater, radon is often coincidentally removed by processes typically used to remove volatile organic compounds (VOCs)-for example, processes such as liquid-phase granular activated carbon (LGAC) adsorption and air stripping with vapor-phase carbon (VGAC). The removal of radon from drinking water is a positive benefit for the water user; however, the accumulation of radon on activated carbon may cause radiologic hazards for the water treatment plant operators and the spent carbon may be considered a low-level radioactive waste. To date, most literature on radon removal by water treatment processes was based on bench- or residential-scale systems. This paper addresses the impact of radon on municipal and industrial-scale applications. Available data have been used todevelop graphical methods of estimating the radioactivity exposure rates to facility operators and determine the fate of spent carbon. This paper will allow the reader to determine the potential for impact of radon on the system design and operation as follows.Estimate the percent removal of radon from water by LGAC adsorbers and packed tower air strippers. Also, a method to estimate the percent removal of radon by VGAC used for air stripper off-gas will be provided.Estimate if your local radon levels are such that the safety guidelines, suggested by USEPA (United States Environmental Protection Agency), of 25 mR/yr (0.1 mR/day) for radioactivity exposure may or may not be exceeded.Estimate the disposal requirements of the waste carbon for LGAC systems and VGAC for air stripper “Off-Gas” systems. Options for dealing with high radon levels are presented.

scholarly journals Association of temporary Environmental Protection Agency regulation suspension with industrial economic viability and local air quality in California, United States

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Emily Chang ◽  
Kenneth Zhang ◽  
Margaret Paczkowski ◽  
Sara Kohler ◽  
Marco Ribeiro
Keyword(s):  
United States ◽  
Air Quality ◽  
Environmental Protection ◽  
Environmental Protection Agency ◽  
Manufacturing Industry ◽  
Economic Viability ◽  
Treatment Control ◽  
Oil Refineries ◽  
Pollution Levels ◽  
The Impact

Abstract Background This study seeks to answer two questions about the impacts of the 2020 Environmental Protection Agency’s enforcement regulation rollbacks: is this suspension bolstering the economic viability of industries as oil and manufacturing executives claim they will and are these regulations upholding the agency’s mission of protecting the environment? Results To answer the former question, we utilized 6 months of state employment level data from California, United States, as a method of gauging the economic health of agency-regulated industries. We implemented a machine learning model to predict weekly employment data and a t-test to indicate any significant changes in employment. We found that, following California's state-issued stay-at-home order and the agency’s regulation suspension, oil and certain manufacturing industries had statistically significant lower employment values. To answer the latter question, we used 10 years of PM2.5 levels in California, United States, as a metric for local air quality and treatment–control county pairs to isolate the impact of regulation rollbacks from the impacts of the state lockdown. Using the agency’s data, we performed a t-test to determine whether treatment–control county pairs experienced a significant change in PM2.5 levels. Even with the statewide lockdown—a measure we hypothesized would correlate with decreased mobility and pollution levels—in place, counties with oil refineries experienced the same air pollution levels when compared to historical data averaged from the years 2009 to 2019. Conclusions In contrast to the expectation that the suspension would improve the financial health of the oil and manufacturing industry, we can conclude that these industries are not witnessing economic growth with the suspension and state shutdown in place. Additionally, counties with oil refineries could be taking advantage of these rollbacks to continue emitting the same amount of PM2.5, in spite of state lockdowns. For these reasons, we ask international policymakers to reconsider the suspension of enforcement regulations as these actions do not fulfill their initial expectations. We recommend the creation and maintenance of pollution control and prevention programs that develop emission baselines, mandate the construction of pollution databases, and update records of pollution emissions.

Impact of high pressure processing on microbiological, nutritional and sensory properties of food: a review

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ajith Amsasekar ◽  
Rahul S. Mor ◽  
Anand Kishore ◽  
Anupama Singh ◽  
Saurabh Sid
Keyword(s):  
High Pressure ◽  
Food Quality ◽  
High Pressure Processing ◽  
Microbial Inactivation ◽  
Sensory Properties ◽  
Process Conditions ◽  
Processed Food ◽  
Content Type ◽  
Food Properties ◽  
The Impact

Purpose The increased demand for high-quality, nutritionally rich processed food has led to non-thermal food processing technologies like high pressure processing (HPP), a novel process for microbial inactivation with minimal loss of nutritional and sensory properties. The purpose of this paper is to highlight the impact of HPP on the microbiological, nutritional and sensory properties of food. Design/methodology/approach Recent research on the role of HPP in maintaining food quality and safety and the impact of process conditions with respect to various food properties have been explored in this paper. Also, the hurdle approach and the effectiveness of HPP on food quality have been documented. Findings HPP has been verified for industrial application, fulfilling the consumer demand for processed food with minimum nutrition loss at low temperatures. The positive impact of HPP with other treatments is known as the hurdle approach that enhances its impact against microorganism activity and minimizes the effects on nutrition and sensory attributes. Originality/value This paper highlights the impact of HPP on various food properties and a good alternative as non-thermal technology for maintaining shelf life, sensory properties and retention of nutrients.

scholarly journals Modeling relevant factors and covariates of carbon stock changes in peatlands using a hierarchical linear mixed modeling approach

2020 ◽  
Author(s):  
Kilian Walz ◽  
Kenneth A Byrne ◽  
David Wilson ◽  
Florence Renou-Wilson
Keyword(s):  
Soil Carbon ◽  
Environmental Protection Agency ◽  
Land Surface ◽  
Carbon Stock ◽  
Dimensional Space ◽  
Carbon Stocks ◽  
Carbon Distribution ◽  
Soil Carbon Stock ◽  
Modeling Approach ◽  
The Impact

<p>While peatlands constitute the largest soil carbon stock in Ireland with 75% of soil carbon stored in an area covering an estimated 20% of the land surface, carbon stocks of peatlands are affected by past and present disturbances related to various land uses. Afforestation, grazing and peat extraction for energy and horticultural use often are major drivers of peatland soil degradation. A comparative assessment of the impact of land disturbance on peatland soil carbon stocks on a national scale has been lacking so far. Current research, funded by the Irish Environmental Protection Agency (EPA), addresses this issue with the goal to fill various gaps related to mapping and modeling changes of soil carbon stock in Irish peatlands. Data from the first nationwide peatland survey forms the basis for this study, in which the influence of different factors and covariates on soil carbon distribution in peatlands is examined. After data exploratory analysis, a mixed linear modeling approach is tested for its suitability to explain peatland soil carbon distribution within the Republic of Ireland. Parameters are identified which are responsible for changes across the country. In addition, model performance to map peat soil carbon stock within a three-dimensional space is evaluated.</p>

scholarly journals EFFECTS OF TEMPERATURE AND CHANGING DISINFECTANTS ON STEEL WATER PIPES CORROSION: CASE STUDY OF MASHHAD, IRAN

2020 ◽  
Vol 5 (2) ◽  
pp. 65-71
Author(s):  
Mobin Rahimi-Golkhandan ◽  
Shahnaz Danesh ◽  
Ali Davoodi
Keyword(s):  
Potassium Permanganate ◽  
Sodium Hypochlorite ◽  
Positive Impact ◽  
Water Disinfection ◽  
Decision Makers ◽  
Water Pipe ◽  
Steel Pipes ◽  
Water Pipes ◽  
Corrosion Of Steel ◽  
The Impact

Water pipe corrosion inflicts big health problems and financial damages to societies. Temperature, pH, type, and dosage of oxidants, and DO are some of the key factors that affect water pipe corrosion. The aim of this research is to assess the impacts of temperature (15 and 25oC), dosage of potassium permanganate (0, 1 and 2 mg/L) and sodium hypochlorite (0, 0.5 and 1 mg/L) on corrosion of steel pipes. To measure the corrosion of steel specimens, OCP, EIS and potentiodynamic polarization tests were conducted. The results showed a direct relationship between temperature and corrosion rate. A 10-degree raise in the temperature, caused a 25% increase in corrosion current density (CCD). Adding sodium hypochlorite to the solution, decreases CCD by around 50%. Moreover, potassium permanganate proved to have a positive impact on reducing CCD by up to 21%. The results demonstrate that simultaneous usage of NaClO and KMnO4 for water disinfection can have beneficial impact on corrosion of steel pipes. Finally, our analysis suggests that when combined with KMnO4, lower dosage of NaClO significantly increases polarization resistance. The findings of this research highlight the impact of disinfectants on steel water pipes corrosion in different temperatures and supports water infrastructure decision-makers in more effective rehabilitation and maintenance of water pipes. Further, our results inform decision-makers for a more effective infrastructure design and resilience planning to random failures caused by corrosion.

Managerial ability and chemical releases

2017 ◽  
Vol 8 (3) ◽  
pp. 281-306 ◽  
Author(s):  
Li Sun
Keyword(s):  
Environmental Protection Agency ◽  
Negative Relationship ◽  
Pollution Prevention ◽  
Managerial Ability ◽  
Policy Makers ◽  
Content Type ◽  
Interest Policy ◽  
Corporate Social ◽  
Chemical Releases ◽  
The Impact

Purpose This study aims to examine the impact of managerial ability on the total amount of chemical releases reported to the Toxics Release Inventory (TRI) at the US Environmental Protection Agency. Design/methodology/approach Regression analysis is used to examine the association between managerial ability and chemical releases. Findings A negative relationship was found between managerial ability and TRI’s chemical releases, suggesting that more-able managers better reduce TRI’s chemical releases, relative to less-able managers. Practical implications By providing useful insights into what determines TRI’s chemical releases, this study should interest policy makers and practitioners. Originality/value This study contributes to and links two research schools: managerial ability in management literature and corporate social responsibility (i.e. pollution prevention) in the broad business literature. To the best of the author’s knowledge, this is the first empirical study that performs a direct test of the association between managerial ability and TRI’s toxic chemical releases.

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