bluuebunny/crossref_metadata_2025_split huggingface dataset:
Potential Risks of Waterborne Transmission ofEscherichiacoliO157:H7
Authors: Weihe Janice , LeChevallier Mark , Bukhari Zia 
Published: July 2005

AbstractEscherichia coliO157:H7 has emerged as a serious human pathogen, capable of causing severe illness and even death in infected individuals. The annual number ofE. coliO157:H7 infections is estimated at approximately 40,000, and up to 250 deaths. Some researchers estimate that the number of infections is as high as 73,000 annually; is 11,000 of those are from transmission of the organism through ingestion of contaminated water. An increasingly common route of transmission is waterborne via recreational or municipal water sources. Recent incidences of waterborne outbreaks ofE. coliO157:H7 have shown a variety of potential sources for water contamination; the common link is fecal contamination combined with inadequate disinfection of the water supply.Escherichia coliO157 is susceptible to chlorination at levels similar to wildE. coli.Detection methods specific forE. coliO157:H7 in water samples are laborious and time‐consuming; however, new methods are in development.
Chemical Drinking Water Standards, Past, Present, and Future
Authors: Sullivan Patrick , Agardy Franklin 
Published: July 2005

AbstractIn today's chemically dependent society, studies undeniably demonstrate that America's drinking water contains numerous industrial chemicals, pesticides, and pharmaceuticals, as well as chemicals from water treatment processes. Each of these chemicals is allowed in drinking water because it is either (1) regulated by federal drinking water standards, which allow concentrations to a defined level, or (2) because many chemicals remain unregulated. Regulated chemicals are known to be hazardous to humans at high concentrations, yet are deemed safe for human consumption at low concentrations based on risk models that are unsupported by validated human studies or consider the risk of consuming mixtures of chemicals. Meanwhile, a vast number of potentially hazardous chemicals exist in our drinking water that remain unregulated. The ability for the USEPA to regulate chemicals in drinking water when the nation's chemical industry produces an estimated 2,000 new chemical compounds each year would seem impossible and, indeed, is impossible under the existing system. Currently, the USEPA must determine whether to regulate not less than five new chemicals from a proposed list of 42 chemicals, which do not even include pharmaceuticals, for inclusion within the drinking water standards. This approach demonstrates that drinking water standards are incapable of keeping pace with the number of unregulated chemicals that are found in our drinking water. When this failure is combined with the fact that standards are not even based on actual human toxicity studies, drinking water standards cannot be relied on to protect the public health. The alternative is to switch to technology‐based standards with the goal of removing the maximum amount of chemical pollutants. As the public becomes more aware of the hazards in their drinking water, they will have no recourse but to turn to litigation to redress these failings. The alternative, continued reliance on drinking water standards to protect the public health, will only perpetuate a false sense of security. Sadly, if federal, state, and local governments cannot effect a change to technology‐based standards, this issue may ultimately be settled by litigation.
Molecular‐Based Detection ofCryptosporidium Parvumin Water
Authors: Pokorny Nicholas J. , Carey Christine M. , Boulter‐bitzer Jeanine L. , Lee Hung , Trevors Jack T. 
Published: July 2005

AbstractMolecular‐based methods are discussed for detecting the protozoan parasite,Cryptosporidium parvum, in water samples. These include antibody technologies, the polymerase chain reaction (PCR), and nucleic acid probes.
Modeling Chlorine Residuals in Urban Water Distribution Systems
Authors: Mohan Kumar M. S. , Munavalli G. R. 
Published: July 2005

AbstractThe water to be supplied to a community should be adequate in quantity to satisfy their demands and potable in quality to safeguard their health. It is not enough to treat water in the treatment works for safeguarding the health of consumers without trying to take adequate steps in preventing deterioration of the water quality in a distribution system. Treatment can be adequate to provide an excellent product for the consumer at the plant outlet, but it is inadequate to overcome inferior protective measures in the distribution system (1). There are various causes for which the potable water may turn to an obnoxious liquid in the distribution system and become unfit for drinking as could be found after quality assessment. The various causes of deterioration of water quality are pipe materials, constituents of water, intermittent supply, cross connections, dead‐end pipes, service reservoirs, commissioning of new distribution system without disinfection, and breakages (2). The significant constituents of water generally include residual chlorine, natural organic matter, nutrient concentrations, temperature, and pH of water. The distribution system plays an important role in assuring a good quality of water to the consumer.
Health Effects of Microbial Contaminants and Biotoxins in Drinking Water
Authors: Venkatapathy Raghuraman , Boutin Brenda , Moudgal Chandrika , Bruce Robert 
Published: July 2005

AbstractContaminated, untreated, or inadequately treated municipal water is known to transmit disease‐causing pathogens such as bacteria (Escherichia coli, Salmonella paratyphi, Bacillus typhosus, Vibrio cholerae), fungi (Penicillium, Candida), viruses (polio, reo, coxsackie), and protozoan parasites (Giardia lamblia, Cryptosporidium parvum, Entamoeba histolytica). In addition, some algae are not pathogenic, but produce biotoxins that may be harmful to humans at high concentrations. Treatment of source waters using disinfectants such as chlorine, chloramine, chlorine dioxide, ozone, and ultraviolet radiation has resulted in a dramatic reduction of waterborne diseases in the world today. However, waterborne pathogens may still be transmitted because of ingestion of water from contaminated service mains; microorganism growth in pipes and fittings; biofilms; sewage; inhalation of aerosols; or dermal contact with contaminated water such as in swimming pools. Waterborne diseases are usually acute in nature, are rarely fatal, and are often characterized by gastrointestinal symptoms. The severity and duration of illness is generally greater in people with weakened immune systems such as children, the elderly, and the immunocompromised, such as people suffering from AIDS.
Health Effects of Commonly Occurring Disinfection Byproducts in Municipal Water Supplies
Authors: Venkatapathy Raghuraman , Moudgal Chandrika , Boutin Brenda , Bruce Robert 
Published: July 2005

AbstractDisinfectants such as chlorine, chloramine, chlorine dioxide, ozone, and ultraviolet radiation have been used to disinfect water containing disease‐causing waterborne pathogens at water treatment plants throughout the world. However, the chemical disinfectants can react with dissolved organic and inorganic constituents in treated water to form disinfection byproducts (DBPs). Although over 600 DBPs have been identified, despite recent improvements in analytical instrumentation, less than 50% of the total organic halides have been accounted for in drinking water. From the present knowledge of occurrence and health effects, the DBPs of concern are trihalomethanes, haloacetic acids, bromate, chlorate, and chlorite, although other DBPs, such as acetonitriles, acetaldehydes, ketones, nitromethanes, and other alkanes, have also been identified in drinking water. Epidemiological studies indicate an association between chronic ingestion of drinking water and increased risk of rectal, bladder, and colon cancer in humans, but these studies do not indicate whether the observed health effects are because of one or more of the hundreds of DBPs that are also present in drinking water. The disinfectants can also be hazardous at high concentrations, but toxicological studies show that their toxicity is likely not relevant at the low concentrations encountered in drinking water.
Filtration
Authors:   National Drinking Water Clearinghouse
Published: July 2005

Abstract
Filtration is the process of removing suspended solids from water by passing the water through a permeable fabric or porous bed of materials. Groundwater is naturally filtered as it flows through porous layers of soil. However, surface water and groundwater under the influence of surface water is subject to contamination from many sources. Some contaminants pose a threat to human health, and filtration is one of the oldest and simplest methods of removing them. Federal and state laws require many water systems to filter their water. Filtration methods include slow and rapid sand filtration, diatomaceous earth filtration, direct filtration, packaged filtration, membrane filtration, and cartridge filtration.
Water Treatment Plant Residuals Management
Authors:   National Drinking Water Clearinghouse
Published: July 2005

Abstract
Water treatment plants produce a wide variety of waste products as well as safe drinking water. These residuals may be organic and inorganic compounds in liquid, solid, and gaseous forms depending on the source of raw water and the type of treatment processes, commonly, coagulation/filtration, precipitative softening plant, membrane separation, ion exchange, granular activated carbon.
Lime Softening
Authors:   National Drinking Water Clearinghouse
Published: July 2005

Abstract
Hard water can cause scaling problems in water heaters and soap does not lather well in hard water. Therefore, some water utilities soften water to improve its quality for domestic use. Lime softening is best suited to groundwater sources, which have relatively stable water quality. The combination of variable source water quality and the complexity of the chemistry of lime softening may make lime softening too complex for small systems that use surface water sources.
Although lime softening has been used successfully by groundwater systems serving fewer than 3,000 people, it is unlikely to be suitable for treating groundwater in systems serving 500 or fewer people unless those systems have some form of contract or satellite operation that would enable a trained operator to monitor the treatment process. Prefabricated lime softening equipment is available for small systems. Also, there is an American Water Works Association Standard for quicklime and hydrated lime (ANSI/AWWA B202‐93) that provides purchasers, manufacturers, and suppliers with the minimum requirements, including physical, chemical, packaging, shipping, and testing requirements.

Either hydrated lime [Ca(OH)
2
] or quicklime (CaO) may be used in the softening process. The choice depends upon economic factors, such as the relative cost per ton of the two materials as well as the size and equipment of the softening plant. Hydrated lime is generally used more in smaller plants because it stores better and does not require slaking (producing a chemical change in lime by combining it with water) equipment. On the other hand, quick‐lime costs less per ton of available calcium oxide and is thus more economical for use in large plants.

Softened water has high causticity and scale‐formation potential; hence, recarbonation is employed to reduce pH and mitigate scaling of downstream processes and pipelines. Onsite combustion generation of carbon dioxide (CO
2
) or liquid CO
2
is the most common source of carbon dioxide for recarbonation.
Membrane Filtration
Authors:   National Drinking Water Clearinghouse
Published: July 2005

Abstract
A membrane or, more properly, a semipermeable membrane, is a thin layer of material capable of separating substances when a driving force is applied across the membrane.
Once considered a viable technology only for desalination, membrane processes are increasingly employed for removal of bacteria and other microorganisms, particulate material, and natural organic material, which can impart color, tastes, and odors to the water and react with disinfectants to form disinfection byproducts (DBP). As advancements are made in membrane production and module design, capital and operating costs continue to decline.
The pressure‐driven membrane processes discussed in this fact sheet are microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO).
Diatomaceous Earth Filtration for Drinking Water
Authors: Bhardwaj Vipin , Mirliss Mel J. 
Published: July 2005

Abstract
Diatomaceous Earth (DE) filtration is a process that uses diatoms or diatomaceous earth—the skeletal remains of small, single‐celled organisms—as the filter media. DE filtration relies upon a layer of diatomaceous earth placed on a filter element or septum and is frequently referred to as pre‐coat filtration. DE filters are simple to operate and are effective in removing cysts, algae, and asbestos from water. DE has been employed in many food and beverage applications for more than 70 years and was used specifically to filter potable water during WWII. Since then, it has been used to produce high‐quality, low‐cost drinking water. DE filtration is currently one of the U.S. Environmental Protection Agency's (EPA) approved technologies for meeting the requirements of the Surface Water Treatment Rule (SWTR) and is most suitable for small communities that need to comply with the rule.
Cross Connection and Backflow Prevention
Authors: Bhardwaj Vipin , Reed Bethany 
Published: July 2005

Abstract
When drinking water is transported to a consumer, it is possible for contaminants to be introduced in the distribution system. This situation may occur due to connections between potable water lines and non‐potable water sources or by a water flow reversal, resulting in contaminated water. This Tech Brief, discusses cross connections and backflow, and explores ways to prevent these situations.
Water Meters
Authors: Satterfield Zane , Bhardwaj Vipin 
Published: July 2005

Abstract
Any viable business must be able to determine how much product it is making and selling and if that product is profitable. Water is a business. And, the best way for a water utility to measure or account for the water produced and then sold is by using water meters. This Tech Brief, discusses the different types of meters, their applications, and their importance for a water utility business.
Answering the Challenge
Authors: Reahl Eugene R. 
Published: July 2005

Abstract
As a result of the need for ever‐expanding drinking water supplies in an area short on such new sources, the City of San Diego purchased an electrodialysis reversal (EDR) system in 1998 to desalinate tertiary treated wastewater. The EDR system was installed to produce a low TDS product from treated wastewater, then blend and supply this high‐quality irrigation water to golf courses, parks, plant nurseries, and other water users. The initial plant produced 3.3 mgd of blended water.
The city elected to use EDR because of its lower costs compared with the conventional use of MF‐RO. EDR also operates at higher water recovery, and with no chemical feed required other than an allowable use of free chlorine in the feedwater.
As a result of the success of the “alternative water supply” program, the EDR system has been expanded to where it will produce a blended flow of up to 12 mgd by early 2005.
This successful installation has been verified by recent testing of EDR and MF‐RO, showing that EDR is up to 40% less costly based on present worth analysis of capital, infrastructure, and long‐term O&M costs.
Use of Redox Potentials in Wastewater Treatment
Authors: Inniss Enos C. 
Published: July 2005

Abstract
Effective process control requires an understanding of where the process is with respect to reaction potential and completion. Online measurements allow for greater monitoring of the state of the process from flowrates to chlorine residuals. A measure of dissolved oxygen in the system is useful until anoxic and anaerobic conditions are encountered. Once those environmental conditions are achieved, as is the case with biological nutrient removal (BNR), the ability to measure a wider range of conditions may be achieved with oxidation–reduction potential (ORP).
Ion Exchange—Use of Magnetic Ion Exchange Resin For
DOC
Removal
Authors: Slunjski Marin 
Published: July 2005

Abstract
Natural organic matter, measured as dissolved organic carbon (DOC), is a major problem in treatment processes for production of drinking water. DOC gives water color and can react with disinfectants to produce by‐products that have adverse health affects. It also interferes with the treatment processes, makes them less effective, and results in increased chemical additions.
Strong base anion exchange resins have a high affinity for DOC. They are currently used in packed columns in the production of drinking water in Norway and the United States. These applications are sensitive to fouling by suspended solids and are limited to smaller scale applications.

MIEX
®

resin, a new approach was developed in Australia by the South Australian Water Corporation, Orica Australia Pty. Ltd. and CSIRO.

It uses a new ion exchange resin designed for DOC removal in a continuous flow, stirred tank system that is not affected by suspended solids (i.e., turbidity).
Competitive Adsorption of Several Organics and Heavy Metals on Activated Carbon in Water
Authors: Mohan Dinesh , Singh Kunwar P. 
Published: July 2005

AbstractIn practice, the water/wastewater/effluents to be treated are multicomponent mixtures. Therefore, other organic or inorganic substances influence the efficacy of activated carbons. In the recent past, most of the research work has been focused on the removal of single solute from its pure solution or a particular solute from a solution having ill‐defined chemical character. The other reports available are addressed to the removal of gross organic/inorganic substances, which are measured in terms of BOD or COD from water/wastewater. In actual practice, the treatment of wastewater by activated carbon normally involves a variety of adsorbates competing for adsorption sites on the carbon surface. Thus, a thorough understanding of the competitive effect on various organic/inorganic compounds on carbon adsorption is a must. Unfortunately, very few reports/papers about the competitive adsorption on activated carbon in aqueous solution are available. Thus, a need exists to explore the current status of the competitive adsorption of various organic/inorganic substances from water/wastewater on activated carbons. Multiion systems received less attention than single ion systems.The adsorption in multicomponent systems is complicated because of the solute–solute competition and the solute‐surface interaction involved. Multicomponent interactions take place at the active adsorption sites where the solid‐liquid phase equilibrium will emerge showing a different capacity of single solute with a new set of isotherm systems. The interpretation of the multicomponent systems has proved to be complex and may be the function of one or all of the following parameters: ionic radii, electronegativity, system pH, and the availability of the active sites on the adsorbent.
Ozone–Bromide Interactions
Authors: Siddiqui M. 
Published: July 2005

AbstractAs utilities consider changing their primary disinfection practices from free chlorine to ozone to provide pathogen control while minimizing chlorinated disinfection by‐product (DBP) formation, the potential for producing ozonation DBPs like bromate ion must be addressed. This article focuses on the interactions, not only of molecular ozone and bromide ion, but also of radical species with bromide ion. The data evaluations include discussions of reaction products, potential for bromate ion formation, reaction kinetics, and the effect of various water quality parameters and treatment conditions on bromate ion formation. Based on evaluation of existing data, areas requiring new or intensified research efforts are identified.An additional aspect of this article is a presentation of most available data on the minimization of bromate ion formation during ozonation. A summary of bromate ion removal processes after ozonation has been incorporated.
Dechlorination
Authors: Ahmad Rasheed 
Published: July 2005

Abstract

Dechlorination is the practice of removing all or a specified fraction of total residual chlorine. In potable water practice, dechlorination is used to reduce the residual chlorine to a specified level at a point where the water enters the distribution system. Dechlorination has been beneficial for waters that are burdened with high concentrations of ammonia nitrogen and organic nitrogen. In some cases where taste and odor control is a severe problem, control is achieved by complete dechlorination, followed by rechlorination. This removes the taste‐producing nuisance residuals and prevents the formation of nitrogen trichloride (NCl
3
) in the distribution systems. Dechlorination of wastewater and power plant cooling water is required to eliminate residual chlorine toxicity, which is harmful to the aquatic life in the receiving waters. Other special applications requiring dechlorination are ahead of demineralizers, boiler makeup water, certain food plant operations, bottled water, and the beverage industry. In these cases, the dechlorination process is arranged to remove all residual chlorine.
Persistence of Pathogens in Water
Authors: Nasser Abid M. 
Published: July 2005

AbstractNatural water sources become contaminated with pathogenic micro‐organisms by the discharge of inadequately treated wastewater. Four major pathogen groups can be found in wastewater: over 100 types of enteric viruses, 7 types of pathogenic bacteria, 10 types of protozoan parasites, and 6 types of helminthes of health significance to humans and animals. The concentration of pathogenic micro‐organisms in wastewater is affected mainly by the amount of precipitation, the season of the year, and the socioeconomic status of the community. For most pathogenic micro‐organisms, the methods of detection are expensive, time‐consuming, and difficult to perform. Therefore, data on the prevalence of pathogenic micro‐organisms in wastewater effluents and natural water sources is limited to types for which a detection technique was developed. The recently developed molecular biology‐based techniques enhanced our capability in detecting human pathogenic micro‐organisms in water sources.