bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrocarbon Treatment Techniques
Authors: Ashworth Samuel C. 
Published: April 2005

Abstract
There are various criteria concerning hydrocarbons for water needs. Some water users have little concern for dissolved hydrocarbons (e.g., agriculture), and some have strict standards (e.g., drinking water). In general the presence of organic compounds, including hydrocarbons, in water can lead to a buildup of biofilms. Biofilms can be problematic in many situations including drinking water, cooling water, recirculating water, and water used for various other industrial processes. During biofilm formation, the first substances on the surface are not bacteria but trace organics. Almost immediately after the clean pipe surface comes into contact with water, an organic layer deposits on the water/solid interface. These organics form a conditioning layer that neutralizes excessive surface charge and surface free energy that may prevent a bacteria cell from approaching near enough to initiate attachment. In addition, the adsorbed organic molecules often serve as a nutrient source for bacteria.
Though there are many criteria, the thrust of this article is on the treatment, including the removal and destruction of hydrocarbons for whatever purpose. It is assumed in this article that the hydrocarbons are dissolved in water, so that technologies such as incineration or decantation will not apply. The focus will be on water‐phase separation and destruction. No economic evaluation is considered. In reality, the trade‐offs would need to be considered, for example, waste disposal costs, electrical cost, and materials.
Industrial Cooling Water—Corrosion
Authors: Bott T. R. 
Published: April 2005

Abstract
Corrosion is often a problem when metals are in contact with an aqueous environment. It may be defined as the deterioration and loss of metal due to some form of chemical attack. In general, it results from impurities in the water, which need only to be in trace quantities to initiate corrosion. Trace impurities can include gases dissolved from the atmosphere, particularly oxygen and carbon dioxide, that play important roles in the corrosion process. Small amounts of mineral salts in water can also become involved in corrosion reactions. Where the metal makes up an essential component of a structure, such as a bridge or equipment forming part of an industrial process, for example, a cooling water circuit, constant vigilance is required to maintain the integrity of the structure and the equipment involved. Corrosion is a complex phenomenon dependent on chemical and physical conditions within the particular system.
Industrial Cooling Water—Scale Formation
Authors: Bott T. R. 
Published: April 2005

AbstractAny source of naturally occurring water used of industrial cooling has been in contact with the earth, soil, and rock formations. As a result, soluble inorganic salts have been taken into solution that can give rise to “scaling” in industrial equipment. The phenomenon is apparent in domestic kettles that have been used to boil so‐called “hard water.” A whitish‐brown deposit forms on the areas within the kettle that are subject to the highest temperatures, for example, the heating element in electric kettles. In cooling water circuits that usually employ water from natural sources such as rivers or lakes, deposition of inorganic salts, or “scaling” as it is often called, can represent a serious problem. The presence of these salts usually results in operating problems. The accumulation of deposits on heat transfer surfaces can lead to severe loss in cooling efficiency if not effectively controlled.
Evaporation
Authors: Endreny Theodore A. 
Published: April 2005

Abstract
Evaporation of water is a solar energy driven phase change from liquid to vapor that maintains the hydrologic cycle by transferring liquid water at the earth's surface to water vapor in the atmosphere, where it may lift, condense, and precipitate to earth as liquid water. In this discussion, evaporation is defined to include the closely associated transpiration process as a subcategory. The coupled processes are often called as evapotranspiration, or ET, where transpiration focuses on the transport of liquid water through the plant roots, stem, and leaf prior to evaporation through the leave's stomata. Further, when the discussion does not make a clear distinction between potential and actual evaporation, potential should be assumed. Potential evaporation refers to the amount of water that available energy and diffusion processes can transfer into atmospheric vapor, which is typically greater then the amount actually transferred due to limits on soil water volumes and resistances in the path.
Frost
Authors: Holst Arthur M. 
Published: April 2005

Abstract
Essentially, a type of dew, frost is ice formed by the condensation of atmospheric water vapor on a surface. It generally occurs at night, and when frost forms, it can sometimes be seen in patterns of ice crystals. Frost can be extremely damaging to outdoor crops and plants. Researchers and weather services throughout the world monitor the effects of damaging frosts. Frost forms on any surface, including cars, grass, and buildings. Frost forms through one of two processes: the formation of dew that subsequently freezes, or deposition, which is the process wherein a gas changes to a solid. In frost formation, this gas is water vapor, and the solid state is ice crystals. These two processes will occur when the air is saturated. Saturation occurs when the air holds as much water vapor as is possible at its temperature and pressure. The temperature at which frost is deposited is known as the frost point temperature.
Isohyetal Method
Authors: Jain Sharad K. , Singh Vijay P. 
Published: April 2005

Abstract
The isohyetal method is used to estimate the mean precipitation across an area by drawing lines of equal precipitation. The method uses topographic and other data to yield reliable estimates. Isohyets are contours of equal precipitation analogous to contour lines on a topographic map. In the isohyetal method, precipitation values are plotted at their respective stations on a suitable base map, and isohyets are drawn to create an isohyetal map. Isohyetal lines are based on interpolation between rain gauge stations. While constructing isohyets, it is assumed that rainfall between two stations varies linearly, unless abrupt changes in topography indicate otherwise.
Permanent Frost
Authors: Holst Arthur M. 
Published: April 2005

Abstract
Frozen soil or rock that remains at a temperature of 0°C (32°F) or below for 2 or more years is permafrost. Permafrost is defined solely by temperature and is not determined by the amount of snow cover, soil moisture content, or its location. Permafrost may contain more than 30% ice or no ice at all, and may be topped by meters of snow cover or no snow at all. The defining characteristic of permafrost is its temperature.
Remote Sensing of Applications in Hydrology
Authors: Black Jessica , Endreny Theodore 
Published: April 2005

AbstractRemote sensing is the science of observing and analyzing an area, object, or phenomenon based on data collected by sensors physically separated from the target. The sensors are mounted on platforms such as ground‐based, airplane, or satellite platforms. Physical radiation transfer is the foundation for remote sensing. Typically, the observation is of radiation reflected or emitted from the object of interest. There are two types of remote sensing: active and passive. In active remote sensing, the object is illuminated by radiation of a known wavelength (or frequency); the backscatter from the object is recorded by the sensor. In passive remote sensing, the sensor records radiation generated from natural sources, such as the sun, or radiation emitted from the earth or atmosphere. Radiation that the sensor receives has a spectral response that reveals properties of the atmosphere and object of interest. By extending remote sensing applications to improve the spatial and temporal resolution of certain key water resource variables, scientists can better understand and quantify water resource processes.
Snow and Snowmelt
Authors: Singh Pratap 
Published: April 2005

Abstract
Snow is a solid form of precipitation. The formation of snow crystals inside a cloud depends on the presence of ice nuclei, water vapor, motion of the cloud, and the temperature of the cloud. Snow crystals are formed when the cloud temperature is below freezing. These crystals experience diffusional, accretional, and aggregational growth inside the cloud. At temperatures greater than about −5°C, crystals usually stick together, and aggregation of ice crystals forms snowflakes. Snowflakes obtain their maximum size when the temperature of a cloud is near 0°C. Aggregation of ice crystals ceases at temperatures below −20°C. Due to changes in the ambient condition of the cloud, the size and form of the crystals change when they descend through a cloud. In a typical cloud, a snowflake of 1 mm diameter can grow to 10 mm in about 20 minutes. Because of the irregular shapes of snowflakes, measurement of their linear dimensions is difficult. The maximum diameter of snowflakes may range from 0.1 mm to several centimeters.
Cloud Seeding
Authors: Holst Arthur M. 
Published: April 2005

Abstract
Cloud seeding is the deliberate treatment of certain clouds or cloud systems to affect the precipitation process within those clouds. The treating of clouds can alter weather conditions, thus cloud seeding is also called weather modification. The technology that led to cloud seeding has been developed only during the past 60 years. Yet as this technology becomes more efficient, increased worldwide application of cloud seeding for practical use is likely to continue into the future.
Waterspout
Authors: Holst Arthur M. 
Published: April 2005

Abstract
Tornadic waterspouts are tornadoes over water. These are stronger, larger, and faster than fair weather waterspouts. However, they do tend to form over land as true tornadoes before moving over water. Fair weather waterspouts form differently from tornadoes. Rather than developing downward, they begin at the surface, building up toward the sky.
For waterspouts to form, a series of things must occur. First, a small portion of air over the surface of water must become heated. As this warm air begins to rise, the cool air around it starts to form a small vortex of rotating air. This vortex of swirling air is carried upward by rising water vapor; waterspouts usually form over warm water because there is more water vapor present. Upon rising to an overhead cloud mass, the vortex forms a funnel cloud. At this point, a fair weather waterspout begins its five‐stage life cycle.
Cyclones
Authors: Holst Arthur M. 
Published: April 2005

Abstract
Cyclones are hazardous weather conditions characterized by extreme gusts of wind moving in a circular pattern, low pressure, and intense rain. They form over tropical or subtropical waters; however, some can reach land, where they have in the past inflicted great amounts of damage on buildings and communities.
Based on wind strength, cyclones are given various names. Tropical depressions have maximum surface winds of less than 39 mph. Those cyclones whose maximum winds are between 39 and 74 mph are known as tropical storms. Upon attaining 74‐mph surface winds, a cyclone is known as one of a number of names that are all regional equivalents of the same type of storm.
Droughts
Authors: Holst Arthur M. 
Published: April 2005

Abstract
A drought is a period of time during which weather is in one way or another excessively dry. A drought's severity is determined by the degree of moisture deficiency in the affected area, as measured by various methods. Droughts are a standard, recurring, and normal feature of long‐term climate. There are four generally accepted categories of drought: meteorological, socioeconomic, hydrologic, and agricultural.
Guide to Selection of Water Treatment Processes
Authors: Muntisov Michael 
Published: April 2005

Abstract
Selecting the appropriate treatment process is a critical step in providing safe, reliable, good quality drinking water at a cost‐effective price.
This article provides guidance in selecting appropriate treatment processes taking into account raw water quality and costs.
There is a need for raw water quality data covering an extended period sufficient to show seasonal and extreme events to make a sound decision on appropriate treatment processes.
Before any process is finally selected, it is important to carry out treatability testing on the actual source water. All waters have subtle differences, and these can have a significant effect on process selection and performance. As a minimum, coagulation jar tests should be performed.
To allow comparison between process options, particularly on a cost basis, it is appropriate to define a “benchmark” process.
The benchmark process is based on the most commonly used treatment configuration in the world, coagulation/clarification/granular media filtration.
Multistage Filtration: An Innovative Water Treatment Technology
Authors: de Jong Dick , Smet Jo 
Published: April 2005

Abstract
The technology of multiple stage filtration (MSF) presented here is a combination of coarse gravel prefiltration and slow sand filtration (SSF). This combination allows treating of surface water that has considerable levels of contamination, well above the levels that can be treated by SSF alone. To improve the performance of MSF, other treatment processes such as simple sedimentation, sand traps, and screens can precede MSF technology. Wherever possible, terminal disinfection needs to be included as a safety barrier after MSF.
MSF retains the advantages of SSF in that it is a robust and reliable treatment method that can be maintained by operators who have low levels of formal education. It is much better suited than conventional chemical water treatment to conditions in rural communities and small and medium size municipalities in the South as well as in more remote areas in the North. The article provides a summary description of the components of MSF systems and the findings of recent research. It gives an overview of cost implications and ends with a selection guide.
Municipal Watersheds
Authors: Downs Timothy J. 
Published: April 2005

Abstract
In a humid environment, as a society moves from a preindustrial economy to an industrial economy, its watersheds experience three main stages of development: (1) few encroachments on water resources; more than enough water for everyone; water is free; (2) transitional infrastructure, including dams for energy and irrigation and interbasin transfers between water‐rich and water‐scarce watersheds; and (3) maximum streamflow regulation achieved, and aquifers are at maximum sustainable yield, so further development is both expensive and threatens to be unsustainable. Unfortunately, in the case of several megacity watersheds, a fourth stage of overexploitation by intensifying exploitive infrastructure and interbasin transfers is testing the functional viability of municipal watersheds.
Reverse Osmosis, Membrane Foulants
Authors: Ning Robert Y. 
Published: April 2005

AbstractPeriodic cleaning of reverse osmosis (RO) membranes is generally accepted as a necessary routine maintenance operation in running water purification plants. Common foulants found in RO membrane elements include calcium carbonate, calcium sulfate, strontium sulfate, barium sulfate, calcium fluoride, calcium phosphate, ferric hydroxide, aluminum hydroxide, silica, silt, polymers from natural sources, and synthetic polymers used in pretreatment. These foulants may occur singly or in most cases, in complex combinations. Single foulants are simpler to address in prevention and dissolving (except for barium sulfate) during cleaning. Complex foulants usually resulting from coagulation of colloidal particles, offer the greatest challenge in prevention and removal during cleaning.
Reverse Osmosis, Process Chemistry
Authors: Ning Robert Y. 
Published: April 2005

AbstractThe RO process is sensitive to upstream treatments and itself impacts downstream operations. The almost infinite variety of contaminants that enter the membrane systems with the feedwater and the economic necessity to expend minimal resources on raw water pretreatment pose a major challenge to RO process chemistry design and control. RO process chemistry itself is important in understanding and controlling the quality of the product permeate water which may be further polished to remove trace contaminants to meet the ultrapure specifications needed in industries such as pharmaceuticals, microelectronics, and power generation. Presented here are the chemistry of feedwater membrane fouling mechanisms, composition of foulants, and chemicals used to prevent fouling.
Ten Key Trends That will Shape the Future of the World Water Industry
Authors: Maxwell Steve 
Published: April 2005

Abstract

Scholarly studies estimating future water demand and prerequisite capital expenditures are being released in rapid‐fire fashion—and each proclaims a more serious future water crisis than the last. The Water Environment Federation has estimated that wastewater capital requirements during the next 20 years in this country will total hundreds of billions of dollars. The AWWA itself published a report in 1999, which estimated that capital expenditures for upgrading the drinking water infrastructure could total more than $300 billion during the next 20 years. Finally, a report done for the House Water Resources Subcommittee leapfrogged all recent studies and estimated that the cost of building, operating, and maintaining the water and wastewater infrastructure in this country during the next two decades will exceed $2
trillion
!

Choose your number, but it is clear that the costs of providing clean water to an expanding population and growing economy will continue to mount. This has led to a gradual reawakening of a rather sleepy water business, and a period of substantial consolidation and realignment has transformed the industry. Ten overarching trends and developments characterize the U.S. drinking water industry and will combine to shape the business in the future.
Water Distribution System Operation
Authors: Buenfil‐Rodriguez Mario O. 
Published: April 2005

Abstract
The operational tasks for distributing clean water in a city involve monitoring flows, pressures, storage levels, and water quality at different network locations; controlling and moving valves; attending to reports and enquiries from the public; billing and charging for consumption; keeping updated infrastructure maps and consumer records and census; repairing leaks; and replacing or improving pipes, hydrants, pumps, and other water distribution networks components.

There is no clear or definite boundary between operational and maintenance tasks, and their distinction is merely the intensity or frequency of a given job. Sometimes, the same employee team performs operational, preventive, or corrective maintenance tasks. In contrast, other rather specialized tasks can require a contract with a private service provider (
as analyzing water samples to detect a specific and difficult pollutant or controlling and supervising a sophisticated automated pump
).
Seasonal Coupling Between Intertidal Macrofauna and Sediment Column Porewater Nutrient Concentrations
Authors: Magni Paolo , Montani Shigeru 
Published: April 2005

Abstract

It is well established that dense bivalve assemblages play a major role in the processes of benthic nutrient regeneration in coastal marine ecosystems. In recent years, there is increasing evidence of the close relationship between nutrient concentrations in sediments and macrofauna‐influenced upward flux of nutrients that enhances benthic primary productivity. This coupling has been shown, to varying degree, for a variety of benthic communities dominated by both suspension and deposit feeders. The former, including semi‐infaunal mussel species, such as
Musculista senhousia
and
Modiolus americanus
, filter particulate matter from the water column; the latter, such as holothurians, consume high amounts of sediment bacteria, microalgae, and dead organic matter. Due to the complexity and multiplicity of mechanisms that govern nutrient cycling in coastal ecosystems, these studies highlight the need for integrated investigations on the variability of porewater nutrient concentrations and the composition, biology, and behavior of
in situ
macrofaunal species.
Chlorine‐36 and Very Old Groundwaters
Authors: Kazemi Gholam A. 
Published: April 2005

Abstract
Chlorine has nine isotopes whose mass numbers range from 32 to 40, but only three of these occur naturally. The remaining six have half‐lives shorter than 1 hour, and this is why they do not occur in nature. The three abundant isotopes of chlorine include two stable isotopes, chlorine‐35 and chlorine‐37, with 75.53% and 24.47% abundances, respectively, and one radioactive isotope, chlorine‐36, with a half‐life of 301,000 ± 2000 years (some references ± 4000 years). The natural mixture of these three isotopes makes up environmental chlorine.

Weapon testing of fusion devices starting in late 1952 and extending through mid‐1958 has led to the production of up to 70,000 atoms m
−2
s
−1
. Chlorine‐36 produced by this phenomenon is used as a marker to age‐date young groundwaters that are less than 50 years old.
Conductivity‐Electric
Authors: Gray David M. 
Published: April 2005

Abstract
Electrical conductivity is the ability of a material to carry electrical current. In water, it is generally used as a measure of mineral or other ionic concentration. Conductivity is a measure of the purity of water or the concentration of ionized chemicals in water. However, conductivity is only a quantitative measurement: it responds to all ionic content and cannot distinguish particular conductive materials in the presence of others. Only ionizable materials will contribute to conductivity; materials such as sugars or oils are not conductive.

In a metal conductor, electrical current is the flow of electrons and is called
electronic
conductance. In water, electrical current is carried by ions because electrons do not pass through water by themselves. This is
electrolytic
conductance.

When a voltage is applied between two inert electrodes immersed in a solution, any ions between them will be attracted by the electrode that has an opposite charge. Ions will move between electrodes and produce a current depending on the electrical resistance of the solution. This is the basis of conductivity measurement—an application of Ohm's law. For high purity waters, it is common to express conductivity as its reciprocal, resistivity.
Dissolved Organic Carbon
Authors: Lead Jamie R. 
Published: April 2005

AbstractThe importance of dissolved organic carbon (DOC) lies in its role in the biogeochemical carbon cycle, as a necessary basis for aquatic microbial processes and in aquatic chemistry. Although the global burden of carbon is dominated by sediments, dissolved organic carbon is of obvious importance as carbon is the basis of life, an energy and nutrient source for microorganisms. DOC is also of significance in trace pollutant binding (and consequently in pollutant transport and bioavailability), in the charge and aggregation behavior of colloids, in weathering, in pH buffering, and in acid–base and redox chemistry of natural waters. It thus has a large and essential role in determining the chemical composition of natural waters. Although microbiological and chemical aspects are frequently taught and researched in isolation, it may be impossible to understand the composition and regulation of natural waters without simultaneously considering the microbiological and chemical processes because they are so closely interlinked. Any distinction between the two processes is therefore likely to be arbitrary and misleading.