bluuebunny/crossref_metadata_2025_split huggingface dataset:
Carbon Dioxide and Carbonate Chemistry of the Oceans
Authors: Cai Wei‐Jun 
Published: December 2019

Abstract

This article describes the acid–base properties of dissolved inorganic carbon (DIC) and the features of its distribution and cycling in the ocean. The DIC pool increases and becomes more enriched in molecular carbon dioxide (CO
2
) and lower in pH from surface to subsurface and from younger to older waters. Waters “age” and accumulate CO
2
as the deep ocean current moves around the global ocean, as organic matter settling from the productive sea surface is decomposed into CO
2
by microbes, and as calcium carbonate minerals are dissolved in the deep sea. In at least the past 500 000 years, CO
2
in the atmosphere regularly varied tightly between an upper bound of 280 and a lower bound of 180 ppm over several glacial cycles, indicating that the Earth's climate system and ocean carbon cycle were stable. Such stability has been disturbed at an unprecedented rate since the Industrial Revolution as human use of fossil fuel, and deforestation have released large amounts of CO
2
into the atmosphere and have pushed the atmospheric CO
2
level to over 400 ppm today. Part of the released anthropogenic CO
2
is taken up by the ocean, which has slowed down the greenhouse gas increase in the atmosphere but has acidified the seawater and altered ocean chemistry. This process, called ocean acidification, will continue and likely endanger marine organisms and ocean biological systems.
Ice Jams: Causes and Effects
Authors: Pawłowski Bogusław 
Published: December 2019

Abstract
In winter, in the temperate and cold climate zone, ice phenomena occur in rivers and lakes. Where the whole surface of water freezes up, an ice cover develops, and affecting the flow of water in rivers. An ice jam is a situation where a local accumulation of ice restricts the water flow. Ice jams can develop both in the initial phase of ice cover formation period and at the time of its breakup. Ice jams usually occur due to hydro‐meteorological conditions and local morphological properties of the river channel. They are formed by ice floes and frazil ice. The most important effect of an ice jam is the swelling of the river section upstream of the jam. The swelling may progress quickly and lead to flooding. The development of ice jams also results in changes of the river channel morphology and – in extreme cases – outside the channel, causing damage to engineering infrastructure. Despite the application of a number of measures to reduce the threat and consequences of ice jams, the phenomena are very difficult to predict. In the last decades, in some regions, their intensity has been curbed by global warming.
Removal of Contaminants of Emerging Concern from Wastewater
Authors: Dosoretz Carlos G. 
Published: December 2019

Abstract
Increased awareness regarding water pollution and resources conservation due to water scarcity and climate change, combined with intensive urbanization and agricultural production, have raised the need for removal of contaminants of emerging concern (CEC) from treated effluents. CEC include, among others, pharmaceuticals, cleaning and sanitation products, endocrine disrupting compounds, suspected carcinogens, and nanomaterials at trace concentration. Added to this are antibiotic‐resistant bacteria (ARB) and antibiotic‐resistant genes (ARG). Conventional wastewater treatment removes bulk organic contaminants leaving CEC in the effluents. This article discusses the incorporation of advanced treatments such as oxidation processes, adsorption, and tight membrane separation, i.e. reverse osmosis (RO), aimed at removing CEC from effluents. Owing to its generic capability to remove dissolved organic and inorganic contaminants at once, RO appears as the core technology for effluents purification. Besides improvements of existing municipal effluents, changes in conception, management and planning of the urban water systems, e.g. reduction at source and decentralization approaches, are required. Removal of dissolved organic pollutants and mineral contaminants at trace levels cannot be done without consuming energy. The water–energy nexus and related life cycle analyses need to be rethought in terms of environmental and health risks and deterioration of water resources and soils.
Advanced Oxidation Processes
Authors: Kovacic Marin , Kusic Hrvoje , Loncaric Bozic Ana , Dionysiou Dionysios D. 
Published: December 2019

AbstractThe efficient water purification is of high priority because water quality faces ever‐increasing challenges due to the pollution by a vast array of various organic pollutants, causing negative impact due to documented and suspected toxicity toward aquatic organisms and humans as well. In current focus are contaminants of emerging concern (CECs), including cyanotoxins, flame retardants, organohalogens and perfluorinated compounds, personal care products, pesticides, plasticizers, and pharmaceuticals, which are largely unaffected by current (waste)water treatment technologies, thus needing upgrade with a tertiary treatment. A potential solution for such water quality issues is advanced oxidation processes (AOPs), technologies exploiting the high reactivity, and nonselectivity of the hydroxyl radical (HO●) that can be generated by either chemical, radiation, electrical, or mechanical energy. Accordingly, AOPs can be classified into chemical, photo‐assisted, electrical, and mechanical (latter two can be gathered under the term “high energy”) processes that are described from the mechanistic point of view in this article.
Management of the Marine Environment: Transdisciplinary and Systemic Approach
Authors: Prouzet Patrick , Monaco André , Sébastien Léa 
Published: December 2019

AbstractSince the beginning of the twentieth century, observations have shown a significant degradation of aquatic environments. This degradation has got worse in the past century in all regions of the Globe. This is observed in many estuarine areas vital for the growth of high‐value species. Given the state of degradation of these coastal environments, their vulnerability to the anthropic effects and the natural hazards has become stronger whereas their resilience capacities have become significantly lower. The same goes for the many human communities living from the exploitation of living resources that can no longer ensure the sustainability of their fishing or farming activities. In addition to all these modifications the impacts, now proven, of climate change alter the temperature of water masses and biogeochemical characteristics of marine ecosystems. This integrated vision of the marine environment and of the aims of research makes it possible to address the issue of environmental governance and the problems involved in coordinating the knowledge and functions of scientific, social, economic and political actors. The three authors who are specialized in different fields of research exchange their points of view, redefine the terms, notions, concepts, and the questions related to the exercise of transdisciplinarity.
Applications of SPM to Studies of Mineral–Water Interface Chemistry
Authors: Higgins Steven R. , Bertagni Angela L. 
Published: December 2019

Abstract

The scanning probe microscope (SPM) has been utilized in studies of solid surfaces for nearly four decades. With resolution as high as the single atom level, valuable information on the structure and other properties of solid surfaces can be obtained. One of the most exciting areas of application for the SPM is in the study of mineral–water interfaces where the chemical reactions taking place are both of fundamental interest as well as important from an environmental/geochemical perspective. In this article, the basic design of one type of SPM, the atomic force microscope (AFM), is introduced followed by an examination of the different levels of resolution that may be exploited to obtain fundamental information on kink, step, and surface microtopography from mineral surfaces immersed in reactive solutions. The examples of these particular applications highlight the influence of solution chemistry on the rates and mechanisms of mineral growth and dissolution reactions that are readily followed with
in‐situ
AFM instrumentation.
Quantification of Anoxia and Hypoxia in Water Bodies
Authors: Nürnberg Gertrud K. 
Published: December 2019

Abstract

Anoxia and hypoxia are wide‐spread in freshwater systems and have been increasing in response to anthropogenic disturbances and climate change with biological and chemical implications. The concept of the
anoxic factor
to quantify anoxia and of the
hypoxic factor
for higher levels of dissolved oxygen concentration (DO) in lakes, reservoirs, and river sections has facilitated the exploration of hypoxia in a number of applications. This method condenses information from numerous individual DO profiles into annual values or
factors
that are comparable between and within lakes and hence invites the formulation and testing of hypotheses related to the DO status in water bodies. Besides the definition of the factors, proven and potential applications are described. They include the description of annual and spatial trend in anoxia or hypoxia, the evaluation of restoration techniques with respect to hypolimnetic oxygen depletion, the determination of internal phosphorus loading in stratified and polymictic lakes, the exploration of habitat constraints of fish due to hypoxia, and the examination of potential effects of climatic change on DO content and internal phosphorus loading.
Biofuels, Water Footprints, and Green Perspectives
Authors: Reijnders Lucas 
Published: December 2019

Abstract
Biofuels that are applied using advanced conversion technologies are promoted as green alternative to fossil fuels. The water footprint, the freshwater consumption, linked to current life cycles of such biofuels is much larger than the corresponding consumption associated with fossil fuels. Wind‐ and photovoltaic energy are also characterized by water footprints that are much lower than the corresponding consumption linked to biofuels. Food production and biofuel production increasingly compete for scarce freshwater resources and freshwater stress may increase when biofuel production expands. Availability of freshwater may be a limiting factor in biofuel production. Biofuel life cycles can also be associated with substantial water pollution burdens of nitrate, phosphate, pesticides, and organic substances. On the other hand, it has been proposed to use wastewater for the production of microalgal biofuels. So far, however, no full‐scale production based on this proposal that meets standards achieved by state‐of‐the‐art wastewater treatment facilities has been reported. In many respects relevant to green perspectives, except the consumption of geochemically scarce mineral resources, solar and wind‐based technologies tend to outperform biofuel‐based energy supply technologies. There would seem to be a case for modest expectations as to the share of biofuels that are applied using advanced conversion technologies in future energy supply.
Barometric Efficiency
Authors: Rasmussen Todd C. 
Published: December 2019

Abstract
The barometric efficiency is used to describe how water levels in wells fluctuate in response to atmospheric pressure. Normally, water levels rise whenever the barometric pressure falls, and vice versa. This phenomenon is observed in both confined and in deep, unconfined aquifers. In confined aquifers, the change in water level is caused by a change in the load (or force) applied to the Earth's surface by the atmospheric pressure. Higher atmospheric pressures increase the load, which is transferred to water in deeper aquifers, causing an increase in fluid pressures within the aquifer. In unconfined aquifers, the water level response is caused by a difference between air movement through the borehole and the existing pressure in the unsaturated zone. This deficit results in rapid water level change in the borehole region followed by a delayed change to the original level once the air pressure change reaches the water table. The slower change is a factor of the thickness and air permeability of the unsaturated zone.
Earth's Surface Energy Balance
Authors: Ohmura Atsumu 
Published: December 2019

AbstractThe Earth's surface energy balance is presented with the up‐to‐date information. The flow of energy is traced from the Sun through the atmosphere till it reaches the Earth's surface. The attenuation of solar radiation in the atmosphere is presented with respect to scattering and absorption, using satellite measurements, model simulations, and the radiation measurements at the surface. The transformation of solar radiation at the surface into various forms of energy is quantitatively illustrated with information obtained by direct flux observations and simulations by GCM. The atmosphere/surface‐combined system absorbs 70% of radiation coming from the Sun, of which 27% and 43% are absorbed by the atmosphere and the Earth's surface, respectively. On the surface, the largest amount of energy, 25% of the primary solar radiation, is expended for evaporation, 13% for net longwave cooling, and 5% for direct heating of the atmosphere. Therefore, the radiative energy at the surface is mainly converted into water vapor and participates for heating the system only by forming clouds. While evaporation takes place slowly from the entire Earth's surface, the formation of clouds happens in restricted space and time. This mechanism contributes to the enhancement of extreme precipitation and temperature in warming climate.
Evapotranspiration Monitoring
Authors: Fuster Rodrigo , Moletto‐Lobos Italo , Vargas Catherine , Mattar Cristian 
Published: December 2019

AbstractOne of the most important components of the earth's surface water balance is evapotranspiration, which regulates the exchange of energy between ground and atmosphere. The effects of global warming intensify the water demand and therefore, the potential scarcity of water could affect several landscapes and agricultural systems. Therefore, it is essential to monitor evapotranspiration in order to assess water use efficiency and drought risks. There are a several methods to estimate and monitor evapotranspiration (ET), which differ in accuracy, cost and complexity. In this article, we present a general background of ET concepts, then, direct, empirical and remote sensing‐based methods to estimate it and finally we conclude with some recent ET applications in Chile.
Ghijben–Herzberg Equilibrium
Authors: Holzbecher Ekkehard 
Published: December 2019

AbstractThe Ghijben–Herzberg equilibrium concerning the relation between the elevation of the freshwater table and the depth of the fresh–salt–water interface in coastal aquifers was formulated at the turn between the nineteenth and twentieth century. It was independently stated by Ghijben in the Netherlands and Herzberg in Germany and provides a simple formula based on the densities of the two water bodies. In the time past since its origin, there have been lots of different studies in research and applications. Limitations have been formulated and discovered. Extensions have been proposed to overcome the limitations and improve the applicability. Analytical and numerical methods have been developed and can be used nowadays for more detailed computations. However, the Ghijben–Herzberg formula has proved to be an easy rule of a thumb and a valid approximation in laboratory experiments and in the field.
Stable Isotopes of Water in Hydrogeology
Authors: Tweed S. , Leblanc Marc , Cartwright I. , Bass A. , Travi Y. , Marc V. , Bach T. Nguyen , Duc N. Dang , Massuel S. , Kumar U. Saravana 
Published: December 2019

Abstract
Groundwater is a pivotal resource for many human populations and ecosystems. However, in groundwater sciences (hydrogeology), there remain many challenges in understanding key processes; including groundwater origins, water fluxes, and controls on water quality. The stable isotopes of water are naturally occurring, form part of the water molecule, can be measured at high spatial and temporal resolutions and have predictable fractionations that may be used to understand key water cycle processes. Such qualities mean that stable isotopes are a key tracer in defining the spatial and temporal heterogeneity of groundwater systems. This article provides an overview of the use of stable isotopes to analyze (i) groundwater recharge from both rainfall and irrigation water, and presents case studies that highlight the use of stable isotopes to determine the frequency, rapidity, and origins of recharge; (ii) groundwater flow pathways including paleo‐groundwater and mixing processes, and case studies of deeply circulating mineral waters, groundwater mixing, and origins of paleo‐groundwater; (iii) groundwater discharge via evaporation, surface waters, and case studies that highlight the modeling of dynamic tropical river inflows and submarine groundwater discharge; and (iv) groundwater salinity, including a comparison of processes driving salinization in two regional groundwater basins.
Drinking Water and Human Health Challenges in the Twenty‐First Century
Authors: Makris Konstantinos C. 
Published: December 2019

Abstract
Water and human health issues are intertwined within a changing urban setting. There is a momentum of societal demand to act on the aging drinking water pipe infrastructure to protect human health and at the same time to devise control options that will promote further the well‐being and quality of urban life in the developed world. The main objective of this work was to critically review the main challenges, opportunities, and risks associated with drinking water's current and emerging pressures as exerted on human health in urban centers of middle‐ and high‐income countries. Discussion about drinking‐water distribution systems did not focus on their portion extending from the water meter to the home tap, i.e. the premise plumbing system characteristics. One city does not hold a single water quality metric that remains constant because it changes in the urban space and time. Bigger urban centers will be differentially more complex to address water and health risks because of their numerous neighborhoods (district‐metered areas, DMA) being spread apart geographically in large distances. The water and health issues are multidisciplinary in nature and demand the close cooperation among health scientists, engineers, environmental scientists, social scientists, economists, and policymakers to address each city's unique risks.
Optimization for Booster Chlorination
Authors: Islam Nilufar , Rodriguez Manuel J. 
Published: December 2019

AbstractContamination in water distribution network (DN) can be catastrophic if free residual disinfection is not present. To ensure drinking water quality in a DN, ensuring detectable levels of free residual chlorine is a common practice in most municipalities. Higher chlorine doses can be applied in this respect, but this can produce detrimental disinfection by‐products (DBPs) such as trihalomethane and Haloacetic acids, and chlorine‐related taste and odor complaints. Booster chlorination can be a possible solution in this regard where additional chlorine dosages are applied where free residual chlorine concentration is less or zero. However, that requires optimization studies to balance various issues related to over chlorination including higher cost related to installation and operation, higher DBPs, and taste and odor complaints. These optimization studies can not only help us in selecting dosages but also can help us in various other aspects including locating booster stations, deciding number of stations, and pumping scheduling. Unlike other optimization studies, booster chlorination‐related optimization studies also require appropriate variables, kinetics, objective functions, constraints, mathematical formulation, algorithm selection, and proper optimization operation. This article will highlight details of all these steps specific to booster chlorination.
Microbial Biofilms
Authors: Maurice Patricia A. 
Published: December 2019

Abstract

A biofilm is a microbial community held together by extracellular attachment features known as extracellular polymeric substances (EPS) in a distinct 3‐dimensional structure or “architecture.” In addition to the organic microbial and EPS components, biofilms generally also include abiotic components such as mineral particles or tooth or bone structures that serve as support and sometimes as sources of nutrients. Biofilms can occur in many environmental settings, from soils to streambeds to suspended particulates in estuaries. Biofilms are important not just in the environment but also in biomedicine; they can occur, for example, on the surfaces of hip and other joint replacements and in the lungs of cystic fibrosis patients. This article serves as an introduction to biofilms, which are covered in greater depth in a variety of other articles in the
Encyclopedia
, particularly within the realm of microbiology and water and wastewater technology.
Deep‐Sea Hydrothermal Vents
Authors: Luke Tara H. 
Published: December 2019

AbstractHydrothermal vents were first discovered on the Galapagos Rift in 1977, and in the intervening 4 decades we have learned a great deal about these unique oases of life in the cold, dark, high pressure environments of the deep seafloor. Found on mid‐ocean ridges, back‐arc basins, and seamounts around the world, they result from the interaction of cold seawater with oceanic crust that has been superheated by underlying volcanic activity. Hydrothermal fluids leave the seafloor and form sulfide chimneys. These fluids are highly reducing, and contain toxic materials such as hydrogen sulfide, which provides the necessary components of life for the chemoautotrophic organisms forming the base of the food web in these ecosystems. Animals living at these vents have adapted to the harsh conditions by relying on chemoautotrophic microorganisms, either directly as a source of food, or in symbiotic association. They use varied strategies to maintain their symbiotic associations and to thrive at hydrothermal vents. While many animals characterize vent communities, some specific examples including tubeworms, Pompeii worms, mollusks, and crustaceans are described in more detail here. As we learn more about these widely spaced communities biogeographical patterns emerge, increasing our understanding of the evolution of vent communities.
Environmental and Public Health Issues: Community Engagement in Environmental Justice Populations
Authors: Neet Matthew J. , Ellis Jamelle H. , Hart Zachary H. , Scott Geoffrey I. , Friedman Daniela B. , Kelsey Rense Heath , Porter Dwayne E. 
Published: December 2019

AbstractEnvironmental factors, ranging from the air we breathe to the food and water we consume to the places where we live and work, serve as major determinants of human health. A particularly relevant source of environmental risk is fish consumption, which provides an important source of protein and other nutrients for communities worldwide. The health risks associated with consuming contaminated fish are pronounced among environmental justice communities – communities that experience a disproportionate exposure to environmental contamination such as water pollution or air pollution. In these communities, which are typically situated in low‐income areas, the fish caught from local waters for sustenance are more likely to contain unsafe levels of contaminants or pathogens. Community engagement is now recognized as an essential strategy for designing and delivering messages that reduce exposure to a range of environmental risks to public health, especially among environmental justice communities. This article reviews a method for identifying environmental justice communities and then discusses a case study in which community engagement was employed successfully to better understand exposure to environmental health risks and examine state‐issued fish consumption advisories within an environmental justice community.