Water

524 KiB

Open AccessArticle

Water Label to Improve Water Billing in Spanish Households

by Ana Castillo-Martinez, Alberto Gutierrez-Escolar, Jose-Maria Gutierrez-Martinez, Jose M. Gomez-Pulido and Eva Garcia-Lopez

Water 2014, 6(5), 1467-1481; https://doi.org/10.3390/w6051467 - 23 May 2014

Cited by 9 | Viewed by 8118

Abstract

A significant decrease in water consumption has been achieved in recent years thanks to different campaigns run by different institutions in Spain. However, most citizens do not have a very clear idea about whether or not they are efficiently using water. To solve [...] Read more.

A significant decrease in water consumption has been achieved in recent years thanks to different campaigns run by different institutions in Spain. However, most citizens do not have a very clear idea about whether or not they are efficiently using water. To solve this situation, this paper aims is to develop two water labels in order to improve the current water billing. These water labels evaluate the total water consumption and the domestic hot water consumption. To make the tags, several research studies were tackled for establishing consumer trends and behavior patterns. Furthermore, a survey and data collection were conducted to obtain updated values to validate information obtained from previous studies. The result are two water labels that establish six different levels to graphically show the efficiency, and they also include a comparison with the average consumption by customers of the same province. To ensure that the benefits of this evaluation are available to citizens, its inclusion on the water bill is proposed. Full article

(This article belongs to the Special Issue Water Consumption and Water End-uses in Buildings)

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743 KiB

Open AccessArticle

Water, Sanitation and Hygiene Conditions in Kenyan Rural Schools: Are Schools Meeting the Needs of Menstruating Girls?

by Kelly T. Alexander, Clifford Oduor, Elizabeth Nyothach, Kayla F. Laserson, Nyaguara Amek, Alie Eleveld, Linda Mason, Richard Rheingans, Caryl Beynon, Aisha Mohammed, Maurice Ombok, David Obor, Frank Odhiambo, Robert Quick and Penelope A. Phillips-Howard

Water 2014, 6(5), 1453-1466; https://doi.org/10.3390/w6051453 - 22 May 2014

Cited by 64 | Viewed by 21653

Abstract

Water, sanitation and hygiene (WASH) programs in African schools have received increased attention, particularly around the potential impact of poor menstrual hygiene management (MHM) on equity for girls’ education. This study was conducted prior to a menstrual feasibility study in rural Kenya, to [...] Read more.

Water, sanitation and hygiene (WASH) programs in African schools have received increased attention, particularly around the potential impact of poor menstrual hygiene management (MHM) on equity for girls’ education. This study was conducted prior to a menstrual feasibility study in rural Kenya, to examine current WASH in primary schools and the resources available for menstruating schoolgirls. Cross-sectional surveys were performed in 62 primary schools during unannounced visits. Of these, 60% had handwashing water, 13% had washing water in latrines for menstruating girls, and 2% had soap. Latrines were structurally sound and 16% were clean. Most schools (84%) had separate latrines for girls, but the majority (77%) had no lock. Non-governmental organizations (NGOs) supported WASH in 76% of schools. Schools receiving WASH interventions were more likely to have: cleaner latrines (Risk Ratio (RR) 1.5; 95% Confidence Intervals [CI] 1.0, 2.1), handwashing facilities (RR 1.6, CI 1.1, 2.5), handwashing water (RR 2.7; CI 1.4, 5.2), and water in girls’ latrines (RR 4.0; CI 1.4, 11.6). Schools continue to lack essential WASH facilities for menstruating girls. While external support for school WASH interventions improved MHM quality, the impact of these contributions remains insufficient. Further support is required to meet international recommendations for healthy, gender-equitable schools. Full article

(This article belongs to the Special Issue Water Treatment and Human Health)

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652 KiB

Open AccessArticle

Global Changes and Drivers of the Water Footprint of Food Consumption: A Historical Analysis

by Chen Yang and Xuefeng Cui

Water 2014, 6(5), 1435-1452; https://doi.org/10.3390/w6051435 - 22 May 2014

Cited by 22 | Viewed by 12270

Abstract

Water is one of the most important limiting resources for food production. How much water is needed for food depends on the size of the population, average food consumption patterns and food production per unit of water. These factors show large differences around [...] Read more.

Water is one of the most important limiting resources for food production. How much water is needed for food depends on the size of the population, average food consumption patterns and food production per unit of water. These factors show large differences around the world. This paper analyzes sub-continental dynamics of the water footprint of consumption (WF_cons) for the prevailing diets from 1961 to 2009 using data from the Food and Agriculture Organization (FAO). The findings show that, in most regions, the water needed to feed one person decreased even if diets became richer, because of the increase in water use efficiency in food production during the past half-century. The logarithmic mean Divisia index (LMDI) decomposition approach is used to analyze the contributions of the major drivers of WF_cons for food: population, diet and agricultural practices (output per unit of water). We compare the contributions of these drivers through different subcontinents, and find that population growth still was the major driver behind increasing WF_cons for food until now and that potential water savings through agricultural practice improvements were offset by population growth and diet change. The changes of the factors mentioned above were the largest in most developing areas with rapid economic development. With the development of globalization, the international food trade has brought more and more water savings in global water use over time. The results indicate that, in the near future and in many regions, diet change is likely to override population growth as the major driver behind WF_cons for food. Full article

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1072 KiB

Open AccessArticle

Assessment of Hydrologic Alterations Caused by the Three Gorges Dam in the Middle and Lower Reaches of Yangtze River, China

by Liuzhi Jiang, Xuan Ban, Xuelei Wang and Xiaobin Cai

Water 2014, 6(5), 1419-1434; https://doi.org/10.3390/w6051419 - 22 May 2014

Cited by 89 | Viewed by 9813

Abstract

Hydrologic regime plays a major role in structuring biotic diversity within river ecosystems by controlling key habitat conditions within the river channel and floodplain. Daily flow records from seven hydrological stations and the range of variability approach were utilized to investigate the variability [...] Read more.

Hydrologic regime plays a major role in structuring biotic diversity within river ecosystems by controlling key habitat conditions within the river channel and floodplain. Daily flow records from seven hydrological stations and the range of variability approach were utilized to investigate the variability and spatial pattern of the hydrologic alterations induced by the construction of the Three Gorges Dam (TGD) in the middle and lower reaches of the Yangtze River, China. Results show that the impoundment of the TGD disturbed the hydrologic regime downstream and directly affected the streamflow variations. The rate of changes and the annual extreme conditions were more affected by the TGD, particularly the low-flow relevant parameters. The alterations in the hydrologic regime were mainly caused by the TGD storing water during early autumn and releasing water during winter and spring. The effects on spatial patterns decreased as the distance from the dam increased, which was mainly attributed to the inflows from large tributaries along the Yangtze River as well as the interaction with the two largest natural lakes (i.e., Dongting Lake and Poyang Lake). These hydrologic alterations not only break the natural balance of eco-flow regimes but also result in undesirable ecological effects, particularly in terms of habitat availability for the fish community. Full article

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381 KiB

Open AccessReview

Long-term Trends of Organic Carbon Concentrations in Freshwaters: Strengths and Weaknesses of Existing Evidence

by Montserrat Filella and Juan Carlos Rodríguez-Murillo

Water 2014, 6(5), 1360-1418; https://doi.org/10.3390/w6051360 - 20 May 2014

Cited by 39 | Viewed by 7811

Abstract

Many articles published in the last few years start with the assumption that the past decades have seen an increase in dissolved organic carbon (DOC) concentrations in the rivers and lakes of the Northern Hemisphere. This study analyses whether the existing evidence supports [...] Read more.

Many articles published in the last few years start with the assumption that the past decades have seen an increase in dissolved organic carbon (DOC) concentrations in the rivers and lakes of the Northern Hemisphere. This study analyses whether the existing evidence supports this claim. With this aim, we have collected published studies where long series of organic carbon concentrations (i.e., longer than 10 years) were analyzed for existing trends and have carefully evaluated the 63 articles found. Information has been collated in a comprehensive and comparable way, allowing readers to easily access it. The two main aspects considered in our analysis have been the analytical methods used and the data treatment methods applied. Both are sensitive issues because, on the one hand, the difficulties associated with correctly determining organic carbon concentrations in surface waters are well known, while, on the other, dealing with real environmental data (i.e., lack of normality, censoring, missing values, etc.) is an extremely intricate matter. Other issues such as data reporting and the geographical location of the systems studied are also discussed. In conclusion, it is clear that organic carbon concentrations have increased in some surface waters in the Northern Hemisphere since the 1990s. However, due to a lack of data in many parts of the world, it is not known whether this phenomenon is general and, more importantly, in the areas for which such data do exist, the reporting and methodological problems in the published studies prevent any conclusion on the existence of a general temporal behavior of organic carbon from being drawn. Full article

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622 KiB

Open AccessArticle

Regional Calibration of SCS-CN L-THIA Model: Application for Ungauged Basins

by Ji-Hong Jeon, Kyoung Jae Lim and Bernard A. Engel

Water 2014, 6(5), 1339-1359; https://doi.org/10.3390/w6051339 - 14 May 2014

Cited by 31 | Viewed by 8918

Abstract

Estimating surface runoff for ungauged watershed is an important issue. The Soil Conservation Service Curve Number (SCS-CN) method developed from long-term experimental data is widely used to estimate surface runoff from gaged or ungauged watersheds. Many modelers have used the documented SCS-CN parameters [...] Read more.

Estimating surface runoff for ungauged watershed is an important issue. The Soil Conservation Service Curve Number (SCS-CN) method developed from long-term experimental data is widely used to estimate surface runoff from gaged or ungauged watersheds. Many modelers have used the documented SCS-CN parameters without calibration, sometimes resulting in significant errors in estimating surface runoff. Several methods for regionalization of SCS-CN parameters were evaluated. The regionalization methods include: (1) average; (2) land use area weighted average; (3) hydrologic soil group area weighted average; (4) area combined land use and hydrologic soil group weighted average; (5) spatial nearest neighbor; (6) inverse distance weighted average; and (7) global calibration method, and model performance for each method was evaluated with application to 14 watersheds located in Indiana. Eight watersheds were used for calibration and six watersheds for validation. For the validation results, the spatial nearest neighbor method provided the highest average Nash-Sutcliffe (NS) value at 0.58 for six watersheds but it included the lowest NS value and variance of NS values of this method was the highest. The global calibration method provided the second highest average NS value at 0.56 with low variation of NS values. Although the spatial nearest neighbor method provided the highest average NS value, this method was not statistically different than other methods. However, the global calibration method was significantly different than other methods except the spatial nearest neighbor method. Therefore, we conclude that the global calibration method is appropriate to regionalize SCS-CN parameters for ungauged watersheds. Full article

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3402 KiB

Open AccessArticle

Benthic Communities of Low-Order Streams Affected by Acid Mine Drainages: A Case Study from Central Europe

by Marek Svitok, Milan Novikmec, Peter Bitušík, Branislav Máša, Jozef Oboňa, Miroslav Očadlík and Eva Michalková

Water 2014, 6(5), 1312-1338; https://doi.org/10.3390/w6051312 - 14 May 2014

Cited by 13 | Viewed by 7491

Abstract

Only little attention has been paid to the impact of acid mine drainages (AMD) on aquatic ecosystems in Central Europe. In this study, we investigate the physico-chemical properties of low-order streams and the response of benthic invertebrates to AMD pollution in the Banská [...] Read more.

Only little attention has been paid to the impact of acid mine drainages (AMD) on aquatic ecosystems in Central Europe. In this study, we investigate the physico-chemical properties of low-order streams and the response of benthic invertebrates to AMD pollution in the Banská Štiavnica mining region (Slovakia). The studied streams showed typical signs of mine drainage pollution: higher conductivity, elevated iron, aluminum, zinc and copper loads and accumulations of ferric precipitates. Electric conductivity correlated strongly with most of the investigated elements (weighted mean absolute correlation = 0.95) and, therefore, can be recommended as a good proxy indicator for rapid AMD pollution assessments. The diversity and composition of invertebrate assemblages was related to water chemistry. Taxa richness decreased significantly along an AMD-intensity gradient. While moderately affected sites supported relatively rich assemblages, the harshest environmental conditions (pH < 2.5) were typical for the presence of a limited number of very tolerant taxa, such as Oligochaeta and some Diptera (Limnophyes, Forcipomyiinae). The trophic guild structure correlated significantly with AMD chemistry, whereby predators completely disappeared under the most severe AMD conditions. We also provide a brief review of the AMD literature and outline the needs for future detailed studies involving functional descriptors of the impact of AMD on aquatic ecosystems. Full article

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509 KiB

Open AccessArticle

Tertiary Denitrification of the Secondary Effluent by Denitrifying Biofilters Packed with Different Sizes of Quartz Sand

by Nan Wei, Yunhong Shi, Guangxue Wu, Hongying Hu, Yihui Wu and Hui Wen

Water 2014, 6(5), 1300-1311; https://doi.org/10.3390/w6051300 - 13 May 2014

Cited by 29 | Viewed by 8297

Abstract

Tertiary denitrification of the secondary effluent in wastewater treatment plants is necessary to control the eutrophication of receiving water bodies. Two denitrifying biofilters (DNBF), one packed with quart sand with sizes of 2–4 mm (DNBF_S) and the other of 4–6 mm [...] Read more.

Tertiary denitrification of the secondary effluent in wastewater treatment plants is necessary to control the eutrophication of receiving water bodies. Two denitrifying biofilters (DNBF), one packed with quart sand with sizes of 2–4 mm (DNBF_S) and the other of 4–6 mm (DNBF_L), were operated for tertiary denitrification under empty bed retention times (EBRTs) of 30 min, 15 min and 7.5 min, respectively. Under EBRTs of 30 min, 15 min and 7.5 min, the NO₃⁻-N removal percentages were 93%, 82% and 83% in DNBF_S, and were 92%, 68% and 36% in DNBF_L, respectively. The nitrogen removal loading rates increased with decreasing EBRTs, and at the EBRT of 7.5 min, the rate was 2.15 kg/(m³·d) in DNBF_S and 1.08 kg/(m³·d) in DNBF_L. The half-order denitrification coefficient of DNBF_S increased from 0.42 (mg/L)^1/2/min at the EBRT of 30 min to 0.70 (mg/L)^1/2/min at the EBRT of 7.5 min, while did not vary much in DNBF_L with values from 0.22 to 0.25 (mg/L)^1/2/min. The performance of both DNBFs was stable within each backwashing cycle, with the NO₃⁻-N removal percentage variation within 5%. Better denitrification was achieved in DNBF_S but with a slightly high decreased flow rate during the operation. Full article

(This article belongs to the Special Issue Wastewater Treatment and Reuse)

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5789 KiB

Open AccessArticle

Simplified Flood Inundation Mapping Based On Flood Elevation-Discharge Rating Curves Using Satellite Images in Gauged Watersheds

by Younghun Jung, Dongkyun Kim, Dongwook Kim, Munmo Kim and Seung Oh Lee

Water 2014, 6(5), 1280-1299; https://doi.org/10.3390/w6051280 - 9 May 2014

Cited by 38 | Viewed by 9961

Abstract

This study suggests an approach to obtain flood extent boundaries using spatial analysis based on Landsat-5 Thematic Mapper imageries and the digital elevation model. The suggested approach firstly extracts the flood inundation areas using the ISODATA image-processing algorithm from four Landsat 5TM imageries. [...] Read more.

This study suggests an approach to obtain flood extent boundaries using spatial analysis based on Landsat-5 Thematic Mapper imageries and the digital elevation model. The suggested approach firstly extracts the flood inundation areas using the ISODATA image-processing algorithm from four Landsat 5TM imageries. Then, the ground elevations at the intersections of the extracted flood extent boundaries and the specified river cross sections are read from the digital elevation to estimate the elevation-discharge relationship. Lastly, the flood extent is generated based on the estimated elevation-discharge relationship. The methodology was tested over two river reaches in Indiana, United States. The estimated elevation-discharge relationship showed a good match with the correlation coefficients varying between 0.82 and 0.99. In addition, self-validation was also performed for the estimated spatial extent of the flood by comparing it to the waterbody extracted from the Landsat images used to develop the elevation-discharge relationship. The result indicated that the match between the estimated and the extracted flood extents was better with higher flood magnitude. We expect that the suggested methodology will help under-developed and developing countries to obtain flood maps, which have difficulties getting flood maps through traditional approaches based on computer modeling. Full article

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240 KiB

Open AccessArticle

Economics of Managed Aquifer Recharge

by Robert G. Maliva

Water 2014, 6(5), 1257-1279; https://doi.org/10.3390/w6051257 - 9 May 2014

Cited by 66 | Viewed by 13343

Abstract

Managed aquifer recharge (MAR) technologies can provide a variety of water resources management benefits by increasing the volume of stored water and improving water quality through natural aquifer treatment processes. Implementation of MAR is often hampered by the absence of a clear economic [...] Read more.

Managed aquifer recharge (MAR) technologies can provide a variety of water resources management benefits by increasing the volume of stored water and improving water quality through natural aquifer treatment processes. Implementation of MAR is often hampered by the absence of a clear economic case for the investment to construct and operate the systems. Economic feasibility can be evaluated using cost benefit analysis (CBA), with the challenge of monetizing benefits. The value of water stored or treated by MAR systems can be evaluated by direct and indirect measures of willingness to pay including market price, alternative cost, value marginal product, damage cost avoided, and contingent value methods. CBAs need to incorporate potential risks and uncertainties, such as failure to meet performance objectives. MAR projects involving high value uses, such as potable supply, tend to be economically feasible provided that local hydrogeologic conditions are favorable. They need to have low construction and operational costs for lesser value uses, such as some irrigation. Such systems should therefore be financed by project beneficiaries, but dichotomies may exist between beneficiaries and payers. Hence, MAR projects in developing countries may be economically viable, but external support is often required because of limited local financial resources. Full article

(This article belongs to the Special Issue Policy and Economics of Managed Aquifer Recharge and Water Banking)

198 KiB

Open AccessArticle

Response of Vegetables to Cadmium-Enriched Soil

by Babak Ebrazi Bakhshayesh, Madjid Delkash and Miklas Scholz

Water 2014, 6(5), 1246-1256; https://doi.org/10.3390/w6051246 - 7 May 2014

Cited by 23 | Viewed by 7005

Abstract

Environmental and water pollution through heavy metals is a growing concern. The recycling of untreated wastewater, which is often contaminated with heavy metals, for agricultural applications is becoming more popular. However, information on the amount of absorption and accumulation of cadmium (Cd) at [...] Read more.

Environmental and water pollution through heavy metals is a growing concern. The recycling of untreated wastewater, which is often contaminated with heavy metals, for agricultural applications is becoming more popular. However, information on the amount of absorption and accumulation of cadmium (Cd) at variable concentrations by different crops is limited. This study aims to analyze the impact of various Cd concentrations (0, 30, 60 and 120 mg/kg) in the root zone on the quantity of its absorption as well as accumulation in various parts of seven different types of common vegetables. The experiments were carried out under laboratory-like controlled conditions. Four treatments and three replicates were selected. Cadmium accumulation exceeded the permissible limits for human consumption, and its accumulation in different plant parts followed this order: Leaves: broccoli > spinach > basil > garlic > carrot > tarragon > dill. Stems: broccoli > spinach > basil > garlic > tarragon > carrot > dill. Roots: broccoli > garlic > basil > spinach > carrot > dill > tarragon. Therefore, the authors recommend the reuse of treated wastewater, which should be virtually free of contaminants such as heavy metals, to irrigate farm lands in the future. Full article

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3701 KiB

Open AccessArticle

Sensitivity of Distributed Hydrologic Simulations to Ground and Satellite Based Rainfall Products

by Singaiah Chintalapudi, Hatim O. Sharif and Hongjie Xie

Water 2014, 6(5), 1221-1245; https://doi.org/10.3390/w6051221 - 7 May 2014

Cited by 29 | Viewed by 7794

Abstract

In this study, seven precipitation products (rain gauges, NEXRAD MPE, PERSIANN 0.25 degree, PERSIANN CCS-3hr, PERSIANN CCS-1hr, TRMM 3B42V7, and CMORPH) were used to force a physically-based distributed hydrologic model. The model was driven by these products to simulate the hydrologic response of [...] Read more.

In this study, seven precipitation products (rain gauges, NEXRAD MPE, PERSIANN 0.25 degree, PERSIANN CCS-3hr, PERSIANN CCS-1hr, TRMM 3B42V7, and CMORPH) were used to force a physically-based distributed hydrologic model. The model was driven by these products to simulate the hydrologic response of a 1232 km² watershed in the Guadalupe River basin, Texas. Storm events in 2007 were used to analyze the precipitation products. Comparison with rain gauge observations reveals that there were significant biases in the satellite rainfall products and large variations in the estimated amounts. The radar basin average precipitation compared very well with the rain gauge product while the gauge-adjusted TRMM 3B42V7 precipitation compared best with observed rainfall among all satellite precipitation products. The NEXRAD MPE simulated streamflows matched the observed ones the best yielding the highest Nash-Sutcliffe Efficiency correlation coefficient values for both the July and August 2007 events. Simulations driven by TRMM 3B42V7 matched the observed streamflow better than other satellite products for both events. The PERSIANN coarse resolution product yielded better runoff results than the higher resolution product. The study reveals that satellite rainfall products are viable alternatives when rain gauge or ground radar observations are sparse or non-existent. Full article

(This article belongs to the Special Issue Advances in Remote Sensing of Flooding)

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612 KiB

Open AccessArticle

Simulating Volumetric Pricing for Irrigation Water Operational Cost Recovery under Complete and Perfect Information

by Luca Giraldo, Raffaele Cortignani and Gabriele Dono

Water 2014, 6(5), 1204-1220; https://doi.org/10.3390/w6051204 - 7 May 2014

Cited by 10 | Viewed by 7151

Abstract

This study evaluated the implementation of a volumetric and cost-recovery pricing method for irrigation water under symmetric information conditions without the inclusion of implementation costs. The study was carried out in two steps. First, a cost function was estimated for irrigation water supplied [...] Read more.

This study evaluated the implementation of a volumetric and cost-recovery pricing method for irrigation water under symmetric information conditions without the inclusion of implementation costs. The study was carried out in two steps. First, a cost function was estimated for irrigation water supplied by a water user association to a typical Mediterranean agricultural area, based on a translog function. Second, the economic impact of a pricing method designed according to this cost function was simulated using a mathematical programming territorial model for the same agricultural area. The outcomes were compared with those for the current pricing method. The impacts of this pricing method are discussed in terms of its neutral effects on total farm income and, conversely, the importance of the redistributive effects. Full article

(This article belongs to the Special Issue Water Policy, Productivity and Economic Efficiency)

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371 KiB

Open AccessArticle

Water Security and Services in the Caribbean

by Adrian Cashman

Water 2014, 6(5), 1187-1203; https://doi.org/10.3390/w6051187 - 5 May 2014

Cited by 33 | Viewed by 17486

Abstract

The efficient management of water resources and services continues to be a concern in many of the small island states of the Caribbean. There are growing concerns over the ability of governments in the region to ensure the good management and provision of [...] Read more.

The efficient management of water resources and services continues to be a concern in many of the small island states of the Caribbean. There are growing concerns over the ability of governments in the region to ensure the good management and provision of water without jeopardizing economic growth and the maintenance of social well-being. This paper provides an overview of the major factors influencing the water security facing the Caribbean Region and how the emerging concerns are being addressed. The key challenges and vulnerabilities may be summarized as lack of data and barriers to making available what information there is. Forward planning has been largely neglected and is symptomatic of a lack of appreciation of the need for having national water policies. In this respect Jamaica’s development of a national master water plan serves as a good example of what is needed. Water service providers have to be efficient, well managed and allowed to do their job. This means that they have to be on a sound financial footing. The challenge is to find the balance between appropriate political and regulatory oversight and the autonomy of water managers and service providers. Full article

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263 KiB

Open AccessArticle

Establishment of the Underlying Rationale and Description of a Cheap Nanofiltration-Based Method for Supplementing Desalinated Water with Magnesium Ions

by Liat Birnhack, Oded Nir and Ori Lahav

Water 2014, 6(5), 1172-1186; https://doi.org/10.3390/w6051172 - 5 May 2014

Cited by 24 | Viewed by 11081

Abstract

The importance of supplying drinking water with a balanced mineral composition, including a minimal concentration of Mg(II) ions, has been recently acknowledged by many publications, as well as in official WHO guidelines. The issue is relevant to naturally occurring soft waters and lately [...] Read more.

The importance of supplying drinking water with a balanced mineral composition, including a minimal concentration of Mg(II) ions, has been recently acknowledged by many publications, as well as in official WHO guidelines. The issue is relevant to naturally occurring soft waters and lately to the rapidly increasing volume of supplied desalinated water. This paper presents an enhancement of a recently developed nanofiltration-based method for the selective separation of soluble Mg(II) species from seawater. The generated rich-Mg(II) brine is demonstrated to be suitable for supplementing soft waters with magnesium ions. The brine, generated using a commercial membrane (DS-5 DL, Osmonics) at various operational conditions is characterized by high Mg(II) concentrations (~8.5 g/L) and low Cl:Mg and Na:Mg molar concentration ratios (1.6 and 0.6, respectively, at 28-bar operation). A food-grade antiscalant is dosed to the feed seawater to prevent scaling; however, since the Mg(II) concentration in the brine is high, for attaining 10 mg Mg/L of desalinated water, the dilution ratio with the desalinated water is ~1:850, resulting in maximal additional concentrations of 0.024 antiscalant, 34.9 Cl(−I), 12.9 Na(I), 0.05 Sr(II) and 0.003 B (all concentrations in mg/L). The overall cost of 1 kg of Mg(II) separated by the presented process amounts to between $0.05 and $0.07, i.e., much cheaper than the estimated costs of alternative processes for Mg(II) addition to desalinated water. Full article

(This article belongs to the Special Issue Water Treatment and Human Health)

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4034 KiB

Open AccessArticle

A New Method for Urban Storm Flood Inundation Simulation with Fine CD-TIN Surface

by Zhifeng Li, Lixin Wu, Wei Zhu, Miaole Hou, Yizhou Yang and Jianchun Zheng

Water 2014, 6(5), 1151-1171; https://doi.org/10.3390/w6051151 - 5 May 2014

Cited by 16 | Viewed by 7955

Abstract

Urban storm inundation, which frequently has dramatic impacts on city safety and social life, is an emergent and difficult issue. Due to the complexity of urban surfaces and the variety of spatial modeling elements, the lack of detailed hydrological data and accurate urban [...] Read more.

Urban storm inundation, which frequently has dramatic impacts on city safety and social life, is an emergent and difficult issue. Due to the complexity of urban surfaces and the variety of spatial modeling elements, the lack of detailed hydrological data and accurate urban surface models compromise the study and implementation of urban storm inundation simulations. This paper introduces a Constrained Delaunay Triangular Irregular Network (CD-TIN) to model fine urban surfaces (based on detailed ground sampling data) and subsequently employs a depression division method that refers to Fine Constrained Features (FCFs) to construct computational urban water depressions. Storm-runoff yield is placed through mass conservation to calculate the volume of rainfall, runoff and drainage. The water confluences between neighboring depressions are provided when the water level exceeds the outlet of a certain depression. Numerical solutions achieved through a dichotomy are introduced to obtain the water level. Therefore, the continuous inundation process can be divided into different time intervals to obtain a series of inundation scenarios. The main campus of Beijing Normal University (BNU) was used as a case study to simulate the “7.21” storm inundation event to validate the usability and suitability of the proposed methods. In comparing the simulation results with in-situ observations, the proposed method is accurate and effective, with significantly lower drainage data requirements being obtained. The proposed methods will also be useful for urban drainage design and city inundation emergency preparations. Full article

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812 KiB

Open AccessReview

Desalination Technologies: Hellenic Experience

by Konstantinos Zotalis, Emmanuel G. Dialynas, Nikolaos Mamassis and Andreas N. Angelakis

Water 2014, 6(5), 1134-1150; https://doi.org/10.3390/w6051134 - 30 Apr 2014

Cited by 74 | Viewed by 21769

Abstract

Beyond doubt, desalination is growing rapidly worldwide. However, there are still obstacles to its wider implementation and acceptance such as: (a) high costs and energy use for fresh water production; (b) environmental impacts from concentrate disposal; (c) a complex, convoluted and time-consuming project [...] Read more.

Beyond doubt, desalination is growing rapidly worldwide. However, there are still obstacles to its wider implementation and acceptance such as: (a) high costs and energy use for fresh water production; (b) environmental impacts from concentrate disposal; (c) a complex, convoluted and time-consuming project permitting process; and (d) limited public understanding of the role, importance, benefits and environmental challenges of desalination. In this paper, a short review of desalination in Greece is being made. Data on the cost of desalination shows a decrease in the future and the potential of water desalination in Greece. The paper summarizes the current status in southeastern Greece (e.g., Aegean islands and Crete), and investigates the possibility of production of desalinated water from brackish water. Full article

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Open AccessArticle

Retention and Curve Number Variability in a Small Agricultural Catchment: The Probabilistic Approach

by Kazimierz Banasik, Agnieszka Rutkowska and Silvia Kohnová

Water 2014, 6(5), 1118-1133; https://doi.org/10.3390/w6051118 - 29 Apr 2014

Cited by 24 | Viewed by 7290

Abstract

The variability of the curve number (CN) and the retention parameter (S) of the Soil Conservation Service (SCS)-CN method in a small agricultural, lowland watershed (23.4 km2 to the gauging station) in central Poland has been assessed using the probabilistic approach: distribution fitting [...] Read more.

The variability of the curve number (CN) and the retention parameter (S) of the Soil Conservation Service (SCS)-CN method in a small agricultural, lowland watershed (23.4 km2 to the gauging station) in central Poland has been assessed using the probabilistic approach: distribution fitting and confidence intervals (CIs). Empirical CNs and Ss were computed directly from recorded rainfall depths and direct runoff volumes. Two measures of the goodness of fit were used as selection criteria in the identification of the parent distribution function. The measures specified the generalized extreme value (GEV), normal and general logistic (GLO) distributions for 100-CN and GLO, lognormal and GEV distributions for S. The characteristics estimated from theoretical distribution (median, quantiles) were compared to the tabulated CN and to the antecedent runoff conditions of Hawkins and Hjelmfelt. The distribution fitting for the whole sample revealed a good agreement between the tabulated CN and the median and between the antecedent runoff conditions (ARCs) of Hawkins and Hjelmfelt, which certified a good calibration of the model. However, the division of the CN sample due to heavy and moderate rainfall depths revealed a serious inconsistency between the parameters mentioned. This analysis proves that the application of the SCS-CN method should rely on deep insight into the probabilistic properties of CN and S. Full article

(This article belongs to the Special Issue Flood Estimation and Analysis in a Variable and Changing Environment)

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Open AccessArticle

Diarrhoeal Health Risks Attributable to Water-Borne-Pathogens in Arsenic-Mitigated Drinking Water in West Bengal are Largely Independent of the Microbiological Quality of the Supplied Water

by Debapriya Mondal, Bhaswati Ganguli, Sugata Sen Roy, Babli Halder, Nilanjana Banerjee, Mayukh Banerjee, Maitreya Samanta, Ashok K. Giri and David A. Polya

Water 2014, 6(5), 1100-1117; https://doi.org/10.3390/w6051100 - 29 Apr 2014

Cited by 13 | Viewed by 9868

Abstract

There is a growing discussion about the possibility of arsenic mitigation measures in Bengal and similar areas leading to undesirable substitution of water-borne-pathogen attributable risks pathogens for risks attributable to arsenic, in part because of uncertainties in relative pathogen concentrations in supplied and [...] Read more.

There is a growing discussion about the possibility of arsenic mitigation measures in Bengal and similar areas leading to undesirable substitution of water-borne-pathogen attributable risks pathogens for risks attributable to arsenic, in part because of uncertainties in relative pathogen concentrations in supplied and end-use water. We try to resolve this discussion, by assessing the relative contributions of water supply and end-user practices to water-borne-pathogen-attributable risks for arsenic mitigation options in a groundwater arsenic impacted area of West Bengal. Paired supplied arsenic-mitigated water and end-use drinking water samples from 102 households were collected and analyzed for arsenic and thermally tolerant coliforms [TTC], used as a proxy for microbiological water quality, We then estimated the DALYs related to key sequelae, diarrheal diseases and cancers, arising from water-borne pathogens and arsenic respectively. We found [TTC] in end-use drinking water to depend only weakly on [TTC] in source-water. End-user practices far outweighed the microbiological quality of supplied water in determining diarrheal disease burden. [TTC] in source water was calculated to contribute <1% of total diarrheal disease burden. No substantial demonstrable pathogen-for-arsenic risk substitution attributable to specific arsenic mitigation of supplied waters was observed, illustrating the benefits of arsenic mitigation measures in the area studied. Full article

(This article belongs to the Special Issue Water Treatment and Human Health)

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Water, Volume 6, Issue 5 (May 2014) – 19 articles , Pages 1100-1481

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