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Water, Volume 5, Issue 2 (June 2013) – 31 articles , Pages 327-851

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582 KiB  
Article
Comparing Two Operating Configurations in a Full-Scale Arsenic Removal Plant. Case Study: Guatemala
by Sofía E. Garrido Hoyos, Martha Avilés Flores, A. Ramírez Gonzalez, Celia Grajeda Fajardo, Saúl Cardoso Zoloeta and Hayron Velásquez Orozco
Water 2013, 5(2), 834-851; https://doi.org/10.3390/w5020834 - 21 Jun 2013
Cited by 8 | Viewed by 8703
Abstract
The present study was conducted in Naranjo County located in the municipality of Mixco, Guatemala. The water supply source comes from two wells with a maximum flow of 25.24 and 33.44 L·s−1. The main problem with this source is the high [...] Read more.
The present study was conducted in Naranjo County located in the municipality of Mixco, Guatemala. The water supply source comes from two wells with a maximum flow of 25.24 and 33.44 L·s−1. The main problem with this source is the high arsenic concentration—between 0.1341 and 0.1671 mg·L−1. The aim of this study was to conduct laboratory tests, basic engineering and supervision of the construction and evaluation of an operations plant using two configurations, A (low-rate sedimentation and ceramic filter) and B (high-rate sedimentation and clinoptilolite filter), to remove arsenic present in water for human use and consumption. This plant supplies water to Naranjo County in Mixco, Guatemala (5000 inhabitants). First, a laboratory Jar Test was performed to evaluate arsenic removal efficiency. And second, a conventional clarification plant was then built (design flow: 25.24 L·s−1). The best results were achieved with configuration B, with the following reagents and dosage as defined by the laboratory tests: 10 mg L−1 ferric chloride as coagulant; 1.8 mg·L−1 CH-polyfocal as flocculant and 0.4 mg L−1 MIT03 as color removal; 1 mg L−1 sodium hypochlorite as oxidant and adjusting pH to ≈7.0 with sodium hydroxide. Once the plant began operating, the efficiency of the treatment process was evaluated. The maximum elimination efficiencies were obtained 100% for turbidity (0 UTN), 89.54% (3.66 UPt-Co) for color and 96.80% (0.005 mg L−1) for arsenic, values that comply with Guatemalan standards. For this case, the relation between Fe(III) dosage/mg and As(V) removal was 1:46. Full article
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1258 KiB  
Article
On the Vulnerability of Water Limited Ecosystems to Climate Change
by Salvatore Manfreda and Kelly K. Caylor
Water 2013, 5(2), 819-833; https://doi.org/10.3390/w5020819 - 21 Jun 2013
Cited by 18 | Viewed by 7282
Abstract
Society is facing growing environmental problems that require new research efforts to understand the way ecosystems operate and survive, and their mutual relationships with the hydrologic cycle. In this respect, ecohydrology suggests a renewed interdisciplinary approach that aims to provide a better comprehension [...] Read more.
Society is facing growing environmental problems that require new research efforts to understand the way ecosystems operate and survive, and their mutual relationships with the hydrologic cycle. In this respect, ecohydrology suggests a renewed interdisciplinary approach that aims to provide a better comprehension of the effects of climatic changes on terrestrial ecosystems. With this aim, a coupled hydrological/ecological model is adopted to describe simultaneously vegetation pattern evolution and hydrological water budget at the basin scale using as test site the Upper Rio Salado basin (Sevilleta, NM, USA). The hydrological analyses have been carried out using a recently formulated framework for the water balance at the daily level linked with a spatial model for the description of the spatial organization of vegetation. This enables quantitatively assessing the effects on soil water availability on future climatic scenarios. Results highlighted that the relationship between climatic forcing (water availability) and vegetation patterns is strongly non-linear. This implies, under some specific conditions which depend on the ecosystem characteristics, small changes in climatic conditions may produce significant transformation of the vegetation patterns. Full article
(This article belongs to the Special Issue Ecological Watershed Management)
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851 KiB  
Article
Decision Support Systems for Water Resources Management in Developing Countries: Learning from Experiences in Africa
by Carlo Giupponi and Alessandra Sgobbi
Water 2013, 5(2), 798-818; https://doi.org/10.3390/w5020798 - 19 Jun 2013
Cited by 46 | Viewed by 17663
Abstract
Decision support system (DSS) tools are rather popular in the literature on water resources management. The European Project “Splash” conducted a survey of the literature and of DSS implementation in developing countries with specific reference on Africa. Experts in the field were consulted [...] Read more.
Decision support system (DSS) tools are rather popular in the literature on water resources management. The European Project “Splash” conducted a survey of the literature and of DSS implementation in developing countries with specific reference on Africa. Experts in the field were consulted through an ad hoc questionnaire and interviews. The results of the survey indicate that the exchange of experiences amongst projects with similar objectives or even the same case study is very limited, with a tendency towards restarting every time from scratch. As a consequence, it seems that DSS developments have produced only limited positive impacts. Most experts contacted shared either the frustration deriving from the limited impacts on intended end-users, who rarely used the tool after the project end, or in the case of ongoing projects, the preoccupation for future maintenance. Responses from the questionnaires indicate that priority efforts should not focus on developing the tools, but rather on improving the effectiveness and applicability of integrated water resource management legislative and planning frameworks, training and capacity building, networking and cooperation, harmonization of transnational data infrastructures and, very importantly, learning from past experiences and adopting enhanced protocols for DSS development. Full article
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170 KiB  
Article
Science to Support Management of Receiving Waters in an Event-Driven Ecosystem: From Land to River to Sea
by Catherine Leigh, Michele A. Burford, Rod M. Connolly, Jon M. Olley, Emily Saeck, Fran Sheldon, James C.R. Smart and Stuart E. Bunn
Water 2013, 5(2), 780-797; https://doi.org/10.3390/w5020780 - 19 Jun 2013
Cited by 36 | Viewed by 10510
Abstract
Managing receiving-water quality, ecosystem health and ecosystem service delivery is challenging in regions where extreme rainfall and runoff events occur episodically, confounding and often intensifying land-degradation impacts. We synthesize the approaches used in river, reservoir and coastal water management in the event-driven subtropics [...] Read more.
Managing receiving-water quality, ecosystem health and ecosystem service delivery is challenging in regions where extreme rainfall and runoff events occur episodically, confounding and often intensifying land-degradation impacts. We synthesize the approaches used in river, reservoir and coastal water management in the event-driven subtropics of Australia, and the scientific research underpinning them. Land-use change has placed the receiving waters of Moreton Bay, an internationally-significant coastal wetland, at risk of ecological degradation through increased nutrient and sediment loads. The event-driven climate exacerbates this issue, as the waterways and ultimately Moreton Bay receive large inputs of nutrients and sediment during events, well above those received throughout stable climatic periods. Research on the water quality and ecology of the region’s rivers and coastal waters has underpinned the development of a world-renowned monitoring program and, in combination with catchment-source tracing methods and modeling, has revealed the key mechanisms and management strategies by which receiving-water quality, ecosystem health and ecosystem services can be maintained and improved. These approaches provide a useful framework for management of water bodies in other regions driven by episodic events, or where novel stressors are involved (e.g., climate change, urbanization), to support sustained ecosystem service delivery and restoration of aquatic ecosystems. Full article
(This article belongs to the Special Issue Ecological Watershed Management)
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331 KiB  
Article
Determination of Perchlorate in Bottled Water from Italy
by Patrizia Iannece, Oriana Motta, Rossella Tedesco, Maurizio Carotenuto and Antonio Proto
Water 2013, 5(2), 767-779; https://doi.org/10.3390/w5020767 - 13 Jun 2013
Cited by 25 | Viewed by 9022
Abstract
Perchlorate is regarded as an emerging persistent inorganic contaminant. It is widely known that perchlorate is an endocrine disruptor as it competitively inhibits iodide transport in the thyroid gland. As drinking water is the major source of human exposure to perchlorate, its occurrence [...] Read more.
Perchlorate is regarded as an emerging persistent inorganic contaminant. It is widely known that perchlorate is an endocrine disruptor as it competitively inhibits iodide transport in the thyroid gland. As drinking water is the major source of human exposure to perchlorate, its occurrence in commercially available bottled waters purchased in different regions of Italy was investigated. Perchlorate was measured using the rapid, sensitive, and selective LC-ESI-MS/MS (liquid chromatography-electrospray tandem mass spectrometry) method by multiple reaction monitoring (MRM) of the transition 98.8→82.8, which corresponds to the loss of one oxygen atom in the perchlorate ion (ClO4→ClO3). The chlorine isotope ratio (35Cl/37Cl) was used as a confirmation tool. The limit of quantification (LOQ) for this method was 5 ng/L, and the recovery ranged from 94% to 108%. Perchlorate was detected in 44 of the 62 drinking waters tested, with concentrations ranging from <5 to 75 ng/L. These values are similar in magnitude to those reported in drinking water from the USA and do not pose an immediate health concern. Full article
(This article belongs to the Special Issue Analytical Chemistry of Water)
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1986 KiB  
Article
Effects of Timber Harvesting with Best Management Practices on Ecosystem Metabolism of a Low Gradient Stream on the United States Gulf Coastal Plain
by Abram DaSilva, Y. Jun Xu, George Ice, John Beebe and Richard Stich
Water 2013, 5(2), 747-766; https://doi.org/10.3390/w5020747 - 13 Jun 2013
Cited by 16 | Viewed by 7402
Abstract
Stream metabolism can be used as a measure of freshwater ecosystem health because of its responsiveness to natural and anthropogenic changes. In this study, we used stream metabolic rates to test for the effects of a timber harvest with Louisiana’s current best management [...] Read more.
Stream metabolism can be used as a measure of freshwater ecosystem health because of its responsiveness to natural and anthropogenic changes. In this study, we used stream metabolic rates to test for the effects of a timber harvest with Louisiana’s current best management practices (BMPs). The study was conducted from 2006 to 2010 in a loblolly pine (Pinus taeda) stand in north-central Louisiana, USA, 45 ha of which was clear cut harvested in the summer of 2007. Dissolved oxygen (DO), water temperature, and stream depth were recorded at a site upstream (serving as a reference) and a site downstream of the harvested area. Using diurnal DO change and an open-system, single-station method at each site, we quantified rates of net ecosystem productivity (NEP), gross primary productivity (GPP), community respiration (CR), and the GPP/CR ratio. The system was predominately heterotrophic, with a GPP/CR ratio of less than one for 82% of the time at the upstream site. No calculated metabolic rate was significantly changed by the timber harvest (two-way ANOVA with interaction; p < 0.001). Overall, the results suggest that timber harvests of similar intensity with Louisiana’s current BMPs may not significantly impact stream biological conditions. Full article
(This article belongs to the Special Issue Inorganic Pollution of Water Environment)
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255 KiB  
Review
Quantifying the Relative Contributions of Forest Change and Climatic Variability to Hydrology in Large Watersheds: A Critical Review of Research Methods
by Xiaohua Wei, Wenfei Liu and Peicong Zhou
Water 2013, 5(2), 728-746; https://doi.org/10.3390/w5020728 - 13 Jun 2013
Cited by 84 | Viewed by 9679
Abstract
Forest change and climatic variability are two major drivers for influencing change in watershed hydrology in forest–dominated watersheds. Quantifying their relative contributions is important to fully understand their individual effects. This review paper summarizes the progress on quantifying the relative contributions of forest [...] Read more.
Forest change and climatic variability are two major drivers for influencing change in watershed hydrology in forest–dominated watersheds. Quantifying their relative contributions is important to fully understand their individual effects. This review paper summarizes the progress on quantifying the relative contributions of forest or land cover change and climatic variability to hydrology in large watersheds using available case studies. It compared pros and cons of various research methods, identified research challenges and proposed future research priorities. Our synthesis shows that the relative hydrological effects of forest changes and climatic variability are largely dependent on their own change magnitudes and watershed characteristics. In some severely disturbed watersheds, impacts of forest changes or land use changes can be as important as those from climatic variability. This paper provides a brief review on eight selected research methods for this type of research. Because each method or technique has its own strengths and weaknesses, combining two or more methods is a more robust approach than using any single method alone. Future research priorities include conducting more case studies, refining research methods, and considering mechanism-based research using landscape ecology and geochemistry approaches. Full article
(This article belongs to the Special Issue Ecological Watershed Management)
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2715 KiB  
Article
Remote Sensing Analysis of Lake Dynamics in Semi-Arid Regions: Implication for Water Resource Management. Lake Manyara, East African Rift, Northern Tanzania
by Dorothea Deus and Richard Gloaguen
Water 2013, 5(2), 698-727; https://doi.org/10.3390/w5020698 - 06 Jun 2013
Cited by 41 | Viewed by 10804
Abstract
We show here that a remote sensing (RS) approach is a cost-efficient and accurate method to study water resource dynamics in semi-arid areas. We use a MODIS surface reflectance dataset and a Modified Normalized Difference Water Index (MNDWI) to map the variability of [...] Read more.
We show here that a remote sensing (RS) approach is a cost-efficient and accurate method to study water resource dynamics in semi-arid areas. We use a MODIS surface reflectance dataset and a Modified Normalized Difference Water Index (MNDWI) to map the variability of Lake Manyara’s water surface area using a histogram segmentation technique. The results indicate that Lake Manyara’s water surface coverage has been decreasing from 520.25 km2 to 30.5 km2 in 2000 and 2011 respectively. We observe that the lake water surface and the lake water balance displayed a similar pattern from 2006 to 2009, probably initiated by heavy rainfall and low temperature in 2006. Lake water surface area appears to have an inverse relationship with MODIS evapotranspiration (ET) and MODIS land surface temperature (LST). We imply that recent fluctuations of Lake Manyara’s surface water area are a direct consequence of global and regional climate fluctuations. We therefore conclude that, by means of RS it is possible to provide timely and up-to-date water resource information to managers and hence enable optimized and operational decisions for sustainable management and conservation. We suggest that the method employed in this research should be applied to monitor water resource dynamics provided that remotely sensed datasets are available. Full article
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7781 KiB  
Article
Long-Term Evolution of Cones of Depression in Shallow Aquifers in the North China Plain
by Yuan Zhang and Guomin Li
Water 2013, 5(2), 677-697; https://doi.org/10.3390/w5020677 - 05 Jun 2013
Cited by 15 | Viewed by 7729
Abstract
The North China Plain (NCP) is one of the places where the groundwater is most over-exploited in the world. Currently, our understanding on the spatiotemporal variability of the cones of depression in this region is fragmentary. This study intends to simulate the cones [...] Read more.
The North China Plain (NCP) is one of the places where the groundwater is most over-exploited in the world. Currently, our understanding on the spatiotemporal variability of the cones of depression in this region is fragmentary. This study intends to simulate the cones of depression in the shallow aquifer across the entire NCP during the whole period from 1960 to 2011. During the simulation, the dominant role of anthropogenic activities is emphasized and carefully taken into account using a Neural Network Algorithm. The results show that cones of depression in the NCP were formed in 1970s and continuously expanded. Their centers were getting deeper with an increasing degree of groundwater exploitation. This simulation provides valuable insights for developing more sustainable groundwater management options after the implementation of the South-to-NorthWater Diversion Project (SNWDP), which is a very important surface water project in China in the near future. The numerical model in this paper is built by MODFLOW, with pumpage data completed by neural network algorithm and hydrogeological parameters calibrated by simulated annealing algorithm. Based on our long-term numerical model for regional groundwater flow in the NCP, one exploitation limitation strategy after the implementation of SNWDP is studied in this paper. The results indicate that the SNWDP is beneficial for groundwater recovery in the NCP. A number of immense groundwater cones will gradually shrink. However, the recovery of the groundwater environment in the NCP will require a long time. Full article
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794 KiB  
Review
Ion Chromatographic Analyses of Sea Waters, Brines and Related Samples
by Nataša Gros
Water 2013, 5(2), 659-676; https://doi.org/10.3390/w5020659 - 05 Jun 2013
Cited by 22 | Viewed by 10010
Abstract
This review focuses on the ion chromatographic methods for the analyses of natural waters with high ionic strength. At the beginning a natural diversity in ionic composition of waters is highlighted and terminology clarified. In continuation a brief overview of other review articles [...] Read more.
This review focuses on the ion chromatographic methods for the analyses of natural waters with high ionic strength. At the beginning a natural diversity in ionic composition of waters is highlighted and terminology clarified. In continuation a brief overview of other review articles of potential interest is given. A review of ion chromatographic methods is organized in four sections. The first section comprises articles focused on the determination of ionic composition of water samples as completely as possible. The sections—Selected Anions, Selected Cations and Metals—follow. The most essential experimental conditions used in different methods are summarized in tables for a rapid comparison. Techniques encountered in the reviewed articles comprise: direct determinations of ions in untreated samples with ion- or ion-exclusion chromatography, or electrostatic ion chromatography; matrix elimination with column-switching; pre-concentration with a chelation ion chromatography and purge-and-trap pre-concentration. Different detection methods were used: non-suppressed conductometric or suppressed conductometric, direct spectrometric or spectrometric after a post-column derivetization, and inductively coupled plasma in combination with optical emission or mass spectrometry. Full article
(This article belongs to the Special Issue Analytical Chemistry of Water)
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645 KiB  
Article
Evolution of Water Management in Shanxi and Shaanxi Provinces since the Ming and Qing Dynasties of China
by Xiaohong Dang, Michael Webber, Dan Chen and Mark Yaolin Wang
Water 2013, 5(2), 643-658; https://doi.org/10.3390/w5020643 - 04 Jun 2013
Cited by 9 | Viewed by 10657
Abstract
This article examines some of the forms of water management in Shanxi [山西] and Shaanxi [陕西] provinces during the Ming and Qing dynasties. Facing serious water shortages and shrinking state power for water management, the local society in Shanxi and Shaanxi took over [...] Read more.
This article examines some of the forms of water management in Shanxi [山西] and Shaanxi [陕西] provinces during the Ming and Qing dynasties. Facing serious water shortages and shrinking state power for water management, the local society in Shanxi and Shaanxi took over water management and gradually formed a local self-government system for the water resources. Depending on water management organizations in which the local gentry were the core power, the water rules were based on natural topographic conditions, historical water practices in the locality, traditional moral-ethical ideas, and even water policies and water laws. This water management system played a positive role in mobilizing the participation of members, preventing opportunistic behavior such as free riding and rent seeking, while decreasing the probability of water conflicts and the costs of litigation. However, this water management system was also subject to endemic corruption because of the lack of effective monitoring from the local government. As similar problems appear to exist in China today, this article analyzes the features of this water management system, and examines the problems that faced those systems so as to provide a warning from history for modern society. Full article
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123 KiB  
New Book Received
Water Governance as Connective Capacity. By Jurian Edelenbos, Nanny Bressers and Peter Scholten, Ashgate, 2013; 374 Pages. Price £58.50, ISBN 978-1-4094-4746-7
by Shu-Kun Lin
Water 2013, 5(2), 640-642; https://doi.org/10.3390/w5020640 - 03 Jun 2013
Cited by 30 | Viewed by 6544
Abstract
The following paragraphs are reproduced from the website of the publisher [1]. Water is becoming one of the world’s most crucial concerns. A third of the world’s population has severe water shortage, while three quarters of the global population lives in deltas which [...] Read more.
The following paragraphs are reproduced from the website of the publisher [1]. Water is becoming one of the world’s most crucial concerns. A third of the world’s population has severe water shortage, while three quarters of the global population lives in deltas which run the risk of severe flooding. In addition, many more face problems of poor water quality. Full article
120 KiB  
New Book Received
The Fourth Phase of Water: Beyond Solid, Liquid, and Vapor. By Gerald H. Pollack, Ebner & Sons Publishers, 2013; 357 Pages. Price US $29.95, ISBN 978-0-9626895-4-3
by Shu-Kun Lin
Water 2013, 5(2), 638-639; https://doi.org/10.3390/w5020638 - 03 Jun 2013
Cited by 30 | Viewed by 14258
Abstract
The following paragraphs are reproduced from the website of the publisher [1]. Professor Pollack takes us on a fantastic voyage through water, showing us a hidden universe teeming with physical activity that provides answers so simple that any curious person can understand. In [...] Read more.
The following paragraphs are reproduced from the website of the publisher [1]. Professor Pollack takes us on a fantastic voyage through water, showing us a hidden universe teeming with physical activity that provides answers so simple that any curious person can understand. In conversational prose, Pollack lays a simple foundation for understanding how changes in water’s structure underlie most energetic transitions of form and motion on earth. Full article
629 KiB  
Article
The Life Cycle CO2 (LCCO2) Evaluation of Retrofits for Water-Saving Fittings
by Yasutoshi Shimizu
Water 2013, 5(2), 629-637; https://doi.org/10.3390/w5020629 - 31 May 2013
Cited by 3 | Viewed by 7502
Abstract
As part of measures being taken against global warming, the reduction of CO2 emissions by retrofitting for water-saving fittings in homes is spreading throughout the world. However, although this retrofitting reduces the environmental impact at the use stage, it generates new impacts [...] Read more.
As part of measures being taken against global warming, the reduction of CO2 emissions by retrofitting for water-saving fittings in homes is spreading throughout the world. However, although this retrofitting reduces the environmental impact at the use stage, it generates new impacts at the production and disposal stages. In addition, there has been little research that discusses the reduction in environmental impact obtained by retrofitting from the viewpoint of the overall life cycle of such fittings. In this paper, an evaluation of the environmental impact of retrofitting in terms of the entire life cycle was carried out for toilet bowls and showerheads. The findings show that even for a toilet bowl that generates a large environmental load at the production stage, there is no overall increase in the environmental impact by retrofitting for the average usable life of 20 years. Full article
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550 KiB  
Article
Air Masses Origin and Isotopic Tracers: A Study Case of the Oceanic and Mediterranean Rainfall Southwest of France
by Luc Lambs, Issam Moussa and Frederic Brunet
Water 2013, 5(2), 617-628; https://doi.org/10.3390/w5020617 - 17 May 2013
Cited by 6 | Viewed by 6391
Abstract
Aquifers recharge mainly by local rainfall, which depend on the air mass humidity and orographic lifting, causing rain. The stable isotopes of the water molecule, i.e., oxygen-18 and deuterium, are useful tracers to determine the water source origin. Moreover, the calculation of [...] Read more.
Aquifers recharge mainly by local rainfall, which depend on the air mass humidity and orographic lifting, causing rain. The stable isotopes of the water molecule, i.e., oxygen-18 and deuterium, are useful tracers to determine the water source origin. Moreover, the calculation of the deuterium excess enables one to differentiate between the air masses from the Atlantic Ocean or the Mediterranean Sea. A transect from one coast to the other one and going through the city of Toulouse have been made to sample the groundwater and determine their isotopic characteristic. A monthly rainfall sampling has also been done over one year, close to the city Toulouse, to see how the d-excess values range over the season. The discussion replaces these results in available isotopic data. Full article
(This article belongs to the Special Issue Environmental Tracers)
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7155 KiB  
Article
Integrating Decentralized Rainwater Management in Urban Planning and Design: Flood Resilient and Sustainable Water Management Using the Example of Coastal Cities in The Netherlands and Taiwan
by Thorsten Schuetze and Lorenzo Chelleri
Water 2013, 5(2), 593-616; https://doi.org/10.3390/w5020593 - 10 May 2013
Cited by 28 | Viewed by 17903
Abstract
Urbanized delta areas worldwide share a growing tendency of exposure to water stress induced by the effects of climate change and anthropogenic factors, threatening the operation of infrastructure systems and future urban development. The important synergistic impacts coexisting with freshwater scarcity are increasing [...] Read more.
Urbanized delta areas worldwide share a growing tendency of exposure to water stress induced by the effects of climate change and anthropogenic factors, threatening the operation of infrastructure systems and future urban development. The important synergistic impacts coexisting with freshwater scarcity are increasing urbanization rates, subsiding soils, saltwater intrusion in aquifers and rivers, coastal erosion, and increased flooding. Innovative design strategies and concepts for the integration of decentralized rainwater management measures can contribute to the integrated and climate resilient planning of urban spaces that are threatened by climate change scenarios that worsen the security of urban infrastructures and the future availability of fresh water. Decentralized rainwater management, including retention, storage, and reuse strategies that are integrated into spatial planning and urban design, can reduce flood risks while simultaneously enhancing freshwater availability. This paper discusses a paradigm shift in urban water management, from centralized to decentralized management (that is, from threats to opportunities), using the example of two case studies. Concepts and strategies for building climate resilient cities, which address flood control, the protection of freshwater resources, and the harmonization of a natural and more sustainable water balance, are presented for Almere (Rhine Schelde Delta, The Netherlands) and Hsingchu (Dotzpu Delta, Taiwan). Full article
(This article belongs to the Special Issue Flood Estimation and Analysis in a Variable and Changing Environment)
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621 KiB  
Article
Influence of Irrigation Water Discharge Frequency on Soil Salt Removal and Rice Yield in a Semi-Arid and Saline-Sodic Area
by Yueqing Chen, Guangxin Zhang, Y. Jun Xu and Zhigang Huang
Water 2013, 5(2), 578-592; https://doi.org/10.3390/w5020578 - 07 May 2013
Cited by 15 | Viewed by 6942
Abstract
Irrigation practice for rice culture can be especially challenging in areas with limited water supply and soil salinization. In this study, we carried out a field experiment to assess the effects of different water discharge frequencies on soil salt content, rice yield and [...] Read more.
Irrigation practice for rice culture can be especially challenging in areas with limited water supply and soil salinization. In this study, we carried out a field experiment to assess the effects of different water discharge frequencies on soil salt content, rice yield and water use efficiency on a saline-sodic soil in a semi-arid region of Northeast China. The experiment comprised of three frequency levels of discharge [9-time (I-9-30), 6-time (I-6-30) and 3-time (I-3-30) discharge, all followed with a 30-mm irrigation] in comparison with the traditional irrigation practice of 2-time discharge followed with an 80-mm irrigation (I-2-80). Our initial hypothesis was that increasing discharge frequency would increase both salt reduction and rice yield. Daily precipitation was recorded by a nearby weather station, and evapotranspiration and soil water percolation rates were measured at experimental sites using soil pits. The measurements were used to establish a water balance for each treatment. Our results showed that soil salt reduction increased with the increasing discharge frequency at a 30-mm irrigation water depth. The 9-time discharge reduced a large amount of soil salt (995.0 kg ha−1) after five months of the study. Rice yield also increased with the increasing discharge frequency with a 30-mm irrigation water depth; however, when compared to the traditional 2-time discharge followed with an 80-mm irrigation, rice yield at the sites with more frequent discharge (i.e., I-9-30, I-6-30 and I-3-30) was 11%–18% lower. Because of this, rice yield and irrigation water use efficiency were significantly higher under the traditional practice of high-irrigation with low-frequency discharge (I-2-80) than under I-9-30, I-6-30 and I-3-30. These results indicate a need for a trade-off amongst salt reduction, rice yield and water use when considering selection of irrigation and discharge schedules. Full article
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826 KiB  
Article
Mean Normalized Force Computation for Different Types of Obstacles due to Dam Break Using Statistical Techniques
by Jasna Duricic, Tarkan Erdik, Ali Osman Pektaş and Petrus H.A.J.M Van Gelder
Water 2013, 5(2), 560-577; https://doi.org/10.3390/w5020560 - 06 May 2013
Cited by 8 | Viewed by 6028
Abstract
The dam-break induced loads and their effects on buildings are of vital importance for assessing the vulnerability of buildings in flood-prone areas. A comprehensive methodology, for risk assessment of buildings subject to flooding, is nevertheless still missing. This research aims to take a [...] Read more.
The dam-break induced loads and their effects on buildings are of vital importance for assessing the vulnerability of buildings in flood-prone areas. A comprehensive methodology, for risk assessment of buildings subject to flooding, is nevertheless still missing. This research aims to take a step forward by following previous research. To this aim, (1) five statistical procedures including: simple correlation analysis, multiple linear regression model, stepwise multiple linear regression model, principal component analysis and cluster analysis are used to study relationship between mean normalized force on structure and other related variables; (2) a new and efficient variable that can take into account both the shape of the structure and flow conditions is proposed; (3) a new and practical formula for predicting the mean normalized force is suggested for different types of obstacles, which is missing in the previous research. Full article
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2108 KiB  
Article
Factors Affecting Phosphorous in Groundwater in an Alluvial Valley Aquifer: Implications for Best Management Practices
by Francisco Flores-López, Zachary M. Easton, Larry D. Geohring, Peter J. Vermeulen, Van R. Haden and Tammo S. Steenhuis
Water 2013, 5(2), 540-559; https://doi.org/10.3390/w5020540 - 02 May 2013
Cited by 7 | Viewed by 7373
Abstract
Many streams in the US are impaired because of high Soluble Reactive Phosphorous (SRP) contributions from agriculture. However, the drivers of ecological processes that lead to SRP loss in baseflow from groundwater are not sufficiently understood to design effective Best Management Practices (BMPs). [...] Read more.
Many streams in the US are impaired because of high Soluble Reactive Phosphorous (SRP) contributions from agriculture. However, the drivers of ecological processes that lead to SRP loss in baseflow from groundwater are not sufficiently understood to design effective Best Management Practices (BMPs). In this paper, we examine how soil temperature and water table depth influence the SRP concentrations in groundwater for a dairy farm in a valley bottom in the Catskills (NY, USA). Measured SRP concentrations in groundwater and baseflow were greater during the fall, when soil temperatures are warmer, than during winter and spring. The observed concentrations were within the bounds predicted by groundwater temperatures using the Arrhenius equation, except during fall, when concentrations rose above these predictions. These elevated concentrations were likely caused by mineralization and consequent accumulation of phosphorous (P) in summer. In addition, SRP concentrations were greater in near-stream areas, where water tables where higher. In short, SRP concentrations are dependent on temperature, demonstrating the importance of understanding the underlying mechanism of ecological processes. In addition, results suggest BMPs that apply manure on land having a deep groundwater, instead of on land with a shallow water table will lower overall SRP contributions. Full article
(This article belongs to the Special Issue Ecological Watershed Management)
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1424 KiB  
Article
Evaluation of Hyperspectral Multi-Band Indices to Estimate Chlorophyll-A Concentration Using Field Spectral Measurements and Satellite Data in Dianshan Lake, China
by Liguo Zhou, Bo Xu, Weichun Ma, Bin Zhao, Linna Li and Hongyan Huai
Water 2013, 5(2), 525-539; https://doi.org/10.3390/w5020525 - 29 Apr 2013
Cited by 15 | Viewed by 7296
Abstract
Chlorophyll-a (Chl-a) concentration is considered as a key indicator of the eutrophic status of inland water bodies. Various algorithms have been developed for estimating Chl-a in order to improve the accuracy of predictive models. The objective of this study is [...] Read more.
Chlorophyll-a (Chl-a) concentration is considered as a key indicator of the eutrophic status of inland water bodies. Various algorithms have been developed for estimating Chl-a in order to improve the accuracy of predictive models. The objective of this study is to assess the potential of hyperspectral multi-band indices to estimate the Chl-a concentration in Dianshan Lake, which is the largest lake in Shanghai, an international metropolis of China. Based on field spectral measurements and in-situ Chl-a concentration collected on 7–8 September 2010, hyperspectral multi-band indices were calibrated to estimate the Chl-a concentration with optimal wavelengths selected by model tuning. A three-band index accounts for 87.36% (R2 = 0.8736) of the Chl-a variation. A four-band index, which adds a wavelength in the near infrared (NIR) region, results in a higher R2 (0.8997) by removing the absorption and backscattering effects of suspended solids. To test the applicability of the proposed indices for routinely monitoring of Chl-a in inland lakes, simulated Hyperion and real HJ-1A satellite data were selected to estimate the Chl-a concentration. The results show that the explanatory powers of these satellite hyperspectral multi-band indices are relatively high with R2 = 0.8559, 0.8945, 0.7969, and 0.8241 for simulated Hyperion and real HJ-1A satellite data, respectively. All of the results provide strong evidence that hyperspectral multi-band indices are promising and applicable to estimate Chl-a in eutrophic inland lakes. Full article
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299 KiB  
Article
Microbial Community Structure of a Leachfield Soil: Response to Intermittent Aeration and Tetracycline Addition
by Janet A. Atoyan, Andrew M. Staroscik, David R. Nelson, Erika L. Patenaude, David A. Potts and José A. Amador
Water 2013, 5(2), 505-524; https://doi.org/10.3390/w5020505 - 25 Apr 2013
Cited by 6 | Viewed by 7358
Abstract
Soil-based wastewater treatment systems, or leachfields, rely on microbial processes for improving the quality of wastewater before it reaches the groundwater. These processes are affected by physicochemical system properties, such as O2 availability, and disturbances, such as the presence of antimicrobial compounds in [...] Read more.
Soil-based wastewater treatment systems, or leachfields, rely on microbial processes for improving the quality of wastewater before it reaches the groundwater. These processes are affected by physicochemical system properties, such as O2 availability, and disturbances, such as the presence of antimicrobial compounds in wastewater. We examined the microbial community structure of leachfield mesocosms containing native soil and receiving domestic wastewater under intermittently-aerated (AIR) and unaerated (LEACH) conditions before and after dosing with tetracycline (TET). Community structure was assessed using phospholipid fatty acid analysis (PLFA), analysis of dominant phylotypes using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR–DGGE), and cloning and sequencing of 16S rRNA genes. Prior to dosing, the same PLFA biomarkers were found in soil from AIR and LEACH treatments, although AIR soil had a larger active microbial population and higher concentrations for nine of 32 PLFA markers found. AIR soil also had a larger number of dominant phylotypes, most of them unique to this treatment. Dosing of mesocosms with TET had a more marked effect on AIR than LEACH soil, reducing the size of the microbial population and the number and concentration of PLFA markers. Dominant phylotypes decreased by ~15% in response to TET in both treatments, although the AIR treatment retained a higher number of phylotypes than the LEACH treatment. Fewer than 10% of clones were common to both OPEN ACCESS Water 2013, 5 506 AIR and LEACH soil, and fewer than 25% of the clones from either treatment were homologous with isolates of known genus and species. These included human pathogens, as well as bacteria involved in biogeochemical transformations of C, N, S and metals, and biodegradation of various organic contaminants. Our results show that intermittent aeration has a marked effect on the size and structure of the microbial community that develops in a native leachfield soil. In addition, there is a differential response of the microbial communities of AIR and LEACH soil to tetracycline addition which may be linked to changes in function. Full article
(This article belongs to the Special Issue Sustainable Wastewater Treatment and Pollution Control)
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1637 KiB  
Article
A Combined Radio- and Stable-Isotopic Study of a California Coastal Aquifer System
by Peter W. Swarzenski, Mark Baskaran, Robert J. Rosenbauer, Brian D. Edwards and Michael Land
Water 2013, 5(2), 480-504; https://doi.org/10.3390/w5020480 - 19 Apr 2013
Cited by 15 | Viewed by 8481
Abstract
Stable and radioactive tracers were utilized in concert to characterize geochemical processes in a complex coastal groundwater system and to provide constraints on the kinetics of rock/water interactions. Groundwater samples from wells within the Dominguez Gap region of Los Angeles County, California were [...] Read more.
Stable and radioactive tracers were utilized in concert to characterize geochemical processes in a complex coastal groundwater system and to provide constraints on the kinetics of rock/water interactions. Groundwater samples from wells within the Dominguez Gap region of Los Angeles County, California were analyzed for a suite of major cations (Na+, K+, Mg2+, Ca2+) and anions (Cl, SO42−), silica, alkalinity, select trace elements (Ba, B, Sr), dissolved oxygen, stable isotopes of hydrogen (δD), oxygen (δ18O), dissolved inorganic carbon (δ13CDIC), and radioactive isotopes (3H, 222Rn and 223,224,226,228Ra). In the study area, groundwater may consist of a complex mixture of native groundwater, intruded seawater, non-native injected water, and oil-field brine water. In some wells, Cl concentrations attained seawater-like values and in conjunction with isotopically heavier δ18O values, these tracers provide information on the extent of seawater intrusion and/or mixing with oil-field brines. Groundwater 3H above 1 tritium unit (TU) was observed only in a few select wells close to the Dominguez Gap area and most other well groundwater was aged pre-1952. Based on an initial 14C value for the study site of 90 percent modern carbon (pmc), groundwater age estimates likely extend beyond 20 kyr before present and confirm deep circulation of some native groundwater through multiple aquifers. Enriched values of groundwater δ13CDIC in the absence of SO42− imply enhanced anaerobic microbial methanogenesis. While secular equilibrium was observed for 234U/238U (activity ratios ~1) in host matrices, strong isotopic fractionation in these groundwater samples can be used to obtain information of adsorption/desorption kinetics. Calculated Ra residence times are short, and the associated desorption rate constant is about three orders of magnitude slower than that of the adsorption rate constant. Combined stable- and radio-isotopic results provide unique insights into aquifer characteristics, such as geochemical cycling, rock/water interactions, and subsurface transport and mixing. Full article
(This article belongs to the Special Issue Environmental Tracers)
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2369 KiB  
Review
Water Quality Improvement Performance of Geotextiles Within Permeable Pavement Systems: A Critical Review
by Miklas Scholz
Water 2013, 5(2), 462-479; https://doi.org/10.3390/w5020462 - 18 Apr 2013
Cited by 38 | Viewed by 10117
Abstract
Sustainable drainage systems (SuDS; or best management practices) are increasingly being used as ecological engineering techniques to prevent the contamination of receiving watercourses and groundwater. Permeable paving is a SuDS technique, which is commonplace in car parks, driveways and minor roads where one [...] Read more.
Sustainable drainage systems (SuDS; or best management practices) are increasingly being used as ecological engineering techniques to prevent the contamination of receiving watercourses and groundwater. Permeable paving is a SuDS technique, which is commonplace in car parks, driveways and minor roads where one of their functions is to improve the quality of urban runoff. However, little is known about the water quality benefits of incorporating an upper geotextile within the paving structure. The review focuses on five different categories of pollutants: organic matter, nutrients, heavy metals, motor oils, suspended solids originating from street dust, and chloride. The paper critically assesses results from previous international tests and draws conclusions on the scientific rigour and significance of the data. Findings indicate that only very few studies have been undertaken to address the role of geotextiles directly. All indications are that the presence of a geotextile leads only to minor water quality improvements. For example, suspended solids are being held back by the geotextile and these solids sometimes contain organic matter, nutrients and heavy metals. However, most studies were inconclusive and data were often unsuitable for further statistical analysis. Further long-term research on industry-relevant, and statistically and scientifically sound, experimental set-ups is recommended. Full article
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1083 KiB  
Article
Mountain Pine Beetles, Salvage Logging, and Hydrologic Change: Predicting Wet Ground Areas
by John Rex, Stéphane Dubé and Vanessa Foord
Water 2013, 5(2), 443-461; https://doi.org/10.3390/w5020443 - 15 Apr 2013
Cited by 5 | Viewed by 7761 | Correction
Abstract
The mountain pine beetle epidemic in British Columbia has covered 18.1 million hectares of forest land showing the potential for exceptionally large-scale disturbance to influence watershed hydrology. Pine stands killed by the epidemic can experience reduced levels of evapotranspiration and precipitation interception, which [...] Read more.
The mountain pine beetle epidemic in British Columbia has covered 18.1 million hectares of forest land showing the potential for exceptionally large-scale disturbance to influence watershed hydrology. Pine stands killed by the epidemic can experience reduced levels of evapotranspiration and precipitation interception, which can translate into an increase in soil moisture as observed by some forest practitioners during salvage logging in the epicenter of the outbreak. They reported the replacement of summer ground, dry firm soil areas, with winter ground areas identified by having wetter, less firm soils upon which forestry equipment operation is difficult or impossible before winter freeze-up. To decrease the likelihood of soil disturbance from harvesting, a set of hazard indicators was developed to predict wet ground areas in areas heavily infested by the mountain pine beetle. Hazard indicators were based on available GIS data, aerial photographs, and local knowledge. Indicators were selected by an iterative process that began with office-based selection of potential indicators, model development and prediction, field verification, and model refinement to select those indicators that explained most field data variability. Findings indicate that the most effective indicators were lodgepole pine content, understory, drainage density, soil texture, and the topographic index. Full article
(This article belongs to the Special Issue Ecological Watershed Management)
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782 KiB  
Article
Dissolved Oxygen Concentration Interlaboratory Comparison: What Can We Learn?
by Teemu Näykki, Lauri Jalukse, Irja Helm and Ivo Leito
Water 2013, 5(2), 420-442; https://doi.org/10.3390/w5020420 - 12 Apr 2013
Cited by 32 | Viewed by 17664
Abstract
Dissolved oxygen concentration is a key parameter for characterizing natural and wastewaters and for assessing the global state of the environment in general. The decrease of dissolved oxygen levels in the world’s oceans, which is becoming increasingly obvious, is expected to have an [...] Read more.
Dissolved oxygen concentration is a key parameter for characterizing natural and wastewaters and for assessing the global state of the environment in general. The decrease of dissolved oxygen levels in the world’s oceans, which is becoming increasingly obvious, is expected to have an impact on the whole ecosystem of the Earth, including the carbon cycle, the climate, etc. Dissolved oxygen measurements by sensors are often deemed easy measurements by routine laboratories. In reality, the physical and chemical processes underlying the measurements are complex and these measurements are not at all as robust as often considered. Recently an international in situ interlaboratory comparison measurement of dissolved oxygen concentration took place at the University of Tartu. The results revealed that the routine laboratories as a rule still do not fully master the art of dissolved oxygen concentration measurement: Out of altogether 63 measurement results obtained by the participants 52% were unacceptable according to the En numbers. Based on the analysis of the results of the intercomparison a set of tools and recommendations are given to the participants of how to improve the quality of their results. Full article
(This article belongs to the Special Issue Analytical Chemistry of Water)
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451 KiB  
Review
Role of Plants in a Constructed Wetland: Current and New Perspectives
by Oren Shelef, Amit Gross and Shimon Rachmilevitch
Water 2013, 5(2), 405-419; https://doi.org/10.3390/w5020405 - 08 Apr 2013
Cited by 167 | Viewed by 16068
Abstract
The role of plants in the treatment of effluents by constructed wetland (CW) systems is under debate. Here, we review ways in which plants can affect CW processes and suggest two novel functions for plants in CWs. The first is salt phytoremediation by [...] Read more.
The role of plants in the treatment of effluents by constructed wetland (CW) systems is under debate. Here, we review ways in which plants can affect CW processes and suggest two novel functions for plants in CWs. The first is salt phytoremediation by halophytes. We have strong evidence that halophytic plants can reduce wastewater salinity by accumulating salts in their tissues. Our studies have shown that Bassia indica, a halophytic annual, is capable of salt phytoremediation, accumulating sodium to up to 10% of its dry weight. The second novel use of plants in CWs is as phytoindicators of water quality. We demonstrate that accumulation of H2O2, a marker for plant stress, is reduced in the in successive treatment stages, where water quality is improved. It is recommended that monitoring and management of CWs consider the potential of plants as phytoremediators and phytoindicators. Full article
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473 KiB  
Article
CO2 Emission Factor for Rainwater and Reclaimed Water Used in Buildings in Japan
by Yasutoshi Shimizu, Satoshi Dejima and Kanako Toyosada
Water 2013, 5(2), 394-404; https://doi.org/10.3390/w5020394 - 08 Apr 2013
Cited by 10 | Viewed by 7588
Abstract
From the standpoint of the preservation of water resources, rainwater and reclaimed water have been widely used in buildings in many countries. However, the CO2 emission factors of these two waters—factors that determine their environmental impacts—have not been calculated. In a previous [...] Read more.
From the standpoint of the preservation of water resources, rainwater and reclaimed water have been widely used in buildings in many countries. However, the CO2 emission factors of these two waters—factors that determine their environmental impacts—have not been calculated. In a previous study, the CO2 emission factor of water for waterworks and sewer systems was determined. In this paper, we evaluate the emission factors of rainwater and reclaimed water in the same manner. First, the emission factor for pumping water in buildings is determined using published values for operating performances. About half of the residential dwellings in Japan are multistory apartments, and these apartments use pumps for the delivery of water. The emission factor of pumping is calculated as 0.69 kg CO2/m3, which adds 16% to the emission factor of waterworks and sewer systems. Next, the CO2 emission factors of rainwater and reclaimed water are calculated for different water delivery cases in buildings. As a result, it is found that the use of reclaimed water increases CO2 emissions by 62%, compared to the use of ordinary water. Full article
(This article belongs to the Special Issue Sustainable Wastewater Treatment and Pollution Control)
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691 KiB  
Article
Transport and Retention of Nitrogen, Phosphorus and Carbon in North America’s Largest River Swamp Basin, the Atchafalaya River Basin
by Y. Jun Xu
Water 2013, 5(2), 379-393; https://doi.org/10.3390/w5020379 - 03 Apr 2013
Cited by 23 | Viewed by 7404
Abstract
Floodplains and river corridor wetlands may be effectively managed for reducing nutrients and carbon. However, our understanding is limited to the reduction potential of these natural riverine systems. This study utilized the long-term (1978–2004) river discharge and water quality records from an upriver [...] Read more.
Floodplains and river corridor wetlands may be effectively managed for reducing nutrients and carbon. However, our understanding is limited to the reduction potential of these natural riverine systems. This study utilized the long-term (1978–2004) river discharge and water quality records from an upriver and a downriver location of the Atchafalaya River to quantify the inflow, outflow, and inflow–outflow mass balance of total Kjeldahl nitrogen (TKN = organic nitrogen + ammonia nitrogen), nitrate + nitrite nitrogen (NO3 + NO2), total phosphorous (TP), and total organic carbon (TOC) through the largest river swamp basin in North America. The study found that, over the past 27 years, the Atchafalaya River Basin (ARB) acted as a significant sink for TKN (annual retention: 24%), TP (41%), and TOC (12%), but a source for NO3 + NO2 nitrogen (6%). On an annual basis, ARB retained 48,500 t TKN, 16,900 t TP, and 167,100 t TOC from the river water. The retention rates were closely and positively related to the river discharge with highs during the winter and spring and lows in the late summer. The higher NO3 + NO2 mass outflow occurred throughout spring and summer, indicating an active role of biological processes on nitrogen as water and air temperatures in the basin rise. Full article
(This article belongs to the Special Issue Inorganic Pollution of Water Environment)
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295 KiB  
Article
Action Research’s Potential to Foster Institutional Change for Urban Water Management
by Dimitrios Zikos and Andreas Thiel
Water 2013, 5(2), 356-378; https://doi.org/10.3390/w5020356 - 03 Apr 2013
Cited by 16 | Viewed by 12422
Abstract
The paper discusses the potential of action research to meet the challenges entailed in institutional design for urban water management. Our overall aim is to briefly present action research and discuss its methodological merits with regard to the challenges posed by the different [...] Read more.
The paper discusses the potential of action research to meet the challenges entailed in institutional design for urban water management. Our overall aim is to briefly present action research and discuss its methodological merits with regard to the challenges posed by the different conceptual bases for extrapolating the effects of institutional design on institutional change. Thus, our aim is to explore how Action Research meets the challenge of scoping the field in an open fashion for determining the appropriate mechanisms of institutional change and supporting the emerging of new water institutions. To accomplish this aim, we select the Water Framework Directive (WFD) as an illustrative driving force requiring changes in water management practices and implying the need for the emergence of new institutions. We employ a case of urban water management in the Volos Metropolitan Area, part of the Thessaly region in Greece, where a Pilot River Basin Plan was implemented. By applying action research and being involved in a long process of interaction between stakeholders, we examine the emergence of new institutions dealing with urban water management under the general principles of the major driving force for change: the WFD. Full article
(This article belongs to the Special Issue Sustainable Urban Water Management)
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2162 KiB  
Article
Modeling and Optimization of New Flocculant Dosage and pH for Flocculation: Removal of Pollutants from Wastewater
by Ammar Salman Dawood and Yilian Li
Water 2013, 5(2), 342-355; https://doi.org/10.3390/w5020342 - 26 Mar 2013
Cited by 41 | Viewed by 14112
Abstract
In this paper, a new ferric chloride-(polyvinylpyrrolidone-grafted-polyacrylamide) hybrid copolymer was successfully synthesized by free radical polymerization in solution using ceric ammonium nitrate as redox initiator. The hybrid copolymer was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Response surface [...] Read more.
In this paper, a new ferric chloride-(polyvinylpyrrolidone-grafted-polyacrylamide) hybrid copolymer was successfully synthesized by free radical polymerization in solution using ceric ammonium nitrate as redox initiator. The hybrid copolymer was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Response surface methodology (RSM), involving central composite design (CCD) matrix with two of the most important operating variables in the flocculation process; hybrid copolymer dosage and pH were utilized for the study and for the optimization of the wastewater treatment process. Response surface analyses showed that the experimental data could be adequately fitted to quadratic polynomial models. Under the optimum conditions, the turbidity and chemical oxygen demand (COD) removal efficiencies were 96.4% and 83.5% according to RSM optimization, whereas the optimum removals based on the genetic algorithm (GA) were 96.56% and 83.54% for the turbidity and COD removal models. Based on these results, wastewater treatment using this novel hybrid copolymer has proved to be an effective alternative in the overseeing of turbidity and COD problems of municipal wastewater. Full article
(This article belongs to the Special Issue Sustainable Wastewater Treatment and Pollution Control)
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