Marthe S. de Graaff, Hardy Temmink, Grietje Zeeman and Cees J. N. Buisman
Article: Anaerobic Treatment of Concentrated Black Water in a UASB Reactor at a Short HRT
Water 2010, 2(1), 101-119; doi:10.3390/w2010101 - published online 26 February 2010
Show/Hide AbstractAbstract: This research describes the feasibility of applying a UASB reactor for the treatment of concentrated black (toilet) water at 25 °C. On average 78% of the influent load of COD at an HRT of 8.7 days was removed. Produced methane can be converted to 56 MJ/p/y as electricity and 84 MJ/p/y as heat by combined heat and power (CHP). Minimum reactor volume at full scale was calculated to be 63L per person (for black water containing 16 gCOD/L produced at 5 L/p/d) and this is more than two times smaller than other type of reactors for anaerobic treatment of concentrated black water.

Iskandar Abdullaev and Peter P. Mollinga
Article: The Socio-Technical Aspects of Water Management: Emerging Trends at Grass Roots Level in Uzbekistan
Water 2010, 2(1), 85-100; doi:10.3390/w2010085 - published online 24 February 2010
Show/Hide AbstractAbstract: In Soviet times, water management was presented generally as a technical issue to be taken care of by the state water bureaucracy. Due to structural changes in agriculture in the two decades post-independence, irrigation water management has become an explicitly political and social issue in Central Asia. With the state still heavily present in the regulation of agricultural production, the situation in Uzbekistan differs from other post-communist states. Water management strategies are still strongly ‘Soviet’ in approach, regarded by state actors as purely ‘technical’, because other dimensions – economic, social and political – are ‘fixed’ through strong state regulation. However, new mechanisms are appearing in this authoritarian and technocratic framework. The application of a framework for socio-technical analysis in some selected Water Users’ Associations (WUAs) in northwest Uzbekistan’s Khorezm region shows that the WUAs are becoming arenas of interaction for different interest groups involved in water management. The socio-technical analysis of Khorezm’s water management highlights growing social differences at grass root level in the study of WUAs. The process of social differentiation is in its early phases, but is still able to express itself fully due to the strict state control of agriculture and social life in general.

Chrysi Laspidou, Kimon Hadjibiros and Stylianos Gialis
Article: Minimizing the Environmental Impact of Sea Brine Disposal by Coupling Desalination Plants with Solar Saltworks: A Case Study for Greece
Water 2010, 2(1), 75-84; doi:10.3390/w2010075 - published online 17 February 2010
Show/Hide AbstractAbstract: The explosive increase in world population, along with the fast socio-economic development, have led to an increased water demand, making water shortage one of the greatest problems of modern society. Countries such as Greece, Saudi Arabia and Tunisia face serious water shortage issues and have resorted to solutions such as transporting water by ships from the mainland to islands, a practice that is expensive, energy-intensive and unsustainable. Desalination of sea-water is suitable for supplying arid regions with potable water, but extensive brine discharge may affect marine biota. To avoid this impact, we explore the option of directing the desalination effluent to a solar saltworks for brine concentration and salt production, in order to achieve a zero discharge desalination plant. In this context, we conducted a survey in order to evaluate the potential of transferring desalination brine to solar saltworks, so that its disposal to the sea is avoided. Our analysis showed that brine transfer by trucks is prohibitively expensive. In order to make the zero discharge desalination plant economically feasible, efforts should be directed into developing a more efficient technology that will result in the production of only a fraction of the brine that is produced from our systems today.

José González-García, Verónica Sáez, Ignacio Tudela, María Isabel Díez-Garcia, María Deseada Esclapez and Olivier Louisnard
Review: Sonochemical Treatment of Water Polluted by Chlorinated Organocompounds. A Review
Water 2010, 2(1), 28-74; doi:10.3390/w2010028 - published online 2 February 2010
Show/Hide AbstractAbstract: As one of several types of pollutants in water, chlorinated compounds have been routinely subjected to sonochemical analysis to check the environmental applications of this technology. In this review, an extensive study of the influence of the initial concentration, ultrasonic intensity and frequency on the kinetics, degradation efficiency and mechanism has been analyzed. The sonochemical degradation follows a radical mechanism which yields a very wide range of chlorinated compounds in very low concentrations. Special attention has been paid to the mass balance comparing the results from several analytical techniques. As a conclusion, sonochemical degradation alone is not an efficient treatment to reduce the organic pollutant level in waste water.

Ryan T. Bailey, John W. Jenson and Arne E. Olsen
Article: Estimating the Ground Water Resources of Atoll Islands
Water 2010, 2(1), 1-27; doi:10.3390/w2010001 - published online 14 January 2010
Show/Hide AbstractAbstract: Ground water resources of atolls, already minimal due to the small surface area and low elevation of the islands, are also subject to recurring, and sometimes devastating, droughts. As ground water resources become the sole fresh water source when rain catchment supplies are exhausted, it is critical to assess current groundwater resources and predict their depletion during drought conditions. Several published models, both analytical and empirical, are available to estimate the steady-state freshwater lens thickness of small oceanic islands. None fully incorporates unique shallow geologic characteristics of atoll islands, and none incorporates time-dependent processes. In this paper, we provide a review of these models, and then present a simple algebraic model, derived from results of a comprehensive numerical modeling study of steady-state atoll island aquifer dynamics, to predict the ground water response to changes in recharge on atoll islands. The model provides an estimate thickness of the freshwater lens as a function of annual rainfall rate, island width, Thurber Discontinuity depth, upper aquifer hydraulic conductivity, presence or absence of a confining reef flat plate, and in the case of drought, time. Results compare favorably with published atoll island lens thickness observations. The algebraic model is incorporated into a spreadsheet interface for use by island water resources managers.

Nutchanart Sriwongsitanon, Kritsanat Surakit and Peter R. Hawkins
Article: A Water Balance Budget for Bung Boraphet—A Flood Plain Wetland-Reservoir Complex in Thailand
Water 2009, 1(1), 54-79; doi:10.3390/w1010054 - published online 30 November 2009
Show/Hide AbstractAbstract: A water balance model was developed for Bung Boraphet reservoir, a large flood plain lake in Thailand, from daily measurements over three inflow outflow cycles between 2003 and 2006. Measurement error was 10% (as one standard deviation) of the total measured volume. The specific yield from the Bung Boraphet catchment was 3.9 m³/ha/yr and surface water inflow from the local catchment was the largest gain term and evaporation was the largest loss term in the water budget. Irrigation was the second largest loss term and dry season demand exceeded the storage supply. Uncontrolled extraction of water for irrigation is regarded as a threat to the reservoir fishery, although the increasing drawdown range may benefit wetland biodiversity. Sustainable management of the Bung Boraphet wetland will depend on careful management based on an informed understanding of the ecohydrological requirements of all wetland uses. Water balance models like this one are recommended as a tool to allocate water equitably and in ways which can be integrated across the Chao Phraya basin.