Search

Adequate quality and reliability of drinking water is vital for all inhabitants and for agriculture and industrial applications. Solar desalination is impactful method for getting potable water from brackish/wastewater in hot climatic condition and/or remote area where the scarcity of water as well as for electricity. In recent years, attention has been focused on development of various designs of solar still in order to overcome limitations possesses by conventional single basin single slope solar still. Pyramid solar still is one of the outcomes of such a development. The present paper reviews the development in the field of pyramid solar still as well as the various techniques to improve the performance of still. From the review on research carried out by the various researchers, it has been found that pyramid solar still is more efficient and economical in compare to conventional single slope single basin still. Thus, the review paper will assist the researchers to understand the fundamentals of pyramid solar still with the need, developments and challenges in pyramid solar still to improve its thermal performance and to make it more and more economic. [ABSTRACT FROM AUTHOR]

Abstract: The present paper deals with a theoretical and experimental study of a new generation of water desalination unit by solar energy using the humidification and dehumidification (HD) principle is constructed at the national engineering school of Sfax (34N, 10E), Tunisia. The good quality of distilled water obtained by this new concept favours its use for producing water for drinking and irrigation. A mathematical model based on heat and mass transfers in each component of the unit is developed. The resulting ordinary differential systems of equations are transformed into a system of algebraic equations using the orthogonal collocation method (OCM) and simulated using C++ software in a steady state regime. The numerical model is used to investigate the thermal performance of this kind of installation exposed to a variation of the control parameters. The thermal performance was evaluated by the gained output ratio (GOR) and the efficiency of the water solar collector. A series of experiments was conducted and compared with the simulation results to validate the developed models. As a result, the proposed models can be used for sizing and testing the behaviour of such a type of desalination unit. [Copyright &y& Elsevier]

The Palmahim Sea Water Desalination plant supplies to the Israeli water net potable water in accordance with all contractual requirements of water quality and quantity. The plant was commissioned on 2007 and produced 110,000 m³ du (30 million m³ per year). Recently, the plant production capacity was enlarged to 150,000 m³ d-1 (45 million m³ per year). Plant enlargement was performed without interrupting the potable water supply while minimizing capital cost investments. The plant original relatively small footprint (3.2 Hectare) and the high degree of operation flexibility remained the same. The enlargement involved the addition of energy recovery devices, membranes and pressure vessels and the modification of the filtration media. As a result of the enlargement, the specific energy consumption of the plant was reduced by 0.2 kWh m-3. [ABSTRACT FROM AUTHOR]

Seawater desalination using nuclear energy is a viable option to meet the growing demand of potable water. This paper summarizes experience on nuclear desalination in member states and recent activities conducted by the IAEA. Over 200 reactor-years of operating experience of nuclear desalination have been accumulated worldwide. Experience also has been accumulated through current nuclear demonstrated projects such as the Indian Kalpakkam plant (6,300 m³/d hybrid RO-MSF plant coupled to a pressurized heavy water reactor (PHWR)), and Pakistani plant (4,800 m³/d MED coupled to a PHWR and has been commissioned early in 2010). These demonstration projects aimed to confirm the technical and economic viability of nuclear desalination under country specific conditions. All projects have demonstrated excellent operational performance, high reliability and safety producing high quality water at competitive costs. An overview of the economic benefits of nuclear desalination is highlighted. Recent case studies conducted under an IAEA coordinated research programmed have revealed that nuclear desalination should be considered as a real option to meet the water needs and shortages in the water scarce areas. Yet, the main challenge for the large-scale deployment of nuclear seawater desalination is the lack of infrastructure and resources in the countries affected by water scarcity problems which are however, interested in adoption of nuclear desalination for the sustainable water resource. A summary of the IAEA activities on seawater desalination using nuclear energy is presented. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to evaluate the effectiveness of aluminum foils, lenses and mirrors in association with sunlight as sterilization media on the destruction of Total Heterotrophic Bacteria (THBC) using raw drinking water samples obtained from local wells in northern Jordan. To achieve this aim, a solar water disinfection with a simple method that is to place the water samples to a direct contact with sunlight that will provide a practical, low-cost approach to the improvement of drinking water quality in developing countries with consistently sunny climates. Microbiological examinations were performed to determined the THBC, Total Coliform (TC) and to detect Pseudomonas aeruginosa according to the American standards for drinking water. Results show that, it is possible to achieve a complete decontamination of water samples without any danger of bacterial re-growth, if the disinfected water is properly stored for one week. The results show that on a conclusion the disinfection process was succeeded and could keep treated water for more than seven days without any further contamination. This implies that solar disinfection will be a promising way for improving water quality in developing countries with low cost and clean energy reliable resource. [Copyright &y& Elsevier]

Abstract: The growing demand for drinkable water and its reliable supply have persuaded populations from many parts of the globe to construct desalination plants. The need for seawater means locating these plants in coastal areas and then naturally to dispose of their brine waste into the sea through outfalls at some distance from the shoreline. However, determining the optimum site for water intake and brine outfalls is the key issue at the planning stage of coastal desalination plant projects. Modeling studies are outlined on the spread of salt concentrated waste that is continuously released into the sea. The principal aim of this case study was to establish a choice of brine outfall location with the least impact on the marine environment. In particular, the increase in salinity in coastal waters where protected vegetation species live was considered as the selection parameter for the disposal of the dense discharge source. Contrary to expectations, the modeling results reveal that the potential impact of salt disposal on vegetation can be alleviated by planning a shorter outfall. [Copyright &y& Elsevier]

Desalination is now being proposed for many countries facing water scarcity as a supplement to existing water supplies. In Korea, however, desalination for domestic water usage was restricted to small isolated communities with access to no other water supply. To date, small-scale RO (reverse osmosis) desalination systems, which size ranges from 10 m3/day to 1000 m3/day, have been constructed to produce potable water from brackish or seawater. The major issue of these systems is the optimization of system design to minimize capital cost and energy consumption, which is likely to be difficult for small-scale systems. This paper reviews the current status and future challenges of small-scale desalination plants in Korea. The design and operation of existing desalination systems were compared in terms of treatment efficiency and energy usage. [Copyright &y& Elsevier]

Abstract: Australia is the driest continent on earth and despite this the installed desalination capacity is still around 1% of the total world''s desalination capacity. This paper reviews the main seawater issues considered in every desalination project—the history, the present situation and the future of desalination in Australia, the suitability of applying reverse osmosis (RO) and the project details of two desalination plants (Sydney and Perth). Ocean currents, seawater temperature and salinity are signifi cant indicators in the assessment of the feasibility of desalination as they aff ect the production costs, the maintenance frequency and the quality of the product water. Seawater reverse osmosis (SWRO) is the only type of desalination technology currently used or proposed for future large-scale desalination plants in Australia. Every capital city except Darwin has considered building at least one desalination plant as a means of providing water security after several years of unprecedented drought that has signifi cantly reduced dam storage levels. Perth was the fi rst major city to use desalinated water for drinking water supply and by early 2009 Sydney will be the second city. Thirteen other large-scale SWRO plants are being planned or proposed at several locations for the purpose of supplying drinking water. [Copyright &y& Elsevier]

With a production capacity of 100,000 m³/d, Qingdao seawater desalination plant (SWDP) will be located in the eastern part of China (Shandong Province) and it is being developed under a 25-year DBOO contract in order to supply drinking water to this city. The Qingdao SWDP is situated near to a seawater lagoon shared with other already existing factory and the raw water is withdrawn to it from the shallow waters of the bay by means of a submerged pipe when the tide is high. Therefore, the raw water has a high suspended solids values and a high level of pollutants. The desalination technology selected has been reverse osmosis (RO) with a previous and specific pretreatment which has been designed to get optimal seawater previously to RO membranes. This pre-treatment consists on: self-cleaning travelling screen, dissolved air flotation (DAF), 100 µm filtration, ultra filtration (UF). Nowadays, to determine the feasibility and efficiency of the process, it is performing some experimental tests by means of different pilot studies. Therefore, this paper shows the engineering design of a high efficiency SWDP that will significantly increase the water resources of the region. [ABSTRACT FROM AUTHOR]

Seventy percent of the Earth''s surface is covered by water. However, many regions of the world suffer from a lack of potable water. River water is rarely accessible in adequate quantities and often not of a quality that corresponds to accepted hygiene standards. Along coastlines, wells contain brackish water of little or no use to households. To counter this lack of water, various technical processes have, therefore, been developed over the last decades to desalinate seawater and brackish water. These techniques, however, require large investments which are frequently beyond the means of most developing countries. The supply of potable water to settlements with modest water needs such as lashing villages along the North Africa''s coast can be ensured through the use of solar stills with which sea water can be desalinated and water of insufficient quality can be made potable. By recuperating and reusing the same quantity of thermal energy in several stages, it has been possible to reduce the total energy needed to the extent that solar energy can now be seen as an acceptable energy source for water desalination (COP: 3.0–4.0). [Copyright &y& Elsevier]

The deep-pool reactor (DPR) is a heating reactor working under atmospheric pressure and moderate temperature for the requirements of seawater desalination. This reactor is distinctive from other nuclear power reactors, with key features including simplicity of structure, proven technology, small power size and inherent safety of the non-pressurized system. In addition, by putting this reactor pool underground and adding a thick concrete shield over the pool as a barrier, it not only prevents loss of pool water but also improves the safety of the reactor. An engineering project pre-feasibility study of a 200 MW DPR for seawater desalination in the coastal area of Tianjin, China, has been completed recently. The nuclear plant coupled with a low-temperature, multi-effect distillation (MED) plant was designed to produce drinking water with a capacity of 80,000 m3/d. The economic evaluation of the nuclear desalination project was carried out using the DEEP program provided by the IAEA. Technical specifications and economic aspects of the project are briefly presented in this paper. [Copyright &y& Elsevier]

The article discusses the proposed Menorah Islands Project, a group of artificial islands to be built off the coast of Israel, which aims to create additional water source using solar-powered atmospheric water generators. Topics include the capacity of the generators to extract water from humidity, the generation of additional water from solar-powered desalination plant and the incorporation of technologies like passive systems to encourage gas-free travel.

RWL Water and Orascom Construction Ltd (OCL) have signed a Memorandum of Understanding (MoU) with the Egyptian government to study the feasibility of building, financing and operating Egypt's first large desalination plant for the supply of potable water. [ABSTRACT FROM AUTHOR]

Caymans-based Consolidated Water Co Ltd, which develops and operates sea-water conversion plants and water distribution systems in areas where natural supplies of drinking water are scarce, has entered into a non-binding memorandum of understanding (MOU) with Newwater Inc. [Copyright &y& Elsevier]