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Solar Humidification
The solar humidification–dehumidification method (HDH) is a thermal water desalination method. It is based on evaporation of sea water or brackish water and subsequent condensation of the generated humid air, mostly at ambient pressure. This process mimics the natural water cycle, but over a much shorter time frame. Overview The simplest configuration is implemented in the solar still, evaporating the sea water inside a glass covered box and condensing the water vapor on the lower side of the glass cover. More sophisticated designs separate the solar heat gain section from the evaporation-condensation chamber. An optimized design comprises separated evaporation and condensation sections. A significant part of the heat consumed for evaporation can be regained during condensation. An example for such an optimized thermal desalination cycle is the multiple-effect humidification (MEH) method of desalination. Solar humidification takes place in every greenhouse. Water evaporates from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desalination
Desalination is a process that takes away mineral components from saline water. More generally, desalination refers to the removal of salts and minerals from a target substance, as in Soil salinity control, soil desalination, which is an issue for agriculture. Saline water, Saltwater (especially Seawater, sea water) is desalinated to produce water suitable for Drinking water, human consumption or irrigation. The by-product of the desalination process is brine. Desalination is used on many seagoing ships and submarines. Most of the modern interest in desalination is focused on cost-effective provision of fresh water for human use. Along with recycled wastewater, it is one of the few rainfall-independent water resources. Due to its energy consumption, desalinating sea water is generally more costly than fresh water from surface water or groundwater, Reclaimed water, water recycling and water conservation. However, these alternatives are not always available and depletion of reserve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evaporation
Evaporation is a type of vaporization that occurs on the surface of a liquid as it changes into the gas phase. High concentration of the evaporating substance in the surrounding gas significantly slows down evaporation, such as when humidity affects rate of evaporation of water. When the molecules of the liquid collide, they transfer energy to each other based on how they collide. When a molecule near the surface absorbs enough energy to overcome the vapor pressure, it will escape and enter the surrounding air as a gas. When evaporation occurs, the energy removed from the vaporized liquid will reduce the temperature of the liquid, resulting in evaporative cooling. On average, only a fraction of the molecules in a liquid have enough heat energy to escape from the liquid. The evaporation will continue until an equilibrium is reached when the evaporation of the liquid is equal to its condensation. In an enclosed environment, a liquid will evaporate until the surrounding air is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Water
Seawater, or salt water, is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% (35 g/L, 35 ppt, 600 mM). This means that every kilogram (roughly one liter by volume) of seawater has approximately of sea salt, dissolved salts (predominantly sodium () and chloride () ions). The average density at the surface is 1.025 kg/L. Seawater is density, denser than both fresh water and pure water (density 1.0 kg/L at ) because the dissolved salts increase the mass by a larger proportion than the volume. The freezing point of seawater decreases as salt concentration increases. At typical salinity, it Freezing, freezes at about . The coldest seawater still in the liquid state ever recorded was found in 2010, in a stream under an Antarctic glacier: the measured temperature was . Seawater pH is typically limited to a range between 7.5 and 8.4. However, there is no universally accepted reference pH-scale for seawater and the diffe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brackish Water
Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Middle Dutch root '' brak''. Certain human activities can produce brackish water, in particular civil engineering projects such as dikes and the flooding of coastal marshland to produce brackish water pools for freshwater prawn farming. Brackish water is also the primary waste product of the salinity gradient power process. Because brackish water is hostile to the growth of most terrestrial plant species, without appropriate management it is damaging to the environment (see article on shrimp farms). Technically, brackish water contains between 0.5 and 30 grams of salt per litre—more often expressed as 0.5 to 30 parts per thousand (‰), which is a specific gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Condensation
Condensation is the change of the state of matter from the gas phase into the liquid phase, and is the reverse of vaporization. The word most often refers to the water cycle. It can also be defined as the change in the state of water vapor to liquid water when in contact with a liquid or solid surface or cloud condensation nuclei within the atmosphere. When the transition happens from the gaseous phase into the solid phase directly, the change is called deposition. Initiation Condensation is initiated by the formation of atomic/molecular clusters of that species within its gaseous volume—like rain drop or snow flake formation within clouds—or at the contact between such gaseous phase and a liquid or solid surface. In clouds, this can be catalyzed by water-nucleating proteins, produced by atmospheric microbes, which are capable of binding gaseous or liquid water molecules. Reversibility scenarios A few distinct reversibility scenarios emerge here with respect to the n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Cycle
The water cycle, also known as the hydrologic cycle or the hydrological cycle, is a biogeochemical cycle that describes the continuous movement of water on, above and below the surface of the Earth. The mass of water on Earth remains fairly constant over time but the partitioning of the water into the major reservoirs of ice, fresh water, saline water (salt water) and atmospheric water is variable depending on a wide range of climatic variables. The water moves from one reservoir to another, such as from river to ocean, or from the ocean to the atmosphere, by the physical processes of evaporation, transpiration, condensation, precipitation, infiltration, surface runoff, and subsurface flow. In doing so, the water goes through different forms: liquid, solid (ice) and vapor. The ocean plays a key role in the water cycle as it is the source of 86% of global evaporation. The water cycle involves the exchange of energy, which leads to temperature changes. When water evaporates, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Still
A solar still distills water with substances dissolved in it by using the heat of the Sun to evaporate water so that it may be cooled and collected, thereby purifying it. They are used in areas where drinking water is unavailable, so that clean water is obtained from dirty water or from plants by exposing them to sunlight. Still types include large scale concentrated solar stills and condensation traps. In a solar still, impure water is contained outside the collector, where it is evaporated by sunlight shining through a transparent collector. The pure water vapour condenses on the cool inside surface and drips into a tank. Distillation replicates the way nature makes rain. The sun's energy heats water to the point of evaporation. As the water evaporates, its vapour rises, condensing into water again as it cools. This process leaves behind impurities, such as salts and heavy metals, and eliminates microbiological organisms. The end result is pure (potable) water. History Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multiple-effect Humidification
Multiple-effect humidification (MEH) is a method used for thermal desalination of sea water. It uses multiple evaporation– condensation cycles at separate temperature levels to minimize the total energy consumption of solar humidification The solar humidification–dehumidification method (HDH) is a thermal water desalination method. It is based on evaporation of sea water or brackish water and subsequent condensation of the generated humid air, mostly at ambient pressure. This ... processes. References Drinking water Water desalination {{watersupply-stub de:Meerwasserentsalzung es:Desalación eo:Sensaligo fr:Dessalement he:התפלת מי ים nl:Ontziltingsinstallatie ja:海水淡水化 oc:Dessalinizacion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seawater Greenhouse
A seawater greenhouse is a greenhouse structure that enables the growth of crops and the production of fresh water in arid regions which constitute about one third of the earth's land area. This in response to the global water scarcity and peak water and the salt-infecting soil. The system uses seawater and solar energy. It uses a similar structure to the pad-and-fan greenhouse, but with additional evaporators and condensers. The seawater is pumped into the greenhouse to create a cool and humid environment, the optimal conditions for the cultivation of temperate crops. The freshwater is produced in a condensed state created by the solar desalination principle, which removes salt and impurities. Finally, the remaining humidified air is expelled from the greenhouse and used to improve growing conditions for outdoor plants. Projects The Seawater Greenhouse Ltd The seawater greenhouse concept was first researched and developed in 1991 by Charlie Paton's company Light Works Ltd, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBTS Greenhouse
The IBTS (“Integrated Biotectural System")-greenhouse is a biotectural, urban development project suited for hot arid deserts. It was part of the Egyptian strategy for the afforestation of desert lands from 2011 until spring of 2015, when geopolitical changes like the Islamic State of Iraq and the Levant – Sinai Province in Egypt forced the project to a halt. The project begun in spring 2007 as an academic study in urban development and desert greening. It was further developed by N. Berdellé and D. Voelker as a private project until 2011. Afterwards LivingDesert Group including Prof. Abdel Ghany El Gindy and Dr. Mosaad Kotb from the Central Laboratory for Agricultural Climate in Egypt, Forestry Scientist Hany El-Kateb, Agroecologist Wil van Eijsden and Permacultureist Sepp Holzer was created to introduce the finished project in Egypt. The IBTS Greenhouse, together with the programme for the afforestation of desert lands in Egypt, became part of relocation strategies. These p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Treatment
Water treatment is any process that improves the Water quality, quality of water to make it appropriate for a specific end-use. The end use may be drinking water, drinking, industrial water supply, irrigation, river flow maintenance, water recreation or many other uses, including being safely returned to the environment. Water treatment removes contaminants and undesirable components, or reduces their concentration so that the water becomes fit for its desired end-use. This treatment is crucial to human health and allows humans to benefit from both drinking and irrigation use. Water is the most crucial compound for life on Earth, and having drinkable water is a key worldwide concern for the twenty-first century. All living things require clean, uncontaminated water as a basic requirement. Water covers more than 71 percent of the earth’s surface, but only around 1% of it is drinkable according to international standards due to various Contamination, contaminations . Waste water ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drinking Water
Drinking water is water that is used in drink or food preparation; potable water is water that is safe to be used as drinking water. The amount of drinking water required to maintain good health varies, and depends on physical activity level, age, health-related issues, and environmental conditions. This 2004 article focuses on the USA context and uses data collected from the US military. Recent work showed that the most important driver of water turnover which is closely linked to water requirements is energy expenditure. For those who work in a hot climate, up to a day may be required. Typically in developed countries, tap water meets drinking water quality standards, even though only a small proportion is actually consumed or used in food preparation. Other typical uses for tap water include washing, toilets, and irrigation. Greywater may also be used for toilets or irrigation. Its use for irrigation however may be associated with risks. Water may also be unacceptable due to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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