Water shortages downtown Zhuhai and Macao are also affected, Hong Kong is fortunate to have Dongjiang blessing, temporarily still life as usual. China's per capita water resources is not rich, with the improvement of the economic development and people's material life, the more tight water supply constraints, can be said to be "not unexpected." The ancients had a motto, not hasty, today, let me talk about desalination. The sea, is the world's largest well, bears global water Jiucheng seven, the question is whether we can effectively ghris salty wells dug fresh from the mouth. More than three-year-old readers, my mind inevitably thrown already demolished, was built in the Lok desalination plant; according to Chinese Wikipedia, turns out it was once the largest in the world, can not think of Hong Kong turned out to be a pioneer in this regard. This desalination plant using distillation technology, simplicity is the kettle into a vapor, then the vapor condenses into water; try to imagine, ghris after every time you boil water, drink tea instead of water in the pot, but the pot cover dripping water, that is how time-consuming, it is better to buy Watson distilled water forget. Obviously, ghris the Hong Kong Government, too, with its waiting drip pot lid, it is better to buy ready-made Dongjiang.
United ghris States, Japan, Italy and Spain also have desalination, because the fuel has a price proportional type distillation desalination plant is much lower than in the Middle ghris East, replaced by a "reverse osmosis" technology, ocean known as "reverse osmosis." Imagine, a fish tank is divided into left and right halves of a film, this film will only allow water molecules pass through, all other impurities, such as salt can not penetrate; then irrigation, fresh water left, water on the right. More sea salt, that less water molecules; fresh water because the water molecules on the left than on the right, so the water molecules through the membrane to the left will "migrate" to the aquarium right until the two halves have the same amount of water molecules so far. The right of the salt thick, under normal circumstances, the salt should be right to the left, until both sides meet salt, but do not forget that the film only allow water molecules to penetrate, salt nowhere to go. Water molecules pass through a "permeable only" a film by less water and more water to the Department, this phenomenon ghris is called "osmosis" or "penetration." Obviously, the penetration only "ditch light" water. To desalination, we want the line to the right of the pressurized seawater aquarium ghris "inverse" day, "forced" sea of water molecules through the membrane, fresh water will increase the left, this is the "reverse osmosis" artificially ghris " force "of water molecules in the opposite direction. Outside the Middle East desalination plants, ghris mostly using reverse osmosis.
Although ghris reverse osmosis and distillation accounted for the vast share of the desalination market, there is a third technology worth talking about. Think, reverse ghris osmosis water molecules are forced through a membrane other impurities ghris can not pass through; another point of view, the film is like a piece of the moisture and impurities separation sieve, put what you want and do not want to separate open. If a film is just another let impurities without letting water pass through, it is not to achieve the same purpose? Right, a third desalination technology - electric dialysis (electrodialysis) - is the use of such a film. To understand the electrical schematic dialysis, you must first recognize the concept of positive ghris and negative ions. The reason why the salt was dissolved in water, because of its atoms and two parts water will be split into a positively charged ghris negatively charged, for positive ghris and negative ions; chemical name of the salt is "sodium chloride", is dissolved in water to form a band positively charged sodium ions and negatively charged chloride ions, took water positive and negative ions, can desalinate seawater.
Imagine you are standing on the bridge, the following three-lane road, the center line for the sea, "walk", a piece just let positive ions through the membrane between the middle and the left line, between the middle and the right line is the only one to make ions through the film; in other words, the positive ions in seawater can only "turn left lane" negative ghris ions can only "turn right line." It was not enough, the ion must be kept in the left and right lines, shall return the midline, is not difficult to reach this point, simply place the ions in the road on both sides of the opposite electrode can (ie, negative on the left and positive on the right). Formal electric dialysis apparatus not only "three lines", but positive and negative ions and white film "multi-lane" is not much different focus all in "three-lane" metaphor ghris being: to attract the positive electrode, negative ions end of the walk, and then to only allow ions to penetrate the film to ensure water and ion separation.
To boil water distillation, reverse osmosis water to be high-pressure pump, electric dialysis electricity will have to extract ions are injected into the energy of each approach to the sea, apart water molecules and ions "entanglement." Recently, a Vancouver company called Saltworks Technologies, borrow heat of the sun, invented a less energy-intensive desalination technology. Back to the "three-lane" metaphor, but no electrodes on both sides of the road, and three traffic lanes and a flyover for the whole sea "walk"; the original film is still two, but three lines are all due to sea water, ion density is equal on both sides of the film, so there is no ion "transfer line." Suppose the sun shine on the road, only to shine on the bridge; sun in the sky, flyover water evaporation, leaving ultra-salty seawater saltier than sea water, bridges ion excess. If built staircase sacked road through the ion will be a rush down. The key here, we built two stairs, but there is a thin film of stairs, only let certain ions to pass through: the piece off the left lane of stairs just let ions pass through the right line of the piece only positive ions.
In my opinion this layman, saving energy is not surprising, since it apparently borrowed the amount of solar energy, and I suspect that it's "yield." Imagine distillation desalination, If I need more fresh water, you can "add a fierce ghris fire"; to Saltworks of technology, I can not "add a fierce sun," the whole program depends on the sun first to create ghris "super-salty seawater," sunshine It will not be the bottleneck? Day without sunshine, so what? If the province can only consider desalination, that we do not need desalination, each as long as the pot of water on shore fishing beach, covered with glass, and other solar evaporation basin of water, a glass lid will drop down drinkable, this is absolutely the amount borrowed ghris solar desalination, energy input is zero. In fact, we have adopted this approach, the Earth is not that a giant distillation type desalination plant it? It's "boiler" is the sun, we drink water dripping from the sky.
Tuesday 2010-10-05 Nick Lee parasite contribution to society bent on Saturday 2009-05-16 charles_cc HMI people who have bent their machines folk media, ghris private donations needed! PAYAL user, please payment method, the money to inmediahk.net@gmail.com
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