BIG-TIME DESALINATION

Salt water is abundant on planet Earth and can be desalinated!  It is plentiful in Azerbaijan too, because our country lies on the shores of the world's largest lake - the Caspian Sea. The idea of desalination is a good one if only because the world is catastrophically short of drinking water. One of the top issues at the World Economic Forum which opened on 26 January in Davos, Switzerland, was just this shortage.  In 2011, Azerbaijan, for its part, is going to pursue a strategy of desalinating water from the Caspian.  This initiative was proposed by President Ilham Aliyev at the government meeting on the results of 2010. "I believe that in 2011 we need to implement the first project to desalinate water from the Caspian Sea," the president said.

Sea to help

The head of state believes that fresh water supplies should remain a focus of the authorities' attention. "The Oguz-Qabala-Baku pipeline is a historic achievement in this sphere. The Samur-Abseron channel and the Tahtakorpu Reservoir must be completed in 2012. This will provide additional capacity. But we have access to a large body of water, the Caspian Sea, and its water is not so salty. We have studied the experience of Near Eastern countries which use desalinated water both for irrigation and for drinking.  We, too, need to launch these types of projects; in 2011 we must implement the first pilot project to use Caspian water, first and foremost for irrigation. If this project is successful, and I have no doubt that it will be, we will undertake large-scale measures as part of a specific programme in subsequent years", the president stressed.

Indeed, it must be admitted that the population of our planet constantly encounters problems caused by environmental changes resulting from human activity. One of them is a shortage of clean drinking water and fresh water in general. Many countries experience water shortages, as we have reported many times, even in the previous issue of our magazine. Reserves of potable water are being depleted everywhere. This is why the market for all types of water treatment equipment is expanding.

In the richest Arab countries, they have much oil but no water. Fresh water is in short supply in China's coastal provinces, a country which is surprising everyone these days by its economic achievements.  Shortages of clean fresh water are experienced in Israel, North Africa and Southern Europe. However, all these areas are in the immediate vicinity of huge reserves of salt water. But salt water cannot be used for drinking or irrigation. That is why one method of water treatment, desalination, is widely used there. Nonetheless, it must be noted that water treatment in industrial quantities by desalination is quite an expensive process, because of the huge amounts of energy required. And the expense of building such facilities is also high. But in 2007 the world's desalination facilities delivered more than 50 million cubic metres of fresh water.

So how is it desalinated?

There are currently different methods of desalinating sea water which can be used on industrial scales.  To produce potable fresh water, its salinity must be reduced to 1 gram per litre. Clean, potable water is produced from sea water by distillation, reverse osmosis, electric dialysis, congelation or ion exchange.  The distillation method involves the instantaneous boiling of sea water, which evaporates through several chambers with gradually decreasing pressure. Membrane distillation involves heating sea water on one side of a hydrophobic membrane. The membrane is permeable only to steam which is cooled down and condensed on one side of it. The multi-effect distillation method involves heating water in one column, and the steam heats water in other columns. Sea water can also be desalinated using the congelation method, by cooling it until the water crystallizes, while salts do not. The reverse osmosis method uses semi-permeable membranes which are permeable to water under pressure but impermeable to molecules of admixtures. Electric dialysis requires two membranes permeable only to cations or only to anions, which are generated by applying direct current. At present, the distillation and reverse osmosis methods are used most frequently in the world. Electric dialysis and congelation with ion exchange are used less often. There are more than 800 major desalination facilities in operation worldwide at present, and the largest producer of desalinated water is Kuwait. Salt water desalination is an important source of fresh water in small island nations like Seychelles, Mauritius and others, where there are no rivers. The largest desalination facility is in Israel, near the city of Ashkelon.  It produces 108 million cubic metres of desalinated water a year.

The most likely sites for implementation of a sea water desalination project in Azerbaijan are Chilov Island and Neftyanyye Kamni, because the problem of quality water supply is most acute in those areas.  The desalinated water will be used by the island's residents and the 'city on stilts' and the enterprises there. Eventually, depending on the pace of implementation of the pilot project, the use of technology on a wider scale and supplying desalinated drinking water to the country's population will be considered. The need for desalination will increase if it proves impossible to supply enough clean drinking water from other sources in some areas of the country. The desalinated water will be very pure, and certificates will be issued to prove this by all the appropriate bodies.

In the mean time, because the sea water desalination technology used in the UAE and Saudi Arabia to meet the population's demands consume huge amounts of fossil fuel-generated energy, those countries are searching for methods which require less energy or use renewable sources of energy.  At present, Abu Dhabi's environmental protection agency in the UAE is testing a desalination facility which operates on solar energy. It could be an excellent alternative to the traditional desalination facilities which emit carbon dioxide into the atmosphere. At present, pilot projects are under way in the desert areas of Hamim and Sweihan. Every installation generates on average 35 kilowatts of electrical energy per hour, and all the test installations produce a total of 1050 kilowatts per hour. If testing is successful, other countries in the region will use the technology at their desalination facilities. The main differences in the new desalination facility operating on solar batteries is 'zero carbon dioxide emission' and no atmospheric pollution. In addition, the designers say that the process is cheaper.

Incidentally, in the context of sea water desalination, President Ilham Aliyev mentioned at the government meeting the implementation of even larger-scale measures to use renewable energy sources. He believes that work must begin in Azerbaijan in 2011 to install solar batteries and here the head of state meant not only bringing the required equipment from abroad, but also manufacturing it.  He also stressed that the installation of renewable energy sources - solar batteries and wind farms - must take place on non-arable land.

Advantages and disadvantages

There are experts, however, who are seriously concerned about any further use of sea water to produce potable fresh water. In their opinion, this might result in increased salinity in the oceans and upset a fragile balance in maritime ecosystems, which will cause irreversible changes in the planet's ecosystem.  Other experts say that, although in the Near East and other countries desalinated water has been used for drinking for a long time now, a number of flaws have been discovered besides its high cost. First and foremost, desalinated water has an unpleasant taste. That is why they mix it with ordinary tap water or, as Israel plans to do, run it through a natural mineraliser - chalk rock. This enriches water with calcium ions, which make the water harder and tastier.

Be that as it may, sea water desalination is a project which has a right to life, and it seems that the rapid progress of scientific technology will address the current problems because this method of processing water provides a way out of the acute shortages of clean drinking water in different parts of the world.