Desalination is the process through which salt, especially sodium chloride, and other minerals are removed from the ocean, sea ground or brackish water to make them suitable for human, animal, industrial, or irrigation purposes. Water can dissolve almost all substances found in the earth’s biosphere. All water contains dissolved substances that need to be desalinated (Cipollina 17). This paper seeks to discuss the desalination process using Kuwait as a case study.
Kuwait’s desalination technology is the first one among the Gulf Cooperation Council (GCC) states. These states are located in arid and semi arid regions of the world. Kuwait has no permanent freshwater sources. Therefore, it depends largely on desalination water plants to supply water for its various needs. In the plants, the sea water is generally first heated. The water evaporates leaving behind the salt. This is followed by the collection of steam that is then cooled. Finally, condensation is supported in huge tanks. The process is repeated several times until the water is totally free of salt (DiPiazza 12). Water desalination is the major undertaking in Kuwait as evidenced by large plant set ups such as the Doha Reverse Osmosis plant. However, multistage flashing (MSF) process dominates the desalination industry in Kuwait (DiPiazza 12).
Water in Kuwait has been an issue of environmental concern. The country has never had permanent fresh water sources. Tracing back to early 19th and 20th century, desertification was an issue threatening the environment in Kuwait. The arid and semi arid lands were quickly changed into more barren deserts. Wadis or dry streambeds that were filled with water during rain could not supply proper and reliable water for drinking as the collected water could sink into the dry land. It increased the dependency on the sea water. People generally boiled sea or rain water to desalinate it.
The people of Kuwait depended on wells to supply their water needs together with fresh water transported from Basra Iraq. The government of Kuwait dug boreholes in vain and thus continued to transport water from Iraq. However, water pollution in the Persian Gulf War and oil spills in the sea complicated the issue further (DiPiazza 13). It triggered Kuwait to be the first country in the 20th century in the GCC region to invest in desalination. The Kuwait oil company established the first desalination plant on the sea in 1951 at Mina Al-Ahmadi that was well known by 1953. The plant supplied 9,200m3 per day in early 1970s which later increased to 2.4 million m3 per day due to the introduction of multistage flash desalination process (MSF) in 2008 (United Nations 12).
Ways of Desalinating Water. Clean water for use has been scarce due to the climate change, population increase, and impacts of human activities on environment. It has reduced water availability and accessibility at individual levels. To address this, desalination of the ocean, sea, ground or brackish water is necessary. Several ways have been employed to desalinate water, although the energy demand for these processes is high. It becomes a problem in areas where electricity is not easily available or is not cost effective (Cipollina 17).
Solar energy is one of the alternative ways of supplying the energy needs of countries without affecting the environment. Use of fossil fuel as an energy source has adverse environmental impacts. Solar desalination can be grouped as direct or indirect collection systems. For direct collection systems, the solar energy is used to heat directly the water to form steam that is then cooled and condensed in a tank. The solar still is very useful in the production of small quantities of water since one basin is used and there are not a lot of technical connections (Cipollina 131).
There are other efficient desalination methods. These include multistage flash (MSF), multi-effect distillation (MED), and Reverse Osmosis (RO). However, these methods are known to use high amounts of energy in terms of electricity and are thus not cost effective. MSF and MED has the same working principle. Water is continuously heated, cooled, and condensed steam is then collected. Reverse Osmosis (RO) method involves movement of water through a semi-permeable membrane under pressure. Water is forced through a membrane against concentration gradient. It leaves salt and other minerals behind (Cipollina 17).
Concerning the indirect solar desalination, the solar energy is collected and stored. The methods are classified as multi-stage flash (MSF), multi-effect distillation (MED), mechanical vapor compression (MVC), membrane distillation (MD), and atmospheric humidification/dehumidification process (H-DH).
Kuwait has installed several MSF plants at different locations in the country to meet the higher demand of water due to the increased population. There are two MSF plants in Shuaiba South Station set up in 1975 and refurbished in 2005. Another seven are established in Doha East station. They were built in 1978-1979 and several others were built after these major ones. The latest built ones were eight MSF units in Sabiya station in years 2006-2007(United Nations 15).
Advantages and Disadvantages of Desalination. The application of various desalination methods has their merits and demerits. One can thus easily point out advantages and disadvantages in comparison to former methods like boiling water and taking the raw water. Desalination has made usable water available to people through the usage of the salty sea water. It has ensured a very stable supply of fresh and clean water to occupants of arid and semi arid lands. In fact, over 100 nations in the world are supplied by portable water using desalination. For example, all fresh water in Kuwait is supplied by this method (United Nations 15). The desalinated water is healthier for drinking and other activities like irrigation in comparison with the one used 200 years ago. Salty water is converted to fresh water suitable for all purposes. The non-desalinated sea water may be rich in nutrients such as nitrogen, phosphates and various inorganic metals like spring sodium. Nonetheless, such water is neither safer nor healthier for drinking. Excess salts in the sea water are not good for the health of a person. This water is also not suitable for agricultural irrigation.
As a country experiencing little or no rain and characterized by long periods of drought, Kuwait has indeed benefited from desalination. Formerly, Kuwait invested huge sums of money in trying to locate underground water, albeit with limited success. All drinking water was transported by boat until 1950 when the desalination began. Indeed, water that was deemed useless like the brackish ground water and sea water is now considered to be an alternative source of water in Kuwait (DiPiazza 12).
Investment in river and brackish water desalination improves the poor quality of the water. It has been seen during the Iraqi desalination process on rivers Tigris and Euphrates. They pumped 30 percent of the 310,000m3 per day. Desalination also results in expansion of urban centers. Places that were once deserts turned into beautiful towns as observed in Egypt. In Kuwait, major towns emerged as a result of good water.
Other than supplying water, embracing desalination and installing plants have since created a lot of employment places for the citizens of the GCC countries. In Kuwait, the ministry has approved several companies in a bid to expand the desalination industry and create more employment opportunities for citizens. Lastly, sometimes the desalination process gives a by-product of table salt that is tasty and healthy for the human consumption.
Desalination of the sea water and brackish water has as well some disadvantages that are notable and critics have risen to challenge them. One of the major concerns is the high power consumption. It can be argued that desalination is expensive and requires a higher amount of energy particularly concerning the running of multi-stage flash (MSF) and multi-effect distillation (MED). However, it is different with the reverse osmosis (RO) and the solar initiated desalination. They need less power to run than would be expected of other industries (Cipollina 18). For example, a 100-million-m3 R-based plant would require an electrical power supply of less than 50MW. Therefore, the energy used is far lower than the common threshold for its usage. It can be noted that there is cost effectiveness when a state decides to establish a large desalination plant rather than small fresh water consumer firms. The small firms advise the public on installation of rain water tanks and storm water harvesting options. It has lead major states like Kuwait to consider establishing large scale water desalination plants that are cost effective and beneficial to the whole nation.
The criticism based on environmental controversies argues that the process will be draining water from the environment leaving less water. They also argue that emissions given out by the plants during desalination of the hot and salty water in particular are dangerous when taken back to the sea. It can potentially be an environmental hazard. The by-product, concentrated sodium chloride (Brine), is a major cause of marine pollution in oceans (United Nations 27). Supporters of desalination would say that the effect will be lesser or minor.
In conclusion, desalination as discussed with an emphasis on the Kuwait’s experience has had significant effects. Desalination has transformed the Gulf Cooperation Council (GCC) states from being deficient of clean and fresh water into states that are stable in fresh water supply. However, the high power consumption is still a challenge.