Clean drinking water is one of the most important international health issues today. The lack of potable water poses a huge problem in parched regions of the world where freshwater is becoming very scarce and expensive. Water is very important in everyday life. Although, more than two-thirds of the Earth is covered by water, shortage of potable water is a serious issue that many countries suffer from. About 94% of world's water is brackish and only 6% is fresh water. Water shortage crisis emerges when, according to the statistics, only 27% of the fresh water is ï¬‚owing water and the rest is in the form of aquifers and underground waters. Only 20% of the world's population has access to the potable water .
Difficulty in obtaining water supply became a big issue for residents in the vicinity of the coast. This is because sea water is not suitable for drinking. This condition causes a variety of initiatives to get clean drinking water and good to drink. Not all areas in Malaysia can enjoy clean water supply facilities. In Sabah, for example, there are several coastal areas that are not getting clean water supply. A low cost portable water purifier that uses solar energy to produce potable water from saltwater be a good alternative choice. This allows those living in the vicinity of the coast to enjoy clean drinking water and safe to drink. Although the total volume of potable water obtained from the low cost portable water purifier is not in a large number, it at least is a way to get clean drinking water. Small-scale, renewable, energy driven desalination water purifier might be the most economical solution for providing potable water to remote and isolated communities where the electric grid and proper infrastructure are lacking.
Basically, saltwater purification can be called as saltwater water desalination that remove some amount of salt from saline water. Desalination is one of the earliest forms of water treatment but it is still a popular treatment solution throughout the world today. In nature, solar desalination produces rain when solar radiation is absorbed by the sea and causes water to evaporate. The evaporated water rises above the surface and it is moved by the wind. Once this vapour cools down to its dew point, condensation occurs and the freshwater comes down as rain. This same principle is used in all man-made distillation systems using alternative sources of heating and cooling.
The basic processes for a low cost solar water purifier are evaporation and condensation by harnessing solar energy. There are two main approaches for the utilisation of solar energy in seawater desalination. The ï¬rst approach utilises the so-called greenhouse eï¬€ect to evaporate salty water enclosed in a simple solar still. The second approach, for the use of solar energy for desalination, is somewhat complicated and often involves more than one subsystem: one for energy collection, another for energy storage, and a third subsystem for energy utilisation in the desalination process.
The low cost portable water purifier can be one of survival kits that should have by fishermen or anglers at sea. Potable water is a matter which is quite critical when stranded at sea even though been surrounded by water. Seawater should be never be ingested in its natural state. People need at least 1 liter of water a day per person to be in a good shape while certain amount of water will lost from body by respiratory and urinary systems. Then the solar portable water purifier can be one of must-have survival kit to saline seawater into potable water in order to survive while stranded at sea.
1.2 Problem Statement
Some of people who are living in coastal area have a trouble to get clean and potable water. They have limited alternative sources to have clean water such as rainwater catchment or wells. However, these alternatives cannot guarantee the cleanliness of the water that safe to be used. They have to be really careful before they can use the water. Moreover, there are some places that did not have water and electrical supply. This can lead to portable solar water purifier that saline seawater into potable water by harnessing the solar energy. The portable solar water purifier is a low cost affordable device and this will give them chance to have one or more for their community.
The portable low cost solar can be used as a survival kit for fisherman as a preparation of emergency cases like stranded at sea. Most of available water purifiers in the market are in a big scale that almost one meter width. It is quite an issue for them regarding the size and the limited space of their boats.
The scopes of project will focus on the developments and designing a portable low cost solar water purifier are as follows:
The purified water is only for drinking and not for the other purposes.
The device will produce certain amount of purified water that enough for one person and multiple devices are needed to produce more potable water.
The size and dimension is quite critical due to the portable purpose.
 Experimental study of an integrated basin solar still with a sandy heat reservoir
Farshad Farshchi Tabrizi, Ashkan Zolfaghari Sharak Department of Chemical Engineering, University of Sistan and Baluchestan, Zahedan, Iran
 Amara Mahmoud Ben, Houcine Imed, Guizani Amenallah, Mï¬alej Mohammed, Experimental study of a multiple-effect humidiï¬cation solar desalination technique, Desalination 170 (2004) 209-221.
 M.T. Ghaibi, An overview of solar desalination for domestic and agriculture water needs in remote arid areas, Desalination 127 (2000) 119-133.
 D. Mowla, G. Karimi, Mathematical modeling of solar stills in Iran, Solar Energy 55
(5) (1995) 389-393.
 A. Sabzevari, Alternative energy sources of Iran, 6th Miami international conference on alternative energy sources, Miami Beach, U.S.A., 1983.