Introduction to Seawater
Water is indispensable to the human body and all other forms of life on earth to survive. However, it can be a health hazard if not all the components and properties are up to the safe standards like chemicals, physical properties and even the biological aspect. This attributes of water determines whether water is safe for use or not. Basic chemical property found in the tissue of all living organisms. Water exists on earth with its solid state, ice, gaseous state, water vapour and steam. Water also exists in a liquid crystal formation state near hydrophilic surfaces. It continuously circulates in earth through hydrologic cycle of water by evaporation, transpiration, precipitation and run off.
Chemical and physical properties of seawater
Other chemicals include Magnesium, Calcium, Potassium, Carbon, Bromine, Boron, Strontium, Fluorine and Nitrogen ions. Most scientists, however, agree that life began in the sea; it is not a surprise that these chemicals are essential to life. Water appears in the environment in all three ordinary states of matter and may take diverse forms. Water vapour and clouds, seawater, and icebergs exist in the Polar Regions. There are also oceans, tropics glaciers, and rivers in high mountains as well as liquid in aquifers as underground water on earth.
Seawater exists in liquid at standard temperature and pressure conditions. Seawater has a salty taste, but it is odourless. The colour component of water and ice is a very slight blue hue, although it appears colourless in when observed in small amounts closely. The seawater vapour is essentially invisible as a gas in this form. Seawater is transparent when viewed in the electromagnetic spectrum (Postel, 1997).
The water molecule of the sea is not always linear and atoms of oxygen have higher electro-negativity as compared to hydrogen atoms. It has an insignificant negative charge, while the hydrogen atoms are somehow positively charged. Therefore, water is a polar molecule with electrical double pole components. It can also form an uncommon large number of intermolecular four bonds of hydrogen for a molecule of the same size. This property has led to strong, attractive forces among the molecules of seawater. This gives rise to high surface tension and capillary strengths in seawater.
Seawater can be good solvent commonly referred to as a universal solvent, though, not like pure. It has the ability to detect and separate the hydrophilic and hydrophobic components. This makes seawater a good solvent though most of it is saline in nature. Seawater, therefore, can dissolve both living and nonliving components like salts and even some properties of cells. It has a high electrical conductivity due to the ionic material dissolved in seawater, but this depends significantly with the amount of dissolved ionic material such as sodium chloride. Unlike pure water, which has quite, low electrical conductivity, unless, dissolved with some amount of ionic material (Vandana, 2002).
The boiling point of seawater depends on the barometric pressure of the place. For example, on the top of high mountains like Everest, water boils at sixty degrees Celsius compared to hundred degrees at sea levels. However, water at deep of the ocean close to geothermal vents get to temperatures of hundreds of degrees and maintain the liquid state. Seawater also has the second uppermost molar specific heat capacity of any identified component, after ammonia also high heat of vaporization. Both are because of the extensive hydrogen bonding between the water molecules (Pinet, 1996).
Seawater also has the anomalous characteristic of becoming less dense when cooled down to its solid forms like ice. It expands to occupy about ten percent more volumes in this solid state, that accounts for ice floating on liquid water. Seawater with most of the oils is immiscible forming some layers according to rising density from the top. Like gaseous substances, water vapour is purely miscible with air. Seawater forms an azeotrope with many solvents when mixed. Water acts as a product of the combustion of hydrogen molecules. Seawater is saline and, therefore, elements that are more electropositive than hydrogen for example, lithium, and caesium displaces hydrogen molecule from water to form hydroxides.
In terms of taste and odour, seawater can dissolve different substances, giving it varying tastes and odours. Humans and animals have senses, which enable them to analyse the portability of water where they avoid water that is too salty and putrid. Seawater has very saline taste, but this can be converted into potable water through various methods of purification. Seawater, though saline can therefore, be purified to drinkable water.
Methods used to convert seawater to drinkable water
Desalination method is used to convert the saline seawater to drinkable water. It refers to processes that remove some amount of salt and minerals from water. Desalination refers to the removal of salts and minerals from seawater that has a lot of salt dissolved in it. The largest world desalination in is the Jebel Ali Desalination of the United Arab Emirates.
Reverse osmosis can also be applied to convert saline water to safe water for human consumption. This method reduces the level of salts in water making it safe for human use. It is predominantly common and is used in the Middle East regions where most of the water used is saline.
Benefits of water purification
Water is a basic utility and forms nearly over seventy percent of human life. The purification of water is essential in maintaining the human health. It balances the nutrient and mineral aspects to safe levels for human use. Purification also assists in maintaining the hydrological balance in the cycle. This would minimize the occurrence of adverse health effects in saline water like teeth fluorosis and even carcinogenesis or cases of renal failure.