Science Articles


Water consists of two molecules of hydrogen and one molecule of oxygen which combines together to give life to all the living organisms.


Natural products are the chemical substances or compounds found in nature that are produced by the living organisms. They can either be produced naturally or through the total or partial synthesis process.

In the world, the most important substance for humans is natural water which breeds life. Water consists of two molecules of hydrogen and one molecule of oxygen which combines together to give life to all the living organisms. Freshwater is important for the development of industries, cooling of products, equipment, processes etc.

The chemical composition of water is formed in the processes of hydrological cycle that occur on the Earth, which connects hydrosphere, atmosphere, lithosphere and biosphere together. Water has a set of unique properties which makes it different from all the other substance. For instance, it has high-temperature values for melting, boiling and even evaporation. It serves as a universal solvent and has heavy dissolving capacity.

Chemically pure water is a complex substance made up of isotopes of oxygen and hydrogen, which can lead to the formation of 18 isotopic varieties of water. Chemically pure water is not available under the natural conditions. Natural water consists of a complex group of minerals, gases, organic substances in form of true solutions, colloidal matters etc. Natural water consists of a large number of chemical elements- so many so that almost all the known chemical elements can occur inside natural water.


There is only a finite amount of water present on the planet Earth. While it might look like there are many sources available, usable water is only a few percent. Hydrological cycle helps in recycling of water. When the sun rays hit the water, evaporation occurs and this turns the liquid state of water into the gaseous state.

As soon as the temperature cools down in the upper atmosphere, the water condenses inside the cloud. With the cloud, the wind transports water to various parts of the planet. After travelling some distance, it starts precipitating. During the process of condensation of water, various gases from the environment are absorbed which leads to acid rain.


Pure water is known for its odourless and colourless appearance. It is also tasteless. There are various substances that come in contact with water which disrupts its purity. Water is known to be a universal solvent since any naturally occurring substance on planet Earth can be dissolved in water. Water acts as a base for various experiments.


Whether it is a river, lake, wetland or any sea, the chemical composition of natural water is- pollutants, microelements, main ions, biogenous substances, dissolved gases, organic substances etc. These impart properties like corrosivity, alkalinity, salinity, acidity etc to the natural water. There are suspended solids found in water impurities. Some of the soluble minerals also give colour to the water solution however, it remains clear. The suspended solids look like particles in water owing to their lack of solubility.

Some of the impurities found in water are-

  • Magnesium and calcium salts– These forms curding of soap, interferes with dyeing process etc. But by softening, using surface active agents, demineralisation etc, it can be treated.
  • Carbon dioxide– These can corrosion in water lines and can be treated by aeration, neutralisation by using alkalies etc.
  • Bicarbonate, carbonate, hydroxide etc can cause the production of carbon dioxide in steam, corrode condensate lines, etc. The acid treatment is a great way of getting rid of this one.
  • Sulphate– These can add solid content in water and can be treated by using electrodialysis method.
  • Nitrate– These can not only add to the solid content in water but can also lead to methemoglobinemia in small babies. Evaporation is one way of treating it.
  • Iron– These changes colour on precipitation, interferes with dyeing, tanning etc. When it comes to treatment, contact filtration, lime softening, aeration etc. are few ways of treating it.
  • Aluminium– It can cause deposits in the cooling system and can be cured by improved filter operation.


In 1974, chlorine was recognised to have adverse reactions as a disinfectant by creating harmful by-products. However, there are various other disinfectants that can potentially cause harm like chloramines, ozone, chlorine dioxide, bromine, iodine and other halogens. This rings warning bells in the minds of scientists who want to work on a new way of treating water.

Chlorine usage leads to yield of trichloroacetate, trihalomethanes, chloramines, chlorophenols etc. Usage of ozone might lead to the production of oleic acid, glyoxal, methylglyoxal etc. Chlorine dioxide might yield chlorinated aromatic compounds, chlorite, chlorate etc. Bromine and iodine might even lead to leaving residue in the drinking water.

It is vital to select the correct disinfectant in order to safeguard the properties of water.