INDUSTRIAL CHEMISTRY

 Introduction

               Chemistry is the study of chemical substances. Study of chemistry deals with the identification of the chemical compounds or element in combination and how they combine to produce these compounds. Chemists have made studies on this subject and they have been able to produce artificial and /or synthetic materials such as metals, minerals, etc. due to the invention and discovery of new substances life has been made easier and comfort. Plastics, Polymers, medicines and agricultural products have made a great change in living styles.

Chemical Fertilizers

chemical fertilizer

               The population in being increased in the world day by day. Moreover, the life span of man is increased. It has been believed that there were no such populations in the history of earth. The food required for overgrowing population is to be fulfilled by the man himself. The major part of food is obtained from plants. Carbohydrates, vitamins, proteins, fats, minerals, etc., are obtained from plants only. It is believed that plant leaves are strange laboratories where food is manufactured.

               Living things have 4 important elements in them. They are carbon, hydrogen, oxygen and nitrogen. For the existence of life Phosphorus, potassium, calcium, etc., are also needed. The elements such as boron, chlorine, iron, magnesium, manganese, molybdenum, zinc, sulphur are also necessary in traces.

               Plants take these substances from water. When plants die these elements go into the soil after decomposition by bacteria (microorganism). This is true in case of forest plants and preserved areas but in a cultivated land, the nutrients absorbed by them do not return to soil as stated above. Thus the content of necessary elements gradually decreased resulting in the desertion of land. Due to erosion also the top fertile soil is taken away and plants do not get sufficient nutrients for crop production. To make the land fertile, we have to add manure (organic fertilizer) and fertilizer (inorganic chemical fertilizer) in the soil.

               The basic elements Oxygen, Hydrogen and carbon is flourished by the atmospheric air and water but when the content of other elements decrease, that is, to be fulfilled by fertilizers. The fertilizers can be categorized into two groups:

a)      Organic fertilizer (manure)

b)      Inorganic (chemical) fertilizer

Manure

               Manure is used in village as organic fertilizer since time immemorial. This fulfils the required elements (nutrients) for the crops and plants. Unfortunately this manure (gobbar or compost) is not readily available and we use inorganic fertilizers. Chemical fertilizers are produced from nitrogen, phosphorous, potassium and calcium rich compounds.

Nitrogen

               Ammonium nitrate (NH₄NO₃) is extensively used to supply the requirements of nitrogen for plants. Plants can readily absorb nitrate part of ammonium nitrate. Nitrifying bacteria in soil helps in decomposition of nitrate from ammonium nitrate.  Such nitrate is soluble in water and thus, plants can absorbs easily. Plants become yellow and wilting due to insufficient amount of nitrogen in soil.

               Ammonium sulphate (NH₄)₂SO₄ and Urea (CO (NH₂)₂) are other nitrogen rich fertilizers.

Phosphorous 

               Ammonium phosphate (NH₄)₃PO₄ fulfils the required phosphorous in soil. Bone meal and calcium superphosphate are chemical fertilizers rich in phosphorous. A mixture of calcium hydrogen phosphate and calcium sulphate is called super phosphate. For the growth of root and better quality crops phosphorous is essential.

POTASSIUM

 POTASSIUM sodium

               Another important element necessary for the growth of plant is potassium. A fertilizer containing potassium is called potash. For the manufacture of food in plants this elements is necessary. Lack of potassium results slow maturation of plant and flowers. This increases the disease resistance. The chemical fertilizers such as potassium sulphate and potassium chloride are used to fulfils the required amount of potassium. Since time immemorial wood ash has been used in soil to supplement potash in soil.

Calcium

Dietary calcium

               Calcium oxide (CaO) is used for the requirement of calcium in soil. This reduces the acidity of soil and makes land more fertile.

Danger from Chemical Fertilizers

               The quality of soil is to be tested to find out the quantity of elements lacking in soil. At the mean time, its acidity and basicity is also to be tested before planting the crops because the plants which grow in acidic soil cannot grow well in basic soil and vice-versa. Moreover, in high acidic or basic soil no plants can grow. With reference to the soil test, only the required fertilizer is to be used to enhance the fertility of soil. But excess use of same fertilizer may lead towards desertion. For example, if nitrate fertilizers are not totally absorbed by plants they will be swept away by water to near water source. Due to excessive nitrates in water algal growth will increase. But as the algae die dissolved oxygen is extremely used by the decomposers. As a result aquatic animals die due to the lack of oxygen. Drinking nitrate rich water results dwarfism in children, which are the adverse affected of fertilizers.