Environmental chemistry insight and how it applies

Environmental chemistry insight and how it applies 

 

Environmental chemistry is the study of chemical and iochemical phenomena that occur in natural places. Environment does not lead to green chemistry but it's quite different. It can be defined as the study of sources, reactions, transport, effects and fates of chemical species in air soil and water environment and effect of human activity on these. It includes atmospheric, aquatic and soil chemistry and beig related to environmental and other areas of science.

 It is true that the term environmental chemistry has no precise definition. It means different things of different people. Since the early beginning of environmental chemistry has expanded rapidly. Natural chemical processes in all sectors of environment particularly soil, water and atmosphere, have been subject to investigation as well as environmental behaviour of contaminating chemicals.

Environmental behaviour of contaminating deals with -

1.      Environmental pollution: It is the effects of undesirable change in our surroundings that have harmful effects on plants, animals and human beings. The substances that cause pollution are known as pollutants. Pollutants can be solid, liquid or in gaseous form.pollutants can be degradable like discarded vegetables which rapidly break down by natural process. On the other hand they may be slowing degradable, remain in environment in an unchanged form for many years such as DDT (dichlorodiphenyletrichloroethane), plastic materials, heavy metals. These are difficuilt to remove from environment. These pollutants are harmful to living organisms. In Th process of environmental pollution pollutants originate from a source and get transported by air or water or dumped into soil.

2.      Atmospheric pollution: In our environment there are several layers of atmosphere like troposphere, stratosphere, and ionosphere. It means earth is not same thickness at all height. There are different things which contaminate the atmosphere at different height. Upto the height of 10km the layer is known as troposphere and pollution occur there due to presence of unburnt carbon, undesirabl solid or gaseous particle in air such as dust, fumes, smoke, H2S and oxides of sulphure, nitrogen and carbon. Due to incomplete cobustion of hydrocarbon used in automobiles. These pollutants cause cancer and some harmful health hazards. They harm plamts by ageing; break down of tissues and shedding of leaves, flower and twigs. Oxides of carbon such as carbonmono oxide and carbon dioxide are main pollutants. It is colorless, odourless and highly poisoneous to living beings. It causes death due to which it binds with blood and made a component carboxyhemoglobin that reduces the percentage of oxygen in human body and causes death.

-  Carbon dioxide is released into air by all living beings (human and animals) by respiration. Excess o carbon dioxide causes global warming which result dangerous to our environment. The melting of Ice Mountains which causes flood and imbalance the aquatic life.

Eco system is totally affected by the melting of ice glaciers. Heating effect of solar energy due to increase by the excess presence of carbon dioxide in the environment is known as green house effect. Carbondioxide is the major contributor of global warming besides carbon dioxide other green house gases are methane, water vapours, nitrous oxide, CFC's and ozone.

-   Methane is produced naturally when vegetation is burnt, digested or rotted in the absence of oxygen, large amount of methane is produced or released in paddy fields, coal mines, from rotting garbages dump fossil fuels.

-   CFC's: Chlorofluorocarbons are manmade industrial chemical used in air conditioning etc. CFC also damaging ozone layer that protects us from ultravilot rays causes cancer.

-   Nitrous oxides: Occur naturally in environment. In recent years it increased significantly due to the use of chemical fertilizers and burning of fossil fiels. If these continue then average temperature will increase to a level which may lead to melting the polar caps and flooding of low laying areas all over the earth. Increase in temperature incidence the infectious like dangue, malaria, yellow fever, sleeping sickness etc. So these bring adverse effect on our environment.

-   Acid rain: Normally the pH value of rain is 5.6 but due to some pollutants causes acid rain. Oxides of sulphure and nitrogen present in air. These oxides react with water in presences of air give some acids as result of reactons. Sulphure dioxide is much more dangerous for our agriculture, trre, plants, as it dissolves and washes away the nutrients that needed for the growth of crops. It causes respiratory ailment for them. When acid rain falls and flow as ground water to reach river, lakes etc. it affects plants and animals life in aquatic eco system.

-  Photochemical smog: unsaturated hydrocarbon. The main component of photochemical smog are ozone, nitric oxide, formaldehyde and peroxyacetyl nitrate (PAN). It causes serious health hazards. Bothozone and PAN act as a powerful eye irritants, nose and throat and their high concentration causes headache, chest pain, dryness and also corrosion of metals, stones, building material. Living example is Tajmahal in Agra; India is badly affected by nitroc acid through acid rain.

3. Water Pollution: Water is a very essential part of our life. It is the most abundant on earth. Without water ther is no life. Human body contains 90% of water. This means that it plays a vital role in our body. Think if water got polluted. We usually intake water for its purity but insure that first the quality of water through different path by human being i.e municipal and industrial discharge pipes where pollutants enters the water source.

Causes of water pollutions are pathogens, organic waste, plants nutrients, toxic heavy metals, sediments, radioactive substances and pesticides etc.

-  Pathogens are most serious water pollutants are the dieses causing agents. It includes bacteria and other organism that enter waterbodies from domestic sewage and animal etc. it causes gastrointestinal disease.

-  Organic waste is major pollutants such as leaves, grass, trash etc. these waste are bio degradable. The large amount of bacteria decomposes the organic matter present in water. The amount of oxygen is limted because they consume oxygen dissolved in water. This causes the depletion in water. As we all know dissolved oxygen is very important for aquatic life. As oxygen level decreased upto a level and growth of fishes get inhibited. The foul smell due to the consumption of oxygen of dissolved water and it depleted the water.

Chemical pollutants: Inorganic soluble chemical including heavy metals such as cadmium, mercury, and nickel etc constituent are important class of pollutants. All these metals are dangerous to human because our body cannot excrete them. It damages our kidney, central nervous system and liver etc. bodegradable detergant contains potassium and sodium in acid form. The addition of phosphate to water enhances the growth of algae. As algae profuse over water, the consumption of oxygen in dissolved water increased and this causes the imbalance in aquatic system. Reduction in concentration of oxygen can cause anaerobic condition commonly with accumulation of abnoxious decay and animal death. This process in which nutrient enriched water bodies support a dense plant population, which kills animals life by giving depriving it of oxygen and result in subsequent loss of biodivesity is known as Eutrophication. Flourides lead, sulphate, nitrate and other metals contaminated water bodies and that cause harmful efects on human being as well as all living creatures.

4. Soil pollution: Contamination the soil by use of undesirable products to enhance the growth of agriculture is known as soil pollution. It can be done by-

 Using pesticides like DDT, during World War 2 DDt was found to be great use in control of malaria and other insect borne disease. Pesticides are put to use in agriculture to control the damages caused by insects, rodents, weeds and varius crop disease. Basically pesticides are toxic in nature and repeated use of this may cause contamination.

- Industrial Waste: The disposal of non-biodegradable waste through indusries is the major cause of soil pollution. It makes the soil infertile and serious threat to environment.

Environmental chemistry is applicable in all through chemical process in our surroundings.

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