Global Warming


 Environmental Pollution is the contamination or other undersirable alteration of the physical, chemical and biological quality of environment. it is the release of potentially harmful substances into the environment.

Air Pollution -

 Pollutant commonly introduce into the air include: Smoke, particulate dust, Gaseous Emissions, Noise

Effect Of Air Pollution

* Health problems e.g respiratory problems

* Ozone Layer Depletion

*Acid Rain

*Photochemical smog

Ozone Layer Depletion - A thin layer of ozone gas, a form of oxygen surrounds the earth, about 25km from the earth surface. it filters out some of the potentially harmful ultravoilet radiation from the sun. studies suggest that this ozone layer is being depleted by some gases, produce as by-products or used in industries, by interacting with the ozone. The gases, which interact with the ozone to deplete the layer are thus:

Gas                                                                  Sources

Chloroflourocarbon                                Refrigerants, Aerosol sprays, Solvent

Carbon tetrachloride                              manufacturing intermediates

Halon                                                             Fire Extinguishers

1,1,1-trichloroethane                             Degreasing Agent

An increase in surface ultraviolet radiation is thought to increase eye damage and skin cancers as well as damage the wider environment. Because of international governement concerns, actions is being taken through the montreal protocol (1987), revised at the Rio de Jeneiro meeting of 1992, to phase out some of these chemicals.

Greenhouse Effect (Global Warming) - Normally, gases emitted in the course of naturally occuring events, such as volcanic eruptions, forest fires, decaying vegetation and living beings, are absorbed by plants and trees to generate materials necessary for their growth and return the by-product oxygen to the atmosphere. However, the cast amount of gases released into the atmosphere by industrial processes are too great for the declinning forest areas to cope with and much remains unabsorbed. The unabsorbed gases now create an envelope round the earth. The earth derives its warmth from the sun and radiates any excess heat back into space as infrared rays. What now happens is that the envelope of gases absorbs the infrared rays reflected from the earth's surface and acts as an insulator preventing the surplus heat from dissipating into the upper atmosphere. This causes the global temperature to rise, the process is referred to as greenhouse effect because of its similarity to the effect of glass in a greenhouse which allows the sun's energy to enter but prevents some of the radiated heat from escaping. Below ia a list of greenhouse gases and their sources:

Gas                                                 Source

Carbon                                    Fossil fuels, deforestation, road vehicles, forest fibres

Methan                                    Agriculture, natural decay of vegetation, landfill

Nitrous oxide                             Fossil fuels, agriculture, road vehicles

Chloroflurocarbon                         Refrigerants, aerosol sprays, solvents.

There is concern over global warming and the extent to which the climate is changing with the consequent melting ice caps and rising sea levels.

Acid Rain - Acid rain is rain that has absorbed some of the acidic gases formed when fossil gases are burnt. The sulphur and nitrogen compounds the fuels contain are first oxidized, they dissolved in rainwater or snow to form dilute sulphuric and nitric acids. These acidify the soil resulting in crop failure, and damage to the fabric of buildings. In addition, the increased acidity of the soil results in aluminium being leachd from the soil into rivers, kiling fish and other aquatic creatures. The source of the original emission can be hundreds of kilometers from where the acid rain is deposited.

Photochemical Smog - Photochemical Smog occurs when strong sunlights acts upon a mixture of notogen oxides released from vehicle emissions which combine with oxygen in the air to form ozone. In the presence of hydrocarbons, again from vehicle emissions a number of complex substances are formed which condense into minute droplet and create the characteristic haze. Health effect can include irritation of the eye and breathing problems. The smog tends to be most intense in the afternoon when the sunlight is most intense. it frequently occurs where high levels of vehicle emission combines with strong sunlight ad little wind to disperse the gases.

Oil Spillage - Oil spillage is an accidental discharge of oil from pipeline or facilities. it can pollute both land and water, depending on where it occurs.

Sources Of Oil Spill Incidents

* Human Error

* Corrosion

* Sabotage/theft

* Drilling Operation

* Emergency Operation

* Others e.g construction, natural effect, like earthquake, tsunami.


Effects Of Oil Spillage

* Community unrest

* Death of aquatic life

* Stunted growth in vegetation

* Disrupt recreational activity

* fire outbreak.


Strategies For Oil Spill Prevention

* Use of equipment designed to specification

* Surveillance of facilities

* Facilities upgrading

* Adoption of corrosion control


Oil Spill Control Methods

* Isolate/stop source

* Containment e.g Boom, Absorbent, Skimmer

* Recovery e.g Barges, Dispersants

* Storage/ transport

* Clean up (mechanical)

* Mop up (physical)