Ozone depletion

Introduction

Ozone is a highly reactive molecule which contains three oxygen atoms. It is constantly being formed and broken down in the high atmosphere. Ozone is a gas composed of three atoms of oxygen. It is bluish gas that is harmful to breathe and early 90% of the Earth's ozone in the stratosphere and referred to the ozone layer. Ozone absorbs a band of ultraviolet radiation called UVB.

Ozone layer depletion is the reduction of the amount of ozone in the stratosphere. Depletion begins when CFC’s get into the stratosphere. Ultraviolet radiation which is from the sun breaks up CFCs. The breaking up action releases the Chlorine atoms. Chlorine atoms react with the Ozone, starting a chemical cycle that destroys the good ozone in that areas. One chlorine atom can break more than 100,000 ozone molecules. From industries and our day to day life many gases like CFC’s , Hydro chlorofluorocarbons (HCFC’s) , halons, halogens e.t.c. get evolved in an atmosphere which is mainly responsible for ozone depletion as it contains or produces Chlorine (Cl) atom.

There is another Ozone Depleting Substances (ODS) such as methyl bromide which is used in pesticides, halons used in fire extinguishers, and methyl chloroform. Other chemicals that naturally destroy Ozone are Noy, Hox, Clx, which belong to the Nitrogen, Hydrogen, and Chlorine respectively. All we can do is to be more responsible with our manufacturing needs.

The reaction involve is:

O2+ UV → O+O

O+O2 → O3

CFCl3 + electromagnetic radiation → Cl· + ·CFCl2

Cl· + O3 → ClO + O2

ClO + O3 → Cl· + 2 O2

The Antarctic Ozone Hole

As a result of ozone depletion, over Antarctica, the ozone hole is formed. This ozone hole caused to melting the ice of Antarctica which increases the sea level and other harmful effects on its environment.

EFFECTS OF OZONE LAYER DEPLETION

Effect on Aquatic System:

Affects phytoplankton, fish, and larval crabs. The decrease in an amount of phytoplankton increases the CO2 in the atmosphere which contributes the global warming.

Effect on Materials:

Degradation of paints and plastic.

Effect on Climate:

Global Warming and seasonal variation.

Effect on Human Health:

Damage genetic materials in the cells. Leads to more people suffering from Cataracts. 10% depletion in ozone layer results in 30% increase in skin cancer infection.

Effects on Biogeochemical Cycles:

SOLUTION

• Afforestation
• Low consumption of CFC’s and HCFC’S gasses
• Public awareness on this issue
• Strong implementation of Montreal Protocol

Sustainability of ecosystems

The sustainability of the ecosystem becomes essential to support the life on earth. The capacity of the ecosystems to maintain their essential functions, processes and retain their biodiversity in the full measure over the long term the ecosystem sustainability. It included the following things

• Enhanced climate regulation through the rebalancing of the carbon cycle.
• Protection of essential ecosystem including enhanced food and water security, the public health and the societal wellbeing.
• Reduction of risks further ecosystem degradation and subsequent societal disruption.

Preservation of the natural environment is very essential for maintaining the economic sustainability. The component is water, energy, air, climate, biodiversity, land and forest.

Four Principles of Ecosystem Sustainability

• For sustainability, ecosystems use sunlight as a non-deplete able nonpolluting form of energy.
• For sustainability, ecosystems break down and recycle all the wastes as nutrients.
• For sustainability, Herbivorous populations must be kept in check so that overgrazing and the destruction of the ecosystem do not occur.
• Biodiversity is healthy for ecosystems.

The need for responsible development practices

Every factor which is related to development should be responsible for responsible development practices to make the development sustainability.

References:
1. Mackenzie L. Davis & David A. Cornwell, “Introduction to Environmental Engineering”, McGraw Hill.
2. Gilbert M. Masters, Standford University, “Introduction to Environmental Engineering and Science”, Printice Hall.
3. Stephan Konz, Kansas State University, “Work design”, Grid Publishing Inc., Colombus, Ohio
4. C. S. Rao, “Environmental Pollution Control Engineering”, New age International (P) Limited, Publishers, India.