DEPLETION OF OZONE LAYER
- Ozone (O3) is a molecule formed by three atoms of oxygen.
- While O2, which we normally refer to as oxygen, is essential for all aerobic forms of life.
- Ozone is a deadly poison. However, at the higher levels of the atmosphere, ozone performs an essential function.
- It shields the surface of the earth from ultraviolet (UV) radiation from the Sun.
- This radiation is highly damaging to organisms, for example, it is known to cause skin cancer in human beings.
- Ozone at the higher levels of the atmosphere is a product of UV radiation acting on oxygen (O) molecules.
- The higher energy UV radiations split apart some molecular oxygen (O) into free oxygen (O) atoms.
- These atoms then combine with the molecular oxygen to form ozone as shown
WASTE MANAGEMENT
- The household wastes (or rubbish) is called garbage. Every household produces a lot of garbage (or wastes)
- ‘Disposal of waste’ means ‘to get rid of waste’.
- The disposal of waste should be done in a scientific way.
- There are different methods of waste disposal.
- The method to be used depends on the nature of the waste.
Some of the important modes of waste disposal are :
MANAGEMENT OF HAZARDOUS WASTES
The following methods are adopted for the disposal of harmful waste materials.
1. Landfills
There are permanent storage facilities in secured lands for military related liquid and radioactive waste materials. High level radioactive wastes are stored in deep underground storage
2. Deep well
Deep well injection It involves drilling a well into dry porous material below ground water. Hazardous waste liquids are pumped into the well. They are soaked into the porous material and made to remain isolated indefinitely.
3. Incineration
The burning of materials is called incineration. Hazardous bio-medical wastes are usually disposed of by means of incineration. Human anatomical wastes, discarded medicines, toxic drugs, blood, pus, animal wastes, microbiological and biotechnological wastes etc., are called bio-medical wastes.
NON-HAZARDOUS WASTE MANAGEMENT OF SOLID WASTE MANAGEMENT
Reuse and recycling technique
The separating out of materials such as rubber, glass, paper and scrap metal from refuse and reprocessing them for reuse is named as reclamation of waste or recycling.
Paper
(54% Paper recovery) Can be repulped and reprocessed into recycled paper, cardboard and other products
Glass
(20% recovery) Can be crushed, remelted and made into new containers or crushes used as a substitute for gravel or sand in construction materials such as concrete and asphalt.
Preparation of Compost
Biodegradable domestic wastes such as left-over food, fruit and vegetable peels, and leaves of potted plants, etc., can be converted into compost by burying in a pit dug into ground, and used as manure.
