CBSE Class 12-science Answered

Different ways of solid waste disposal are

1. Waste segregation: At the household level, the wastes are first separated into dry and wet solid wastes. The wastes are then stored in separate containers. 

2. Composting: The rotting and conversion of organic waste into manure is known as composting. The household garbage as well as farmland wastes can all be converted into useful compost.

3. Vermicomposting : The method which involves the use of worms to decompose the wastes is called vermicomposting. The earthworms can degrade or decompose the wastes such as domestic waste, cow dung, coconut thresh etc. in few days.

4. Secured landfill: Secured landfill is the best disposal option for solid wastes, particularly, hazardous wastes. It prevents leaching of waste.

5. Deep well injection method: A well is drilled into the dry porous material below the groundwater. Hazardous waste liquids are pumped into the well. They soak into the porous material and, in this way, remain isolated indefinitely.

6. Pyrolysis: The process of pyrolysis transforms hazardous organic materials into gaseous components, small quantities of liquid and coke. It is possible to generate gas and electricity through the process of pyrolysis.

7. Incineration: Hazardous biomedical wastes, such as discarded medicines, toxic drugs, human anatomical wastes, blood, pus, microbiological and biotechnological wastes etc., are usually disposed of by incineration. It helps to reduce the weight and volume of waste and converts these toxic wastes into less toxic or even non-toxic substances.

8. Recycling: E-wastes can be recycled in specifically built facilities or manually to recover important metals.