Question

7. Describe any four modes of disposal of waste.

Answer 1

Disposal of waste needs a scientific way of disposal. Some important methods of waste disposal are open dumping, landfilling, composting, incineration, recycling and reuse.

1. Open Dumping: This is a conventional and widely used method for waste disposal. In this method, solid wastes are simply dumped in selected areas of the town. This method has several disadvantages it creates pollution.
2. Landfilling: In this method, waste is dumped at a low lying area and is compacted by rolling with bulldozers. The waste is then covered by a layer of soil.
3. Composting: Household waste such as peeling of fruits and vegetables, left over food, fallen dead leaves of kitchen garden plants and potted plants is converted into compost and is used as manure.
4. Incineration: In this process, combustible wastes are burnt at very high temperature (more than 1000°C). The ash obtained after incineration constitutes less than 10% of the total mass of waste. Generally, hospital wastes, household wastes and chemical wastes are burnt by this method.
5. Recycling: In this process solid waste is broken down into its constituent materials. These materials are then used again to make new items. Non-biodegradable wastes like, paper, plastics, glass, metals, etc., can be recycled in recycling units.
6. Reuse: It is the practice of using an item again and again after proper cleaning and repair. For example, plastic bags and containers, cold drinks and milk bottles and paper can be used again to carry and for storage of household articles.