Question

(a) Name my two places where it is essential to install electrostatic precipitators to do so? (b) Mention one limitation of electrostatic precipitation.

Answer 1

Hint: Electrostatic precipitates are known to remove particulate matter from the exhausts. .An electrostatic precipitator is a filtration device that removes fine particles, like dust and smoke, from a flowing gas using electrical energy to charge particles either positively or negatively. Smokestacks of thermal power plants, smelters, and other industries release particulate and gaseous air pollutants.

Complete answer:
(a) Two places where it is essential to install electrostatic precipitation are automobile vehicles and thermal power plants. These produce toxic gases. There are several ways to remove particulate matter; the most widely used of which is an electrostatic precipitator which can remove over 99 percent of particulate matter present in exhaust from a thermal power plant. It has electrode wires that are maintained at several thousand volts, which produce a corona that releases electrons. These electrons attach to dust particles giving them a net negative charge. The collecting plates are grounded and attract the charged dust particles. A scrubber can remove gases like Sulphur dioxide. In a scrubber, the exhaust is passed through a spray of water or lime.
(b) Electrostatic precipitators have high initial capital cost, which makes it prohibitive for small scale industries. They are expensive to purchase and install. In addition to being costly, they require a large space to be set up. Also, they cannot remove particulate matter that are very small particles that are less than 2.5 micrometers in diameter.

Additional Information:
- It has been realized that particulate matters that are very small are very dangerous and that cannot be removed by these precipitators.
- According to the Central pollution control board, particulate matters which are less than 2.5 micrometers are responsible for causing harm to human health.
- These fine particulates can be inhaled deep into the lungs causing certain respiratory diseases.
- Automobiles and thermal power plants form a major cause of air pollution releasing highly toxic gases to the atmosphere.

Note:
- In India, the Air (prevention and control of pollution) Act came into force in 1981 but was amended in 1987 to include noise as an air pollutant.
- Noise Causes psychological and physiological disorders in humans. This was the first attempt by the government in India to combat air pollution.
- The act's preamble states that it is an act to provide for the prevention, control, and abatement of air pollution.