Consider the following statements:
1. Coal ash contains arsenic, lead and mercury.
2. Coal-fired power plants release sulphur dioxide and oxides of nitrogen into the environment.
3. High ash content is observed in Indian coal.
Which of the statements given above is/are correct?
Explanation
Statement 1 is correct: Fly ash and bottom ash produced by thermal power stations contain hazardous heavy trace metals, including arsenic, lead, mercury, cadmium, and selenium, which can leach into groundwater if fly ash ponds are unlined.
Statement 2 is correct: The combustion of pulverized coal in thermal power boilers oxidizes inherent sulfur and atmospheric nitrogen at high temperatures, releasing sulfur dioxide (SO2) and oxides of nitrogen (NOx) along with particulate matter into the atmosphere.
Statement 3 is correct: Due to its drift origin in the Gondwana coal basin, Indian thermal coal is characterized by high ash content (ranging from 30% to 45% or higher), possessing low sulfur but high abrasive inorganic mineral matter compared to imported coals.
Therefore, all three statements are correct — Option D.