Context:
Recently, the Union Ministry of Environment, Forests and Climate Change (MoEF&CC) clarified the compliance dates for the complete utilisation of fly ash for Thermal Power Plants (TPP) in a new notification.
Relevance:
GS III: Environment and Ecology
Dimensions of the Article:
- About Fly Ash
- Properties of fly ash
- Harmful Effects
About Fly Ash:
- Fly ash is an unwanted unburnt residue of coal combustion in a coal thermal power plant.
- It is emitted along with flue gases during the burning of coal in a furnace and collected using the electrostatic precipitators.
- The fly ash collected with the help of precipitators is converted into a wet slurry to minimise fugitive dust emissions.
- It is then transported to the scientifically designed ash ponds through slurry pipelines.
- Composition:
- The composition of fly ash is influenced by the coal being burned. Beryllium, arsenic, unburned carbon, silicon oxides, dioxins, aluminium oxide, ferric oxide, calcium oxide, etc. could all be present.
- These substances are quite harmful to the environment.
Properties of fly ash:
- Resemble Portland cement but is chemically different.
- Portland cement is a binding material in the form of a finely ground powder that is manufactured by burning and grinding a mixture of limestone and clay.
- Its chemical composition includes calcium silicates, calcium aluminate and calcium aluminoferrite.
- Exhibit cementitious properties.
- A cementitious material is one that hardens when mixed with water.
- It is utilised in a variety of products, including mineral filler, road base, metal recovery, and concrete and cement products.
Harmful Effects:
- Particles of fly ash are hazardous air pollutants. Heart disease, cancer, respiratory conditions, and stroke can all be brought on by them.
- They cause the leaching of heavy metals into groundwater when mixed with water.
- Additionally, it degrades soil quality and interferes with trees’ root systems.
- Fly ash has accumulated to a total of 1,670 million tonnes over the years due to gross under-utilisation of this byproduct, according to the Joint Committee’s Summary of Ash Generation and Utilisation during 2020–2021, which was previously established by the NGT.
-Source: Down to Earth
