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The National Green Tribunal has directed all States and Union Territories to submit an action plan on the usage of fly ash that is generated from thermal power plants.
• A Bench headed by judicial member Raghuvendra Rathore noted that despite previous orders passed by the green panel, the States had not submitted the action plans.
• “The relevant notification was issued by the Environment Ministry in 2016. The very purpose of issuance is frustrated, if follow up action is not taken up promptly. Therefore, we direct the Ministry to expedite the matter and collect the action plan from the States immediately,” the Bench said.
• The directions came after the Ministry submitted that only eight States had submitted “information but not the action plan”.
• Fly ash is ejected mostly by thermal power plants as byproducts of coal burning operations.
• Fly ash pollutes air and water and may cause heavy metal pollution in water bodies.
• It affects vegetation as a result of its direct deposition on leaf surfaces or indirectly through its deposition on soil.
• Fly ash in the air slowly settles on leaves and crops in fields in areas near to thermal power plants and lowers the plant yield.
• It is now being used for making bricks and as a land fill
• Its particles are oxide rich and consist of silica, alumina, oxides of iron, calcium, and magnesium and toxic heavy metals like lead, arsenic, cobalt, and copper.
• Major oxides are present are Aluminium silicate (in large amounts), silicon dioxide (SiO2) and calcium oxide (CaO).
Advantages of Fly Ash
• It is highly economical.
• Use of Fly Ash is environmentally friendly as the waste materials from industries are effectively being used to create quality building materials.
• Fly Ash has very small particles which makes the concrete highly dense and reduces the permeability of concrete. It can add greater strength to the building.
• The concrete mixture generates a very low heat of hydration which prevents thermal cracking.
• Fly Ash concrete is resistant to acid and sulphate attacks.
• The shrinkage of fly ash concrete is very less.
• The use of fly ash gives concrete good work ability, durability and finish
Disadvantages of Fly Ash
• The quality of fly ash can affect the quality and strength of Cement concrete.
• Poor quality fly ash can increase the permeability of the concrete and cause damage to the building.
Q. Which of the following major oxides are present in the Fly ash
1) Aluminum silicate
2) silicon dioxide
3) and calcium oxide
Choose the correct answer from the codes given below
a) 1 only
b) 1 and 2 only
c) 1 and 3 only
d) All of the above
Answer: d) all of the above