What is the specific gravity of Anthracite used in a dual media filter?
Explanation: The specific gravity of Anthracite is 1.4 and due to this, the beds of it can be expanded at a same backwash rate as sand bed when the size of anthracite grains is twice of sand grains.
In which of the following filter, two layers filtering media is provided for filtration?
Explanation: In dual media filter, filtration takes place from coarse to fine media by the provision of two layers filtering media called as dual media and that is why it is called as a dual media filter.
What is the size of sand used in a dual media filter?
Explanation: The size of sand used in a dual media filter is 0.5-1mm and it has a thickness of 20 to 30 cm.
The coarser layer used in a dual media filter is of
Explanation: Anthracite is a coarser filter medium used in the dual media filter. It is costlier than sand and it is used as a substitute for sand.
The thickness of Anthracite used in dual media filter is
Explanation: Anthracite is used as a top layer in dual media filter having a thickness of 30-40cm.
How the performance of rapid sand filter can be improved?
Explanation: The performance of rapid sand filter can be improved by capping sand filters with coal where the top 15 cm layer of sand is replaced with Anthracite.
The size of Anthracite used in dual media filter is
Explanation: The size of Anthracite used in dual media filter is 1.25-2.5mm and it is placed over a sand of 0.5 to 1mm size.
In mixed media filter, the filtration is done from ______
Explanation: In mixed media filter, the filtration is from coarse to fine and impurities and suspended matter are stored and removed throughout the full depth of the bed.
What is the ratio in which coal, sand and garnet are present in the mixed media filter?
Explanation: In mixed media filter, the coal is placed on top, sand in the middle and garnet at the bottom in the proportion of 60%, 30%, 10% respectively.
Which of the following order is correct regarding the specific gravity of the materials used in the mixed media filter?
Explanation: Anthracite coal has a specific gravity of 1.42, sand has a specific gravity of 2.65 and Garnet sand has a specific gravity of 4.2. So, coal has lower, sand has medium and Garnet sand has the highest specific gravity between them.