Question

Explain the steps involved in purification of water.

Answer 1

The Eight Steps Involved in Water Purification

Pre-Treatment
Pumps bring “raw" or untreated water, often from lakes or rivers, into the purification plant through screens that exclude fish, weeds, branches and large pieces of debris. Screening may not be necessary for groundwater. The plant may aerate the water at this point to increase the oxygen content and thus help remove problematic odors and tastes.

Coagulation & Flocculation
The purpose of these two steps is to clear water of the small particles that cause it to be turbid or cloudy. Turbidity renders the water hard to disinfect. The water is rapidly agitated to disperse coagulant chemicals throughout it. The small particles, including many bacteria, begin to form large clumps called flocs or floccules. In flocculation, the water is mixed gently so that these clumps combine and precipitate out further.

Sedimentation
The water and flocs are pumped into sedimentation basins. Here, the flocs settle beneath the water so that they can be removed. About 85 to 90 percent of the suspended particles responsible for turbidity are removed at this point, including large amounts, but not all, of the bacteria.

Filtration
In filtration, the water flows through a multilayer medium such as quartz sand, activated carbon or anthracite coal in order to remove up to 99.5 percent of the solid materials remaining in it, whether flocs, microbes or minerals. This step usually is the last one in the process of removing solids from the water.

Disinfection
Disinfection kills off disease-bearing organisms in the water. Most water treatment plants use chemicals, generally chlorine compounds, as disinfectants. Although chlorine is still one of the most common disinfectants, ultraviolet radiation and ozone gas are becoming more widespread. Chlorine is increasing in cost and has some known toxic effects on humans and fish. In addition, some disease-carrying microbes like Giardia and Cryptosporidium resist chlorine.

Corrosion & Scale Control
The pH of the water is adjusted so that it neither corrodes nor deposits too much scale in pipes. Excessive amounts of scale can disrupt plumbing systems, but small quantities help pipes to function at their best. However, no amount of corrosion in the water distribution system is desirable. As well as causing leaks and other damage, corrosion releases pipe metals like lead and copper that jeopardize human health.

Taste & Odor Control
Unpleasant tastes and odors remaining in the water, such as those from algae, often do not pose any health hazards. Yet consumers prefer to do without them. So water purification plants often remove tastes and odors through additional chemical treatment, ozonation or filtration. At this stage, some municipalities also require the addition of fluoride to the water for dental health.
Hope this helps you
Please mark me as brainliest

Answer 2

There is 5steps for water purification. Screening, coagulation, sedimentation, filtration and disinfection. 

1) Screening: Water from the river or land passes through the screen as it enters the water treatment plant.

2)Coagulation: This floc pulls the dirt particles, making it eventually heavy enough to sink to the bottom of the water storage tank.

3)Sedimentaion: Water and floc flow into moisture deposition. When the water sits there, the heavy floc settles down on the bottom, where they remain until the removal.

4)Filtration: Water passes through a layer of gravel, sand and may be charcoal, which works to filter the remaining particles. The pebble layer is usually about 1 foot and the sand layer is about 2½ feet deep.

5) Disinfection.
Water enters the closed tank or closed reservoir. Chlorine or other extermination chemicals kill any remaining microorganisms or bacteria in the water and helps maintain clean water up to distribution. If the water treatment facility uses groundwater as the only source of water, disinfection may be the only step required to treat the water adequately. After it is disinfected, purified water is located in a closed tank or reservoir until it flows through the pipes to the home and business.

Hope it helps you :)