How Is Impure Water Treated In A Water Treatment Plant?

Water treatment plants play an important role in making sure that the water we consume is safe and clean. Water impurity is an issue of great concern, as it affects the quality of our water and can cause health risks when water is consumed. In order to make sure that this happens, impure water has to be treated in a series of steps. These steps include coagulation, flocculation, sedimentation, filtration, and disinfection.

What Is Water Impurity?

Water impurity is the presence of any physical, chemical, biological, or radiological substance in water that makes it unfit for human consumption.

What Is Water Purification?

Water purification is the process of removing unwanted contaminants from water. It can involve a variety of steps, including coagulation, sedimentation, filtration, and disinfection.

How Does Impure Water Get Treated In A Water Treatment Plant?

Coagulation introduces chemicals such as alum or iron salts into the water, which neutralize the charge on dirt particles that are suspended in it. This causes them to clump together, forming larger masses called aggregates. These aggregates are then heavy enough to settle out of the water, making them easier to remove. The process of coagulation also helps to reduce turbidity in the water by trapping particles that would otherwise remain suspended in it.

The chemicals used during coagulation can help in breaking down certain organic compounds that may be present. After coagulation is complete, flocculation is used to further aid in the settling of particles.

In flocculation gently stir the water to help the dirt particles clump together into large masses called flocs. This helps them settle out of the water easier, due to their larger size and increased weight. Some chemicals may be added during this process to further help in the clumping of particles.

Once all the suspended matter has been removed from the water, it is then sent to a sedimentation basin where it can settle out further. This is usually done over several hours and involves allowing the water to sit undisturbed so that any remaining heavy particles can sink to the bottom.

Filtration requires passing the water through a series of filters that are designed to capture and remove any remaining particles. The type of filter used will depend on the size and type of particles that need to be removed from the water.

Disinfection is used to kill any harmful microorganisms present in the water. This is accomplished by adding chemicals such as chlorine, ozone, or ultraviolet light to the water in order to destroy any bacteria or viruses that may be present.

Signs Of Impure Water

Unusual Taste: Impure water often has a metallic taste or an unpleasant odor. This is caused by dissolved metals and other chemicals in the water.

Cloudy Appearance: Impurities in the water can make it appear cloudy or murky, as sediment settles out of the solution.

Unusual Color: Contaminants in the water can give it an unusual hue, such as a yellow or green tint.

Odor: Impurities can also cause a foul odor in the water, which could be indicative of bacterial growth.

Molecular Interference: Impurities can cause interference in the molecules of the water, making it harder for certain organisms or chemical reactions to take place.

What Is The International Standard Of Drinking Water?

The World Health Organization (WHO) has set an international standard for drinking water quality, known as the Guidelines for Drinking-water Quality. These guidelines define a maximum permissible level of certain chemical and microorganism contamination. This includes limits on chemicals such as arsenic, fluoride, lead, and mercury; and organisms like bacteria, viruses, and parasites.

Is Boiling Enough?

Boiling water is a simple and effective way to make it safe for drinking. However, it does not remove all contaminants from the water and thus cannot be used as a reliable method of purification. Boiling can also reduce the amount of oxygen in the water, making it taste flat or unpleasant.

Other Techniques

  • Boiling
  • Distillation
  • Reverse Osmosis
  • Filtration
  • Chemical Disinfectants
  • Purification Tablets
  • Sand Filters
  • Uv Light
  • Residual Disinfectants (Chlorine Or Chloramines)

The Different Ways to Test for Water Purity

Chemical Testing involves using reagents to measure the presence of specific chemical contaminants.

Bacterial Testing involves collecting samples of water and then incubating them in order to detect the presence of bacteria.

Viral Testing involves taking a sample of water and then using a polymerase chain reaction (PCR) technique to detect the presence of viruses.

Parasite Testing involves taking a sample of the water and then using a microscope to detect the presence of parasites.

Turbidity Testing involves measuring the degree of cloudiness in a sample of water and is typically used to measure suspended particles such as silt, clay, or algae.

Taste And Odor Testing involves using a panel of taste testers to detect the presence of off-flavors or odors in the water.

Colorimetric Testing involves using color indicators to measure the presence of certain chemical contaminants.

Atomic Absorption Spectroscopy involves using a spectrometer to measure the presence of metals and other contaminants in the water.

Types Of Water Impurities

Sediments: Sand, silt, clay, and other small particles that are suspended in the water are termed sediments.

Organic Matter: These usually consist of decaying plant or animal remains and microorganisms such as bacteria, fungi, and viruses.

Industrial Waste: Manufacturing processes often dispose of waste byproducts into water sources. These may include volatile compounds, suspended solids, and heavy metals.

Chemicals: Chlorine is the most common chemical used for disinfection in a water treatment plant to make it safe for consumption. Other chemicals such as sodium hydroxide, alum, chlorine dioxide, and ferric chloride are used to remove sediments, metals, and organic compounds.


What Is The Most Effective Way To Remove Bacteria From Water?

The best way is filtration. This process involves passing water through a physical barrier that filters out larger particles, such as dirt and debris, along with bacteria.

What Is Aerobic Water Treatment?

Aerobic water treatment is a process used to treat wastewater and remove contaminants. The process uses oxygen to help break down organic material and reduce the number of bacteria in the water. This type of water treatment can be done in a few ways, such as using an aerator, an activated sludge process, or a trickling filter system.

Which Organization Is Responsible For Setting Water Standards In Laboratories?

The Environmental Protection Agency (EPA) sets standards for water quality in laboratories. It regulates the levels of certain contaminants and determines safe drinking water levels for public consumption.

What Determines Water Purity?

The purity of water is determined by a variety of factors, including the presence of contaminants like bacteria and microorganisms, suspended solids, and dissolved minerals. The concentration of these pollutants can vary greatly depending on their source and local environmental conditions.

What Do Contaminants Mean For Labs And Experiments?

Contaminants in water can have a significant impact on the accuracy of laboratory experiments that rely on pure water. The presence of impurities, such as dirt and bacteria, can interfere with delicate measurements.


The water treatment plant can effectively clean impure water and make it safe for human consumption. Each step plays an essential role in making sure that the water is safe and clean. Without proper treatment, the water we consume could contain contaminants or microorganisms that can cause illnesses. It is important to make sure that water treatment plants are properly maintained and operated so that they can successfully purify our drinking water.

Leave a Comment