What is a Water Purifier?

A water purifier is used to eliminate dissolved and suspended materials from drinking water. There are many different techniques that can be used in a water purification plant.


When selecting a water filter it’s important to know what contaminants you want to remove from the water. No one water filter removes all contaminant types.


Often, the quality of the water supply will require pre-treatment to remove unwanted substances. These substances can be minerals (like fluoride and calcium), ions such as iron and manganese, or organic chemicals.

In general, pre-treatment removes dissolved and particulate matter that can foul or damage the membranes of a filtration system or cause it to operate less efficiently. This can be done by physical pretreatment, coagulation and filtration processes or chemical pretreatments like prechlorination and preozonation, as well as adsorption using different types of powdered and granular activated carbon.

The physical pretreatment process uses flocculation and sedimentation basins to collect and settle suspended contaminants, such as minerals, oxidants, living organisms and undissolved solids. The sludge formed at the bottom of the tank is then removed and treated. This is a key step in ensuring the longevity and performance of a membrane system as well as meeting regulatory requirements.

In the industrial world, proper water pretreatment is vital for a range of processes, including heating, cooling, washing, rinsing and manufacturing. Without it, problems like scale build-up and bacterial contamination can occur, which can damage or limit the efficiency of equipment. This can lead to lost production and higher operational costs. There are a variety of specialized technologies used for this type of pretreatment, which include ion exchange and membrane systems.


When water reaches its reservoirs, it can pick up contaminants from the environment. These include leaves and trash that may wash into rivers and streams; bacteria, protozoa, and viruses that come from livestock, sewage treatment plants, gas stations, and septic systems; salts and metals from mining, oil exploration, agriculture, and stormwater runoff; synthetic organic chemicals, which can leach out of natural soil; and humic substances, which are produced by the decay of vegetation.

These contaminants are very small — smaller than hydrogen and oxygen molecules — so they remain in the water alongside other molecules. The most effective way to remove them is by disinfection. Disinfection kills the bacteria, protozoa, and viruses in drinking water so they can’t infect people with diseases.

The last step is to filter the water to remove any particles that didn’t coagulate or float in the earlier stages. Activated carbon filters, which contain millions of tiny pores, can absorb many contaminants. Other types of filters include membrane filters, slow sand, and rapid sand.

The filtered water then goes through further purification to ensure it meets acceptable standards for drinking and other uses. For example, fluoride might be added to the water; and radium might be removed by ion exchange or by precipitation.


Water purification is a process that removes organic and inorganic contaminants from water. It also kills bacteria, viruses, and other microscopic organisms that can be ingested.

The most common chemicals used in the water purification process are chlorine and iodine. Chlorine is the most common disinfectant used in public drinking water and swimming pools because it is very effective at killing bacteria. It is a respiratory and eye irritant, however. Iodine is a safe alternative to chlorine and is recommended by the American Red Cross.

Other chemical water purification treatments include ion exchange and reverse osmosis. Ion exchange is most commonly used to treat hard water, which contains heavy concentrations of calcium and magnesium that can leave skin and hair feeling irritated and dry. It uses chemicals such as sodium chlorite and zinc orthophosphate to soften water and reduce corrosiveness.

Reverse osmosis is a high-tech process that uses membranes to filter out harmful chemicals and metals. It is highly efficient and can reduce the amount of dissolved solids, turbidity, and many types of organics from drinking water. It can even remove radioactive contaminants such as strontium and plutonium. Water purification is a complex and expensive process that involves multiple steps. Because of this, a visual inspection alone cannot determine if water is suitable for human consumption. Therefore, chemical and microbiological analyses are often required to assess water quality and determine the best treatment method for it.

Reverse Osmosis

Reverse Osmosis (RO) works by using water pressure to push tap water through a semi-permeable membrane that removes the majority of dissolved salts, organics, and bacteria. The clean water goes into a pressurized storage tank while the contaminants are flushed down the drain.

Most RO systems have a pre-filter that is designed to protect the membranes by reducing fine suspended material that can damage the thin film materials. The system then has a carbon filter that is designed to reduce a variety of aesthetic and taste-related contaminants. Most systems also have a pre-filter that is designed specifically to reduce chlorine since it damages the membranes. Lastly, the system will have a post-filter that is designed to remove any residual bacteria.

Reverse osmosis is one of the most comprehensive methods of water filtration available. It can remove a variety of different contaminants including fluoride, lead, nitrates and many other dangerous substances. However, reverse osmosis is not without its drawbacks. First, it wastes a large amount of water. Studies show that RO systems typically waste between 3 and 20 times as much water as they produce. This is problematic on an environmental scale, but it can also be a financial issue for homeowners. Additionally, reverse osmosis strips beneficial minerals from the water. These nutrients are important to our health, but they can be found in many foods.