water treatment technologies

Understanding Water Treatment Technology

It is critical for homeowners to understand that no one water treatment system can solve all water quality issues and that all methods have limits. You must match the treatment method to the problem(s) you want to fix with the water quality.

Before you buy a treatment system, have your water tested for chemicals at a state-approved lab. Then, contact multiple dealers to get prices on systems that can get rid of the type and number of contaminants found in your water.

Proper care and frequent maintenance are essential for preserving the device’s continued operation. Consider all expenditures, including the cost of power to run the device and the price of upkeep or filter replacement. Keep in mind that manufacturer and dealer statements may not always fully reflect what the device will do.


Aeration is the process of introducing air into water to lower the concentration of dissolved gas pollutants such as VOCs, hydrogen sulfide, and radon. The dissolved gas is released into the environment when air is introduced into the water; the pollutant should always be vented to the surrounding atmosphere to avoid exposure to dangerous compounds. Aeration is a type of oxidation that can be used with a particle filter to fix problems with iron and manganese.

Activated Carbon

Filters made of activated carbon or charcoal are quite popular. There are many tiny holes and tubes in the carbon particles. When water flows through the channels, the carbon traps or collects particles and various kinds of impurities.

Many common taste and odor issues are eliminated by carbon filters. They may also be useful in removing some organic and inorganic substances that are harmful to one’s health, such as pesticides. They are ineffective at removing pollutants like arsenic, nitrate, or microorganisms.

Activated carbon filters are quite adaptable and available in a variety of sizes and designs; the design has a significant impact on how effectively they operate and how much water they can cleanse before needing to be changed. Some devices attach to kitchen faucets and can only treat a modest volume of water before losing efficacy. As a result, such filters must be changed on a regular basis.

Under-the-sink units are intended to treat larger volumes of water. Others are intended to treat all water entering the house.

Three issues arise while using carbon filters. For starters, although you will notice when the filter stops eliminating an odor-producing substance, such as hydrogen sulfide, other impurities will be harder to detect.

As a consequence, without testing, you can’t always tell whether a carbon filter is effective. Second, consuming water that has been filtered for an extended period of time could be more harmful than consuming unfiltered water. Water passing through such a filter may have significant amounts of pollutants that get trapped in the filter. 

Finally, germs may grow if the filter is not utilized for an extended period of time. Always follow the manufacturer’s operating and maintenance directions.

Anion Exchange

Anion exchange units are often used to remove nitrate, but they may also remove sulfate, fluoride, bicarbonate, and other negatively charged ions known as anions. Anion exchange units remove anions from water, such as nitrate or bicarbonate, and replace them with chloride.

Water becomes more caustic once bicarbonate (acid) is removed; it may also remove sulfate, fluoride, bicarbonate, and other negatively charged ions known as anions. Anion exchange units remove anions from water, such as nitrate or bicarbonate, and replace them with chloride. 

Water becomes more caustic once bicarbonate (acid) is removed. If sulfate concentrations are moderate to high, the unit’s capacity to remove nitrate may be compromised, necessitating regular monitoring.

Disinfection Methods

Disinfection equipment is intended to destroy and/or remove germs or viruses. When dealing with germs, it is essential to choose the most efficient way of creating clean water. Reconstruction or a new well are the initial solutions for wells with recurring bacteria issues, unless it is assessed that these methods are unlikely to solve the problem.

If you want to install a treatment mechanism to treat a bacteriologically hazardous water supply, you must first get permission from the Department of Natural Resources’ Bureau of Drinking Water and Groundwater. Bacteria-infested water in private wells can be treated with either chlorine or ultraviolet light.


Water may be disinfected in the home by injecting chlorine or hypochlorite (similar to household bleach). For chlorination to work well, the design needs to keep track of how much chemical is used and how long the disinfectant is in the water.

The fact that chlorine can react with organic compounds in groundwater to make harmful organic compounds is one of the most important problems with chlorination.

Chlorination does not eliminate nitrates or many other substances, although it may oxidize and eliminate a portion of the color and odor issues caused by iron and hydrogen sulfide. Using an activated carbon filter after chlorination will get rid of extra chlorine and a lot of chlorine’s byproducts.

UV (ultraviolet) light

Without the use of chemicals, it disinfects. On contact with water, it kills bacteria, viruses, and some cysts. UV light’s efficiency in destroying bacteria is proportional to its intensity and exposure period.

Pretreatment is often required, depending on the condition of the water. Light-blocking substances such as tannins, suspended sediment, and turbidity must be eliminated prior to UV disinfection. To avoid scale accumulation on the light, a water softener may be necessary. UV lights lose their intensity with time; therefore, bulbs should be changed on a regular basis.


Stills, or distillation units, boil water to produce steam, which is then cooled (condensed) and gathered as pure water. Most distillation systems work in batches, where water is put in, distilled, and stored for later use. Other systems, on the other hand, may work all the time.

Distillation may get rid of more contaminants than any other method, such as metals, nitrates, and many organic contaminants.
There are various disadvantages to distillation. One disadvantage is that the procedure eliminates minerals such as calcium and magnesium, leaving water with a bland flavor.

Second, because they can only clean small amounts of water for drinking and cooking, many stills are made to be used right where the water is needed.

Third, some stills allow pollutants with a lower boiling point than water, like some insecticides and volatile solvents, to evaporate with the water and condense with the treated water.

A fractional distiller solves this difficulty; however, not all distillers are of this sort. Depending on the architecture of the machine, maintenance may potentially be an issue.

Minerals and other pollutants may build up in the boiling chamber, causing it to malfunction. A distiller may rapidly get clogged by hard water. Some units are simple to clean by hand, while others are difficult to clean or need scrubbing with a strong acid.

Some units also use a lot of electricity. Distilled water is corrosive and must be kept or carried in plastic, glass, or stainless steel to prevent undesirable pollutants from dissolving.


Neutralizers cure corrosive (acidic) water by boosting alkalinity and pH, which reduces the acidity of the water. Passing the water through granular calcite (marble, calcium carbonate, or lime) is the most common method, although some other materials may also be used.
Most of the time, granular calcite (marble, calcium carbonate, or lime) is used. However, other materials can also be used.

The addition of calcite may result in scale building, especially in the hot water heater. If your water is very acidic or you want a high flow rate, you may require a system that incorporates soda ash (sodium carbonate) or caustic soda (sodium hydroxide).
These chemicals make the water saltier, which may not be as good as the calcium increase that comes from using calcite or lime. 


Many aesthetic issues with taste, odor, or color in water are caused by declining conditions in the aquifer. Reduced conditions are caused by low oxygen levels in groundwater, which cause certain minerals in soil and bedrock, such as iron and manganese, to become soluble.

When iron and manganese are introduced into the water using a treatment device as it enters the residence, they become insoluble and create precipitates that may be filtered out of the water. This avoids the taste and color issues that are connected with these two components.

Chemical Oxidation

Although it is not often employed, chemical injection of powerful oxidizers such as chlorine, hydrogen peroxide, or ozone can be employed to oxidize dissolved iron and manganese, allowing them to precipitate, or detach, from the solution.

To catch the particulate iron and manganese, a particle filter will need to be placed after the chemical injection unit. These oxidizers may also be used to treat odors caused by hydrogen sulfide. This method’s chemicals may be dangerous to deal with. Consider the issues connected with storing and managing huge volumes of chemicals if you are considering this form of treatment.

Because the chemicals will be pumped into a source of potable water, they must be approved as food grade. The Department of Commerce must authorize any chemical injection system. In the event of chlorine injection, an activated carbon filter may be required to remove any dangerous chlorine byproducts.

Iron Filters

Iron filters are the most popular kind of oxidation treatment and have been utilized for many years with effectiveness. Iron, manganese, and hydrogen sulfide may be removed from water using natural green sand or manufactured resins coated with manganese dioxide.

The surface of the manganese dioxide oxidizes the iron, which is subsequently filtered out by the sand or resin. To revitalize the gadget, backwash it and apply potassium permanganate on a regular basis.

If you don’t want to soften your water and/or the iron content is between 3 and 10 mg/L, iron filters are ideal. The quantity of iron in the water and the amount of water used determine the frequency of maintenance.

Particle Filters

In residential water treatment, particle filters are used to remove sediment or chemicals such as iron and manganese precipitates. Particles get caught on the filter’s surface or inside it. What particles the filter may catch are determined by the size of its pores or the intervals between the granules or fibers.

According to how much grit or other debris you remove, you may need to change filters on a regular basis. If the iron and manganese are in reduced form, pretreatment may be required. Particle filters may get blocked if iron or sulfur bacteria are present.


Pellet chlorinators are meant to pump a granular chlorine pellet into the well on a regular basis. They may be used to control the cosmetic effects of severe iron and sulfur bacterial issues.

Pellet chlorinators are not an authorized treatment technique for bacterially contaminated water. Installing a pellet chlorinator on a well requires prior DNR clearance. Installing a pellet chlorinator may require the installation of a carbon filter to eliminate any remaining chlorine from the water.

Reverse Osmosis

RO eliminates impurities by pushing water across a membrane with microscopically tiny pores that enable water molecules to pass through but not big chemicals or microbes. The impurities trapped by the membrane are flushed away by water.

Because they can only treat tiny volumes of water at a time, RO systems are often used as point-of-use water purification devices for drinking and cooking. In addition to the membrane, RO systems often contain a sediment and carbon filter, as well as a storage tank for treated water.

The efficiency of the gadget will be considerably influenced by pressure and temperature. Although they cannot remove all compounds from water, RO systems can remove more forms of contaminants than any other single technology other than distillation.

Because the RO process may remove organic compounds, including certain pesticides, but not others, many RO systems add an activated carbon filter (see “activated carbon”).

RO devices also waste a lot of water. Only around 10% to 30% of the water entering the unit is treated water; the rest is released as trash along with the pollutants. Precipitate accumulation and scaling may potentially cause issues with the membrane.

To address this issue, pretreatment of the water before it enters the reverse osmosis unit is sometimes required. The membranes are built of a range of materials, each of which has a distinct efficacy for various substances. Replace the filters on a yearly basis or as directed by the manufacturer.

Water Softener

Water softeners are a fairly common kind of water treatment in areas with hard water. Hardness is caused by calcium and magnesium from natural mineral sources. The cleaning activity of soaps and detergents might be hampered by hard water. While little calcium might minimize the corrosion of plumbing, excessive amounts can create scale accumulation, especially in hot water pipes, water heaters, and fixtures.

Home water softeners employ a synthetic resin or natural zeolite material that attracts calcium, magnesium, and other positively charged metal ions known as cations. The resin is first soaked with charged sodium ions from a salt solution (often sodium chloride).

Sodium exchanges with calcium and magnesium when water travels through the resin. If iron and manganese are in soluble (reduced) form, certain softeners may remove a small quantity of them. When the ability of the resin to remove calcium and magnesium is depleted, it must be refilled.

Water softeners do have certain drawbacks. One difference is that if sodium chloride salt is used, calcium and magnesium are removed, and sodium is substituted. Individuals on reduced sodium diets may be at risk from sodium.

If you must drink softened water, potassium chloride may be substituted for sodium chloride if you want to restrict your salt consumption. Many individuals choose not to soften the water they use for drinking and cooking. Outdoor water faucet softening is unnecessary.

Several Words of Warning

If you have a water quality issue that is affecting your health, it is preferable to first get a safe water source before turning to water treatment devices. If water treatment seems to be your only option, read this paper carefully to understand how it can only help so much.

No system is perfect, and all need maintenance and/or monitoring to ensure appropriate operation. Obtain documented assurance from the provider on the impurities that the equipment is able to remove, the efficacy of the unit’s removal, the unit’s life expectancy, and yearly maintenance and operating expenses.


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