Water purification is the process of removing impurities from water. It removes contaminants such as germs, chemicals, and dirt. This process is essential because untreated water can contain harmful metals and bacteria. These can make you sick now or later. Clean water ensures that every sip benefits your body and is not harmful to your family.
Here are nine common ways that people purify their drinking water.
- Boiling
This traditional method uses high heat to kill bacteria and viruses by bringing the mixture to a rolling boil for at least 1 minute.
- Distillation
This method turns water into steam and then back into a liquid, leaving behind salts and heavy metals.
- Reverse Osmosis (RO)
RO is a strong system that pushes water through a membrane, keeping almost all dissolved solids and chemicals out.
- Chemical Disinfection
Use chemicals like chlorine or iodine to kill and neutralize harmful microorganisms in the water supply.
- Ultraviolet (UV) Purification
Ultraviolet (UV) purification is a chemical-free method that uses germicidal light to destroy the DNA of bacteria and viruses, thereby stopping their reproduction.
- Activated Carbon Filtration
This method uses porous carbon to “magnetize” and trap organic chemicals, pesticides, and unpleasant chlorine odors.
- Sedimentation and Flocculation
A pretreatment step where dirt particles clump together and sink to the bottom of a tank for easy removal.
- Solar Purification (SODIS)
A low-cost survival technique that uses UV rays from the sun and heat to disinfect water inside clear plastic bottles.
- Ion Exchange
This chemical exchange process removes hard minerals and toxic elements by exchanging them for harmless ions.
Choosing the correct method depends on what you want to achieve. You need to think about your budget, how much water you use each day, and the specific pollutants in your area. For most people, the safest way to drink water is to use a combination of these methods. We at Water Filter Way make the complicated world of purification easier to understand with this clear guide. We are here to help you find a dependable system that works well in your home so you drink clean, healthy water every day.
1. Boiling
Boiling is the oldest method for removing biological threats from a water supply. This method uses very high temperatures to kill harmful microorganisms. This method only makes water safe to drink by killing harmful organisms, not by removing dirt or chemicals.
How It Works
Thermal energy moves from a heat source to water molecules. This heat changes the shape of proteins and enzymes in bacteria, viruses, and protozoa. These organisms die when their structures are damaged, and they can’t spread infection.
Almost all known waterborne pathogens can be killed in just one minute of rolling boil. Because boiling temperature decreases with increasing altitude, the boiling time should be increased to 3 minutes.
Pros
- Kills nearly all biological contaminants, including E. coli, Salmonella, and Giardia.
- Does not require expensive equipment or a replacement filter.
- Provides a dependable solution when water safety is uncertain.
Cons
- Does not remove heavy metals, nitrates, or chemical pesticides.
- Uses significant amounts of fuel, such as wood, gas, or electricity.
- Can concentrate certain pollutants like lead as the water evaporates.
Cost
The price depends on the fuel source. It doesn’t cost much to boil a gallon of water, so it’s a good option for short-term or emergency use.
Best-Case Uses
Boiling water is a viable option when the municipality issues boil-water advisories. It is also suitable for camping, emergencies, and traveling to places where the safety of drinking water is not guaranteed.
2. Distillation
Distillation is the process of separating water from impurities through evaporation. It produces clean, soft water for various uses by mimicking the natural rain cycle.
How It Works
A heater inside the device warms the water until it boils, producing steam. This steam rises through a stainless steel cooling coil. Heavy pollutants such as lead, salt, and arsenic remain in the boiling pot. Cooled air from a non-working fan is blown over the coil, turning hot vapor back into liquid droplets. Clean water passes through a small carbon post-filter to remove any remaining organic odors before reaching the collection jug.
Pros
- Produces water with extreme purity by removing nearly all dissolved solids.
- Eliminates the need for complex multi-stage mechanical filters.
- Works effectively on extremely dirty or salty water sources.
Cons
- The production of a single gallon of water takes several hours.
- The device emits a constant humming noise and heats the room during operation.
- Removes “good” minerals, such as calcium, resulting in a very bland taste.
Cost
Budget countertop units typically cost between $80 and $200. High-end stainless steel models can cost up to 500 dollars. Operating expenses average about 40 cents per gallon of water produced in electricity.
Best-Case Uses
Distillation is the ideal choice for people with very high levels of arsenic or fluoride in their drinking water. It is also the standard for people who need mineral-free water for medical devices and steam irons.
3. Reverse Osmosis (RO)
RO is an advanced water treatment method that uses a membrane with tiny pores to remove dissolved salts and other contaminants. It makes water that is as good as bottled water right in your kitchen sink.
How it Works
After entering the system, water is filtered through a sediment filter to remove impurities such as rust and dirt. A carbon filter then eliminates chlorine. The water is then forced through membrane pores that are only 0.0001 microns wide by applying pressure. These microscopic holes serve as a defense against bacteria, pesticides, and heavy metals. After that, unwanted impurities are flushed down the drain, and the cleaned water is kept in a tank for future use.
To see this microscopic process in action, watch this brief animation.
Pros
- Eliminates a massive range of contaminants, including lead, PFAS, and chromium-6.
- Significantly improves the taste of coffee, tea, and cooked food.
- Provides a continuous supply of purified water without a long wait time.
Cons
- Wastes a significant amount of water by sending several gallons down the drain for every gallon saved.
- Requires a dedicated faucet and a hole in the countertop for installation.
- Requires regular maintenance to replace the various filters annually.
Cost
Standard systems typically cost between $180 and $450. Replacement filter sets usually cost between $60 and $120 per year, depending on the number of filtration stages.
Best-Case Uses
RO systems are great for homeowners who want a long-term, easy way to get drinking water. They are very useful in cities with old pipes that leak lead into the water supply.
4. Chemical Disinfection
Chemical disinfection involves adding certain chemicals to water to kill or deactivate harmful pathogens. Cities use this method to keep millions of people safe from drinking water.
Types of Chemical Disinfection
- Chlorination: The process of adding chlorine gas or sodium hypochlorite to water. This is the most common way to clean up a lot of municipal water.
- Iodination: This method uses iodine crystals or tablets. It works very well against most viruses and bacteria, but you shouldn’t use it every day for long.
- Chlorine Dioxide Treatment: This is a much stronger oxidizer than regular chlorine. It gets through the cell walls of tough parasites like Cryptosporidium that other chemicals can’t kill.
- Chloramine Disinfection: This method uses chlorine and a small amount of ammonia together. It lasts longer than pure chlorine and remains more stable as the water travels through miles of underground pipes. It also makes fewer harmful byproducts, but it takes longer to kill germs.
- Ozonation: This method bubbles ozone gas through the water. It is a powerful disinfectant that leaves no chemical taste behind, though it requires specialized equipment.
How it Works
When added to water, the chemical reacts with the organic matter in bacterial and viral cells. It breaches the protective outer layer and destroys the germ’s internal structures that sustain it. This process takes time, so people have to wait at least 30 minutes for the chemical to fully circulate. If the water is cold or cloudy, wait longer or add the chemical a second time to be safe.
Pros:
- Fits in a small pocket and treats large amounts of water with zero effort.
- Provides “residual” protection, which keeps killing germs even if the water sits for a day.
- Costs the least per gallon among portable purification methods.
Cons
- Leaves a distinct chemical smell and taste that many people find unpleasant.
- Requires precise measurements because excess chemicals can be harmful to your health.
- Fails to remove physical dirt, heavy metals, or chemical pollutants.
Cost
A pack of 50 purification tablets costs about 12 dollars. This makes the cost per quart of treated water less than 25 cents.
Best-Case Uses
Chemical tablets are essential for international travelers or anyone building an emergency earthquake kit. They also serve as a great backup for hikers in case their primary mechanical filter breaks.
5. Ultraviolet (UV) Purification
UV purification is a process that uses ultraviolet light to kill germs in water. They kill germs by damaging their DNA so that they can no longer grow or make you sick. In many home systems, it serves as the last line of defense.
How it Works
Water flows through a chamber that contains a specially designed mercury vapor or LED lamp. As the water passes by the bulb, the UV-C rays penetrate the cells of bacteria, viruses, and cysts. This radiation damages the organism’s genetic code. Once the DNA is broken, the pathogen cannot reproduce or cause an infection in a human host. The water must be clear for this to work. If the water is cloudy, dirt particles can block light and “shade” the bacteria from sunlight.
Pros:
- Destroys 99.99% of biological threats, including chlorine-resistant Cryptosporidium.
- Adds no chemicals and creates no harmful byproducts in the water.
- Requires very little maintenance beyond a once-a-year bulb change.
Cons
- Needs a constant electrical supply to power the lightbulb.
- Fails to remove heavy metals, salts, or physical sediment.
- Loses effectiveness if the water is not clear before entering the chamber.
Cost
Home UV systems typically cost between $200 and $500. A replacement bulb usually costs between $50 and $100 per year.
Best-Case Uses
UV purification is ideal for homeowners on well water who worry about bacterial runoff from nearby farms. It is also an excellent final stage for a reverse osmosis system.
6. Activated Carbon Filtration
Activated carbon filtration uses a highly porous material to “grab” and hold onto chemical impurities. It is the most popular method for improving the taste and safety of tap water in cities.
How it Works
The “activation” process creates millions of tiny pores and a massive surface area on the carbon. As water travels through the filter, the carbon acts like a chemical magnet. Organic chemicals, pesticides, and chlorine stick to the surface of the carbon pores. Because the surface area is so large, a single gram of activated carbon can have a surface area of over 1,000 square meters. This allows the filter to trap a huge amount of toxins before the carbon becomes “full.”
Pros
- Removes the “swimming pool” taste and smell of chlorine effectively.
- Eliminates common organic chemicals and many man-made pesticides.
- Keeps healthy minerals in the water while only removing the bad stuff.
Cons
- Does not remove heavy metals like lead or dissolved salts on its own.
- Becomes a breeding ground for bacteria if the filter is not changed on time.
- Fails to kill viruses or tiny bacteria.
Cost
Pitcher filters usually cost about $20, but under-sink models cost anywhere from $50 to $150. Replacement cartridges cost between $10 and $40.
Best-Case Uses
Use carbon filters if your tap water smells like dirt or tastes like chlorine. It’s the best way to make drinking and cooking water taste better every day.
7. Sedimentation and Flocculation
Sedimentation and flocculation are pretreatment steps that remove larger particles and reduce water cloudiness. With these earlier steps complete, advanced filtering can proceed.
How it Works
The treatment process starts with the addition of a chemical called a “coagulant” to the water, followed by rapid stirring. The coagulant neutralizes the electrical charge on the dirt particles. Once the charge is gone, the dirt starts to clump together. The water then flows into a quiet tank, where these heavy clumps sink to the bottom. The clear water at the top is then siphoned off for the next stage of purification. The procedure removes the “cloudiness” that otherwise blocks UV light or clogs sensitive membranes.
Pros
- Removes the majority of visible dirt, mud, and silt from the source.
- Reduces the workload on expensive filters such as reverse osmosis.
- Can be done on a large scale for very little money using simple minerals.
Cons
- Requires a lot of space for large settling tanks.
- Takes a long time for the particles to settle completely.
- Does not kill germs or remove dissolved chemicals on its own.
Cost
In a home setting, this typically involves a sediment filter cartridge that costs between $5 and $15. For survival use, it only costs the price of a small bag of alum.
Best-Case Uses
This is a vital first step for people using river water or well water with high levels of sand and clay. It prevents your expensive drinking water filters from clogging up in just a few days.
8. Solar Purification (SODIS)
SODIS, or Solar Water Disinfection, involves filling clear plastic bottles with water and placing them directly in sunlight. It combines UV radiation and heat to destroy biological pathogens. In the absence of fuel or electricity, this method is a lifesaver.
How it Works
The process works through two simultaneous mechanisms. First, UV-A rays from the sun penetrate the bottle and react with the water’s oxygen, creating highly reactive oxygen molecules that attack and kill germs. Second, the sun’s infrared rays heat the water. When the water reaches 122°F to 140°F, disinfection occurs much faster. For best results, the bottles should remain in full sunlight for at least six hours. On cloudy days, they should be left out for up to two full days.
Pros
- Costs nothing since it only requires sunlight and old bottles.
- Simple enough for a child to perform correctly in a survival situation.
- Provides a safe alternative when firewood or gas is unavailable.
Cons
- Only treats a small amount of water at a time (whatever fits in the bottles).
- Requires perfectly sunny weather and a long wait time.
- Does not remove chemical toxins or physical dirt from the water.
Cost
There is zero cost for this method. You only need clean, clear plastic bottles and a sunny spot on the ground or a roof.
Best-Case Uses
SODIS is a primary method for hikers in emergencies and for people living in developing countries with plenty of sunlight. It is the ultimate low-cost backup for biological safety.
9. Ion Exchange
Ion exchange is a process in which “bad” ions are exchanged with “good” ions present in the water. This technology is the mainstay for deionization and water softening systems.
How it Works
The process takes place inside a tall tank filled with millions of microscopic plastic beads with a specific electrical charge. As the source water flows through the tank, the resin beads “grab” onto the unwanted mineral ions. For example, in a water softener, the beads hold onto sodium. When calcium-heavy water enters, the beads release the sodium and grab the calcium instead. Once the beads are full of minerals, the system flushes them with a salt brine solution to “recharge” them for the next cycle.
Pros
- Prevents “scale” buildup in pipes, water heaters, and coffee makers.
- Effectively removes specific harmful toxins such as nitrates and arsenic.
- Makes soap and detergent work much better for cleaning and bathing.
Cons
- Adds a small amount of sodium to the drinking water, which might be a concern for some diets.
- Requires the regular purchase and lifting of heavy bags of salt for the brine tank.
- Discharges salty wastewater into the sewer system during the cleaning cycle.
Cost
A quality home ion exchange system or water softener typically costs between $600 and $2,000. Additionally, expect to spend about $10-$20 per month on salt for maintenance.
Best-Case Uses
Ion exchange is the standard solution for anyone living in a “hard water” area where white crusty spots appear on faucets. It is also essential for households that need to remove specific pollutants, such as nitrates, from their well water.
Comparison of Water Purification Methods
| Method | Primary Target | Removes Metals? | Speed | Maintenance Level | Impact on Taste | Typical Cost | Power Required? |
| Boiling | Bacteria, Viruses | No | Fast | Low (Clean the pot) | Makes water taste “flat.” | Low (Fuel cost only) | Yes (Heat) |
| Distillation | All Contaminants | Yes | Very Slow | High (Scale removal) | Very bland/Neutral | $150–$500 | Yes (Electricity) |
| Reverse Osmosis | All Contaminants | Yes | Moderate | Medium (Filter swaps) | Excellent/Crisp | $200–$600 | No (Uses water pressure) |
| Chemicals | Bacteria, Viruses | No | Slow | Low (Check dates) | Strong chemical odor | $10–$20 | No |
| UV Light | Bacteria, Viruses | No | Instant | Low (Yearly bulb) | No change | $200–$500 | Yes (Electricity) |
| Activated Carbon | Chlorine, Organics | Partial | Fast | Medium (Regular swaps) | Greatly improved | $20–$150 | No |
| Sedimentation | Dirt, Sand, Silt | No | Slow | Low (Clean the tank) | No change | $5–$15 | No |
| Solar (SODIS) | Bacteria, Viruses | No | Very Slow | Low (Replace bottles) | No change | Free | No (Sun only) |
| Ion Exchange | Minerals (Hardness) | Yes | Fast | Medium (Adding salt) | May taste slightly salty | $600–$2,000 | Yes (For regeneration) |
What Factors Should You Consider When Choosing a Water Purification Method?
Factors to consider when choosing a water purification method include your specific water source, household budget, and the types of pollutants you need to remove.
To find the perfect fit for your lifestyle, weigh these critical decision-making elements:
- Source Water Quality
Find out if your water comes from a public tap, a private well, or a natural stream. City water contains a lot of chlorine. Well water contains bacteria, nitrates, or heavy minerals. Using a home kit or a lab report to test your water will show you exactly which pollutants you need to remove first.
- Contaminant Target List
Find out which specific contaminants are in your local water supply, such as lead, fluoride, or germs. Some methods, such as UV light, only kill germs, while others, such as activated carbon, address taste and chemical issues. You need to choose a technology that works with the chemicals and living things in your water.
- Daily Water Demand
Determine the amount of clean water your family uses for various purposes. A pitcher on the counter is fine for one person. But a big family needs an under-sink or whole-house system to keep up with the noise. Choose a system that matches your needs.
- Initial Cost and Long-Term Maintenance
Keep everything from the purchase price to the costs of replacing filters and paying for a regular power supply in mind. Cheap filters require changing the cartridge every few months. Sophisticated systems have higher initial costs, but savings in operating costs per gallon over several years offset those costs.
- Ease of Installation
Renters typically choose portable countertop units or faucet attachments. They are simple to set up and take down. Most homeowners opt for built-in systems. They hide neatly under the sink for a permanent look.
- Space Availability
See how much room you have. Check your utility room or under your sink. Some systems have large tanks and many filters, which take up a lot of space. First, measure the space to make sure everything fits, and your pipes remain easy to access.
You need to find a method that works for you by weighing these practical needs against your health goals. You’ll have safe, clean water for many years to come if you take the time to think about these things now.
Can Different Water Purification Methods Be Combined?
Yes, different water purification methods can be combined to create a more powerful and comprehensive treatment system for your home. Using a single method leaves gaps in your protection because no technology removes every single type of pollutant on its own.
A carbon filter, for example, is excellent at removing chlorine and improving the taste of water. But it cannot kill viruses or remove dissolved salts. You make a “multi-stage” defense by stacking processes on top of each other in a specific order. This plan ensures that if a contaminant gets through the first layer, the next layer catches it before it reaches your glass.
Most effective water systems purify the water in steps. First, a sediment filter removes sand and rust. This process keeps the main filters safe. Next, a carbon filter removes odors and chemicals. Finally, RO or UV filtration removes small germs. Putting layers on top of each other makes the water safer and helps the system last longer.
Which Is the Best Water Purification Method for Drinking Water?
The best water purification method for drinking water depends on where it comes from before it gets to your tap. A universal approach fails to account for the risks associated with the diverse types of pollution found in different locations. The only way to ensure every glass you drink is pure and refreshing is to use the right technology for your water source.
Best Method For Municipal Water
People who live in cities do best with an activated carbon filter or a reverse osmosis (RO) system. City water is already treated for bacteria, but it often has too much chlorine, and it comes through old pipes that leak lead into your home. A carbon filter removes “swimming pool” smells. An RO system protects against dissolved salts and heavy metals, providing an extra layer of protection.
Best Method For Well or Groundwater
The best recommendation would be the UV purification system combined with a water softener if you use a private well. The earth filters groundwater naturally; however, it can easily become contaminated by bacteria from farms nearby or heavy minerals that cause “hard” water. The UV light provides a chemical-free way to kill living germs instantly. At the same time, the softener uses ion exchange to remove minerals that cause white, crusty spots on your faucets and dry out your skin.
Best Method For Surface Water (Rivers, Lakes)
Untreated water collected from a lake or river undergoes a multi-stage filtration process involving sedimentation and ultrafiltration (UF). Surface water is clouded with mud and organic debris, which conceals dangerous parasites. The pathogens and dirt are kept out by letting the bigger particles settle at the bottom first, and then forcing the water through a filter with tiny holes. This ensures the water is clear and safe for your body before you drink it.
You’re not the only one who doesn’t know which water purification system to buy. Water Filter Way offers clear guides and expert reviews to help you choose the best water purifier for your home. We give you clear, honest information so you can be sure that the water you drink is safe.
FAQs About Water Purification Methods
Can Water Purification Methods Completely Remove Viruses?
Yes, certain water purification methods, or combinations thereof, can effectively kill or remove almost all viruses. Standard microfilters don’t work very well because viruses are tiny. You have to physically block them with ultrafiltration, distillation, or reverse osmosis. Alternatively, UV light or chemical disinfectants such as chlorine destroy their DNA, rendering the water safe.
Which Water Purification Method Works Best During Power Outages?
The water purification method that works best during power outages is boiling because it only requires a simple flame. You do not need electricity to run a stove or a campfire. This makes it the most reliable backup when pumps and electronic filters stop working. It eliminates all living threats by using intense heat.
Do Water Purifiers Change the pH of Drinking Water?
Yes, water purifiers can change the pH of drinking water. The filtration system used greatly influences the result. In reverse osmosis, the removal of alkaline minerals often reduces pH, making the water slightly acidic. Others have a remineralization stage in which calcium and magnesium are added back to the liquid, raising the pH.
How Long Does Purified Water Stay Safe for Drinking?
The safety of purified water for drinking depends heavily on how you store it and the surrounding area. It stays fresh for a few days if you store it in a cool place in a sealed, food-safe container. Bacteria grow better in open containers or warm rooms. You need to drink open water within 48 hours.
Do Water Purification Techniques Work on Salty or Brackish Water?
Yes, specialized water purification techniques such as reverse osmosis or distillation work on salty or brackish water. These techniques use either heat or high pressure to separate water from dissolved salts, collecting pure water while concentrating the salts into other waste containers.
Which Contaminants Are Commonly Removed by Water Purification Systems?
Common contaminants removed by water purification systems include dirt, heavy metals, and parasites. Some systems focus on common water contaminants, such as lead and chlorine, to make water safer and taste better. High-end units also eliminate pesticides and other industrial chemicals. This deep-cleaning process ensures that your family doesn’t accidentally ingest harmful chemicals that are hiding in city pipes.
Which Purification Method Requires the Least Maintenance?
The purification method that requires the least maintenance for home use is ultraviolet light. Change the UV bulb once a year for maximum efficiency. SODIS and boiling also require considerably less maintenance, as they do not employ any advanced equipment. This makes them the best choice for those seeking quick fixes.
Do Water Purification Systems Need Regular Cleaning?
Yes, water purification systems require regular cleaning to prevent slime and mold growth. Over time, filters can clog, slowing water flow and increasing the risk. Your system lets more pollutants into your glass if you don’t follow the maintenance schedule. Regularly cleaning your equipment keeps it in top shape.
Can Water Purification Methods Improve Cooking and Food Taste?
Yes, water purification methods improve cooking and food taste by removing bitter chemicals like chlorine. When you boil pasta or make soup with clean water, the ingredients’ natural flavors come out. Your coffee and tea will taste much better without these impurities. It also keeps your vegetables from smelling strange.
Can Purified Water Be Safely Stored in Plastic Containers?
Yes, purified water can be safely stored in plastic containers as long as they are BPA-free and food-grade. Keep these jugs in a cool, dry place to prevent the plastic from degrading. Heat causes chemicals from the container to leach into your water. Always use opaque bottles to block sunlight and prevent algae growth.
