What is a Water Purifier?

Water purifiers remove contaminants like bacteria, protozoa and chlorine-resistant cysts (Giardia and cryptosporidium). Some filter products also eliminate viruses, which are too tiny to catch by carbon filters.


Pocket-sized designs like the LifeStraw Peak and Sawyer’s QuickDraw thread onto a bottle or soft flask to allow you to suck clean water through as you hike. Other models use UV treatment to kill bacteria and protozoa.

Purification Process

The water purification process involves removing contaminants that affect the safety and quality of drinking water. This includes chemical and biological contaminants and suspended solids. During the purification process, a physical barrier is created that filters out the unwanted materials and organisms. This makes the water safe for consumption. The most common methods of purification include filtration, distillation and deionization.

Filtration removes bacteria and larger particles from water. It does not, however, remove chemicals or viruses. Distillation uses heat to separate pure water from other disease-causing organisms and contaminants. The vapor is then condensed into liquid water, making it suitable for drinking. This method is not commonly used at home, but it is often found in labs and industrial settings.

Other forms of purification use UV treatment and disinfectants to kill harmful pathogens in the water. This is particularly effective in treating water that has been contaminated by sewage or other sources of illness. It is important to test water for contaminant levels before it is treated because not all types of water require the same treatment.

The pretreatment stage of the purification process includes screening, which removes large debris like sticks and trash from water before it is pumped into tanks. It may also include reducing plumbosolvency, which is the water’s ability to dissolve impurities like lead.

Activated Carbon Filter

Activated carbon filters are among the front-runners in home water filter systems. This is due to their effectiveness at reducing chlorine, chloramines and other organic chemicals found in drinking water. They remove these contaminants by a process called adsorption, which is similar to how a sponge absorbs water. The porous surface of the activated carbon attracts impurities by exerting a magnetic-like pull that’s much stronger than the forces keeping them dissolved in the water. Once the contaminant has been adsorbed, the filtered water moves on to the next stage of filtration.

Depending on the type of activated carbon, the way it was produced (heated in the absence of oxygen to bake off impurities and create cracks) and its chemical properties, it can be more or less effective at removing specific chemicals and metals. Most residential filters use granular activated carbon (GAC) that’s been processed to increase its surface area, which makes it more effective at adsorbing impurities.

However, a carbon filter can only adsorb so many contaminants before it becomes saturated and the contaminant molecules start to merge together. That’s why it is important to change the filter at regular intervals, usually every six months or so. If you’re looking for a home water purification system that removes even more contaminants, consider options that combine GAC with ion exchange and ultrafiltration layers.

Reverse Osmosis Filter

Reverse Osmosis filtration is a highly advanced method of water treatment. It can reduce Total Dissolved Solids (TDS) by 98% or more. It’s also one of the only drinking water filtration systems that reduces chlorine and fluoride. It removes heavy metals like lead and copper, nitrates, phosphates, cyanide, sodium, sulfates, volatile organic compounds, bacteria and viruses.

The basic principle behind reverse osmosis is that a solvent in an area of lower concentration will naturally migrate to an area of higher concentration across a semi-permeable membrane. The energy required to push a solvent through the membrane is called osmotic pressure. A reverse osmosis system uses an external pressure to overcome the natural tendency of a solvent, such as water, to move towards a more concentrated solution by using a high-pressure pump.

A reverse osmosis water filter system separates the clean drinking water from the waste water that goes down the drain. This ensures that the drain water cannot contaminate the drinking water supply and prevents an unwanted backflow of water from the system into the cleaner drinking water.

Reverse osmosis systems require between 200 and 400 pounds-per-square-inch of water pressure to operate properly. A home reverse osmosis system typically includes a sediment filter to prevent anything larger than a spec of flour from passing through the filter, a pre-carbon block that prevents chemical compounds from clogging the filter and the reverse osmosis membrane that removes dissolved salts, minerals and other chemicals, including many viruses and microorganisms.

Mineral Filter

During the purification process, your water will go through several stages to get rid of unwanted chemicals and toxins. As it goes through these stages, it will also lose healthy minerals. Often times, bottled water is treated with chemical additives that aren’t necessary. These additives can have a negative impact on your health, so it is important to look for a filter that does not add any extra chemicals to your water.

The Black Berkey Filter has a unique design that addresses this issue. This filter is made from a ceramic material with ion exchange properties that address both bad and good minerals in your water. The Black Berkey Filter will address things like aluminum, chlorine, fluoride and arsenic in your water. It will not however address calcium, magnesium or potassium, which are essential to the human body.

Once your water reaches the holding tank, it will then go through a remineralization cartridge to allow your water to retain healthy minerals such as calcium, magnesium, sodium and potassium. This is important because these minerals help to keep your bones strong, promotes proper muscle function and helps to regulate your heart rhythm. Water that is remineralized also tastes better and helps to boost energy levels. Whether your water is filtered without healthy minerals or with, it’s always best to drink as much clean, healthy water as possible.