Drinking water purifiers remove chemicals, microorganisms and particulate matter like dirt from drinking water. They can also reduce the concentration of dissolved substances.
Tap water is usually regulated by government agencies and meets health standards, but you can use a drinking water purifier to ensure that your home’s water is safe for consumption.
Reverse Osmosis
Reverse osmosis is one of the best methods for water purification. It uses pressure to force water molecules through a semi-permeable membrane that separates the solute and solvent. The solute is discarded down the drain and the pure water is collected in a storage tank.
The first step in a reverse osmosis system is the sediment filter which strains out silt, dirt and rust to prevent them from damaging the membrane and clogging the subsequent filters. The second stage is the pre-carbon block that removes a wide range of contaminants like chlorine, cyanide, radon and volatile organic compounds (VOCs) from your drinking water. The third stage is the reverse osmosis membrane that eliminates more contaminants including high levels of lead, sodium and dissolved minerals. Finally, a post-carbon filter polishes the drinking water.
There are two types of RO membranes used in home filtration systems: thin film composite (TFC) and cellulose tricephalate (CTA). Both have different rejection rates and cost-to-performance ratios. The best choice for your home depends on the type of contaminant you want to remove and your budget.
A major drawback of a reverse osmosis system, especially the quick-change cartridge models, is that they waste up to 20 times as much water as they produce. This is not only wasteful on an environmental scale but also wastes money for homeowners who are paying for excess water they don’t need.
Distillation
Distillation is one of the oldest water treatment methods and remains in use today. It is effective in removing bacteria, inorganic compounds and some organic contaminants. However, it is not very common as a home water treatment method.
The distillation process uses evaporation to purify drinking water. The contaminated water is heated until it boils and evaporates, leaving behind inorganic compounds and large non-volatile organic molecules. The vapor then cools and condenses to form pure water. The boiling process also kills microorganisms, making the resulting water highly purified.
Home distillation units vary in size and design, with smaller units that can distill less than a quart of water per hour. They require electricity for operation and can be noisy when operating. They should be kept in a cool, dry location away from children and pets. Distillers should be regularly cleaned and distilled, especially after heavy usage or if minerals build up. Keep a log book to record water test results, equipment maintenance and repairs.
Home water distillers do not remove all contaminants from drinking water. For example, some organic compounds have lower boiling points than water and will recontaminate the resulting distilled water. Other treatment processes may be more effective for these contaminants. The best way to identify these contaminants is to have your water tested at a state certified laboratory.
Chemicals
Chemicals are a huge part of our world and our everyday lives. Some naturally occur in nature, like water, while others are manufactured and used by people, such as chlorine (used for bleaching fabrics or disinfecting swimming pools).
Most of the time, our bodies are protected from chemical contaminants by our immune systems. But, when drinking water directly from a natural source, such as a lake or river, we must rely on more advanced methods to ensure its safety. This includes filtration and distillation processes.
The first step in purifying water involves pretreatment. Depending on the nature of the water and the level of contamination, this could include screening to remove large debris such as sticks and trash, prechlorination to kill bacteria, and a process called sand filtration to remove dissolved solids.
Water treatment plants are responsible for the majority of water purification in industrialized nations. In addition to pretreatment, they often use ion exchange to rid water of fluoride, sulfates, nitrates and arsenic.
Other forms of water purification focus on killing biological contaminating agents, including viruses. These are too small for most filter elements to effectively catch, so they require special treatment, such as iodine or ultraviolet radiation. A UV treatment uses light to destroy the DNA of the contaminating organisms, rendering them harmless.
Boiling
Boiling is a common method of water purification and is effective in killing bacteria, parasites and other organisms that can cause health problems. However, it does not remove other contaminants such as chemicals and heavy metals. This is why it is important to boil the water for at least one minute before drinking.
Whether you are camping, travelling in an area where the local water supply has become contaminated or you are worried about toxins in your own home’s tap water, boiling is a simple way to kill germs and make your water safe to drink. Typically, it is recommended to bring the water to a full rolling boil for one minute before use. At higher altitudes, it may be necessary to boil for a little longer.
Bacteria are most active in the “danger zone” – temperatures between 40 and 140 degrees Fahrenheit. But when they are exposed to boiling temperatures for more than 30 minutes, they will be killed and inactivated.
While boiling can eliminate organic contaminants, it will not remove chemicals such as chlorine and lead from tap water. Furthermore, boiling tap water with high levels of PFAS chemical contamination will concentrate these chemicals in the water and make it dangerous to consume. Therefore, it is always best to filter your tap water before boiling it for safety.