Ensuring that your home’s tap water is safe can be a daunting task. What options are available to purify your water? How can you determine which option is best? This article will cover the basic ways that water can by purified. A commercially available water purifying system may contain some or all of these treatment strategies. Understanding the difference between these strategies (including what kinds of contaminants they can and cannot remove!) may help you choose what kind of water purifier is right for you.
Reverse Osmosis: Reverse osmosis (RO) is an important step at most water treatment facilities, and is a component of many large, at-home water purifying systems like whole-house purification systems, or under the sink purification systems. Reverse osmosis uses high pressure to force water molecules through a very tight barrier. This barrier (or membrane) will trap many contaminants, allowing the water to be purified as it passes through. RO filters can remove the majority of water contaminants, including microorganisms, heavy metals like and copper and lead, and minerals like sodium and magnesium. RO may even improve the taste of your water. However, RO is not without disadvantages: RO systems can waste lots of water and may remove some minerals that can be good for you.
Activated Carbon: Activated carbon (or activated charcoal) is found in nearly all water purification systems, from huge, whole-house purification systems, to many brands of pitcher filters. Activated charcoal utilizes the tiny pores naturally found in carbon deposits (like charcoal) in order to trap contaminants. Contaminants in water passing through the carbon will become trapped in these tiny pores. Activated carbon is best at filtering chlorine, volatile organic compounds (chemicals left behind by things like gasoline or household cleaners), and sediment (dirt, sand, etc.) Activated carbon can also eliminate sources of bad smells or taste from your water. However, activated carbon is not useful for removing salt, minerals, or chemicals that dissolve in water.
Ion Exchange: Ion exchange systems are another strategy common in most purification systems. As with activated carbon, ion exchange systems may be found in any purification system ranging from large, whole-house systems to small, tabletop pitcher filters. Ion exchange steps utilize resin (material with special chemical properties) to trap unwanted ions. Specifically, this resin can trap harmful molecules like lead, mercury, arsenic, and more. Ion exchange resins cannot usually remove contaminants like chlorine or microorganisms.
UV: Ultra-violet light is sometimes incorporated as a treatment step in large purifiers like whole-house purifiers, or sometimes sold as a single-step water treatment system, such as portable devices designed to sterilize water from natural sources. UV light is very effective at killing microorganisms and leaves no harmful byproducts like bleach or chlorine. Unfortunately, UV light cannot remove any other contaminants like dirt, minerals, or chemicals. Even more unfortunately, the presence of dirt or lots of minerals in the water can reduce the effectiveness of UV light, as these particles can “block” the light from killing the microorganisms. Thus, UV treatment is very effective when used in combination with other purification steps, but is not very helpful as a single-step water treatment strategy.
Ceramic Filters: Ceramic filters are a stand-alone purification strategy, similar to pitcher filters. These filters take advantage of ceramic’s natural tiny pore size. These filters can be very effective at removing large contaminants like dirt, sediment, and bacteria. Unfortunately, smaller contaminants like chemicals or viruses will not be removed as they are small enough to pass through the pores with the water. However, some commercially available ceramic filters will also contain secondary purification steps like activated carbon in order to remove contaminants that can’t be removed with ceramic filtration.
When considering purchasing a water purification system, it is important to know what kinds of strategies or components it might contain. Every purification strategy possess its own advantages and limitations. By understanding these advantages and limitations you can choose a purification system that contains the strategies that are best for your home and your tap water.