How Does Carbon Filtration Work?

The Science of Carbon Filtration

Carbon filtration works by a process called ”adsorption”—spelled with a “d” and not to be confused with absorption (spelled with a “b”).

Adsorption happens when impurities in the water chemically bind to the surface of activated carbon.

Activated carbon is a porous material treated to have an extremely high surface area. A single gram of activated carbon can have a surface area of over 32,000 square feet.

When water flows through the carbon filter, contaminants like chlorine, volatile organic compounds (VOCs), and certain chemicals adhere to the carbon. The result? Cleaner, better-tasting water and ice.

Why Activated Carbon Works So Well

These traits of carbon filtration contribute to its effectiveness as a water purifier:

• Porous Structure: Activated carbon’s tiny pores capture molecules of contaminants effectively.
• Chemical Bonding: Chlorine and organic compounds form weak chemical bonds with the carbon, trapping them.
• Odor and Taste Removal: Carbon effectively removes the chlorine taste and odor that’s common in municipal tap water.

Beyond Carbon Filtration: Tackling Tougher Contaminants

While carbon is excellent at removing many common impurities, it doesn’t filter out everything. Heavy metals like lead, nitrates, and bacteria can sometimes pass through a basic carbon filter. This is where modern refrigerator water filters step up their game with additional filtration tactics.

Mechanical Filtration

Mechanical filtration works like a fine sieve, using a barrier membrane to physically remove particles from the water.

Refrigerator filters often include a mesh pre-filter or microfilter that traps sediment, rust, and other larger particulates before water reaches the carbon filter.

Ion Exchange Technology

To tackle heavy metals like lead and mercury, some filters incorporate ion exchange resins. These resins exchange harmful metal ions in the water with harmless ones, such as sodium or potassium, effectively removing contaminants that carbon alone cannot capture.

Microporous Membranes

For enhanced purification, some advanced filters include a microporous membrane layer. This membrane is capable of filtering out microscopic contaminants like bacteria and cysts, ensuring safer drinking water.

Silver Impregnation

To prevent bacterial growth within the filter itself, some refrigerator water filters integrate silver into the carbon. Silver has natural antimicrobial properties, inhibiting the proliferation of microorganisms that might otherwise thrive in a moist filter environment.

Maintenance: Ensuring Maximum Efficiency

Even the best refrigerator water filters lose effectiveness over time as they become saturated with impurities. To keep your water and ice tasting fresh, replace your filter as recommended—usually every 6 months. For heavy water users, more frequent changes may be necessary.

If you notice a decline in water flow, odd tastes, or smells, these are clear signs your filter needs replacement. Ignoring filter maintenance can result in diminished filtration performance and may allow contaminants to slip through.

Choosing the Right Water Filter for Your Refrigerator

When replacing your filter, always choose a model that is compatible with your refrigerator and certified to remove the contaminants specific to your water supply.

Replacing the fridge water filter with the exact type made by the original manufacturer ensures that you get the best and safest water filtration results.

Less expensive aftermarket water filters are available for almost every refrigerator. Sometimes, these aftermarket alternatives only use activated carbon and may not filter out the same contaminants as the original filters made by the manufacturer for your model.

When considering aftermarket refrigerator water filters, only use filters that match the NSF (National Sanitation Foundation) certifications for the manufacturer’s original water filter for your fridge. Here are some key NSF certifications to look for:

• NSF/ANSI Standard 42: For improving taste and odor.
• NSF/ANSI Standard 53: For removing specific health-related contaminants like lead.
• NSF/ANSI Standard 401: For filtering out emerging contaminants, including pharmaceuticals.

Procedure for Replacing Your Refrigerator Water Filter

Follow the owner’s manual guidelines for replacing the water filter in your fridge.

Here’s a helpful YouTube video that shows how to replace the water filter in common types of refrigerators:

Don’t forget to purge water through the water dispenser after replacing the water filter as shown in the video.

Final Thoughts

Carbon filtration is a cornerstone of refrigerator water filters, effectively removing many common impurities to provide fresh-tasting water and ice. However, today’s filters often go beyond simple carbon technology, incorporating additional mechanisms to handle tougher contaminants.

By understanding how these systems work and replacing your refrigerator water filter regularly, you can enjoy clean, crisp water straight from your fridge.