Silver’s History Of Water Filtration

Silver was one of the three metals, along with bronze and gold, that we know ancient people used in their solid forms for water purification and filtration as far back as the Persian Empire. Documents attest that some emperors would refuse to drink water that wasn’t stored in a silver container. While they may not have understood it fully at the time, our ancestors knew that silver keeps water fresh and good to drink.

Silver Chalice with Apostles Venerating the Cross, Date: early 7th century (Late Antique), Source: Wikipedia Commons.

Through science, we now understand how silver’s natural antimicrobial properties, kills off harmful bacteria and other illness-causing pests such as Giardia and Cryptosporidium cysts. Even beyond its use in keeping water potable, silver and silver compounds have found a variety of medical uses in the form of both equipment and topical salves.

While silver may more commonly be known for its applications in jewelry and electronics today, it’s still hard at work fighting germs in hospitals and maybe even your own home. Silver-impregnated water filters are becoming more common, as silver works to filter out the microbes that traditional carbon filtration can leave behind.

It is not only microbes. Pesticides can also be neutralized using silver. In areas near farms that use chemical pesticides on their plants or anywhere else where water may be contaminated by similar organic compounds, silver can force these compounds to decompose and neutralize in ways other processes like chlorination or standard filtration can’t.

Industrial applications, too, are arising for these kinds of filters. Silver impregnated carbon filters are used in many different settings for their bacteria fighting abilities. Hospitals find these filters exceptionally important, especially for their ability to fight disease causing bacteria like Legionella among the already sick patients.

One use many may not think of for these kinds of filters is in cooling towers for factories and other industrial buildings. Cooling towers create steam by evaporating water as a means of removing waste heat. This naturally allows the opportunity for bacteria to grow in the lukewarm environment. Filtering the water as it flows, eliminates what could be a potentially major health hazard.

So how does silver impregnation in filters actually work?

Silver Impregnated Activated Carbon Surface (Image for representational purpose only)

While activated carbon is great at removing unwanted materials from our drinking water, bacteria tends to grow on it, thus turning the activated carbon itself into a pollutant. This problem is solved by silver impregnation. Introducing a small amount of silver into the surface of the carbon has been shown to inhibit the growth and reproduction of bacteria. Studies have shown how effective silver impregnation can be against common bacteria like E.coli and S.aureus(1).

Both throughout history and the modern day, silver has been used as a water purifier and filter for its adept ability to kill microbial organisms in water. Whether it’s to clean what we’re planning to drink or for a variety of other reasons, silver and silver impregnated carbon filtration units are a boon to our modern lives.