Crushed Recycled Glass as a Filtration Medium

Crushed Recycled Glass

Thought to be the oldest manufactured substance in the world, glass dates back to around 1500 BC, with finds in Egypt and Eastern Mesopotamia. It was believed, however, that stone age people fashioned weapons and decorative objects from black volcanic glass (obsidian) far before this time.

Fast forward to today: Manufactured in mass qualities, glass is made entirely from natural raw materials, and is used to hold everything from milk to jelly. Glass can also be made into a wide variety of products including decorative objects, lamps and more.

Despite the benefits of reusing glass, a whopping 12.5 million tons of glass waste is produced worldwide every year, according to the Environmental Protection Agency (EPA). Only 30 percent of this waste winds up in recycling programs while glass is 100 percent recyclable.

Currently in its infancy, but not far off the beaten path, glass is making the headlines as a viable option for water-filtration mediums. Said to be a direct replacement for sand, the glass medium is processed through a series of crushers, dryers and screens in order to make it safe to use.

Reduce, Reuse, Recycle: Glass Facts

  • Glass can be recycled endlessly without risk of losing its quality.
  • Glass is made from sand, soda ash, limestone and cullet.
  • Recycling 1,000 tons of glass creates over 8 jobs. Do the math.
  • Recycled glass can be substituted for up to 95% of raw materials.
  • Recycled glass used for water-filtration feels like beach sand.

Glass Opposed To Sand

All of the case studies currently completed on the benefits of using crushed recycled glass as a water-filtration medium have provided glowing results. Some studies have even proven the fact that glass works just as, if not better, than sand when filtrating water.

According to other case studies glass provides many advantages such as improved water treatment efficiency, lower backwash rates and lower costs – not to mention the environmental benefits to using crushed recycled glass in place of sand as it guarantees its removal from landfills.

Notable disadvantages to using crushed glass as opposed to sand include recent literature from the EPA which speaks of the fact that glass is not a proven technology for alternative media filters and that it may not be readily available when needed for replacement – but don’t rule it out quite yet.

One More Advantage: Longevity

Yet another advantage that has researches and pool builders/operators alike talking is the fact that glass can last 10 years or longer. But this advantage also raises the question of how it should be disposed of when its expiration date is finally maxed out.

Crushed recycled glass manufactures have replied by informing pool operators to 1) make sure the medium really needs to be replaced. It may be beneficial to clean it using chlorine and top of the filter with a fresh layer. And 2) dispose of it in much the same way you would sand.