• May 21, 2024
  • Particle Size
  • By Gina Kahl

Sand: It’s Not Just for Beaches!

While the word “sand” may conjure up visions of shimmering beaches or children’s sandboxes, in everyday life, sand plays a critical role in many water filtration systems used for municipal water treatment and industrial wastewater effluent. Sand filters have been used by industries for years to process water for both potability as well as pre-discharge treatment.

In the sand filtration process, over years of water moving through a filter bed, the individual sand particles slowly erode. Each filtration system is engineered to work with a specific size range of sand particles. PTL’s particle sizing capabilities can assist water treatment facilities in monitoring their sand’s particle size so facilities can replace filter sand when required for optimal operation.

For filtration purposes, there are two important definitions to understand. One is effective size. The effective size of a sample of sand is the 10th percentile diameter. In other words, 10% of the material (by weight) is smaller than this diameter. The other important metric is the uniformity coefficient (UC). The UC is calculated by the ratio of the 60th percentile size by the 10th percentile size. Both a filter bed’s effective size and uniformity coefficient must be monitored to assess the bed’s overall particle size distribution to ensure it continues to perform as designed.

Particle Size Data Summary
 

PTL Project Filter Sand

 

Sieve Test Analysis at PTL

PTL has a full range of analytical sieves in most standard ASTM E11 sizes. A sieve stack can be customized to most accurately reflect the particle size range in a client’s sand sample. The data from this sieve analysis is then analyzed to predict a d10 (10th percentile) and d60 (60th percentile) particle size diameter.

From the d10 and d60, PTL can then report a sand sample’s effective size and uniformity coefficient along with an overall size distribution. Our goal is to assist the users of industrial filtration systems to better understand the current condition of their sand beds to best know when to replace sand media.

PTL can perform sieve analysis as well as other physical characterization testing on a variety of filtration media; please contact our team to find the right technique for your needs!

By Gina Kahl, Particle Characterization Chemist III.

Sieve Analysis

Particle size determination by Sieving dates back to the time of the ancient Egyptians. The continuing use and popularity of this technique can be attributed to the fundamentally simple principle, methodology, historical reference, and cost effectiveness.

Learn More About this Technique