Why is Silica Sand Used for Water Filtration and Purification – and How Does It Work?
Silica sand has been used for a long time to clean and purify water. There are four main forms of silica sand used globally for water purification The oldest record of silica sand filtration dates back to 1804, when a man named John Gibb designed and installed an experimental filter This remarkable filtration method was later improved and reached a milestone in 1829 when James Simpson installed the world’s first public water supply system for the Chelsea Waterworks Company.
Water treatment became more widespread after Dr. John Snow linked water quality to cholera outbreaks in 1845–1855.Today, we offer a wide range of products to meet your needs In modern times, providing safe drinking water is taken for granted in many developed countries. But how exactly does it work? Natural silica sand has a semi-angular to round shape, making it an ideal filtration media capable of trapping suspended solids in water Due to its high silica content, this sand is durable and highly resistant, which allows for precise grading and effective filtration.
Common sand grades include Why Is Silica Sand Used in Filtration:
16/30, 8/16, 6/14, 14/25, 20/40, 18/8, 2/4, 3/6, 6/13, 13/19, and 14/25 Silica grade can be identified by either particle size range or by effective size (D10) and uniformity coefficient (UC).During filtration, silica sand is layered above a gravel support bed inside the filter tank. Incoming water flows through the silica sand layer, successfully removing suspended debris and particles Thanks to its unique properties, silica sand is widely used in applications like Swimming pools, leisure water, paper processing, power generation, chemical treatment, and portable wastewater treatment.
Types of Water Filters
There are several types of water filters, including:
- Pressure Filters
In this system, water enters the filter and passes through the silica sand layer under pressure (typically 2 to 5 bar).Commonly used in recreational applications, pressure filters can capture very fine particles As particles accumulate in the filter bed, pressure loss increases for a given flow rate When pressure loss or flow becomes unacceptable, backwashing is performed to remove the trapped debris.
- Rapid Gravity Filters
These are widely used for drinking water treatment and require less space compared to slow sand filters They use silica sand along with other granular media to remove particles and impurities.
- Slow Sand Filters
These filters require more land space than rapid gravity filters, which has led many cities to switch to rapid filters due to increasing demand and limited land availability Slow sand filters are still used to treat raw water and produce potable drinking water.
- Filtration & Water Production
The most common application of silica sand is in water purification, wastewater treatment, and filtration of well or tap water Thanks to its uniform shape and size, silica sand is a highly effective filtration medium, consistently removing contaminants from water It also remains stable and resistant to acidic chemical exposure, making it a reliable long-term solution.
