Sand Filtration System

Sand & Gravel Multimedia Filtration System


Sand filtration is a process that consists of the removal of suspended solids by passing fluids through a filter bed. The filters can operate at atmospheric pressure or higher. The version most widely implemented consists of layers of sand and gravel in a concrete or plastic container approximately 0.9 meters tall and 0.3 meters square. The water level is maintained to 5-6 cm above the sand layer by setting the height of the outlet pipe. To use the filter, users simply pour water into the top, and collect finished water out of the outlet pipe into a bucket. Over time, especially if source water is turbid, the flow rate can decrease. Users can maintain flow rate by cleaning the filter through agitating the top level of sand, or by pre-treating turbid water before filtration.


The filtration medium consists of a multiple layer of sand with a variety in size and specific gravity.

A sand filter has a dirt holding capacity of 3 to 6 kg TSS / m2 of sand surface.
When the filters are loaded with particles, the flow direction is reversed and the flow is increased to clean the filter again. This step is called a backwash.

Application for sand filtration:

★ Preparation of cooling water
★ Treatment of waste water
★ Production of drinking water
★ Filtration in swimming pools
★ Pre filtration for membrane systems
★ Filtration of grey or surface water
★ Removal of iron


Physical Specifications

★ Effective Sizes: .20mm - 2.5mm
★ Uniform Coefficient: 1.3 - 1.7
★ Specific Gravity: 2.67
★ Moh's Hardness: 7
★ Density: 105 - 115 lbs per cubic foo