Spatial velocity (SV) is the reciprocal of the time that raw water comes into contact with the filtration layer per unit time. Simply put, it is the number of times the volume of filter media is processed per unit time,　and it is calculated by dividing the flow rate by the volume of filter media. Spatial velocity (SV) is required when the contact time between the filter media　and water affects the treatment performance, especially in the design of catalytic oxidation treatment performed in iron removal　and manganese removal treatment,　or the adsorption of organic substances on activated carbon. Used for processing design. When removing iron　and manganese from water with a large amount of SS, anthracite　or ceramic filter medium is often used together on top of the catalytic oxidation catalyst type filter medium (ferrorite). In this case, contact Please be careful to use the amount of filter media only for the oxidation catalyst type filter media (ferrolite) in the design.

The SV is set by the software designer. Decreasing the value makes the device compact and leads to cost reduction, but if it is too fast, sufficient processing will not be performed, so careful design is required.
Although it depends on the water quality, it is often designed as SV10 to 20h-1 for manganese removal treatment and SV2 to 8h-1 for organic matter adsorption treatment.