The SDI test entails forcing water through a small diameter (47 mm), 0.45-micron absolute membrane filter while maintaining a pressure of 30 psi. The time required to pass 500 mls at the end of 5, 10, and 15 mins is taken and used to calculate the unit-less SDI value.

Silt Density Index testing is a widely accepted method for estimating the rate at which colloidal and particle fouling will occur in water purification systems, especially using reverse osmosis …

The silt density index is a measure for the fouling capacity of water in reverse osmosis systems. The test measures the rate at which a 0.45- micrometre filter is plugged when subjected to a constant water pressure of 206.8 kPa (30 psi).

The Silt Density Index (SDI) test is a means of quantifying the amount of particulate contamination in a water source. The test was specifically developed as means of predicting the rate of colloidal and particulate fouling of Reverse Osmosis (RO) membranes.

The SDI is a popular method for determining feed water quality in RO applications. It is based on the time required to filter a volume of feedwater through a 0.45 m filter pad at a feed pressure of 30 psig. Operating an RO system with SDI <4.0 results in a lower rate of colloidal fouling.

In the SDI test, are the t2, t3 (etc) tests made by passing water through the membrane for 5, 10 and 15 minutes each -- in other words, do you keep the water running through the whole test.

Measurements of Silt Density Index (SDI) are carried out for relatively clean water supplies (water from waterworks) in order to determine the contents of colloids, thereby indicating how fast an NF or RO membrane will be clogged (fouling).

SDI test are used to determine the feed water quality for water feeding a membrane filtration systems. The most common is a reverse osmosis or RO system. This test method indicates the quantity of particulate matter in low turbidity (<1.0 NTU) waters.

This test method covers the determination of the silt density index (SDI) of water. This test method can be used to indicate the quantity of particulate matter in water and is applicable to relatively low (<1.0 FTU) turbidity waters such as well water, filtered water, or clarified effluent samples.

2016年9月13日 · Silt density index (SDI) estimates the quantity of suspended solids and colloids inside of water. SDI is measured following the ASTM D19.08 Standard Test Method for Silt Density Index (SDI) of Water, using a 0.45 micron membrane.