Silt density index

Silt Density Index - SDI
|Membrane Fouling Control |
|Membrane fouling is the maincause of permeate flux decline and loss of product quality in reverse osmosis (RO) Systems, so fouling control |
|dominates RO system design and operation. Sources of fouling can be divided intofour principal categories: scale, silt (particular), |
|bacteria (bio fouling, growth of bacteria) and organic fouling (oil, grease).|
|Fouling control involves pre-treatment of the feed water to minimize fouling as well as regular cleaning to handle fouling that still |
|occurs. Fouling by particulates (silt), bacteria andorganics generally affects the first modules in the plant the most. Scaling is worse |
|with more concentrated feed solutions; therefore the last modules in the plant are most affected, becausethey are exposed to the most |
|concentrated feed water. |
|Silt density Index|
|Silt is composed by suspended particulates of all types that accumulate onthe membrane surface. Sources of silt are organic colloids, iron |
|corrosion products, precipitated iron hydroxide, algae, and fine particular matter. Silt Density Index testing is a widely acceptedmethod |
|for estimating the rate at which colloidal and particle fouling will occur in water purification systems, especially using reverse osmosis |
|(RO) or Nanofiltration membranes.|
|SDI is a measurement of the fouling potential of suspended solids. It’s not measuring the quantity...