Silt Density Index: A Fresh Perspective on an Old Index

This paper demonstrates the need for consistency in the use and selection of silt density index (SDI) filter pad chemistries by membrane treatment plant operators for their specific facility. While it is not the authors? intention to identify the ?best? filter pad for use in the SDI test, the findings will illustrate the need for a thoughtful consideration of the filter pad used in the SDI test and how it may impact the operator?s ability to achieve the reverse osmosis (RO) warranty conditions.