Monthly Archives: November 2015

This document gives general guidelines for cleaning Nanostone RO or NF elements in the ST, ST+, ST++ and DT-Module-Configuration. During normal operation the membrane elements can become fouled by constituents in the feed water. The most common foulants include mineral scale, biological, organic, colloidal particles, and metal oxides. The nature of the fouling is dependent on the system design and feed water. Proactive cleaning is necessary to reduce the potential for irreversible fouling. If the membranes are heavily fouled, the cleaning effectiveness may be reduced and the performance may be permanently impacted. At a minimum, RO/NF elements should be cleaned when:

• Normalized permeate flow drops 10-15%
• Normalized permeate quality decreases by 10-15%
• Normalized pressure drop increases 10-15%.

Notes:

• Ensure that the all water used in the cleaning process is chlorine free
• Ensure the