The Membrane Cleaning Triangle – An Operators Perspective on CIP Systems

The Membrane Cleaning Triangle An Operator’s Perspective on CIP Systems Allyson Felsburg, March 2024 Introduction Town of Jupiter Utilities SE Coastal town in Palm Beach County, Florida Population served: ~95,000 Service Connections: 30,873 Raw Water Supply Two distinct raw water supply sources: Surficial aquifer: fresh water, 140’ – 220’ deep Floridan aquifer: brackish water, 1,100’ – 2,000’ deep Treatment Overview 13. MGD Reverse 1. MGD Anion 14. MGD Nanofiltration Osmosis Process Exchange Process Process Constructed in 1990 Constructed in 2000 Constructed in 2010 Expanded in 1996 & 2005 Approach to Cleaning RO permeate used to make cleaning solutions Solutions are heated Typically make cleaning batch at end of prior day and start heater overnight so cleaning solution is ready to go in the morning Instrumentation for pH, flow monitoring and temperature All trains have 4 cleaning blocks 3, 1st stage 1, 2nd stage Single train cleaning typically takes about 40 man hours For RO Cleaning start with low pH and then go to a high pH For Nano Cleaning start with high pH and then go to a low pH Approach to Cleaning low pH Citric acid or muriatic acid (2% solution) Follow membrane manufacturer recommendations for pH and solution strength Past use of propriety blended chemicals with success 2-6 hour minimum per block with recirculation and soak times depending on degree of cleaning required Add additional chemical for pH adjustments to sustain pH strength during recirculation Dump solution based on color and observations of cleaning solution Rinse with RO permeate Approach to Cleaning High pH Sodium hydroxide or combination of EDTA and TSP Follow membrane manufacturer recommendations for pH and solution strength Past use of propriety blended chemicals with success 2 hour minimum per block with recirculation and soak times Add additional chemical as pH increases Dump solution based on color Rinse with recirculated RO permeate Final rinse to waste with feed water RO Plant Cleaning System Overview Cleaning system constructed with original plant construction in 1990 pH and flow monitoring 2, 1,200-gallon tanks Vertical cartridge filter NF Plant Cleaning System Overview Cleaning system reflects design improvements that have evolved with the industry and were constructed in 2009 Horizontal cartridge filter 2, 3,000-gallon tanks.