Transcription of FILMTEC™ Reverse Osmosis Membranes - Technical Manual
1 Dow Water & Process Solutions FILMTEC Reverse Osmosis Membranes Technical Manual The contents of this Manual are for reference purposes and for a better understanding of Reverse Osmosis equipment and operations. The specifics set forth herein may change depending on the operating systems and other conditions. Nothing in this Manual should be considered an express or implied warranty. All warranties with respect to any purchase will be provided depending on a specific product and other terms and conditions. Page 2 of 181 Trademark of The Dow Chemical Company ("Dow") or an affiliated company of Dow Form No.
2 609-00071-0416 Table of Contents 1. Basics of Reverse Osmosis and Nanofiltration .. 7 Historical Background .. 7 Desalination Technologies and Filtration Processes .. 7 Principle of Reverse Osmosis and Nanofiltration .. 10 membrane Description .. 13 membrane Performance .. 14 FILMTEC membrane Safe for Use in Food Processing .. 15 Element Construction .. 16 Element Characteristics .. 17 2. Water Chemistry and Pretreatment .. 19 Introduction .. 19 Feedwater Type and Analysis .. 20 Scale Control .. 24 Introduction .. 24 Acid Addition .. 25 Scale Inhibitor Addition .. 26 Softening with a Strong Acid Cation Exchange Resin.
3 26 Dealkalization with a Weak Acid Cation Exchange Resin .. 26 Lime Softening .. 27 Preventive Cleaning .. 28 Adjustment of Operating Variables .. 28 Scaling Calculations .. 28 General .. 28 Calcium Carbonate Scale 30 Brackish Water .. 30 Seawater .. 34 Calcium Sulfate Scale Prevention .. 38 Barium Sulfate Scale Prevention /8/ .. 40 Strontium Sulfate Scale Prevention .. 40 Calcium Fluoride Scale Prevention .. 41 Silica Scale Prevention .. 45 Calcium Phosphate Scale Prevention .. 49 Colloidal and Particulate Fouling Prevention .. 50 Assessment of the Colloidal Fouling Potential .. 50 Media Filtration .. 52 Oxidation Filtration.
4 53 In-Line Filtration .. 53 Coagulation-Flocculation .. 54 Microfiltration/Ultrafiltration .. 54 Cartridge Microfiltration .. 54 Other Methods .. 55 Design and Operational Considerations .. 55 Page 3 of 181 Trademark of The Dow Chemical Company ("Dow") or an affiliated company of Dow Form No. 609-00071-0416 Biological Fouling Prevention .. 56 Introduction .. 56 Assessment of the Biological Fouling Potential .. 56 Culture Techniques .. 57 Total Bacteria Count .. 57 Assimilable Organic Carbon (AOC) .. 57 Biofilm Formation Rate (BFR) .. 58 Chlorination / Dechlorination .. 58 Sodium Bisulfite .. 60 DBNPA .. 61 Combined Chlorine.
5 61 Other Sanitization Agents .. 62 Biofiltration .. 62 Microfiltration/Ultrafiltration .. 62 Ultraviolet Irradiation .. 62 Use of Fouling Resistant Membranes .. 63 Prevention of Fouling by Organics .. 63 Prevention of membrane Degradation .. 63 Prevention of Iron and Manganese Fouling .. 63 Prevention of Aluminum Fouling .. 64 Treatment of Feedwater Containing Hydrogen Sulfide .. 65 Guidelines for Feedwater Quality .. 66 Summary of Pretreatment Options .. 67 3. System Design .. 70 Introduction .. 70 Batch vs. Continuous Process .. 73 Single-Module System .. 74 Single-Stage System .. 75 Multi-Stage System .. 75 Plug Flow vs.
6 Concentrate Recirculation .. 76 Permeate Staged System .. 78 Special Design Possibilities .. 79 membrane System Design Guidelines .. 80 membrane System Design Guidelines for 8-inch FILMTEC Elements .. 81 membrane System Design Guidelines for Midsize FILMTEC Elements .. 82 The Steps to Design a membrane System .. 83 System Performance Projection .. 87 System Operating Characteristics .. 87 Design Equations and Parameters .. 89 Testing .. 93 Screening Test .. 93 Application Test .. 93 Pilot Tests .. 94 System Components .. 94 Page 4 of 181 Trademark of The Dow Chemical Company ("Dow") or an affiliated company of Dow Form No.
7 609-00071-0416 High Pressure Pump .. 94 Pressure Vessels .. 95 Shutdown Switches .. 95 Valves .. 96 Control Instruments .. 96 Tanks .. 96 Materials of Construction, Corrosion 98 System Design Considerations to Control Microbiological Activity .. 99 System Design Suggestions for Troubleshooting Success .. 99 4. Loading of Pressure Vessels .. 101 Preparation .. 101 Element Loading .. 101 Shimming Elements .. 103 Element Removal .. 104 Interconnector Technology for 8-inch Diameter FILMTEC Elements .. 104 New Interconnector Advantages .. 104 Summary of Large Element Interconnectors .. 106 Installing an Element Spacer.
8 106 5. System Operation .. 108 Introduction .. 108 Initial Start-Up .. 108 Equipment .. 108 Pre-Start-Up Check and Commissioning Audit .. 109 Start-Up Sequence .. 110 membrane Start-Up Performance and Stabilization .. 112 Special Systems: Double Pass RO .. 112 Special Systems: Heat Sanitizable RO .. 112 Operation Start-Up .. 112 RO and NF Systems Shutdown .. 112 Adjustment of Operation Parameters .. 113 Introduction .. 113 Brackish Water .. 113 Seawater .. 114 Record Keeping .. 114 Introduction .. 114 Start-Up Report .. 114 RO Operating Data .. 115 Pretreatment Operating Data .. 117 Maintenance Log .. 117 Plant Performance Normalization.
9 117 6. Cleaning and Sanitization .. 121 Introduction .. 121 Safety Precautions .. 121 Cleaning Requirements .. 122 Page 5 of 181 Trademark of The Dow Chemical Company ("Dow") or an affiliated company of Dow Form No. 609-00071-0416 Cleaning Equipment .. 122 Cleaning Procedure .. 124 Cleaning Tips .. 125 Effect of pH on Foulant Removal .. 126 Cleaning Chemicals .. 127 Cleaning Procedure for Specific Situations .. 127 General Considerations .. 127 Sulfate Scale .. 127 Carbonate Scale .. 128 Iron Fouling .. 128 Organic Fouling .. 129 Biofouling .. 130 Emergency Cleaning .. 131 Sanitizing RO/NF membrane Systems.
10 131 Introduction .. 131 Hydrogen Peroxide and Peracetic Acid .. 131 Chlorinated and Other Biocidal Products .. 132 Heat Sanitization .. 132 7. Handling, Preservation and Storage .. 134 General .. 134 Storage and Shipping of New FILMTEC Elements .. 134 Used FILMTEC Elements .. 134 Preservation and Storage .. 134 Re-wetting of Dried Out Elements .. 135 Shipping .. 135 Disposal .. 135 Preservation of RO and NF Systems .. 136 8. Troubleshooting .. 137 Introduction .. 137 Evaluation of System Performance and Operation .. 137 System Tests .. 139 Visual Inspection .. 139 Type of Foulant and Most Effective Cleaning.
