Membrane Cleaning RESAT EGYPT WATER TREATMENT 3 ALKHALEEG BUILDING ALMARUTIA PYRAMEIDS GIZA Telefax: 202 37447164 – 0101480286 By Chemist Ayman Awny Mahmoud

Membrane Cleaning

RESAT EGYPT WATER TREATMENT

3 ALKHALEEG BUILDING ALMARUTIAPYRAMEIDS GIZA

Telefax: 202 37447164 – 0101480286

By Chemist Ayman Awny Mahmoud

FOULINGFOULING

Low WaterLow Water ProductionProduction

Membrane DamageMembrane Damage

Poor Permeate QualityPoor Permeate Quality

Frequent CleaningFrequent CleaningRESAT EGYPTWATER TREATMENT

Website :www.resategypt.com

Fouling IndicatorsPermeateFlow

SaltPassage

Diff.Pressure

DirectCause

IndirectCause

CorrectiveMeasure

Scaling Poor ScaleControl

Cleaning;ScaleControl

ColloidalFouling

InsufficientPretreatment

Cleaning;ImprovePretreatment

BiologicalFouling

Feed water;InsufficientPretreatment

Cleaning;Biocide;ImprovePretreatment

OrganicFouling

PolymerOverfeed;Humics;Oil

Cleaning;ImprovePretreatmentRESAT EGYPT

WATER TREATMENTWebsite :www.resategypt.com

AVERAGE FOULANT DISTRIBUTIONWORLDWIDE

14.1%

2.6%3.7%

3.6%

50.2%

13.5% 4.7%

7.6%ORG

Fe2O3

SiO2

Al2O3

CaPO4

CaCO3

CaSO4

OTHERS

Common Fouling RisksSurvey of 150 Membrane Autopsies

RESAT EGYPTWATER TREATMENT






Calcium Sulfate Scaling on the Vexar spacer



Silica Fouling



BIOFOULING RESAT EGYPTWATER TREATMENT


SEM: Biomass and Rod Shaped Bacteria

When do I clean? When do I clean? • When any ONE of the following changes:

Differential Pressure by 15% NPF by 15% Salt Passage by 15%

• Exceeding these limits may be irreparable

• Start planning your strategy at the 1st indication of a minimum change!



Maintenance CleaningMaintenance Cleaning

•RO’s need to be Cleaned!

•Typically: SDI 3 -5 Cleaning 4 /year SDI 1- 3 Cleaning 2 /year SDI < 1 Cleaning 1 /year

NormalizedNormalizedPermeatePermeateFlowrateFlowrate

TimeTime

Proper Cleaning MaintenanceProper Cleaning Maintenance

Cleaning after 10-15% declineCleaning after 10-15% decline

NormalizedNormalizedPermeatePermeateFlowrateFlowrate

TimeTime

Improper Cleaning MaintenanceImproper Cleaning Maintenance

Cleaning after > 15% declineCleaning after > 15% decline

Cleaning after aCleaning after a10-15% decline10-15% decline maximizes ROmaximizes RO performanceperformance

Waiting too Waiting too longlongto clean reduces to clean reduces RO RO performanceperformance

Telescoped membrane due to high differential pressure

Operator waited too long before cleaning



Permanent membrane damage

User did not clean in time



Chemical Cleaning Products

• Biocontrol-11: Non-oxidising Biocide

• RESAT-DE 22 PC-33: Chelating Agent

• Biocontrol-22: Non-oxidising Biocides

• Anti-chlorination : Cl2 Release Sanitizer

• RESAT-DE-67: Mild Alkaline Surfactant

• RESAT-DE-77: Weak Acid

• RESAT-DE-87: Strong Mineral Acid

• RESAT-DE-99: Alkaline Surfactant

Chemical Cleaning Products

Factors Influencing Cleaning

• Plant Design - Ensure CIP tank & pump

is correct size• Plant Operation

• Membrane - Max pH/Temp limits

• Chemicals Selected



Factors Influencing Cleaning

• Temperature

• pH

• Flow vs. Soaking

• Time

• Velocity



• Pressure drop < 60 PSIPressure drop < 60 PSI

• Flow 35- 40 GPM per pressure vessel (8”)Flow 35- 40 GPM per pressure vessel (8”)

• Cleaning Solution Volume: Use 8 - 10 Cleaning Solution Volume: Use 8 - 10 Gallons Per 8” element. Each pressure Gallons Per 8” element. Each pressure vessel = 50 gallons volumevessel = 50 gallons volume

• Use Alkaline cleaners first if organic Use Alkaline cleaners first if organic fouling is suspected - acid can tighten fouling is suspected - acid can tighten organic foulant onto the membraneorganic foulant onto the membrane

Cleaning TipsCleaning Tips

• Max Solution Temperature advised by Max Solution Temperature advised by Membrane ManufacturerMembrane Manufacturer

• Soak Membranes - reduces cleaning Soak Membranes - reduces cleaning solution channelingsolution channeling

• Clean “stage by stage”Clean “stage by stage”

• Replace Turbid Cleaning Solutions Replace Turbid Cleaning Solutions

• Keep good recordsKeep good records

Cleaning TipsCleaning Tips



Keep Good RecordsKeep Good Records

LL

P PCleaning

Tank

Heater

P

Pressure Vessels

2:1

Permeate

Concentrate Brine

FeedCartridge

Filter

Cleaning SkidCleaning Skid

Membrane PreservationMembrane Preservation

• Preserve if out of service >24 hrs

• Sodium Bisulfite - 1%

• RESAT-DE 55 or / 56 - 0.05%

• Formaldehyde - NO - carcinogenic

• Glutraldehyde - NO - membrane damageRESAT EGYPT

WATER TREATMENTWebsite :www.resategypt.com

Membrane FlushingMembrane Flushing

• Permeate flush if system shuts down

• Acts as a “mini clean” and removes concentrate

• Reduces fouling and scaling



Membrane Autopsy ServiceMembrane Autopsy Service

• Destructive procedure consisting of Destructive procedure consisting of observations and analytical tests observations and analytical tests on used membraneon used membrane

• Determines cause of failure or poor Determines cause of failure or poor performanceperformance

• Results used to develop site specific Results used to develop site specific custom cleaning programcustom cleaning program



Flat sheet test rig to determine flow and rejection of autopsied membrane



Flat sheet testing will ensure most effective cleaning program is developed & used

Use RESAT-DE Autopsy as a preventative tool

See RESAT-DE Autopsy Report Example



Thank YouQuestions



Documents

Membrane Cleaning RESAT EGYPT WATER TREATMENT 3 ALKHALEEG BUILDING ALMARUTIA PYRAMEIDS GIZA Telefax: 202 37447164 – 0101480286 By Chemist Ayman Awny Mahmoud