Dr.praveen.malavade

WATER TREATMENT AND QUALITY CONTROL OF DIALYSATE

INTRODUCTIONINTRODUCTION

Survival of Haemodialysis patient is steadily Survival of Haemodialysis patient is steadily improving which has led to increasing improving which has led to increasing problems due to contaminants of dialysis problems due to contaminants of dialysis water. water.

Haemodialysis patients are exposed to 25 to Haemodialysis patients are exposed to 25 to 30 times of water compared to normal 30 times of water compared to normal individuals drinking water needs. individuals drinking water needs.

Contaminants enter the blood compartment of Contaminants enter the blood compartment of dialysers and accumulate in the body due to dialysers and accumulate in the body due to inability of these patients to excrete them via inability of these patients to excrete them via their kidneys.their kidneys.

INTRODUCTION INTRODUCTION contd..contd..

Water treatment for preparation of Water treatment for preparation of dialysate is probably the most neglected dialysate is probably the most neglected area of renal replacement-with dialysis .area of renal replacement-with dialysis .

Quality of water contributes very Quality of water contributes very significantly in morbidity and life significantly in morbidity and life threatening reactions in dialysis patients in threatening reactions in dialysis patients in both; an acute sense, as well as in long-both; an acute sense, as well as in long-term prognosis term prognosis

Toxic effects of water contaminants in Toxic effects of water contaminants in hemodialysis patientshemodialysis patients

Schematic representation of a water Schematic representation of a water treatment device for haemodialysistreatment device for haemodialysis

COMPONENTS OF WATER COMPONENTS OF WATER TREATMENT PLANT TREATMENT PLANT

1.1. Water SupplyWater Supply2.2. Back-flow Back-flow

preventerpreventer 3.3. Temperature Temperature

blending valveblending valve 4.4. Booster pumpBooster pump 5.5. Acid injection Acid injection

metering devicemetering device 6.6. Multimedia depth Multimedia depth

filterfilter

7.7. Water softenerWater softener 8.8. Brine tankBrine tank 9.9. Carbon tanksCarbon tanks 10.10. Reverse Reverse

Osmosis (RO) Osmosis (RO) Systems: PrefilterSystems: Prefilter

11.11. RO RO membranesmembranes

12. 12. Distribution Distribution SystemSystem

Water supplyWater supply

There are two sources of municipal water: There are two sources of municipal water: surface water and ground water surface water and ground water

Surface water is generally more contaminated Surface water is generally more contaminated with organisms and microbes, industrial wastes, with organisms and microbes, industrial wastes, fertilizers, and sewage. fertilizers, and sewage.

Ground water is generally lower in organic Ground water is generally lower in organic materials but contains higher inorganic ions materials but contains higher inorganic ions such as iron, calcium, magnesium, and sulfate such as iron, calcium, magnesium, and sulfate

Back-flow preventer Back-flow preventer

All water treatment systems require a form of All water treatment systems require a form of back-flow prevention device. back-flow prevention device.

A back-flow preventer prohibits the water in the A back-flow preventer prohibits the water in the water treatment components from flowing back water treatment components from flowing back into the potable drinking water lines. into the potable drinking water lines.

This protects the drinking water from This protects the drinking water from contamination with disinfectants and cleaners contamination with disinfectants and cleaners that are used in the water treatment system. that are used in the water treatment system.

Backflow Prevention DeviceBackflow Prevention Device ( Reverse Flow Prevention Device), ( Reverse Flow Prevention Device),

What to monitorWhat to monitor: : Pressure drop across Pressure drop across the device, annual the device, annual testingtesting

What to look forWhat to look for: A : A pressure drop change pressure drop change of 10 PSI from of 10 PSI from baselinebaseline

Temperature blending valveTemperature blending valve

The temperature blending valve mixes hot and The temperature blending valve mixes hot and cold water to a RO membrane industry standard cold water to a RO membrane industry standard temperature of around 77 [degrees] F (25 temperature of around 77 [degrees] F (25 [degrees] C).[degrees] C).

These valves are widely used on large central These valves are widely used on large central RO systems that tend to have cold incoming RO systems that tend to have cold incoming water. water.

The colder the source water, the less purified The colder the source water, the less purified water the RO membrane will produce water the RO membrane will produce

Temperature blending valve Temperature blending valve

Per 1 [degrees] F Per 1 [degrees] F temperature drop, the temperature drop, the RO membrane RO membrane produces 1.5% less produces 1.5% less purified water purified water

For instance, an For instance, an incoming temperature incoming temperature of 50 [degrees] F would of 50 [degrees] F would result in an approximate result in an approximate loss of 40% (product loss of 40% (product water flow). water flow).

Booster Pump Booster Pump

The RO system requires a constant supply The RO system requires a constant supply of water flow and pressure in order to of water flow and pressure in order to operate successfully.operate successfully.

Dialysis facilities experience fluctuating or Dialysis facilities experience fluctuating or decreased incoming water pressure and decreased incoming water pressure and flow, especially since back flow preventers flow, especially since back flow preventers and temperature blending valves and temperature blending valves substantially lower pressure substantially lower pressure

Booster PumpBooster Pump

Acid injection metering device Acid injection metering device

By increasing the pH of the city water supply using lime By increasing the pH of the city water supply using lime softening agents or calcium carbonate prevent leaching softening agents or calcium carbonate prevent leaching of lead, copper, and other metals from the city and of lead, copper, and other metals from the city and residential piping systems.residential piping systems.

In order for the RO to operate properly and carbon tanks In order for the RO to operate properly and carbon tanks to remove chlorine/chloramine effectively, the ideal to remove chlorine/chloramine effectively, the ideal incoming water pH should be between 5-8.5. incoming water pH should be between 5-8.5.

In many areas the pH is higher than 8.5, so an acid In many areas the pH is higher than 8.5, so an acid injection system may be incorporated into the design of injection system may be incorporated into the design of the pretreatment, especially with the presence of the pretreatment, especially with the presence of chloramine. chloramine.

Multimedia depth filterMultimedia depth filter

Large particulates of 10 microns or greater Large particulates of 10 microns or greater that cause the supply water to be turbid -- that cause the supply water to be turbid -- such as dirt, silt, colloidal matter such as dirt, silt, colloidal matter (suspended matter) -- are removed by a (suspended matter) -- are removed by a multimedia filter, sometimes referred to as multimedia filter, sometimes referred to as a depth bed filter. a depth bed filter.

Foulants can clog the carbon and softener Foulants can clog the carbon and softener tanks, destroy the RO pump, and foul the tanks, destroy the RO pump, and foul the RO membrane RO membrane

Multi-Media and Cartridge FilterMulti-Media and Cartridge Filter

Multimedia depth filterMultimedia depth filter

Multimedia filters contain multiple layers of Multimedia filters contain multiple layers of various sized rocks ranging from sand to gravel various sized rocks ranging from sand to gravel that literally trap the large particles as the water that literally trap the large particles as the water is filtered downward. The first layer is usually is filtered downward. The first layer is usually composed of anthracite coal, followed by layers composed of anthracite coal, followed by layers of garnet, sand, then gravel.of garnet, sand, then gravel.

All the tiers are constructed of different sized All the tiers are constructed of different sized media so that not all the particulates are media so that not all the particulates are collected at the top but rather distributed through collected at the top but rather distributed through the media bed, a phenomenon known as the media bed, a phenomenon known as depth depth filtration. filtration.

Water SoftenerWater Softener

Water containing calcium and magnesium form Water containing calcium and magnesium form scale deposits on the RO membrane and scale deposits on the RO membrane and eventually foul the membrane eventually foul the membrane

Softeners work on an ion exchange basis. The Softeners work on an ion exchange basis. The resin beads within the tank have a high affinity resin beads within the tank have a high affinity for the cations calcium and magnesium (both for the cations calcium and magnesium (both divalent) present in the source water and divalent) present in the source water and release two sodium ions (monovalent) for one release two sodium ions (monovalent) for one calcium or magnesium captured calcium or magnesium captured

Water SoftenerWater Softener

The softener needs regenerating on a The softener needs regenerating on a routine basis with concentrated sodium routine basis with concentrated sodium chloride solution (brine) before the resin chloride solution (brine) before the resin capacity is used up capacity is used up

The resin is backwashed to loosen the The resin is backwashed to loosen the media and clean any particulates from the media and clean any particulates from the tank. After the backwashing step, the brine tank. After the backwashing step, the brine solution is drawn into the tank to solution is drawn into the tank to regenerate the resin. regenerate the resin.

Water SoftenerWater Softener

Water softenerWater softener

A hardness test on the effluent softened water A hardness test on the effluent softened water should be done, at a minimum, once a day and should be done, at a minimum, once a day and recorded. However, to determine the efficacy of recorded. However, to determine the efficacy of the softener, it is best to test the softened water the softener, it is best to test the softened water twice a day; once in the morning to determine twice a day; once in the morning to determine that the softener did regenerate and once at the that the softener did regenerate and once at the end of the day to prove that the softener end of the day to prove that the softener performed adequately all day. performed adequately all day.

Hardness tests should be less than 2 grains per Hardness tests should be less than 2 grains per gallon (gpg) hardness (35 mg/L) and performed gallon (gpg) hardness (35 mg/L) and performed on "fresh" water, on "fresh" water,

Carbon tanks Carbon tanks

One of the most critical tasks regarding One of the most critical tasks regarding patient safety in the day of a dialysis patient safety in the day of a dialysis technician is checking the water treatment technician is checking the water treatment system for chlorine and chloramines.system for chlorine and chloramines.

Chlorine and its combined form, Chlorine and its combined form, chloramine, are high-level oxidative chloramine, are high-level oxidative chemicals. They are added to municipal chemicals. They are added to municipal water systems to kill bacteria—but they water systems to kill bacteria—but they also destroy red blood cells.also destroy red blood cells.

Injection of sodium metabisulfiteInjection of sodium metabisulfite

RO Pre-filterRO Pre-filter

RO Pre-filterRO Pre-filter

Prefilters are particulate filters positioned Prefilters are particulate filters positioned after all the pretreatment and immediately after all the pretreatment and immediately before the RO pump and RO membrane. before the RO pump and RO membrane. Carbon fines, resin beads, and other Carbon fines, resin beads, and other debris exiting the pretreatment destroy the debris exiting the pretreatment destroy the pump and foul the RO membrane.pump and foul the RO membrane.

Typically, prefilters range in pore size Typically, prefilters range in pore size from 3-5 microns from 3-5 microns

RO pump and motorRO pump and motor

The RO pump increases water pressure across The RO pump increases water pressure across the RO membrane to increase both product the RO membrane to increase both product water flow and rejection characteristics of the water flow and rejection characteristics of the RO membrane. RO systems typically operate RO membrane. RO systems typically operate between 200-250 PSI between 200-250 PSI

RO pumps are made of high-grade stainless RO pumps are made of high-grade stainless steel, inert plastics, and carbon graphite-wetted steel, inert plastics, and carbon graphite-wetted parts. Brass, aluminum, and mixed metal pumps parts. Brass, aluminum, and mixed metal pumps will leach contaminants into the water and are will leach contaminants into the water and are not compatible with peracetic acid type not compatible with peracetic acid type disinfectants disinfectants

RO membranes RO membranes RO membranes reject dissolved inorganic RO membranes reject dissolved inorganic

elements such as ions of metals, salts, and elements such as ions of metals, salts, and chemicals and organics including bacteria, chemicals and organics including bacteria, endotoxin, and viruses.endotoxin, and viruses.

Rejection of charged ionic particles ranges from Rejection of charged ionic particles ranges from 95-99%, whereas contaminants such as 95-99%, whereas contaminants such as organics that have no charge are rejected at a organics that have no charge are rejected at a greater than 200 molecular weight cut-off. greater than 200 molecular weight cut-off.

Ionic contaminants are highly rejected compared Ionic contaminants are highly rejected compared to neutrally charged particles, and polyvalent to neutrally charged particles, and polyvalent ions are more readily rejected than monovalent ions are more readily rejected than monovalent ions.ions.

Reverse Osmosis systemReverse Osmosis system

The RO membrane is The RO membrane is the heart of the system. the heart of the system. It produces the purified It produces the purified water through RO. RO water through RO. RO is just that, it is the is just that, it is the opposite of osmosis.opposite of osmosis.

Thin film (TF) RO Thin film (TF) RO membranes made of membranes made of polyamide (PA) are the polyamide (PA) are the most common type most common type used in HD. used in HD.

DeionisationDeionisation

Do not remove nonionic Do not remove nonionic contaminants,bacteria or endotoxinscontaminants,bacteria or endotoxins

Cationic resins contain sulfuric radicals Cationic resins contain sulfuric radicals and exchange hydrogen radicals for other and exchange hydrogen radicals for other cations such as sodium,calcium and cations such as sodium,calcium and aluminiumaluminium

Anionic resins contain ammonium radicals, Anionic resins contain ammonium radicals, which exchange hydroxyl ions for which exchange hydroxyl ions for chloride,phosphate and flouridechloride,phosphate and flouride

Distribution SystemDistribution System

RO distribution systems can be grouped into two RO distribution systems can be grouped into two categories, direct feed and indirect feed. categories, direct feed and indirect feed.

A direct feed system "directly" delivers the A direct feed system "directly" delivers the product water from the RO unit to the loop for product water from the RO unit to the loop for distribution. distribution.

An indirect feed system involves a storage tank An indirect feed system involves a storage tank that accumulates the product water and delivers that accumulates the product water and delivers it to the distribution loop. it to the distribution loop.

Unused portions of the product water are Unused portions of the product water are recirculated back into the storage tank recirculated back into the storage tank

Distribution piping systemsDistribution piping systems

Though there continues to be some water Though there continues to be some water treatment systems that have nonreturning treatment systems that have nonreturning lines that go to drain, a continuous loop lines that go to drain, a continuous loop design is recommended by AAMI. No design is recommended by AAMI. No dead-ends or multiple branches should dead-ends or multiple branches should exist in the distribution system, as these exist in the distribution system, as these are places for bacteria biofilm to grow.are places for bacteria biofilm to grow.

Bacterial filters Bacterial filters

Ultraviolet IrradiationUltraviolet Irradiation

This is used finally just prior to the dialysis This is used finally just prior to the dialysis machine, to inhibit bacterial growth, after machine, to inhibit bacterial growth, after all other water treatment is done.all other water treatment is done.

Bacteria may grow resistant to ultraviolet Bacteria may grow resistant to ultraviolet light. light.

If used without pro- treatment the If used without pro- treatment the effectiveness is lost because suspended effectiveness is lost because suspended particulate matter may block light waves. particulate matter may block light waves.

Composition of the dialysate Composition of the dialysate

The composition of The composition of dialysis fluid should dialysis fluid should be similar to that of be similar to that of normal interstitial normal interstitial body fluid body fluid appropriately appropriately corrected for protein corrected for protein content content

Composition of extracellular fluid and a standard Composition of extracellular fluid and a standard

dialysis fluiddialysis fluid

Serum water (mmol/l)Serum water (mmol/l)Dialysis fluid (mmol/l)Dialysis fluid (mmol/l)

Sodium Sodium 152 152 140–145 140–145

Potassium Potassium 4.5 4.5 0-40-4

Calcium Calcium 1.5 1.5 1.5 1.5

Magnesium Magnesium 0.5 0.5 0.5 0.5

Chloride Chloride 109 109 100–110 100–110

Acetate Acetate 0 0 2-42-4

or  or 

Bicarbonate Bicarbonate 32–38 32–38

Glucose Glucose 5 5 0–10 0–10

Scheme of dialysate flow Scheme of dialysate flow

Water Water Treatment Treatment

SystemSystem

Bacteriological Monitoring :Bacteriological Monitoring :HemodialyzersHemodialyzers

The maximum level of bacteria in water used to The maximum level of bacteria in water used to prepare dialysis fluid and reprocess prepare dialysis fluid and reprocess hemodialyzers must not exceed the AAMI hemodialyzers must not exceed the AAMI standard of 200 colony forming units (CFU). The standard of 200 colony forming units (CFU). The AAMI action level is 50 CFU for bacteria in water AAMI action level is 50 CFU for bacteria in water used to prepare dialysis fluid. used to prepare dialysis fluid.

An action level is defined as a point when An action level is defined as a point when measures must be taken to correct the potential measures must be taken to correct the potential source to remain in compliance with AAMI source to remain in compliance with AAMI standards.standards.

Endotoxin Standard for Water Used to Prepare Endotoxin Standard for Water Used to Prepare Dialysis Fluid and Reprocess HemodialyzersDialysis Fluid and Reprocess Hemodialyzers

The maximum level of endotoxin in water The maximum level of endotoxin in water used to prepare dialysis fluid and used to prepare dialysis fluid and reprocess hemodialyzers must not exceed reprocess hemodialyzers must not exceed the AAMI standards of 2 Endotoxin Units the AAMI standards of 2 Endotoxin Units per Milliliter (EU/ml).per Milliliter (EU/ml).

The action level of endotoxin in water used The action level of endotoxin in water used to prepare dialysis fluid is 1 EU/mlto prepare dialysis fluid is 1 EU/ml

Frequency of Testing for Frequency of Testing for Bacteria and Endotoxin levelsBacteria and Endotoxin levels

Testing should be performed monthly. Testing should be performed monthly. If standards are exceeded, testing should If standards are exceeded, testing should

be performed weekly until the problem is be performed weekly until the problem is resolved. resolved.

.

Ultrapure dialysis solutionUltrapure dialysis solution

Decrease c-reactive protein and il-6,Decrease c-reactive protein and il-6, Improve response to anaemia to epoImprove response to anaemia to epoPromote better nutritionPromote better nutritionReduce plasma levels of b2-microglobulinReduce plasma levels of b2-microglobulinSlow loss of residual renal functionSlow loss of residual renal functionLower cardiovascular morbidityLower cardiovascular morbidity Bacteria level below 0.1cfu/ml and Bacteria level below 0.1cfu/ml and

endotoxin level below 0.03EU/mlendotoxin level below 0.03EU/ml

Sample CollectionSample Collection

The sample ports used to collect the samples The sample ports used to collect the samples must be rinsed for at least one minute at normal must be rinsed for at least one minute at normal pressure and flow rate before drawing the pressure and flow rate before drawing the samples. Samples should be collected using a samples. Samples should be collected using a “clean catch” technique to minimize potential “clean catch” technique to minimize potential contamination of the sample, leading to false contamination of the sample, leading to false positive results. positive results.

Sample ports should not be disinfected. If a Sample ports should not be disinfected. If a facility insists on disinfecting the ports, alcohol facility insists on disinfecting the ports, alcohol should be used and allowed to completely dry should be used and allowed to completely dry before the sample is drawn. before the sample is drawn.

Bleach or other disinfectants should not be usedBleach or other disinfectants should not be used

Sample collection Sample collection

Samples for bacteriological testing should be processed within 1-2 hours or refrigerated and processed within 24 hours.

The AAMI standard recommends culturing samples of 0.5 to 1.0 cc for 48 hours at 35 C, using tryptic soy agar as the culture medium.

CONCLUSIONCONCLUSION

1.1. Water treatment is a generally neglected area of dialysis Water treatment is a generally neglected area of dialysis therapy.therapy.

2.2. Due to increased survival of dialysis patients, in creased Due to increased survival of dialysis patients, in creased use of bicarbonate dialysate and high flux membranes use of bicarbonate dialysate and high flux membranes water treatment has become essential.water treatment has become essential.

3.3. It is worthwhile achieving the goal of sterile, pyrogen It is worthwhile achieving the goal of sterile, pyrogen tree and chemically pure water for dialysis.tree and chemically pure water for dialysis.

4.4. The above goal is achievable with a combination of The above goal is achievable with a combination of various technologies available.various technologies available.

5.5. After designing a system based on requirements of After designing a system based on requirements of individual unit both quality, quantity and cost individual unit both quality, quantity and cost effectiveness, it is essential to monitor the effluent water effectiveness, it is essential to monitor the effluent water regularly.regularly.

Thank you