DEIONIZED WATERDEIONIZED WATER SYSTEMSYSTEMPatti Fuller-BloechlMuscatine WPCP

OverviewOverview• City Source Watery

• Testing Uses for the Deionized Water System • BOD Preparation of Deionized Water

Water System Components and Cost of Use• Water System Components and Cost of Use

• Issues we have experiencedIssues we have experienced • Positive and Negative Aspects of the System

Muscatine WPCP Source WaterMuscatine WPCP Source Water• City of Muscatine water is supplied from a 50 square mile y pp q

aquifer which consists of sand and clay• Supplied by Muscatine Power and Water – City Owned• Does not require much pretreatment

• Chlorine, Fluoride

• Issues -• Hard Water • WPCP sits at the bottom of the bluff from where the water is stored

and brings in a lot of black sediment from Magnesium and sand• The Pressure of water coming into the plant is 50 – 80 PSI

City Water Report Limit MDL

Metals in Source Water

City Water Report Limit MDL

Result

mg/L ug/L ug/L

Arsenic <0.006 6 4.1

Barium 0.07 1.5Testing performed by Muscatine WPCP

Calcium 68.35 40.5

Copper 0.3516 20 6.5

Iron 0.07672 50 100

EPA 200.7

Iron

Mercury <0.001 1 0.9

Potassium 1.399 67.1

Magnesium 21.16 25.7

Manganese 0.03243 25 2.3

Sodium 10.06 42.9Sodium

Lead <0.020 20 3.5

Muscatine Lab Water UsesMuscatine Lab Water Uses

• E. coli – sterilized water• Required to have low bacteria water to make Sterilized Water for E.

coli testingcoli testing• Cost of purchasing sterilized water was about $8 per 100 mL• Cost for making sterilized water =

• Toxicity testing of our washing procedures – 1 time fee of ~$100-$200• Monthly Heterotrophic Plate Count - $14/sample plus shipping • Cost for sending out sample - $288 per year vs purchase of Sterile Water

$350 (testing 40 – 60 samples per year)$350 (testing 40 60 samples per year)

• RO type III water is fed into the flask washer/lab dish hwasher

Lab Water Uses (con’t)Lab Water Uses (con t)• Metals Testingg

• Metal Finishing/ Categorical Industrial Dischargers in Muscatine is 14 (8 of which are metal finishers)

• Muscatine WPCP performs testing using a Dual ICP on industries• Muscatine WPCP performs testing using a Dual ICP on industries, WPCP Influent and Effluent (and Primary Effluent), monitor lift stations, storm water run off, and dry weather stream testing

• BOD/CBOD Testing• Use 2 day old cured water for testing, Type Iy g y• Test 40 – 60 BOD samples per week • Test Industrial, WPCP and some outside work

BOD AnalysisBOD AnalysisBOD analysis is performed by YSI LDO using the YSI y p y gSoftware• Water Used – Type I – Pure Water• Volume of Water

• 19 L carboy and a 9 L Carboy 3 days per week

• Water Procedure• Water Procedure • Water is typically drawn 2 days ahead• Sits in dark for one day• 19 L – Aerated with a fish tank aerator for 2 hours in BOD Incubator

and sits overnight• pHed between 6.5 and 7.5 • HACH buffer added on day of use

Water SystemWater System • Lab water is run through a water softener before going g g g

into the lab

• The water is filtered through a 5 micron, carbon wrapped whole house filter from Menards

• System Cost • Purchased in 2008 for $9,000 (not including storage system)

• Water feeds into a (Formerly) Barnstead Diamond Reverse OsmosisReverse Osmosis

Water SystemyWall Mounted

100 L Storage Tank

RO System (below) Whole House Pre-Filter

Deionized Water System

Whole House Filter

Changed every 2-4 weeks

MPW flushing the lines the pre-filter is changed weekly

During droughts filter is changed every 1-2 weeks

Normal amount of water changed once per month

RO Water SystemRO Water System • The RO Water System Produces Type III water for the y yp

laboratory (as defined by the manufacturer)• Requires < 3ppm Free Chlorine, Iron <0.5 ppm, Silica <30 ppm

• System produces 12 Liters/HourSystem produces 12 Liters/Hour • Replaced an existing system, which was used for BOD

analysis (Manufacturer did not recommend for BOD analysis)analysis)

• Filter Schedule • Replace Carbon Filter Monthly (or when signaled 1-2 months)• Replace RO Membrane Yearly – Signal as to when to replace

• Feeds into a 100 L storage tank mounted on the wall• Supplies Water to the Dish Washer and the Deionized Water pp

System

Deionized SystemDeionized System• Deionized System y

• (Formerly) Barnstead Diamond Nano Pure UV• Features

• Carbon Rapped to remove residual chlorineCarbon Rapped to remove residual chlorine• 0.2 micron filter for final water polish (micro-organisms are > 0.2 micron)• UV – Disinfection of Microorganisms• Calibrate internal Conductivity Meter Yearly electronically• Produces pure water – 18.2 micro Ohms

• UV Light sanitizes at two wavelengths 254 and 185 nmg g• 185 nm produces hydroxyl free radicals to oxidize residual organic

carbon and CO2

Deionized Ultrapure SystemDeionized Ultrapure System• System produces good water to use for ICP and Ion y p g

Chromatography

• Filters to 0.2 um

Easy to install Cartridge Pack• Easy to install Cartridge Pack

• Replace the Cartridge Pack every 3-4 months and p g ysanitize the system

• Automatic Cleaning Cycle

Annual Costs to Run 2014Annual Costs to Run 2014Cost per Item

Number Total

Pre‐Filtration

Whole House Filter 7 15 $           105 

Rock Salt

Reverse OsmosisReverse Osmosis

RO Carbon Filter 75 12 $           900 

RO Treatment Filter 80 4 $           320 

RO Membrane 500 1 $           500 

Deionized Filter System

UV Bulbs  120 4 $           480 

Deionized Filter Pack 650 4 $        2,600 

Cleaning Agent 35 4 $ 140Cleaning Agent 35 4 $           140 

Total  $        5,045 

City Water Report Limit MethodMetals in Deionized Water

City Water Report Limit Method

Result

mg/L ug/L EPA

Arsenic <0.001 1.0 200.8

Barium <0.010 10 200.7

Testing performed by

Iowa State Calcium <1.0 1000 200.7

Copper <0.01 10 200.7

Iron <0.020 20 200.7

Iowa State Hygienic

LaboratoryIron

Mercury <0.0002 0.2 200.8

Potassium <1.0 1000 200.7

Magnesium <0.50 500 200.7

Manganese <0.02 20 200.7

Sodium <1.0 1000 200.7Sodium

Lead <0.001 1.0 200.8

ISSUE: Constantly Changing Filters on y g gRO System for Carbon• Carbon Filters were going bad more quickly due to the g g q y

source water

• Initially had a 10 micron filter (not carbon wrapped)

Carbon Wrapped Filter Knocks down Chlorine in system• Carbon Wrapped Filter – Knocks down Chlorine in system which can cause issues with the filters,

• Changing the Prefilter prevents the RO Membrane and g g pCarbon Membranes from becoming clogged

Issues with Elevated BOD BlanksIssues with Elevated BOD Blanks• Blanks are usually 0.05 – 0.10 mg/Ly g• BOD blanks are closer to the 0.2 mg/L limit• Cause for high blanks for BOD is most likely nitrogen

related• Occasionally we get a hit with Ammonia with our system

• Fix to problem• Very Dilute Bleach – Set over night (200 mL)y g ( )• Rinse 100 L four or five times before using again• Needs to be done every 6 months

BOD Blanks decreasing in depletionBOD Blanks decreasing in depletion• Blanks go from a positive number to a negative number g p g

• Potentially caused from Algae growing in the 100 L tank

• Problem FixCl t th 100 L t k ith E Cl i l ti ERA• Clean out the 100 L tank with Enzyme Cleaning solution – ERA Free Enzyme Detergent

• Kill sources of Algae• Rinse Line from 100 L tank to Deionized Filter System• Place a hose wrap around the feed from the tank to the system to

inhibit Algae growth

All Dilution Water BadAll Dilution Water Bad• Blanks are 0.5 -0.8 mg/L (data is thrown out)g ( )

• Most likely cause is due to Sanitation Process of Deionized Water System

Resolved by :Resolved by :

Corrective Action – Rinse Deionized System with 50 liters of water after sanitation before using the water againafter sanitation before using the water again

Uncontrolled/Unregulated Incoming Water g gPressure

• Due to the size of the service line into the plant, variable water pressure coming into the plant

• Problems it cause –• Back Pressure issues on the pump system greater than pressure• Back Pressure issues on the pump system greater than pressure

pump is to pressurize to on the RO Unit

Fi• Fix –• Add a pressure relief valve • Replace DI Water system pump when it wears outp y p p

ConclusionConclusion• Water system delivers pure watery p• May consider purchasing a Type II RO System • It is easy to use from the previous system that we had • System is not noisy or loud• Monthly maintenance is required• Relatively low cost to purchase, but more expensive to

run on a yearly basis• Replacement Pumps were a little difficult to obtain butReplacement Pumps were a little difficult to obtain, but

was able to get field sales rep to release pump for emergency