World class ceramic water filters

DOULTON UNDERCOUNTER DRINKING WATER SYSTEM WITH SINGLE ULTRACARB CERAMIC CANDLE

Cyst and Turbidity Reduction

Report Number - 0561B-020794 - revision 1

to: Mr. Anthony Frost, Doulton Water Care, Filleybrooks, Stone, Staffordshire, ST150PU
from: Spectrum Labs Inc., 301 West County Road E2, New Brighton, MN 55112

November 15, 1994

original signed by:
Sandra L. Games (15/11/94) and Margeret L. Bicking (22/11/94)

Introduction
Doulton Water Care has developed a proprietary drinking water treatment system that utilizes a radial flow activated carbon block filter cartridge in conjunction with a ceramic candle to remove specific contaminants from drinking water. This product is designed for long life filtration and is available directly through Doulton Water Care to distributors and retailers of point of use (POU) home water filtration systems.

The use of activated carbon block filter cartridges incorporating proven sorbent technology is becoming more prevalent in the design and development of drinking water treatment devices as manufacturers seek to combine the contaminant reduction capabilities of both organics and heavy metal removal technology. Ceramic filter cartridges are commonly used for the removal of harmful bacteria and cysts. Each technology has been established as an effective means for specific contaminant reduction under defined operating conditions.

Reliable information on contaminant removal capabilities is important in marketing this product to potential distributors and to the general public. Furthermore, several states have now implemented regulations which govern the sale and marketing of residential water treatment systems. Therefore, it is now necessary to have verification of contaminant reduction claims by a state certified independent third-party laboratory, using an approved protocol. Spectrum Labs, Inc. is pleased to provide this laboratory report as the result of an independent evaluation of the Doulton HIF undercounter drinking water treatment system containing an Ultracarb filter cartridge for cyst and turbidity reduction

Experimental Section

Selection of Analytes and Spiking levels

The Doulton HIF undercounter drinking water treatment system containing an Ultracarb filter cartridge was evaluated for cyst and turbidity reduction in accordance with the test protocol contained in NSF International Standard Number 53, "Drinking Water Treatment Units/Health Effects," Annex C, "Mechanical Filtration Performance Test Methods," Section V, "Method - Plumbed-In Units Without Reservoir," revised September 1993. Influent challenge waters were prepared by adding a known amount or' Powder Technologies. Inc. (PTI) fine test dust to achieve a target spike level of 104 particles/mL of 3-4 micrometers and a turbidity of 10-12 NTU.

Influent and effluent samples were analyzed for cyst reduction using American Society for Testing and Materials (ASTM) Method Number F795 which is a standard particle counting method (betaratiometry) and turbidity was analyzed using EPA Method Number 180.1 which is a nephelometric method. The corresponding Method Detection Limit (MDL), EPA Maximum Contaminant Level (MCL), and Target Spike Level for these analytes are provided in Table 1.

Analyte Selection for Contaminant Reduction Studies

Experimental Design

The experimental and mechanical system design for the cyst and turbidity reduction evaluation was based on the test protocol contained in NSF Standard Number 53. This design allows for the uninterrupted testing of two identical units simultaneously.

All influent samples were taken immediately prior to the test units to demonstrate that the mechanical test system had no effect on the water characteristics or on the concentration of the challenge analyte. Pressure gauges and flow meters were installed appropriately to allow documentation of system operation.

Test units were installed, conditioned and operated according to the manufacturer's instructions. Prior to spiking the challenge water, background influent and effluent samples were collected until samples obtained a steady state condition. Samples of the influent and effluent water were collected at the start of the test and when original flow from each unit decreased 25 percent. 50 percent, and 75 percent. The test units were operated 16 hours per day using a 5 minute on/10 minute off operating cycle, followed by an 8 hour rest period under pressure. Samples were collected for each test at the beginning of the "on" cycle immediately following the passage of one unit volume.

Cyst and Turbidity Reduction Results

The results of laboratory analysis for the cyst reduction evaluation are summarized in Table 2 and Table 3. The influent and effluent results for each sample point are tabulated along with the percent reduction. The turbidity results are summarized in Table 4. Influent and effluent turbidity results are tabulated at the start of the test and when the original flow from each unit decreases 25 percent, 50 percent, and 75 percent. Both units evaluated meet the current NSF acceptance levels of at least 99.95 percent cyst reduction and not more than 1.0 NTU of turbidity.

Cyst Reduction Studies for the Doulton Drinking Water System with Ultracarb

Instrumentation: HIAC/Royco 8000A Counter, LD400 Sensor
Fluid: DI Water
Contaminant: PTI Fine Test Dust
Gallons Treated 35.1

Fluid: DI Water
Contaminant: PTI Fine Test Dust
Initial Flow Rate: Unit 1=0.50, Unit 2=0.43
Final Flow Rate: Unit 1=0.13, Unit 2=0.11 gpm

Conclusion

The Doulton IP100UC undercounter drinking water treatment system containing an Ultracarb filter cartridge was found to be very effective at removing cyst and turbidity from spiked challenge water. According to NSF International Standard Number 53, Annex C, both units evaluated meet the current NSF acceptance levels of at least 99.95 percent reduction for cysts and not more than 1.0 NTU for the turbidity reduction.