World class ceramic water filters

DOULTON UNDERCOUNTER DRINKING WATER SYSTEM WITH SINGLE ULTRACARB CERAMIC CANDLE

Lead Reduction

Report Number - 0561D-020194 - 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 HIP undercounter drinking water treatment system containing an Ultracarb filter cartridge (Ultracarb) for lead reduction.

Experimental Section

Selection of Analytes and Spiking levels

The Doulton HIP undercounter drinking water treatment system containing an Ultracarb filter cartridge was evaluated for lead reduction in accordance with test protocol contained in NSF International Standard Number 53, "Drinking Water Treatment Units/Health Effects," Annex B, "Chemical Reduction Performance Test Methods," Section V, "Method Plumbed In Units Without Reservoir," revised September 1993. Influent challenge waters for the lead reduction evaluation were prepared with an influent target spike level of 0.15 mg/L (150 ppb).

Two separate tests were conducted. One using the high pH and alkalinity challenge water, and one using the low pH and alkalinity challenge water as outlined in NSF Standard Number 53, Annex B under "Metal Reduction Test Waters." Influent and effluent samples were analyzed for lead using EPA Method Number 239.2 which is a graphite furnace atomic absorption spectrophotometry method. The corresponding Method Detection Limit (MDL), EPA Action Level, and Target Spike Level for this analyte is provided in Table 1.

Analytes Selection for Contaminant Reduction Studies

Experimental Design

The experimental and mechanical system design for the lead reduction evaluation was based on test protocol contained in NSF Standard Number 53. A mechanical test system plumbed entirely of Teflon was used for this set of experiments. The use of Teflon provides a chemically inert system which eliminates any corrosion or leaching of system components which may add unwanted contaminants to the challenge test water.

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. Spiked challenge water was prepared in 525 gallon lots by adding known volumes of lead nitrate to attain an influent target spike level of 0.15 mg/L (150 ppb). Table 2 provides a summary of the system operation and sampling sequence for the Doulton HIP undercounter drinking water treatment system containing an Ultracarb filter cartridge. A total of 720 gallons of spiked challenge water was passed through test units during both the high and low pH and alkalinity lead reduction. An operating cycle of 50 percent on, 50 percent off with a 15 minute cycle was used during periods of system operation which did not exceed more than 16 hours per day. The flow rate from each unit was measured at approximately 0.4 GPM using a constant inlet static pressure of 60 PSIG. Characteristics for the influent challenge water are presented in Table 3. Deionized water was used for the challenge water makeup in order to meet the test water specifications contained in NSF Standard Number 53.

System Operation and Sampling Sequence for the Doulton HIP Undercounter Drinking Water Treatment System with Ultracarb

Note: Refer to NSF Standard 53, Annex B, pages B3 and B4 for specific test protocol details.

Influent Challenge Water Characteristics

Lead Reduction Results

The results of laboratory analysis the lead reduction evaluation are summarized in Tables 4 through 7. The influent data depicts the reproducibility of the spiking level and analytical methodology for this analyte. Effluent lead levels below the NSF Maximum Effluent Concentration of 0.0 15 mg/l were observed in all effluent samples collected from identical test units in both the high and low pH and alkalinity lead reduction evaluations. Calculated contaminant reduction percentages were greater than 95 percent which exceeds the current NSF requirement of 90 percent minimum reduction for lead contained in NSF Standard Number 53. The percent contaminant reduction was calculated for each of the influent/effluent pairs and is tabulated in Tables 4 through 7.

Conclusions

The Doulton HIP undercounter drinking water treatment system containing an Ultracarb filter cartridge was found to be very effective at removing lead from the spiked challenge water. Calculated contaminant reduction percentages were 96 percent or greater in both the high and low pH and alkalinity lead reduction evaluations throughout the entire 720 gallon test. Since the Doulton CIF undercounter drinking water treatment system does not contain a flow monitoring device, this set of laboratory results would establish a capacity rating of 600 gallons for lead reduction claims based on the current requirements for compliance under NSF Standard Number 53 for units tested to 120 percent of capacity.

Live cysts test at University of Arizona US   Live cysts test at Water Research Council (WRc) UK   E.coli test   NSF standard 42 particulate US   NSF standard 42 chlorine US   NSF standard 53 turbidity US   Salmonella typhi, shigella dysenteriae and vibrio cholerae Inaba bacteria test UK   Pesticides and herbicides test UK   E.coli, heavy metals and THM's test Hong Kong   Serratia marcescens and escherichia coli bacteria test UK

*ANSI/NSF Standard 42, Drinking Water Treatment Units–Aesthetic Effects
**ANSI/NSF Standard 53, Drinking Water Treatment Units–Health Effects

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