KDF® 55
and 85 Process Media in Point-of-Entry
Water Treatment Systems
– Chlorine, Iron
and
Hydrogen Sulfide Reduction
T e c h n i c a l B u l l e t i n
Purchase KDF Media Here
KDF Process Media are high purity copper-zinc granules that
reduce contaminants in water using oxidation/reduction (redox) reaction.
KDF 55
process medium is an effective chlorine removal agent used in point-of-entry
(POE) treatment of municipal water supplies.
KDF 85
process medium is an effective iron (ferrous) and hydrogen sulfide (H2S) removal
agent that may be used alone or to protect existing water
filtration/purification technologies in POE treatment of groundwater supplies.
These
unique, innovative and environmentally responsible media consist of high
purity copper-zinc granules that use redox (the exchange of electrons) in
patented products to effectively reduce/remove chlorine, iron, hydrogen
sulfide, heavy metals,
and control microorganisms in potable water without the use of chemicals.
What’s more, KDF 55 and 85 media are highly efficient and tank size
requirements are modest for more economical system engineering and installation.
This
bulletin describes the proper use of KDF media in residential (whole house),
commercial, institutional, and light industrial buildings and facilities with
potable water service flows in a range from 3 to 324 gallons per minute with
maximum chlorine, iron, and H2S
concentrations of 5 ppm/mgl.
Medium
Requirements and System Sizing
Easily
the most critical aspect of pressure filter performance is the relationship of
flow rate to surface of KDF media. Inaccurate sizing is the most common reason
for trouble in filter systems. The nominal flow rate in the service cycle
depends on surface area available. For most types of filter media, the service
flow rate must not exceed
five gallons per minute (gpm) per square foot of surface area, with at least a
30-inch filter bed depth.
Service
flow rates with KDF Process Media,
however, may be calculated at 15 gpm
per square foot of surface area (0.104 gpm per square inch). This
is three times the effective flow rate
of other filter media.
Backwashing
KDF Process Media
In
electrochemical reduction processes,
surface products are formed when KDF®
media are used in point-of-entry
(POE) water
treatment systems. These byproducts, along with any calcium and magnesium
precipitate, must
be periodically
backwashed. For backwash rates of 3 to 25 gpm, use a high quality 3-cycle
backwash valve (service, backwash, purge). One with a high-flow backwash mode is
best. For 36 to 324 gpm, use a diaphragm nest valve. Remember
to remove any backwash flow restrictors.
Select a distributor based on backwash flow rate. For 3 to 11 gpm, use a fine
slotted distributor and for 15 to 324 gpm, use a hub and lateral distributor (#8
garnet underbedding is recommended). Time the backwash cycle for ten minutes and
purge for three minutes. Backwash at least three times per
week, more frequently if necessary, depending upon the quality of the water
supply. If more backwashing is required, repeat the entire cycle. Backwash flow
rates are a function of backwash water temperature; type, size and density of
media; and the specific design of the pressure filter. KDF Process Media have a
density of 171 pounds per cubic foot, which makes it a very high density medium
requiring a backwash flow rate of twice the service flow. KDF media require 30
gallons per minute per square foot of bed surface area. Very cold water requires
somewhat lower backwash rates and warmer water requires higher rates. Do not
restrict pipe size to the drain.
Note:
If
backwashing procedures are not properly followed, KDF Process Media may become
fouled.



