KDF Process Media Leads in Chlorine Removal
High-purity copper-zinc redox media consistently remove 99% of free chlorine by electrochemically reducing dissolved chlorine gas to water-soluble chloride ions.
- National clinical laboratory used KDF 55 media as a pretreatment to reverse osmosis membranes for high-purity. System has been in operation for 9 years at 6,000 gallons per day.
- Northeastern U.S. commercial laundry facility uses KDF 55 process media as a pretreatment to ion exchange resins at 200 gpm (gallons per minute). The switch from granular activated carbon (GAC) represented a major cost savings for the company.
- Major U.S. blue jean manufacturer uses KDF 55 media for pretreatment to ion exchange systems at 600 gpm; 175 gpm also used for reclaiming plant's waste stream from production.
- KDF process media are being used to complement or replace activated carbon filters, removing the chlorine in municipal water. KDF media pretreatment of granular activated carbon also extends the carbon's life and limits bacteria growth in the bed.
A typical chlorine redox reaction with KDF process media:
Zinc loses 2 electrons (Oxidation)
KDF Process Media Removes Iron
Redox media alloys function as catalysts to change soluble ferrous cations (positively-charged ions) into insoluble ferric hydroxide, which can be removed with regular backwashing. With enough oxygen dissolved in the water, iron removal rates of 98 percent or better are common. (More information on how KDF process media work.)
- Major municipal organization uses KDF 85 granules to effectively remove iron from the ground water at 350 gpm (gallons per minute).
Examples of iron redox reactions with KDF process media.
KDF Process Media Removes Hydrogen Sulfide
Typical redox reactions with KDF process media:
Copper loses 1 electron (oxidation). Sulfur gains 1 electron
(reduction). Copper sulfide is insoluble in water and can be backwashed
off KDF 85 media. (More information on how KDF process media work.)
KDF 55 and 85 Metal Applications
Redox media remove up to 98% of water-soluble cations (positively-charged ions) of lead, mercury, copper, nickel, chromium, and other dissolved metals. (More information on how KDF process media work.)
When filtered through KDF media, soluble lead cations are reduced to insoluble lead atoms, which are electroplated onto the surface of the media. Other heavy metals bond to the media and may be recovered when the exhausted media pass through a copper smelter.
- New Jersey's Department of Environmental Protection and Energy uses KDF 55 redox alloy media in point-of-entry treatment systems (POET) to remove mercury in residential applications. KDF media consistently reduce mercury from initial concentrations of 13 ppb through 24 ppb (parts per billion) to concentration levels below 0.5 ppb.
- Major U.S. circuit board manufacturer uses KDF media to remove 94.4% of lead in the effluent water used to rinse off printed circuit boards. The water is now recycled in a closed-loop rinse-down system, which saves the company approximately $10,000 each year.
A typical metal redox reaction with KDF process media:
Zinc loses 2 electrons (oxidation).
Lead gains 2 electrons (reduction). Lead plates on copper and replaces
zinc which goes into solution as ion.
KDF Process Media Control Microorganism Growth
KDF media are incorporated into carbon blocks and other matrices for bacteria control and scale reduction. (More information on how KDF process media work.)
The oxidation/reduction potential (ORP) shift by a factor of -300mV or more for water filtered through redox media controls microorganism growth. Treating water reduces bacteria and other microorganisms by disrupting electron transport, causing cellular damage. KDF process media also kill bacteria by direct electrochemical contact and by the flash formation of hydroxyl radicals and hydrogen peroxide, both of which interfere with a microorganism's ability to function.
- A major plastic injection molder uses KDF media to treat cooling water for a 60,000 sq. foot plant. Mineral hardness scale is virtually eliminated at about 25 percent of the cost of chemicals, and none of the heat exchangers have been replaced. With chemical treatments, scale continues to form in the cooling towers, causing damage to the heat exchangers, which often results in expensive repairs. KDF redox alloy media provides an effective, less costly alternative to chemical treatments.
- Major municipal cooling towers depend on KDF media to
effectively control algae and bacteria, without the use of chemicals harmful
to the environment.