Client Satisfaction
Project Experience
About DES
Contact DES



 806 West Queen St

 Southington, CT 06489


 Contact Information:

 Phone: 860-621-3630

 Fax: 860-621-0067

 E-mail: info@desct.com




Filter Introduction

Activated Carbon Filters
Neutralizing Filters
Acid Correction:
Multi-Media Depth Filters
Sediment Filters
Iron Filters

Activated Carbon Filters: are used to reduce chlorine, organic, color, tannin, and objectionable tastes and odors from water. These filters will also trap sediment and particulate matter, however, are not designed for that use. If sediment problems exist, a sediment filter should be installed ahead of the carbon filter. DES supplies different types of granular activated carbon and recommends equipment sizing for filters based on the application. In addition, DES manufactures carbon filters with or without sand and gravel underbedding, and offers a full range of filter types for all activated carbon applications.

Neutralizing Filters: are used where low pH water is a problem. Naturally occurring acidic water and potable drinking water, such as that produced by reverse osmosis, can be effectively neutralized by using special neutralizing media. The media will require periodic replacement as it is consumed in the neutralizing process. Calcium and magnesium carbonate are introduced into the ionic makeup of the water during neutralization which may necessitate the installation of a water softener or deionizer to reduce hardness added to the water, depending on the desired water quality.

Acid Correction: A mixture of Calcite and Corosex typically allows for correction of 5.0 pH and up. Freeboard in the filter should be checked annually and media if short. Less than 5.5 pH, addition of soda ash or Sodium Hydroxide may be necessary.

Multi-Media Depth Filters: are filters containing two or more types of media and gravel underbedding. DES manufactures several types of depth filters. 

    Multi-media filtration is a proven concept; the coarse media layers in the top of the tank trap large particles, and successively smaller particles are trapped in the finer layers of media deeper in the bed. The result is a highly efficient filtering since removal takes place throughout the entire bed. Multi-media depth filters typically remove particles 5 to 15 microns in size and larger.

    Correct layering is the key to proper performance in a depth filter. All media are selected according to particle size and density, so the media retains its stratification during backwashing and rinse.

    In addition to efficient production of high clarity water, depth filters generally allow higher service flow rates of 10 to 20 gpm per square foot of surface area, and longer service runs between backwashes.

    When compared to gravity filters, multi-media pressure filters installed in municipal applications generally require less space and can out perform single media filters.

Sediment Filters: For cloudy, dirty, or turbid water, evenly graded silica or granite sand is the filter medium. The addition of a layer of garnet will increase filtration. Filter Ag (a light weight medium) is available at no extra charge when backwash water is limited. Water containing colloidal or suspended matter that will not settle out may require pretreatment with ARGO Filtermate injection into the water with our chemical feeder and 20 minutes retention time. (ARGO Filtermate is a coagulant.) Wells pumping sand need sand trap (upflow) or a sand separator, not a sediment filter as it will fill the sediment filter up.

Iron Filters: manufactured by DES include media that is best suited for the application, based on the water analysis.

    Manganese Greensand filters provide excellent removal of iron and manganese. The manganese dioxide coated greensand is regenerated with potassium permanganate continuously, or in batch regenerations. As water with iron and manganese passes down through the filter bed, the iron and manganese is oxidized into a filterable state and retained by the filter media. Backwashing and rinsing the filters discharges the filtered contaminants to the drain. MTM™ is a substitute with the same specifications for Greensand.

    BIRM® is a media that does not require a regenerate and is an effective iron removal media when this is ample dissolved oxygen. BIRM® should not be used if oil or hydrogen sulfide are present in the raw water. BIRM® is often used in place of greensand on water with less than 5 ppm of iron. Filter operation is similar to a sand or multi-media filter.

    PYROLOX® is a high capacity filter media for hydrogen sulfide, iron, and manganese removal. Chemical regeneration is not required, as these contaminants are oxidized on the surface of the media, and then removed from the media by simple backwashing. Flow design characteristics are similar to greensand. Higher capacities and no regenerate requirements make PYROLOX® a logical alternative to other iron removal media.

    KDF® contains dissimilar metal products and combine mechanical filtration with a redox potential (oxidation/reduction) for reduction of suspended solids, chlorine, hydrogen sulfide and iron bearing compounds. Don not use KDF® on water containing polyphosphates.