What Are Greensand Filters?
Greensand filters are often used in an array of commercial and industrial water treatment applications to remove iron, manganese, hydrogen sulfide, arsenic, and radium.
How Do Greensand Filters Remove Iron and Other Contaminants?
Greensand filter media oxidizes dissolved metals and contaminants like iron and manganese on contact. This results in precipitation (the forming of solids) of the dissolved substances as they pass through the filter. The iron filter backwashes these small particles to drain every few days in the middle of the night (can be scheduled for your needs), thus cleaning and restoring the filter media.
At Complete Water Solutions, we use a product called GreensandPlus™, which has several advantages over traditional manganese greensand. GreensandPlus™ is a black filter media with a silica sand core coated in manganese dioxide. This coating acts as a catalyst in the oxidation reduction reaction of iron and manganese, while the silica core allows the media to withstand waters that are low in silica, total dissolved solids (TDS), and hardness without breakdown.
GreensandPlus™ is effective at higher operating temperatures and differential pressures than the standard manganese greensand. The advantage of this tolerance is that it can provide longer run times between backwashes and offers a greater margin of safety for your industrial water system. Unlike other media, GreensandPlus™ doesn’t need extensive preconditioning of filter media or lengthy startup periods.
Manganese Greensand vs. GreensandPlus™ Filters
The main difference between GreensandPlus™ and manganese greensand is in the substrate that forms the core of the media, as mentioned above, and the method by which the manganese dioxide coating is attached to the substrate. While GreensandPlus™ has a silica sand core and the coating is fused to it, Manganese Greensand has a glauconite core and the coating is ionically bound to it. Traditional greensand requires the use of potassium permanganate to create the reaction, while GreensandPlus™ does not. However, GreensandPlus™ does require the use of chlorine upstream from the filter. We suggest GreensandPlus™ due to its overall benefits for your industrial water system.
Water Conditions for Effective Greensand Filtration
For Greensand filtration to be effective, the water must have a pH of 6.7 to 8.8. If the water has a pH lower than 6.8, in fact, we usually recommend treating the water first with a neutralizer filter. The best applications also have a feed or raw water of less than 15 PPM of iron and manganese, combined. The maximum practical removal rate for hydrogen sulfide is 5 PPM and the water should contain no tannins or oil. When working with Complete Water Solutions, we will ensure that your water system meets all of the necessary conditions for your greensand filter to be effective as well as the overall quality of your water. If you have any questions, call us today at (855) 787-4200 and we’ll be glad to help!
Industrial Iron Filters
In the example to the right, Complete Water Solutions was contracted to provide a turnkey iron filter replacement for a client whose existing iron filter was leaking media into their food production facility. Complete Water Solutions came to the rescue by installing a quad fiberglass system complete with Aquamatic blocking valves, a 48ES stager controller, as well as a Y strainer downstream as insurance in the event of future problems. (Should a lower distributor break, the media will get trapped in the Y strainer rather than ending up in the facility and product.)
Read on to learn more about Greensand filters and contact Complete Water Solutions today for help with your industrial iron removal needs!
Commercial Hydrogen Sulfide Removal
A high amount of hydrogen sulfide in your water is commonly characterized by a foul smell (often equated to that of rotten eggs). Greensand filters will remove up to 5 PPM of hydrogen sulfide. If your commercial water system smells like rotten eggs or sulfur, contact the water system experts at Complete Water Solutions today! We would be happy to help you install or replace your Greensand filter and discuss any other possible solutions for your water treatment system. Call us today or email us at firstname.lastname@example.org