Raw waters having a natural pH of 6.2 or above can be passed through manganese greensand without pH correction; water with a pH lower than 6.2 should be pH corrected to 6.2-6.5 before treatment with manganese greensand. If a pH higher than 6.5 is desired in the water system, the additional alkali should be added following the filter due to the possible adverse reaction (formation of colloid) that sometimes occurs with the iron and alkali at a pH above 6.5
Removing Fines and Initial Conditioning
Prior to placing a CR filter into service, manganese greensand should be thoroughly backwashed and the top layer of finer material removed by undercutting. This is especially important if anthracite is placed on top of the manganese greensand bed. Each bag of manganese greensand as shipped contains sufficient material to compensate for removing 1 inch of finer material.
CR and IR Operation
Manganese greensand is NOT shipped in regenerated form; therefore it is necessary, prior to use, to regenerate with a solution of potassium permanganate solution contacting the bed for a minimum of 4 hours. A regeneration level of 4 ounces of potassium permanganate per cubic foot is recommended. Before placing in service, the filter must be rinsed of all remaining traces of potassium permanganate.
Radium and Arsenic Removal
The manganese greensand process has been found to be successful in removing radium and arsenic from well water supplies. This occurs via adsorption onto the manganese and/or iron precipitates that are formed. For radium removal, soluble manganese must be present in the raw water for removal to occur. Arsenic removal has been achieved with either iron or manganese being present in the water. Pilot plant testing is recommended.
A partial listing of companies/distributors using GreensandPlus
- Graver Water
- Hungerford & Terry, Inc.
- Carbon Enterprises
- Matt-Son Osmonics
- Roberts Filter
- CWG Water Technology
- Tonka Equipment Co.
- Garnet Abrasives
- Water & Power Tech.
- BI Pure Water
- WesTech, Inc.
A properly operated manganese greensand filter should never have potassium permanganate or “pink water” in the filter effluent. If, however, it is felt that insurance against pink water should be provided, there are detectors available to signal an alarm or shut down chemical feed equipment should pink water be detected in the filter effluent. Further details are available from your equipment manufacturer.
The information and recommendations in this publication are true and reliable to the best of our knowledge. They are offered in good faith but without warranty or liability for consequential damage as conditions and method of use of our products are varied and beyond our control. We suggest the suitability and performance of our products be determined by the end user before they are adopted on a commercial scale.