Methods of Water Treatment


Water Contaminants

Acidic Water
Aluminum
Ammonia
Arsenic
Bacteria
Barium
Benzene
Bicarbonate
Borate (Boron)
Bromine (Bromide)
Cadmium
Calcium
Carbon Dioxide
Carbon Tetrachloride
Chloride
Chlorine
Chromium
Color
Copper
Cryptosporidium
Cyanide
Fluoride
Giardia Lamblia
Hardness
Hydrogen Sulfide
Iron
Lead
Legionella
Magnesium
Manganese
Mercury
Methane
Nickel
Nitrate
Nitrite
Odor
Organics
Pesticides
pH
Potassium
Radium
Radon
Selenium
Silica
Silver
SOC's
Sodium
Strontium
Sulfate
Taste
THM's
TOC
Total Dissolved Solids
Turbidity
Uranium
Viruses
VOCs

Manganese

Source
Manganese (Mg+4, Mn+2) is present in many soils and sediments as well as in rocks whose structures have been changed by heat and pressure. It is used in the manufacture of steel to improve corrosion resistance and hardness. Manganese is considered essential to plant and animal life and can be derived from such foods as corn, spinach, and whole-wheat products. It is known to be important in building strong bones and may be beneficial to the cardiovascular system. Manganese may be found in deep well waters at concentrations as high as 2 - 3 mg/i. It is hard to treat because of the complexes it can form which are dependent on the oxidation state, pH, bicarbonate-carbonate-OH ratios, and the presence of other minerals, particularly iron. Concentrations higher than 0.05 mg/i cause manganese deposits and staining of clothing and plumbing fixtures. The stains are dark brown to black in nature. The use of chlorine bleach in the laundry will cause the stains to set. The chemistry of manganese in water is similar to that of iron. A high level of manganese in the water produces an unpleasant odor and taste. Organic materials can tie up manganese in the same manner as they do iron; therefore destruction of the organic matter is a necessary part of manganese removal.

Treatment
Removal of manganese can be done by ion exchange (sodium form cation - softener) or chemical oxidation - retention - filtration. Removal with a water softener dictates that the pH be 6.8 or higher and is beneficial to use countercurrent regeneration with brine make-up and backwash utilizing soft water. It takes 1 ppm of oxygen to treat 1.5 ppm of manganese. Greensand filter with potassium will remove up to 10 ppm if pH is above 8.0. Birm filter with air injection will reduce manganese if pH is 8.0 to 8.5. Chemical feed (chlorine, potassium permanganate, or hydrogen peroxide) followed by 20 minutes retention and then filtered with birm, greensand, carbon, or Filter Ag will also remove the manganese.