Solutions for treating water pollution
Manganese greensand
Manganese greensand, as the name implies, is a green sand that is effective in removing manganese, iron, and hydrogen sulfide from water.
Manganese greensand will lose its effectiveness over time, but can be regenerated using a potassium permanganate solution. If the iron concentration in the water is high, using potassium permanganate to continuously dose the sand is usually a better option.
Chlorine Dosage
Another way to oxidize manganese and iron in water is to add chlorine, which converts the dissolved minerals into iron hydroxide and manganese dioxide. These are then filtered out of the water. Adding more chlorine speeds up the chemical reaction.
Other Options
Aeration
Iron is easily oxidized by oxygen in the atmosphere. Manganese is less easily oxidized, but using aeration can provide enough dissolved oxygen to the water to convert both manganese and iron into solids. Using air to oxidize manganese and iron is cost-effective because no additional chemicals need to be purchased.
However, it also has disadvantages. When manganese levels are high, the oxidation process will be slow, and the process requires a larger tank. If the water quality changes, this will also affect the oxidation rate, and in some cases, it may even stop the entire process altogether.
