Lime is essential for the potable water treatment sector where it plays a role in making water safe to drink by softening pH and assisting to remove heavy metals and other impurities.
The main benefits associated with lime in potable water treatment are as follows:
pH Adjustment/Coagulation - Hydrated lime is widely used to adjust the pH of water to prepare it for further treatment. Lime is also used to combat "red water" by neutralizing the acid water, thereby reducing corrosion of pipes and mains from acid waters. The corrosive waters contain excessive amounts of carbon dioxide. Lime precipitates the carbon dioxide to form calcium carbonate, which provides a protective coating on the inside of water mains.
Water Softening - Hydrated lime is used to remove carbonate "hardness" from the water. Hardness caused by other calcium and magnesium salts, called noncarbonate hardness, is generally treated by means of the lime-soda process, which entails the precipitation of magnesium by lime. The co-produced calcium salt reacts with the soda ash to form a calcium-carbonate precipitate. Lime-enhanced softening can also be used to remove arsenic from water.
Coagulation - Lime is commonly used in conjunction with alum or iron salts for coagulating suspended solids in order to remove turbidity from water. Lime serves to maintain the proper pH for most satisfactory coagulation conditions. In some water treatment plants, alum sludge is treated with lime to facilitate sludge thickening on pressure filters.
Phenol treatment - Phenols can make drinking water unpalatable. By raising the pH of water through the addition of lime, water treatment operators can create the correct conditions to treat phenolic water. This process, called 'excess alkalinity treatment', also removes most heavy metals.
Removal of Impurities - One of the most common methods of removing silica from water involves the use of dolomitic lime. The magnesium component of this lime is the active constituent in silica removal. Lime can also be used to remove manganese, fluoride, organic tannins and iron from water supplies.
Desalination Plants – Lime aids the re-introduction of essential minerals back into the water prior to discharge into reservoirs.
Please refer to our related products shown or contact our sales team about potable water treatment.