Alum for Water Treatment

Generally, one of the several steps that municipal water suppliers use to purify water for distribution is getting it clear and particulate-free to the extent possible, for achieving the same, the water is treated with aluminium sulphate, commonly known as alum, which serves as a flocculant. Raw untreated water often holds tiny suspended particles that are very difficult for a filter to catch, alum treatment causes them to clump together so that they can settle at the bottom and could be easily trapped by a filter. Usually, a mixing water with 48 percent of filter alum and then injecting it into the raw incoming water at a rate of 18 to 24 parts per million helps in coagulation of fine particles which help resolve problems of colour as well as turbidity. If the process is given enough time to work and is applied properly, it not only suspends impurities in the water but actually results in removing most of the aluminium used in the process.