Aluminium sulphate is one of ...
Published by Rachi Rajagopaul, Senior Scientist at Umgeni Water
Aluminium sulphate is one of the better coagulants for the application. The challenge in a community application is that pH is not maintained in the optimum range (6.5 to 7.5) and if it falls below the solubility pH range, aluminium carryover into the filtered water is experienced.
If maintaining pH in the optimum range is difficult, can use ferric chloride that works in a wider pH range, between 4 and 10.