Coagulation

Coagulation/Settling Vessels are used for a wide variety of applications which require the addition of chemicals to the water being treated to form precipitates and settle suspended solids in the raw water. Such applications include the addition of lime to raw water in the cold lime softening process, which also reduces the alkalinity of the raw water, and addition of lime or other alkalis to effect precipitation of insoluble hydroxides.

The water to be treated is mixed with the chemicals and flows down to the base of the coagulation vessel via a central chamber. The water then flows up the outside of the vessel where the suspended solids and precipitates settle out. The sludge is removed from the bottom and the treated water is collected at the top of the vessel.

Coagulation is the primary step in treating poor quality surface water before other forms of treatment such as ion exchange, reverse osmosis or even filtration can be used. It is also used extensively in the soft drinks industry where alkalinity reduction is required. AWE coagulators are specifically designed for each application taking into account raw water quality and equipment requirements.