SURFACE WATER TREATMENT

Among the technologies used are Coagulation-flocculation-simple or lamellar precipitation to clarify turbid and humic waters, pressure or gravity fast sand filtration, slow sand filtration;  ion exchange for the treatment of hard water, ion exchange and reverse osmosis for desalination; biological treatment for organic matter removal, activated carbon adsorption for disinfection, chlorination, ozonation and ultraviolet methods.

COAGULATION
Adding certain chemicals to water can modify find suspended solids and colloidal material, which will not precipitate on its own, causing “Flocs” to grow in size and so precipitate more easily. Coagulation is the rapid mixing of water by adding chemical substances, destabilizing colloidal and suspended solids and combining destabilized solid substances.

FLOCCULATION
After coagulation the “Flocs” tend to accrete or bind together into larger Flocs.  This can be assisted by slow mixing, either mechanically or with air bubbles or hydraulic mixing.

FILTRATION
Filtration is the process of passing the water through the filter medium in order to keep the suspended solids that have not been precipitated in the raw water that is coagulated with chemicals and to obtain high quality drinking water.