Screening

Screening is the first treatment, both for surface and wastewater. It's is purpose to:

• Protect the structure downstream against large objects which could create obstructions.
• Easily separate and remove large matter carried along with the raw water.

Screening is carried out by a manually cleaned bar screen or, preferably, by an automatically cleaned bar screen.

Chemical Coagulation

Coagulation is the destabilization of colloids by neutralizing the forces that keep them apart. Coagulation implies formation of smaller compact aggregates.

Chemical coagulation is an important unit process in water treatment for the removal of turbidity. The most widely used coagulants are:

• Aluminum sulphate {Alum}
• Poly aluminum chloride {PAC}
• Ferrous sulphate
• Sodium Aluminate
• Silicon Derivatives
• Lime
• Synthetic Organic Polymers

Electro Coagulation

Electrocoagulation offers an alternative to the use of metal salts or polymers and polyelectrolyte addition for breaking stable emulsions and suspensions. The technology removes metals, colloidal solids and particles, and soluble inorganic pollutants from aqueous media by introducing highly charged polymeric metal hydroxide species. These species neutralize the electrostatic charges on suspended solids and oil droplets to facilitate agglomeration or coagulation and resultant separation from the aqueous phase. The treatment prompts the precipitation of certain metals and salts.