Coagulation Controller – CoagSense

What’s the best way to control coagulation on a water treatment plant? The answer is that it depends on the water, the type of plant and the coagulant used. Pi’s CoagSense automatic coagulation controller is an integrated coagulation controller that accepts multiple inputs from appropriate parameters including pH, flow, temperature, UV254, turbidity and streaming current. From these measured parameters, the CoagSense coagulation controller outputs a flow proportional coagulation control signal that can go to a site SCADA or direct to control a coagulant dosing pump.

Coagulation is affected by lots of different variables like:

  • Raw water pH and alkalinity, turbidity, organic loading, and temp.
  • The type of coagulant used
  • Post coagulant pH, temperature
  • Physical aspects of the plant including mixing etc.

FAQs

Coagulation is the process by which suspended and dissolved solids clump together which is necessary to remove them.

Flocculation is the process of the coagulated solids clumping togetehr to make large aggregations or “flocc”.

A coagulant is a chemical, added to water that enables coagulation. Typically a charged metal salt such as Ferric or Alum or PACl.

A flocculant is a chemical added to water to enable flocculation, typically a charged organic chemical.

Charge neutralization is when solids are held in suspension in water by the negative surface charges. Charge neutralization happens when a positively charged coagulant is added to neutralize the negative charges thereby enabling coagulation.

Many things affect coagulation but the most important ones are;

  • pH
  • Coagulant charge
  • Temperature
  • Suspended solids
  • Dissolved organics
  • Mixing of the coagulant

 

 

The most common coagulants are;

  • Ferric – Iron Chloride
  • Alum – Aluminum Sulphate
  • PACl – Polyaluminum Chloride

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