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 controller that accepts multiple inputs from appropriate parameters including pH, flow, temperature, UV254, turbidity and streaming current. From these measured parameters, the CoagSense 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.


What is the CoagSense Coagulation Controller?

In the past most coagulant control has been dosed automatically with the setpoint determined manually by looking at the variables and sometimes by using lab methods such as jar testing. There are two main problems with this approach. The first is that when the main goal of coagulation was to remove turbidity, operators eyeballing the water and changing the dose was a good method of determining the dose of coagulant required. Now that the focus is on enhanced coagulation and the removal of organics that are often not visible to the naked eye.

This method of manually determining the coagulant dose is no longer providing operators with the outcomes that they need. In addition the consequence of under dosing coagulant is often more severe than the consequence of overdosing coagulant. For this reason the tendency is for operators to add more coagulant than is required leading to shorter filter run times and more sludge to dispose of. This overdosing of coagulant is typically approximately 30%. The implementation of automatic coagulation control will typically save money (often giving a ROI of months rather than years) while improving water quality and plant outcomes.

If you have any questions or would like to find out more about CoagSense and automatic coagulation control get in touch with one of our technical experts.


Provides remote controller access over local area networks such as those belonging to a certain organization or location.

Provides remote controller access over mobile networks.

Provides Modbus communication and remote controller access over LAN.

Provides Modbus communication and remote controller access over RS-485 networks.

The CoagSense is able to take in outputs from other site instruments potentially saving money.

Provides data logging for investigation and troubleshooting purposes.

Offers the ability to manipulate process variables such as pressure, speed, temperature, flow and others.

The CoagSense allows for the direct control of the dosing pumps for pH correction and coagulant addition.

Allows you to gather and analyze real-time data via the use of SCADA systems.

Focus On

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