Visualization and control of the treatment process at the wastewater treatment plant in the town of Ujezd u Brna

In the early 1990s, a new wastewater treatment plant was built in Ujezd to provide the treatment of water from the sewer system. The clean water is then released to the river Litava. The plant underwent complete reconstruction in 2010.

The main reason for the renovation was that the plant's capacity was insufficient. What is more, the treatment process did not meet the current strict environmental standards. In addition, a new visualization and control system designed to monitor the treatment process was also installed.

Control system

WAGO PLCs were chosen to control the treatment process. One controller is connected to the operator's PC via Ethernet. Communication between the devices is provided via the MODBUS-TCP protocol.

Clear visualization is provided by the Reliance SCADA/HMI system, which is installed on the PC located in the plant's operator room. Using several well-arranged visualization screens, Reliance allows for monitoring and controlling the whole treatment process from the plant intake through biological treatment to the sludge dewatering process. For some devices, a number of engine hours can be set up in the Reliance system. After exceeding the limit, an alarm message displaying the number of completed engine hours appears on the PC's screen. Additionally, all operating data is automatically stored in the Reliance database and can be used for future analysis.

In the intake section, Reliance provides

• Visualization and control of the rainwater harvesting system's pumps
• Visualization of trash rakes and the sand separator
• Visualization and control of wastewater pumps (wastewater intended for the pre-treatment and biological stages)
• Visualization and control of the sand chamber's valves

In the biological section, Reliance provides

• Visualization and control of submersible mixers in the anoxic tank and in activated sludge tanks
• Visualization and control of blowers
• Visualization and control of recirculation pumps
• Visualization and control of pumps for return and excessive sludge
• Visualization and control of the return and excessive sludge lock

In the sludge treatment section, Reliance provides

• Visualization and control of the aeration blower and the sludge mixer
• Visualization and control of the flocculant pump, feeder, and mixer
• Visualization and control of the sludge pump, centrifuge, and conveyor
• Visualization and control of water-filling and rinse valves

Examples of visualization windows