Applications > Wastewater > Inlet

Monitoring the inlet of a WWTP

For monitoring the inlet of a municipal wastewater treatment plant, continuous measurement of the expected load of the wastewater is required. The ISA UV/Vis spectrometer from GO Systemelektronik is ideally suited for the simultaneous determination of the necessary parameters. The system also offers the advantage of reagent-free operation and low maintenance thanks to automated cleaning.

Overview Wastewater Inletscreen house municipal wastewater treatment plant


The degree of pollution is measured, in part, by the concentrations of the Chemical Oxygen Demand (COD), Ammonium (NH4) and Total Nitrogen (TN). Based on the measurement data, decisions for the optimization of the control processes can be derived, as well as early warnings when limit values are exceeded, thus preventing an accident in the wastewater treatment plant and ensuring operational safety. For this task a high-resolution measurement with a short measuring interval is essential.
For this application, the installation conditions require that the sensor technology is installed in the explosion-hazardous area of the screen house of the unmanned sewage treatment plant.

Products & Parameters
BlueBox T4
ISA UV/Vis Spectrometer Module

Configuration of the measurement system

configuration monitoring inlet treatment plant ex-zone

The BlueBox controller is the heart of the measuring system configuration. It collects all measurement data and transfers them to the local company network via a TCP/IP interface.
An ISA UV/Vis spectrometer is attached via an optical fiber to a UV/Vis spectrometer module, which is connected to the BlueBox. The measuring head of the UV/Vis spectrometer is made of stainless steel 1.4404 and is ATEX certified (standard ATEX class III). It can therefore be used in hazardous areas. The spectrometer is calibrated for this application for the simultaneous determination of the parameters Chemical Oxygen Demand (COD), Ammonium (NH4) and Total Nitrogen (TN).

UV/Vis Spektrometer
UV/Vis Spectrometer
ATEX zertifiziert
ATEX Certified
customized calibration
Customized Calibration
Bus Konnektivität CAN-Bus Modbus
Remote Access & Control

Construction of the measurement system

inlet wastewater treatment plant ex-zonemeasurement technology inlet waste water treatment plant safe-zone

The BlueBox controller and the spectrometer module, in which the electronics are integrated, are installed in the adjacent safe area. The corresponding ISA measuring head, which is ATEX certified, is led into the Ex zone through an opening in the wall. The measuring head is installed in an open channel directly behind the rake and is inserted via a pipe at the edge. The achieved angle of insertion ensures optimum cleaning performance of the automatic compressed air flushing and prevents air bubbles from getting stuck in the measuring gap. The sensor is additionally secured to the channel railing by a chain, which can also be used to remove it for manual cleaning.

Availability of the measurement data

All parameters are measured every minute and automatically transferred to the local company network via TCP/IP interface. The measured data is thus accessible to the operator at any time. In addition to providing the data, the connection also allows remote maintenance to make changes to the settings if necessary. Thanks to the availability of the data and the possibility of remote maintenance, the ideal time for on-site maintenance operations can be determined. Especially, for unmanned treatment plants this information ensures that the system is always in perfect working order.

Measurement graph inlet wastewater treatment plant COD


measurement graph inlet wastewater treatment plant nh4


measurement graph inlet wastewater treatment plant TN