INL advances heavy metal detection in industrial wastewater

February 14, 2024

The advances in industrial modernisation are driving research towards the development of new sensors for the Industrial Internet of Things (IIoT) or Internet of Robotic Things (IoRT), aiming to enhance efficiency, production rates, and quality standards.

However, current solutions face technical limitations in accuracy, and adaptability to real-world conditions. The Next-Gen Quality Control (NGQC) IoRT project focuses on developing an automated monitoring system to detect heavy metals in industrial effluents. This ecosystem includes environmental monitoring, as well as wastewater.

Pilot testing is currently underway at Stellantis in Mangualde, embracing the principles of Industry 4.0. The monitoring system is integrated into a wastewater treatment plant to understand its evolution and whether water quality limits are being exceeded. Raquel Queirós, staff researcher in the Water Quality Group, explains, “This system collects a small sample from the tank at the beginning and end of the process. This sample is then filtered to detect the presence of the heavy metals”.

Raquel Queirós and Samuel Silva | *Water Quality – INL*

Samuel Silva, research fellow in the Water Quality research group, adds, “The developed electrochemical sensors have been optimised to detect nickel and zinc.” The prototype has integrated an algorithm that calculates and estimates the concentration of the heavy metals. “The system is able to detect as low as 50 μg/L for zinc and 5 μg/L for nickel”, adds Raquel Queirós.

The NGQC project also explores collaborative robotic systems and artificial vision mechanisms to achieve versatile and transparent non-conformity detection, by the project partners FEUP and Controlar.

The final prototype is currently being validated in the field. The monitoring system was assembled in the factory’s water treatment plant and it is monitoring the water for a month in an automated way, i.e., without the need for human intervention. The obtained results will then be compared with the values obtained from certified laboratory analyses of samples collected at the same time that the automated system takes the measurement.

Raquel recently participated in ‘90 Segundos de Ciência’, a series of science communication episodes with daily broadcasts on Antena 1 Portuguese public radio, where Raquel explains the NGQC project in just 90 seconds. You can listen to the episode (in Portuguese) here.

The research team at INL hopes that this system will improve wastewater treatment in this industry, making the process more efficient and less expensive. The NGQC IoRT – Next-Gen Quality Control IoRT System project is financed under the COMPETE 2020 program.