To meet the growing demand for monitoring the quality of water streams and detecting contaminants, cheap and accurate sensors are needed. Although electrochemical sensing methods such as Electrochemical Impedance Spectroscopy (EIS) provide a versatile monitoring platform, selectively sensing (multiple) contaminants, and identifying their unique EIS response still remain a challenge.

The conducted research is based on the principle that the EIS response is strongly influenced by the physical interactions occurring at the surface between the electrode, used for the EIS measurements, and the water (acting as the electrolyte). The objective is to identify an optimised EIS setup, focusing on the electrode material and its surface topology. To achieve this, a selected number of electrodes will be examined for their EIS response with an industrial application for wastewater monitoring in mind. Furthermore, both in-situ and ex-situ electrochemical and surface/interface characterisation techniques will be employed to correlate the distinct EIS responses with the specific physical phenomena occurring at the interface.

Although the project focus will lie on the detection of heavy metal ion contaminants in wastewater, the project developments and the related electrode surface modification processes can also be adapted to variety of other domains, depending on the industrial demand. Relevant examples of water streams include industrial waste/process water, beverages and surface water. In addition to heavy metal ions, potential contaminants of interest encompass chemicals such as phosphates, nitrates, PFAS and other emerging pollutants like N2O.