Detection of Poisonous Substances in Their Water Solutions by Using Dielectric Waveguide

In this study, a non-invasive method is presented for the detection of toxic substances in water by measuring the transmission coefficient (including amplitude and phase values) of electromagnetic waves through a dielectric waveguide surrounding a liquid-filled container. Electromagnetic waves in two different frequency ranges, 75-110 GHz and 90-140 GHz, interact with the liquid as they propagate through the waveguide and radiate into the external environment. The study tested various dissolved toxic substances in water using both plastic and glass containers. It was observed that the spectral transmission properties of these toxic substances are significantly different from water, especially when using millimeter waves. These differences in transmission characteristics were analyzed using machine learning algorithms such as k-means clustering and principal component analysis (PCA), effectively distinguishing between hazardous substances and water. This approach provides a very fast and reliable method for the quick and immediate detection of hazardous substances in water. This study also offers a potential method for applications in environmental monitoring and public health, such as safety assessments of drinking water.