Water Pollution Level Detection using Patch Antenna Measurements at Microwave Frequencies

Abstract

The detection of pollutants and their concentrations in water is very important because they can be a public hazard. The level of pollution in water can be determined using various microwave and chemical measurement/analysis techniques. This work aims at demonstrating a new technique of determining the pollution levels in water by detecting the change in resonant frequency of simple patch antenna while immersed in water that is mixed with chemicals of various concentrations. Water mixed with chemi-cals has a dielectric constant different from that of pure water. This change in the dielectric constant of water will result in shift of resonant frequency of antenna (when the antenna is immersed in water). In addition, a theoretical study has been performed to determine the dielectric constant of water with different concentrations of sodium chloride. The calculated dielectric constant is used to set the parameters in a simulation software that also simulates the shift in resonant frequency when an antenna is immersed in water. Both the simulated and the measured shift in resonant frequency is found to be comparable. The effectiveness of this method is demonstrated by performing antenna measurements immersed in water collected from various sources in Kerala, India.