(583c) Performance of Ion Selective Electrodes (ISE) on Wastewaters from Power Plants
As of 2015, more than 66 companies are manufacturing water related sensors in the world but only a handful of them market Ion Selective Electrodes (ISE). An ISE (with its own internal reference electrode) is immersed in an aqueous solution containing the ions to be measured, together with a separate, external reference electrode. The external reference can be completely separate or incorporated in the body of the ISE to form a Combination Electrode). The electrochemical circuit is completed by connecting the electrodes to a sensitive (milli)volt meter using special low-noise cables and connectors. A potential difference is developed across the ISE membrane when the target ions diffuse through from the high concentration side to the lower concentration side.
In this project, we have investigated the feasibility of using inexpensive sensors for FGD water measurements and ISE sensors for chemical composition. FGD wastewaters were collected from AEPâs coal-fired power plant. Before testing the ISE electrodes in FGD wastewaters, it is important to quantify the targeted compounds in the FGD wastewater. Therefore, we have used high accuracy gas chromatography, ion chromatography, high-performance liquid chromatography, and induced coupled plasma available for organic and inorganic compounds detection and quantification. Targeted compounds for this project were mercury, selenium, arsenic, nitrate, nitrites, calcium, and chloride. ISEs purchased from Thermo-scientific and NIKO (London, UK) were tested on the known FGD wastewaters individually to determine the performance of each electrodes.
In future, we will select the working electrodes and make a sensor package for wastewater quality monitoring. The package will be designed as a self-powered, wireless, water-resistant, robust, and cheap. The sensor package is expected to demonstrate at the AEPâs site for the real-time data monitoring.