Real Time Monitoring of Selenium Species, Mercury, and Arsenic in Coal-Fired Power Plant Wastewaters

The Environmental Protection Agency (EPA) has released pending regulations on toxic heavy metal effluents (selenium, mercury, and arsenic) to natural bodies of water from coal-fired power plants. Therefore, power plants will need to measure the concentrations of these contaminants in their wastewaters accurately, and this translates to the need for an accurate, rapid, and automated wastewater analyzer. In addition, the wastewater itself is dirty with suspended particles which makes an on-line measuring instrument challenging. An analyzer with these capabilities is also of interest in other wastewater compliance and treatment applications. The technology developed in this project will result in an automated and rapid analyzer of total selenium, selenite, selenate, mercury, and arsenic in wastewater from coal-fired power plants. In addition, we will also develop a module to clean the water sufficiently so that our measurement instrument will not be affected by any particulates or other issues. The instrument is inexpensive resulting in a quick payback to our customers. Our instrument has already been lab tested on selenium so we are confident it is feasible. Our Phase I objective is to enhance our already tested instrument and extend its operation by including mercury and arsenic and, in our lab, experimentally verify that it can accurately measure the elements of interest down to levels required by EPA regulations. Additionally, we will develop and test our module to process and clean the wastewater. Our existing equipment will be optimized and extended to measure mercury and arsenic and we will build and test the module to clean the water. The main commercial application of this project is an accurate, automated, on-line, and inexpensive analyzer for power plants to demonstrate compliance with upcoming EPA effluent regulations. The commercial market is substantial, with many power plants currently unable to meet the new regulations. The system can also be used to monitor drinking water for lead and other contaminants, which is a second market for the system. A consequence of industry-wide adoption of the technology resulting from this project will be a decrease in the amount of emitted heavy toxic metals into the nation’s bodies of water, and a concomitant improvement in human health measures and the health of the environment.