Priority trace elements, such as arsenic, selenium, cadmium, chromium, copper, lead, silver, and zinc are often present in the discharges from coal-fired electric power plants. These elements may be eliminated from the waste streams by coprecipitation with amorphous iron oxyhydroxide. Iron oxyhydroxide is formed when a ferric salt (for example, ferric chloride) is added to the waste.
Field Evaluation of Arsenic and Selenium Removal by Iron Coprecipitation
Authors: Douglas T. Merrill, Mark A. Manzione, Denny S. Parker, Jeffrey J. Petersen, Winston Chow, Alexander O. Hobbs
1986 Journal Water Pollution Control Federation, Vol. 58, No.1