Reaching Part Per Trillion Clean-Up Criteria for Mercury in Water

In the last couple of years, emphasis on environmental mercury contamination and elimination of mercury use has increased. The U.S. Department of Energy has for many decades maintained a stockpile of elemental mercury for operations and, as a consequence of its routine use, spills have occurred. These historical spills have resulted in some contamination of water streams and soils. In this work we examine a newly developed technique for removal of mercury from contaminated groundwater. In this application the mercury concentration was approximately 2.3 parts per billion and the treatment criterion was 200 parts per trillion. Several forms of mercury species contributed to the contamination. The treatment technique developed for this water was to convert all forms of mercury, through a series of fast chemical reactions, to elemental mercury, which was air-stripped from the water. This paper presents preliminary laboratory work on the method.