title: Stabilization and solidification of elemental mercury for safe disposal and/or long-term storage.
abstract: A simple and highly effective stabilization/solidification (S/S) technology of elemental mercury using only sulfur with paraffin is introduced. First, elemental mercury is mixed with an excess of sulfur powder and heated to 60 degrees C for 30 min until elemental mercury is converted into mercuric sulfide (HgS black, metacinnabar) (Step 1). Then, metacinnabar with additional sulfur is poured into liquid paraffin (Step 2). Finally, the mixture is melted at 140 degrees C and settles to the bottom of the vessel where it cools and solidifies under the layer of liquid paraffin (Step 3). The proposed S/S method with sodium sulfide nonahydrate (Na2S x 9H2O) as an additive is also tested for comparison. The average toxicity characteristic leaching procedure test values are 6.72 microg/L (no additive) and 3.18 microg/L (with additive). Theses concentrations are well below the Universal Treatment Standard (25 microg/L). Effective diffusion coefficient evaluated from accelerated leach test and average headspace concentration of Hg vapor after 18 hr are 3.62 x 10(-15) cm2/sec, 0.55 mg/m3 (no additive) and 5.86 x 10(-13) cm2/sec, 0.25 mg/m3 (with additive).
authors: Department of Chemical and Biomolecular Engineering, Yonsei University, Seoul, Korea. teddy.lee@yonsei.ac.kr
authors: Tai Gyu
authors: TG
authors: Lee
authors: Yujin
authors: Y
authors: Eom
authors: Chul Hun
authors: CH
authors: Lee
authors: Kyung Su
authors: KS
authors: Song
mesh_terms: D000465:Algorithms; D004784:Environmental Monitoring; D006256:Hazardous Waste / Q000032:analysis*; D008628:Mercury / Q000032:analysis* / Q000633:toxicity; D017669:Mercury Compounds / Q000032:analysis; D012037:Refuse Disposal / Q000379:methods*; D014481:United States; D014484:United States Environmental Protection Agency; D014874:Water Pollutants, Chemical
chemical_list: D006256:Hazardous Waste; D017669:Mercury Compounds; D014874:Water Pollutants, Chemical; D008628:Mercury