Mercury in the Environment and Water Supply




Mercury Analysis (Univ. of Alberta)













Removal of Mercury in the Environment


Removing mercury from the water can be achieved using four processes: Coagulation/Filtration, Granular Activated Carbon, Lime Softening, and Reverse Osmosis.
Coagulation/filtration is a common treatment which uses AlSO4 that reacts with the mercury to form a solid which can precipitate out of the water. The sludge then must be disposed of in a hazardous waste landfill. This process is beneficial because it costs very little and is reliable.
Granular activated carbon uses porous carbon media. This media is a very heavy charcoal material. As the water passes through, the dissolved contaminants are absorbed and held on the solid surface. This process has its limitations because the effectiveness depends on the concentration of mercury in the water.
Lime Softening uses excess Ca(OH) to raise the pH level and then the heavy metal precipitates out as Hg(OH). A benefit of this method is lower costs and proven reliability.
In reverse osmosis, water is pushed through a semi permeable membrane. A Common membrane material is a polyamide film. This produces high quality water, but is fairly expensive.