Removal of mercury from an alumina refinery aqueous stream.
Digestion condensate is formed as a by-product of the alumina refinery digestion process. The solution exhibits a high pH and is chemically reducing, containing many volatile species such as water, volatile organics, ammonia, and mercury. Because digestion condensate is chemically unique, an innovative approach was required to investigate mercury removal. The mercury capacity and adsorption kinetics were investigated using a number of materials including gold, silver and sulphur impregnated silica and a silver impregnated carbon. The results were compared to commercial sorbents, including extruded and powdered virgin activated carbons and a sulphur impregnated mineral. Nano-gold supported on silica (88% removal under batch conditions and 95% removal under flow conditions) and powdered activated carbon (91% under batch conditions and 98% removal under flow conditions) were the most effective materials investigated. The silver and sulphur impregnated materials were unstable in digestion condensate under the test conditions used.
Mullett
Mark
M
School of Applied Sciences (Applied Chemistry), RMIT University, PO Box 2476V, Melbourne 3001, Australia.
Tardio
James
J
Bhargava
Suresh
S
Dobbs
Charles
C
D000537:Aluminum Oxide; D002244:Carbon / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D008628:Mercury / Q000737:chemistry*; D008669:Metallurgy; D012822:Silicon Dioxide / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
D007220:Industrial Waste; D014874:Water Pollutants, Chemical; D002244:Carbon; D012822:Silicon Dioxide; D008628:Mercury; D000537:Aluminum Oxide