title: Immobilization of mercury in sediment using stabilized iron sulfide nanoparticles.
abstract: Mercury (Hg) immobilization using stabilized iron sulfide (FeS) nanoparticles was investigated through a series of batch and column experiments. The nanoparticles were prepared using a low-cost, food-grade cellulose (sodium carboxymethyl cellulose, CMC) as the stabilizer. The hydrodynamic diameter of fresh FeS-CMC nanoparticles was measured to be 38.5+/-5.4nm. Batch tests showed that the nanoparticles can effectively immobilize Hg in a clay loam sediment. The Hg distribution coefficient for the nanoparticles was determined to be 8930+/-1480L/g, which is >4 orders of magnitude greater than for the sediment. When the Hg-laden sediment was treated at an FeS-to-Hg molar ratio of 26.5, the Hg concentration leached into water was reduced by 97% and the TCLP (toxicity characteristic leaching procedure) leachability of Hg was reduced by 99%. Column tests showed that water-leachable mercury from the sediment containing 3120mg/L Hg was reduced by 67% and the TCLP leachability by >77% when the sediment was treated with 67 pore volumes (PVs) of a 0.5g/L FeS nanoparticle suspension. Column tests proved that the stabilized nanoparticles were highly mobile in the sediment and full breakthrough of the nanoparticles occurred at approximately 18 PVs.
authors.affiliation: Environmental Engineering Program, Department of Civil Engineering, Auburn University, Auburn, AL 36849, USA.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Xiong
authors.forename: Feng
authors.initials: F
authors.lastname: He
authors.forename: Dongye
authors.initials: D
authors.lastname: Zhao
authors.forename: Mark O
authors.initials: MO
authors.lastname: Barnett
mesh_terms: D052918:Environmental Restoration and Remediation / Q000379:methods; D019015:Geologic Sediments / Q000737:chemistry*; D007501:Iron / Q000032:analysis / Q000737:chemistry*; D007700:Kinetics; D008628:Mercury / Q000032:analysis* / Q000737:chemistry; D053768:Metal Nanoparticles / Q000032:analysis / Q000737:chemistry* / Q000648:ultrastructure; D013440:Sulfides / Q000032:analysis / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
chemical_list: D013440:Sulfides; D014874:Water Pollutants, Chemical; D007501:Iron; D008628:Mercury