title: Impact of dissolved silica on arsenite removal by nano-particulate FeS and FeS-coated sand.
abstract: This work evaluated the inhibitory effect of dissolved silica on arsenite adsorption to nanoparticulate FeS (NP-FeS) or mackinawite and FeS-coated sand (CS-FeS) sorbents. Arsenite retention by the NP-FeS solid was not affected by dissolved silicate over a wide range in pH, in contrast to the known inhibitory effect of dissolved silica on As(III) uptake by Fe-(hydr)oxide systems. However, some inhibition was observed in CS-FeS system at pH 9. This latter result is attributed to the co-existence of both FeS and small amounts of Fe-(hydr)oxide phases on the sand surface. Given the ubiquitous presence of dissolved Si in groundwater, FeS-based sorbents may have an advantage for As retention compared to those based on Fe-(hydr)oxides in reducing subsurface environments.
authors.affiliation: Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, MI 48109, United States. han.youngsoo@gmail.com
authors.forename: Young-Soo
authors.initials: YS
authors.lastname: Han
authors.forename: Avery H
authors.initials: AH
authors.lastname: Demond
authors.forename: Kim F
authors.initials: KF
authors.lastname: Hayes
mesh_terms: D000327:Adsorption; D018053:Arsenites / Q000737:chemistry*; D052918:Environmental Restoration and Remediation; D005296:Ferrous Compounds / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D053768:Metal Nanoparticles / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D018053:Arsenites; D005296:Ferrous Compounds; D012822:Silicon Dioxide; C015001:arsenite; C022597:ferrous sulfide