title: Schwertmannite Synthesis through Ferrous Ion Chemical Oxidation under Different H2O2 Supply Rates and Its Removal Efficiency for Arsenic from Contaminated Groundwater.
abstract: Schwertmannite-mediated removal of arsenic from contaminated water has attracted increasing attention. However, schwertmannite chemical synthesis behavior under different H2O2 supply rates for ferrous ions oxidation is unclear. This study investigated pH, ferrous ions oxidation efficiency, and total iron precipitation efficiency during schwertmannite synthesis by adding H2O2 into FeSO4 · 7H2O solution at different supply rates. Specific surface area and arsenic (III) removal capacity of schwertmannite have also been studied. Results showed that pH decreased from ~3.48 to ~1.96, ~2.06, ~2.12, ~2.14, or ~2.17 after 60 h reaction when the ferrous ions solution received the following corresponding amounts of H2O2: 1.80 mL at 2 h (treatment 1); 0.90 mL at 2 h and 14 h (treatment 2); 0.60 mL at 2, 14, and 26 h (treatment 3); 0.45 mL at 2, 14, 26, and 38 h (treatment 4), or 0.36 mL at 2, 14, 26, 38, and 50 h (treatment 5). Slow H2O2 supply significantly inhibited the total iron precipitation efficiency but improved the specific surface area or arsenic (III) removal capacity of schwertmannite. For the initial 50.0 μg/L arsenic (III)-contaminated water under pH ~7.0 and using 0.25 g/L schwertmannite as an adsorbent, the total iron precipitation efficiency, specific surface area of the harvested schwertmannite, and schwertmannite arsenic(III) removal efficiency were 29.3%, 2.06 m2/g, and 81.1%, respectively, in treatment 1. However, the above parameters correspondingly changed to 17.3%, 16.30 m2/g, and 96.5%, respectively, in treatment 5.
authors.affiliation: Environmental Engineering Laboratory, College of Resource and Environment, Shanxi Agricultural University, Taigu, China.
authors.forename: Fenwu
authors.initials: F
authors.lastname: Liu
authors.affiliation: College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Environmental Engineering Laboratory, College of Resource and Environment, Shanxi Agricultural University, Taigu, China.
authors.forename: Shasha
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Environmental Engineering Laboratory, College of Resource and Environment, Shanxi Agricultural University, Taigu, China.
authors.forename: Lanlan
authors.initials: L
authors.lastname: Liu
authors.affiliation: Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China.
authors.forename: Lixiang
authors.initials: L
authors.lastname: Zhou
authors.affiliation: Environmental Engineering Laboratory, College of Resource and Environment, Shanxi Agricultural University, Taigu, China.
authors.forename: Wenhua
authors.initials: W
authors.lastname: Fan
mesh_terms: D000327:Adsorption; D001151:Arsenic / Q000302:isolation & purification*; D005296:Ferrous Compounds / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D058085:Iron Compounds / Q000138:chemical synthesis*; D010084:Oxidation-Reduction; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification
chemical_list: D005296:Ferrous Compounds; D058085:Iron Compounds; D014874:Water Pollutants, Chemical; C511969:schwertmannite; C020748:ferrous sulfate; D006861:Hydrogen Peroxide; D001151:Arsenic