Synthesis of reactive iron
Chemical reduction method of Ferric chloride by sodium borohydride following reaction (Eq.1), was used to synthesize ZVI [14].
〖2FeCl〗_3+〖6NaBH〗_4+〖18H〗_2 O→〖2Fe〗^0+〖21H〗_2+〖6B(OH)〗_3+6NaCl (1)
Ferric chloride hexahydrate solution was prepared by dissolving 5 g of FeCl_3.H_2 O (99.0%, Junsei Chemical Co., Japan) in 125 mL of deoxygenated deionized (DI) water. Moreover, 3.5 g of Sodium borohydride (NaBH_4, 98.0%, Sigma–Aldrich Inc., USA) were dissolved in 125 mL of (DI) water and pumped dropwise into a 500 mL four-nick flask kept in water bath with stirring (at 25 ± 0.5° C and 250 rpm) containing the former ferric chloride solution using a roller pump at a rate of 20 mL/min. In order to reduce the oxidation of ZVI, anaerobic environment was provided through a continuous nitrogen gas purging during the synthesis. With regard of ensuring a complete reaction, the aging time of the mixture inside the four-nick flask was 20 min. The black iron precipitates were collected by vacuum filtration and then washed three times with DI water and anhydrous ethanol.
Batch experiments
All batch experiments were conducted in 300 mL conical flasks sealed with screw caps at room temperature (25 ± 0.5°), and mixed with a standard magnetic stirrer …show more content…
The surface morphology was investigated using a transmission electron microscopy (TEM, JEM- 2100F, JEOL Co., Japan). Laser diffraction (LD) analyzer (SALD- 2300, Shimadzu Co., Japan) was used to determine particle size of the synthesized iron particles after 30 min of ultra-sonication (US-101, SND Co, Ltd, Japan) . In order to distinguish the mineral composition of ZVI, X-ray diffraction (XRD) analysis was performed using Cu K_α radiation (λ = 1.5418 Å) on TTR Rigaku diffractometer conducting at 40 kV and 40 mA, with scanning angle (2θ) ranged from 3° to 90° and scanning speed of 2°
Chemical reduction method of Ferric chloride by sodium borohydride following reaction (Eq.1), was used to synthesize ZVI [14].
〖2FeCl〗_3+〖6NaBH〗_4+〖18H〗_2 O→〖2Fe〗^0+〖21H〗_2+〖6B(OH)〗_3+6NaCl (1)
Ferric chloride hexahydrate solution was prepared by dissolving 5 g of FeCl_3.H_2 O (99.0%, Junsei Chemical Co., Japan) in 125 mL of deoxygenated deionized (DI) water. Moreover, 3.5 g of Sodium borohydride (NaBH_4, 98.0%, Sigma–Aldrich Inc., USA) were dissolved in 125 mL of (DI) water and pumped dropwise into a 500 mL four-nick flask kept in water bath with stirring (at 25 ± 0.5° C and 250 rpm) containing the former ferric chloride solution using a roller pump at a rate of 20 mL/min. In order to reduce the oxidation of ZVI, anaerobic environment was provided through a continuous nitrogen gas purging during the synthesis. With regard of ensuring a complete reaction, the aging time of the mixture inside the four-nick flask was 20 min. The black iron precipitates were collected by vacuum filtration and then washed three times with DI water and anhydrous ethanol.
Batch experiments
All batch experiments were conducted in 300 mL conical flasks sealed with screw caps at room temperature (25 ± 0.5°), and mixed with a standard magnetic stirrer …show more content…
The surface morphology was investigated using a transmission electron microscopy (TEM, JEM- 2100F, JEOL Co., Japan). Laser diffraction (LD) analyzer (SALD- 2300, Shimadzu Co., Japan) was used to determine particle size of the synthesized iron particles after 30 min of ultra-sonication (US-101, SND Co, Ltd, Japan) . In order to distinguish the mineral composition of ZVI, X-ray diffraction (XRD) analysis was performed using Cu K_α radiation (λ = 1.5418 Å) on TTR Rigaku diffractometer conducting at 40 kV and 40 mA, with scanning angle (2θ) ranged from 3° to 90° and scanning speed of 2°