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Direct Synthesis of Novel and Reactive Sulfide-modified Nano Iron through Nanoparticle Seeding for Improved Cadmium-Contaminated Water Treatment.

Su Y, Adeleye AS, Huang Y, Zhou X, Keller AA, Zhang Y - Sci Rep (2016)

Bottom Line: Syntheses monitoring experiments show that seeding accelerates the reduction rate from Fe(2+) to Fe(0) by 19%.Both X-ray diffraction and Mössbauer analyses further confirm that increased nanoparticle seeding results in formation of more Fe(0) crystals.The synthesized nanohybrid has high cadmium removal capacity and holds promising prospects for treatment of metal-contaminated water.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai 200092, China.

ABSTRACT
Magnetic sulfide-modified nanoscale zerovalent iron (S-nZVI) is of great technical and scientific interest because of its promising application in groundwater remediation, although its synthesis is still a challenge. We develop a new nanoparticle seeding method to obtain a novel and reactive nanohybrid, which contains an Fe(0) core covered by a highly sulfidized layer under high extent of sulfidation. Syntheses monitoring experiments show that seeding accelerates the reduction rate from Fe(2+) to Fe(0) by 19%. X-ray adsorption near edge structure (XANES) spectroscopy and extended X-ray absorption fine structure analyses demonstrate the hexahedral Fe-Fe bond (2.45 and 2.83 Å) formation through breaking down of the 1.99 Å Fe-O bond both in crystalline and amorphous iron oxide. The XANES analysis also shows 24.2% (wt%) of FeS with bond length of 2.4 Å in final nanohybrid. Both X-ray diffraction and Mössbauer analyses further confirm that increased nanoparticle seeding results in formation of more Fe(0) crystals. Nano-SiO2 seeding brings down the size of single Fe(0) grain from 32.4 nm to 18.7 nm, enhances final Fe(0) content from 5.9% to 55.6%, and increases magnetization from 4.7 to 65.5 emu/g. The synthesized nanohybrid has high cadmium removal capacity and holds promising prospects for treatment of metal-contaminated water.

No MeSH data available.


Related in: MedlinePlus

Cd2+ removal performance of FeSSi in batch experiments (A) and simulated permeable reactive barrier (PRB) (B) remediation experiment.
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f7: Cd2+ removal performance of FeSSi in batch experiments (A) and simulated permeable reactive barrier (PRB) (B) remediation experiment.

Mentions: Our previous study showed that sulfidation of nZVI can improve its Cd2+ removal capacity13, but the magnetic properties of the synthesized particles decreases with increasing sulfidation. The loss of magnetism makes it difficult to perform magnetic solid-liquid separation, and thus makes it difficult to apply S-nZVI for water treatment. Through nanoparticles seeding, not only was sulfidation enhanced further, but magnetization was preserved. Cd2+ removal capacity of FeSSi was determined as 105 mg/g (Fig. 7A), which is much higher than that of nZVI (40 mg/g) and S-nZVI (80 mg/g)13. Chemical adsorption and precipitation are responsible for the Cd2+ immobilization. Additionally, FeSSi was also used to sequester Cu2+, Pb2+, Ni2+, Sb2O74− and Mo2O72− from artificial wastewater. After 2 hr reaction, in FeSSi system, the final concentration of metals were below the detection limit of ICP (Table S2), indicating that FeSSi is able to immobilize both metal cations and metal-oxo cluster anions.


Direct Synthesis of Novel and Reactive Sulfide-modified Nano Iron through Nanoparticle Seeding for Improved Cadmium-Contaminated Water Treatment.

Su Y, Adeleye AS, Huang Y, Zhou X, Keller AA, Zhang Y - Sci Rep (2016)

Cd2+ removal performance of FeSSi in batch experiments (A) and simulated permeable reactive barrier (PRB) (B) remediation experiment.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4837343&req=5

f7: Cd2+ removal performance of FeSSi in batch experiments (A) and simulated permeable reactive barrier (PRB) (B) remediation experiment.
Mentions: Our previous study showed that sulfidation of nZVI can improve its Cd2+ removal capacity13, but the magnetic properties of the synthesized particles decreases with increasing sulfidation. The loss of magnetism makes it difficult to perform magnetic solid-liquid separation, and thus makes it difficult to apply S-nZVI for water treatment. Through nanoparticles seeding, not only was sulfidation enhanced further, but magnetization was preserved. Cd2+ removal capacity of FeSSi was determined as 105 mg/g (Fig. 7A), which is much higher than that of nZVI (40 mg/g) and S-nZVI (80 mg/g)13. Chemical adsorption and precipitation are responsible for the Cd2+ immobilization. Additionally, FeSSi was also used to sequester Cu2+, Pb2+, Ni2+, Sb2O74− and Mo2O72− from artificial wastewater. After 2 hr reaction, in FeSSi system, the final concentration of metals were below the detection limit of ICP (Table S2), indicating that FeSSi is able to immobilize both metal cations and metal-oxo cluster anions.

Bottom Line: Syntheses monitoring experiments show that seeding accelerates the reduction rate from Fe(2+) to Fe(0) by 19%.Both X-ray diffraction and Mössbauer analyses further confirm that increased nanoparticle seeding results in formation of more Fe(0) crystals.The synthesized nanohybrid has high cadmium removal capacity and holds promising prospects for treatment of metal-contaminated water.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai 200092, China.

ABSTRACT
Magnetic sulfide-modified nanoscale zerovalent iron (S-nZVI) is of great technical and scientific interest because of its promising application in groundwater remediation, although its synthesis is still a challenge. We develop a new nanoparticle seeding method to obtain a novel and reactive nanohybrid, which contains an Fe(0) core covered by a highly sulfidized layer under high extent of sulfidation. Syntheses monitoring experiments show that seeding accelerates the reduction rate from Fe(2+) to Fe(0) by 19%. X-ray adsorption near edge structure (XANES) spectroscopy and extended X-ray absorption fine structure analyses demonstrate the hexahedral Fe-Fe bond (2.45 and 2.83 Å) formation through breaking down of the 1.99 Å Fe-O bond both in crystalline and amorphous iron oxide. The XANES analysis also shows 24.2% (wt%) of FeS with bond length of 2.4 Å in final nanohybrid. Both X-ray diffraction and Mössbauer analyses further confirm that increased nanoparticle seeding results in formation of more Fe(0) crystals. Nano-SiO2 seeding brings down the size of single Fe(0) grain from 32.4 nm to 18.7 nm, enhances final Fe(0) content from 5.9% to 55.6%, and increases magnetization from 4.7 to 65.5 emu/g. The synthesized nanohybrid has high cadmium removal capacity and holds promising prospects for treatment of metal-contaminated water.

No MeSH data available.


Related in: MedlinePlus