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

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Yiming Su ◽  
Adeyemi S. Adeleye ◽  
Yuxiong Huang ◽  
Xuefei Zhou ◽  
Arturo A. Keller ◽  
...  
Keyword(s):  
Groundwater Remediation ◽  
Direct Synthesis ◽  
Reduction Rate ◽  
Zerovalent Iron ◽  
Contaminated Water ◽  
Cadmium Removal ◽  
Edge Structure ◽  
X Ray ◽  
Nanoscale Zerovalent Iron ◽  
Removal Capacity

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 Fe2+ to Fe0 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 Fe0 crystals. Nano-SiO2 seeding brings down the size of single Fe0 grain from 32.4 nm to 18.7 nm, enhances final Fe0 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.

scholarly journals Removal of hexavalent chromium from wastewater by Cu/Fe bimetallic nanoparticles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jien Ye ◽  
Yi Wang ◽  
Qiao Xu ◽  
Hanxin Wu ◽  
Jianhao Tong ◽  
...  
Keyword(s):  
Hexavalent Chromium ◽  
Removal Efficiency ◽  
Photoelectron Spectroscopy ◽  
Bimetallic Nanoparticles ◽  
Chemical Reduction ◽  
Particle Surface ◽  
Zerovalent Iron ◽  
Order Model ◽  
X Ray ◽  
Nanoscale Zerovalent Iron

AbstractPassivation of nanoscale zerovalent iron hinders its efficiency in water treatment, and loading another catalytic metal has been found to improve the efficiency significantly. In this study, Cu/Fe bimetallic nanoparticles were prepared by liquid-phase chemical reduction for removal of hexavalent chromium (Cr(VI)) from wastewater. Synthesized bimetallic nanoparticles were characterized by transmission electron microscopy, Brunauer–Emmet–Teller isotherm, and X-ray diffraction. The results showed that Cu loading can significantly enhance the removal efficiency of Cr(VI) by 29.3% to 84.0%, and the optimal Cu loading rate was 3% (wt%). The removal efficiency decreased with increasing initial pH and Cr(VI) concentration. The removal of Cr(VI) was better fitted by pseudo-second-order model than pseudo-first-order model. Thermodynamic analysis revealed that the Cr(VI) removal was spontaneous and endothermic, and the increase of reaction temperature facilitated the process. X-ray photoelectron spectroscopy (XPS) analysis indicated that Cr(VI) was completely reduced to Cr(III) and precipitated on the particle surface as hydroxylated Cr(OH)3 and CrxFe1−x(OH)3 coprecipitation. Our work could be beneficial for the application of iron-based nanomaterials in remediation of wastewater.

scholarly journals Synthesis of Nanoscale Zerovalent Iron (nZVI) Supported on Biochar for Chromium Remediation from Aqueous Solution and Soil

2019 ◽  
Vol 16 (22) ◽  
pp. 4430 ◽  
Author(s):  
Haixia Wang ◽  
Mingliang Zhang ◽  
Hongyi Li
Keyword(s):  
Aqueous Solution ◽  
Photoelectron Spectroscopy ◽  
Zero Valent Iron ◽  
Zerovalent Iron ◽  
X Ray ◽  
Nanoscale Zerovalent Iron ◽  
Before And After ◽  
Pseudo Second Order ◽  
Xrd Patterns ◽  
Co Precipitation

Maize straw biochar-supported nanoscale zero-valent iron composite (MSB-nZVI) was prepared for efficient chromium (Cr) removal through alleviating the aggregation of zero-valent iron particles. The removal mechanism of MSB-nZVI was investigated by scanning electron microscopy with energy dispersive X-ray (SEM-EDX), X-ray diffractometry (XRD), and X-ray photoelectron spectroscopy (XPS). Cr(VI) removal from aqueous solution by MSB-nZVI was greatly affected by pH and initial concentration. The removal efficiency of Cr(VI) decreased with increasing pH, and the removal kinetics followed the pseudo-second-order model. XRD patterns of MSB-nZVI before and after reaction showed that reduction and precipitation/co-precipitation (FeCr2O4, Fe3O4, Fe2O3) occurred with the conversion of Cr(VI) to Cr(III) and Fe(0) to Fe(II)/Fe(III). The produced precipitation/co-precipitation could be deposited on the MSB surface rather than being only coated on the surface of nZVI particles, which can alleviate passivation of nZVI. For remediation of Cr(VI)-contaminated saline–alkali soil (pH 8.6–9.0, Cr 341 mg/kg), the released amount of Cr(VI) was 70.7 mg/kg, while it sharply decreased to 0.6–1.7 mg/kg at pH 4.0–8.0, indicating that the saline–alkali environment inhibited the remediation efficiency. These results show that MSB-nZVI can be used as an effective material for Cr(VI) removal from aqueous solution and contaminated soil.

scholarly journals Tunable formation of copper metal, oxide, chloride and hydroxyl chloride nanoparticles from aqueous copper solutions using nanoscale zerovalent iron particles

2019 ◽  
Vol 9 ◽  
pp. 184798041988617 ◽  
Author(s):  
Richard Crane ◽  
Devin Sapsford
Keyword(s):  
High Purity ◽  
High Surface ◽  
High Surface Area ◽  
Zerovalent Iron ◽  
One Pot ◽  
Physicochemical Composition ◽  
Nanoscale Zerovalent Iron ◽  
Removal Capacity ◽  
Initial Ph ◽  
Process Solutions

The influence of different parameters (solid–liquid ratio, initial pH, initial Cu concentration and anion type) on the cementation of aqueous copper (Cu) with nanoscale zerovalent iron (nZVI) has been studied. The work has been established to study both the influence such parameters have on the kinetics and efficacy of the cementation process but also the physicochemical composition of resultant Cu-bearing products. The nZVI exhibited high Cu removal capacity (maximum removal 905.2 mg/g) due to its high surface area. X-ray diffraction determined the most common Cu-bearing precipitates were Cu2O, CuCl2 and Cu2(OH)3Cl for solutions containing Cl− counterions (CuCl2 salt precursor), while Cu0 and Cu2O were the most common phases for those containing [Formula: see text] counterions (CuSO4 salt precursor). Transmission electron microscopy determined such precipitates were discrete nanoparticles of relatively high purity Cu (e.g. >80 wt% Cu or ≥99.9 wt% Cu and O). Overall the results demonstrate nZVI as effective for the one-pot transformation of aqueous Cu into a range of different high purity Cu-bearing nanoparticles. The methodology developed herein is therefore likely to have important application in the recovery of Cu from wastewater and process solutions where the direct upcycling to high-value Cu-bearing nanoparticles is an advantageous form in which to recover Cu.

Nanoscale zerovalent iron particles for groundwater remediation: a review

2014 ◽  
Vol 77 ◽  
pp. 10-21 ◽  
Author(s):  
Tiziana Tosco ◽  
Marco Petrangeli Papini ◽  
Carolina Cruz Viggi ◽  
Rajandrea Sethi
Keyword(s):  
Groundwater Remediation ◽  
Zerovalent Iron ◽  
Iron Particles ◽  
Nanoscale Zerovalent Iron

scholarly journals Removal of Different Kinds of Heavy Metals by Novel PPG-nZVI Beads and Their Application in Simulated Stormwater Infiltration Facility

2019 ◽  
Vol 9 (20) ◽  
pp. 4213
Author(s):  
Xiaoran Zhang ◽  
Lei Yan ◽  
Junfeng Liu ◽  
Ziyang Zhang ◽  
Chaohong Tan
Keyword(s):  
Metal Ions ◽  
Adsorption Process ◽  
Guar Gum ◽  
Removal Rate ◽  
Zerovalent Iron ◽  
Contaminated Water ◽  
Maximum Adsorption Capacity ◽  
Covalent Bonds ◽  
Nanoscale Zerovalent Iron ◽  
Stormwater Infiltration

Polyvinyl alcohol and pumice synthetized guar gum-nanoscale zerovalent iron beads (PPG-nZVI beads) were synthesized, and their adsorption towards Pb2+, Cu2+, and Zn2+ ions was evaluated. The adsorption kinetics of metal ions was well fitted by the pseudo-second-order model. The adsorption rate decreased followed in the order of Cu2+ > Pb2+ > Zn2+, consistent with the reduction potential of the ions. The sorption isotherm was well fitted by Langmuir model. The maximum adsorption capacity decreased followed in the order of Pb2+ > Cu2+ > Zn2+, which suggested that the strength of covalent bonds between the metal ions and surface functional groups substituted to the beads is one of the major factors in the adsorption process. Adsorption increased with the increase of pH and the largest sorption occurred at pH 5.5, while ionic strength did not significantly influence the adsorption process. The application of PPG-nZVI beads as filling materials in the simulated stormwater infiltration facility shows good removal efficiency in treating the contaminated water containing Pb2+, Cu2+, Zn2+, Cr6+, and Cd2+ and the removal rate was more than 65% at least. The results indicated that the PPG-nZVI beads could be applied as promising sorbents for purification of heavy metal contaminated water.

Potential of zerovalent iron nanoparticles for remediation of environmental organic contaminants in water: a review

2013 ◽  
Vol 68 (7) ◽  
pp. 1425-1439 ◽  
Author(s):  
Trishikhi Raychoudhury ◽  
Traugott Scheytt
Keyword(s):  
Organic Contaminants ◽  
Reaction Rates ◽  
Zerovalent Iron ◽  
Azo Compounds ◽  
Contaminated Water ◽  
Molecular Weights ◽  
Nanoscale Zerovalent Iron ◽  
Iodinated Contrast ◽  
Zerovalent Iron Nanoparticles ◽  
Time Required

Zerovalent iron (ZVI) has the potential to degrade different organic contaminants. Nanoscale zerovalent iron (NZVI) can reduce the contaminants even more rapidly due to its small size and large specific surface area (SSA), compared to granular ZVI. The main objective of this paper is to assess and compare the potential of NZVI for degradation of different contaminants in water under specific environmental conditions. As a first step, the potential reactive functional groups/bonds associated with different contaminants are identified and possible reaction mechanisms are discussed. Thereafter, the reaction efficiencies of different organic contaminants with NZVI are compared. Mass of ZVI and reaction time required to transform a certain amount of contaminated water are calculated based on literature data. Sources of contaminants in the environment and their environmental occurrences are discussed to understand the potential locations where NZVI could be applied for removal of different contaminants. Overall it is observed that azo-compounds are readily transformed in the presence of NZVI particles. Reaction efficiencies of ZVI for reduction of nitro-organic compounds are also reasonably high. However, halogenated compounds with high molecular weights or complex structures (i.e., iodinated contrast media, DDT, polychlorinated biphenyls, etc.) show lower reaction rates with NZVI compared to the widely studied chlorinated hydrocarbons (i.e., trichloroethylene).

Sign in / Sign up

Export Citation Format

Share Document