scholarly journals New insights into the activity of a biochar supported nanoscale zerovalent iron composite and nanoscale zero valent iron under anaerobic or aerobic conditions

RSC Advances ◽  
2017 ◽  
Vol 7 (15) ◽  
pp. 8755-8761 ◽  
Author(s):  
Xiangqi Peng ◽  
Xiaocheng Liu ◽  
Yaoyu Zhou ◽  
Bo Peng ◽  
Lin Tang ◽  
...  
Keyword(s):  
Zero Valent Iron ◽  
Zerovalent Iron ◽  
Batch Experiments ◽  
Aerobic Conditions ◽  
Nanoscale Zerovalent Iron ◽  
Nanoscale Zero Valent Iron ◽  
Insight Into

To gain insight into the mechanism of p-nitrophenol removal using the biochar supported nanoscale zerovalent iron composite and nanoscale zero valent iron under anaerobic or aerobic conditions, batch experiments and models were conducted.

Properties and reactivity of sulfidized nanoscale zero-valent iron prepared with different borohydride amounts

2021 ◽  
Author(s):  
Zhen Cao ◽  
Hao Li ◽  
Shuangyu Zhang ◽  
Yunxuan Hu ◽  
Jiang Xu ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Reduction Method ◽  
Zero Valent Iron ◽  
Zerovalent Iron ◽  
Nanoscale Zerovalent Iron ◽  
Phase Reduction ◽  
Nanoscale Zero Valent Iron

The liquid-phase reduction method with NaBH4 as the reductant is the most widely used method for sulfidized nanoscale zerovalent iron (SNZVI) synthesis. However, it is unclear how the reductant amount...

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 Surface coating with Ca(OH)2 for improvement of the transport of nanoscale zero-valent iron (nZVI) in porous media

2013 ◽  
Vol 68 (10) ◽  
pp. 2287-2293 ◽  
Author(s):  
Cai-jie Wei ◽  
Xiao-yan Li
Keyword(s):  
Porous Media ◽  
Surface Coating ◽  
Coating Layer ◽  
Zero Valent Iron ◽  
Mass Ratio ◽  
Batch Experiments ◽  
Effective Protection ◽  
Transmission Electron ◽  
Nanoscale Zero Valent Iron ◽  
Protection Layer

A novel thermal deposition method was developed to coat Ca(OH)2 on the surface of nanoscale zero-valent iron (nZVI). The nZVI particles with the Ca(OH)2 coating layer, nZVI/Ca(OH)2, had a clear core-shell structure based on the transmission electron microscopy observations, and the Ca(OH)2 shell was identified as an amorphous phase. The Ca(OH)2 coating shell would not only function as an effective protection layer for nZVI but also improve the mobility of nZVI in porous media for its use in environmental decontamination. A 10% Ca/Fe mass ratio was found to result in a proper thickness of the Ca(OH)2 shell on the nZVI surface. Based on the filtration tests in sand columns, the Ca(OH)2-based surface coating could greatly improve the mobility and transport of nZVI particles in porous media. In addition, batch experiments were conducted to evaluate the reactivity of Ca(OH)2-coated nZVI particles for the reduction of Cr(VI) and its removal from water.

scholarly journals Removal of cadmium from aqueous solutions using industrial coal fly ash-nZVI

2018 ◽  
Vol 5 (2) ◽  
pp. 171051 ◽  
Author(s):  
Lixia Ma ◽  
Qi Wei ◽  
Yueqin Chen ◽  
Qiuyang Song ◽  
Conghui Sun ◽  
...  
Keyword(s):  
Fly Ash ◽  
Low Cost ◽  
Coal Fly Ash ◽  
Zerovalent Iron ◽  
Solution Properties ◽  
Batch Experiments ◽  
Nanoscale Zerovalent Iron ◽  
Wide Range ◽  
Short Time ◽  
Cd Removal

Batch experiments were conducted to test the effects of various solution properties, such as pH, temperature, initial concentration and anoxic and aerobic atmosphere, on Cd removal by nanoscale zerovalent iron (nZVI) supported on industrial coal fly ash. Cd (II) could be removed by adsorption on fly ash-nZVI in a very short time (5 min) with high removal rates (greater than 99.9%) over a wide range of concentration (5–100 mg l −1 ). Cd (II) was physically adsorbed on the surface of fly ash-nZVI. The preparation of fly ash-nZVI can incorporate the use of waste media, making the overall adsorbent more removal efficient and low cost.

Evaluation of the effects of nanoscale zero-valent iron (nZVI) dispersants on intrinsic biodegradation of trichloroethylene (TCE)

2014 ◽  
Vol 69 (11) ◽  
pp. 2357-2363 ◽  
Author(s):  
Y. C. Chang ◽  
S. C. Huang ◽  
K. F. Chen
Keyword(s):  
Zero Valent Iron ◽  
Adverse Impact ◽  
Tween 20 ◽  
Anaerobic Conditions ◽  
Sorbitan Monolaurate ◽  
Aerobic Conditions ◽  
Microcosm Study ◽  
Nanoscale Zero Valent Iron ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

In this study, the biodegradability of nanoscale zero-valent iron (nZVI) dispersants and their effects on the intrinsic biodegradation of trichloroethylene (TCE) were evaluated. Results of a microcosm study show that the biodegradability of three dispersants followed the sequence of: polyvinyl alcohol-co-vinyl acetate-co-itaconic acid (PV3A) > polyoxyethylene (20) sorbitan monolaurate (Tween 20) > polyacrylic acid (PAA) under aerobic conditions, and PV3A > Tween 20 > PAA under anaerobic conditions. Natural biodegradation of TCE was observed under both aerobic and anaerobic conditions. No significant effects were observed on the intrinsic biodegradation of TCE under aerobic conditions with the presence of the dispersants. The addition of PAA seemed to have a slightly adverse impact on anaerobic TCE biodegradation. Higher accumulation of the byproducts of anaerobic TCE biodegradation was detected with the addition of PV3A and Tween 20. The diversity of the microbial community was enhanced under aerobic conditions with the presence of more biodegradable PV3A and Tween 20. The results of this study indicate that it is necessary to select an appropriate dispersant for nZVI to prevent a residual of the dispersant in the subsurface. Additionally, the effects of the dispersant on TCE biodegradation and the accumulation of TCE biodegrading byproducts should also be considered.

Insight into the removal of graphene oxide by nanoscale zero-valent iron

2020 ◽  
Vol 314 ◽  
pp. 113553
Author(s):  
Zehua Zhang ◽  
Xia Liu ◽  
Jin Wu ◽  
Xuemei Ren ◽  
Jiaxing Li
Keyword(s):  
Graphene Oxide ◽  
Zero Valent Iron ◽  
Nanoscale Zero Valent Iron ◽  
Insight Into

scholarly journals Removal of Zinc by Nano-Scale Zero Valent Iron in Groundwater

2015 ◽  
Vol 773-774 ◽  
pp. 1231-1236 ◽  
Author(s):  
Nik Nurul Ilani Nik Redzauddin ◽  
Jalina Kassim ◽  
Amnorzahira Amir
Keyword(s):  
Electron Microscope ◽  
Outer Part ◽  
Zero Valent Iron ◽  
Basic Knowledge ◽  
Zerovalent Iron ◽  
Toxic Heavy Metals ◽  
Reactive Surface Area ◽  
Nanoscale Zerovalent Iron ◽  
Transmission Electron ◽  
Potential Alternative

Groundwater has long been identified as potential alternative of clean water supply due to its reliable quantity. However, pollution of groundwater due to anthropogenic factor still remains a challenging issue. To date, nanoscale zero valent iron (nZVI) has received great attention for its capability to treat various contaminants including chlorinated organics and metals. This study investigate Zinc (Zn) removal in aqueous solution by nanoscale zerovalent iron (nZVI). The characteristics study of the synthesized nZVI particles were investigated by its particle size and surface morphology using Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). SEM and TEM analyses verified that the particles size of synthesized nZVI were 71nm (< 100 nm). Structure of nZVI congragate to each other and a thin layer of oxide layer formed on the outer part of the nZVI particle. In the batch study, removal kinetic of Zn increased from 0.14 to 0.18 mins-1 as the concentration of Zn increased from 0.1 to 0.5 ppm. However, the removal kinetic decreased from 0.162 to 0.148 mins-1 as the amount of nZVI was increased from 0.25 mg/L to 2.50 mg/L. At pH 7, removal kinetic reached 0.157 mins-1. However as the pH suspension decreases to pH 6.5, the removal kinetics decreased significantly to 0.144 mins-1. The same behaviour was observed at pH 9 where the removal kinetics was decreased to 0.117 mins-1. Removal kinetic of Zn significantly decreased at basic condition due to the formation of passivation layer which decreased the density of reactive surface area (e.g., Fe0 and Fe2+) on the surface of nZVI. Experimental results from this study can provide basic knowledge of effectiveness of Zn removal mechanisms by nZVI at different environment conditions and provide potential remediation technology for the treatment of toxic heavy metals in groundwater.

Sign in / Sign up

Export Citation Format

Share Document