Enhanced removal of nitrate by a novel composite: Nanoscale zero valent iron supported on pillared clay

Zhang, Yun; Li, Yimin; Li, Jianfa; Hu, Liang; Zheng, Xuming

doi:10.1016/j.cej.2011.04.022

Cited by 184 publications

(63 citation statements)

References 32 publications

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“…Indeed, the achieved performances, taking into account the different operational conditions tested, are comparable with those observed using other types of materials containing nanoscopic zero-valent iron [1,3]. The results detected in this work, being the experiments carried out without the deoxygenation of treatment solutions, proved also that the Pb 2+ removal can occur efficiently in an aerobic environment [18].…”

Section: Tests With Mgo_nzvisupporting

confidence: 72%

Nanoscopic Zero-Valent Iron Supported on MgO for Lead Removal from Waters

Siciliano

Limonti

2018

Water

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Lead is one of the most toxic heavy metals that can create a severe risk to water ecosystem health. Zero-valent iron is an effective material for Pb 2+ removal treatments. In particular, nanoscopic zero-valent iron (nZVI) particles are characterized by high reaction rates; nevertheless, their utilization in water and groundwater remediation techniques requires further investigations. Indeed, it is necessary to define effective methods able to avoid the drawbacks due to the aggregation tendency of nanoparticles and their potential uncontrolled transport in groundwater. In this work, nZVI was supported on magnesium oxide grains (MgO_nZVI) to synthesize an alternative material for lead removal from aqueous solutions. Many experiments were conducted under several operating conditions in order to analyze the effectiveness of the produced material in Pb 2+ abatement. The performance of MgO_nZVI was also compared with those detected using commercial microscopic Fe 0 (mZVI) as a reactive material. The experimental findings showed a much greater reactivity of the supported nanoscopic iron particles. By means of a kinetic analysis of batch tests results, it was verified that, both for MgO_nZVI and mZVI, the lead abatement follows a pseudo-second-order kinetic law. The reaction rates were affected by the initial pH of the treatment solution and by the ratio between the Fe 0 amount and initial lead concentration. The efficiency of MgO_nZVI in a continuous test was steadily around 97.5% for about 1000 exchanged pore volumes (PV) of reactive material, while by using mZVI, the lead removal was approximately 88% for about 600 PV. X-ray diffraction (XRD) and energy-dispersive spectroscopy EDS analyses suggested the formation of typical iron corrosion products and the presence of metallic lead Pb 0 and Pb 2+ compounds on exhausted materials.

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Section: Tests With Mgo_nzvisupporting

confidence: 72%

Nanoscopic Zero-Valent Iron Supported on MgO for Lead Removal from Waters

Siciliano

Limonti

2018

Water

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“…According to our previous research on the NZVI supported on pillared bentonites, the enhanced adsorption by bentonites has resulted in the surprising advance on NZVI reactivity. For example, NZVI supported on poly(hydroxo Al(III)) cations-pillared bentonite (Al-bent) resulted in the enhanced nitrate removal [26], while NZVI supported on hydrophobic organobentonite showed enhanced removal of organic contaminants [27,28]. Despite the compelling results on the enhanced removal of various contaminants by using NZVI supported on pillared bentonites, the understanding on mechanisms responsible for the enhancement is still insufficient due to the complexity of this novel supported NZVI system.…”

Section: Introductionmentioning

confidence: 95%

Mechanism insights into enhanced Cr(VI) removal using nanoscale zerovalent iron supported on the pillared bentonite by macroscopic and spectroscopic studies

Zhang

2012

Journal of Hazardous Materials

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“…Using support materials to immobilize NZVI is one possible way to solve the above-mentioned problem. As reported in the literatures, active carbon [21,22], clay minerals [23], zeolite [24] and polymeric resin [25,26] have been successfully employed as supporters to control the size and morphology of iron nanoparticles. It is well-known that the removal capacity of supported NZVI is directly related to the Fe 0 loading.…”

Section: Introductionmentioning

confidence: 97%

Effect of Fe loading quantity on reduction reactivity of nano zero-valent iron supported on chelating resin

Shi

Long

et al. 2015

Front. Environ. Sci. Eng.

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In this study, nanoscale zero-valent iron (NZVI) were immobilized within a chelating resin (DOW 3N). To investigate the effect of Fe loading on NZVI reactivity, three NZVI-resin composites with different Fe loading were obtained by preparing Fe(III) solution in 0, 30 and 70% (v/v) ethanol aqueous, respectively; the bromate was used as a model contaminant. TEM reveals that increasing the Fe loading resulted in much larger size and poor dispersion of nanoscale iron particles. The results indicated that the removal efficiency of bromate and the rate constant (K obs ) were decreased with increasing the Fe loading. For the NZVI-resin composite with lower Fe loading, the removal efficiency of bromate declined more significantly with the increase of DO concentrations. Under acidic conditions, decreasing the pH value had the most significant influence on NZVI-R3 with highest Fe loading for bromate removal; however, under alkaline conditions, the most significant influence of pH was on NZVI-R1 with lowest Fe loading. The effects of co-existing anions NO -3 , PO 3 -4 and HCO -3 were also investigated. All of the co-existing anions showed the inhibition to bromate reduction.

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Enhanced removal of nitrate by a novel composite: Nanoscale zero valent iron supported on pillared clay

Cited by 184 publications

References 32 publications

Nanoscopic Zero-Valent Iron Supported on MgO for Lead Removal from Waters

Nanoscopic Zero-Valent Iron Supported on MgO for Lead Removal from Waters

Mechanism insights into enhanced Cr(VI) removal using nanoscale zerovalent iron supported on the pillared bentonite by macroscopic and spectroscopic studies

Effect of Fe loading quantity on reduction reactivity of nano zero-valent iron supported on chelating resin

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