Effect of common ions on nitrate removal by zero-valent iron from alkaline soil

Tang, Cilai; Zhang, Zengqiang; Sun, Xiaojing

doi:10.1016/j.jhazmat.2012.06.042

Cited by 54 publications

(20 citation statements)

References 39 publications

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“…Moreover, nitrate reduction by ZVI can occur at pH>8.0 (Tang et al 2012). However, previous studies also showed that although nitrate reduction by ZVI is effective under acidic conditions (pH<7.0), it is insignificant in alkaline conditions (pH>8.0) (Huang et al 1998;Choe et al 2004;Huang and Zhang 2004).…”

Section: Evolution Of Nitrogen Compounds In Various Systemsmentioning

confidence: 94%

“…In situ chemical reduction of nitrate is achievable mainly using zero-valent iron (ZVI), which is the most frequently utilized media both in laboratory studies and field applications (Bruzzoniti and Fiore 2014;Obiri-Nyarko et al 2014;Kowalski and Søgaard 2014). Although previous studies have shown ZVI to be effective in nitrate reduction, this process has some drawbacks regarding product ammonium which must be successively removed (Alowitz and Scherer 2002;Huang and Zhang 2002;Su and Puls 2004); the requirement for acidic conditions (Fan et al 2009) and, furthermore, some coexistent ions and pollutants acting as ligands on ZVI significantly reduce nitrate reduction rate (Tang et al 2012). However, a study has shown that the use of hydrogenotrophic bacteria in the process of nitrate reduction by nanoscale ZVI can decrease the ammonium generation and transform nitrate to nitrogen gas ).…”

Section: Introductionmentioning

confidence: 99%

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Nitrate-Contaminated Water Remediation Supported by Solid Organic Carbon and ZVI-Combined System

Wang

et al. 2015

Water Air Soil Pollut

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Solid organic carbon and zero-valent iron (ZVI) have been used separately as reactive media in permeable reactive barriers (PRBs) to degrade nitrate in groundwater, but few studies have examined the combination of the two materials in one system for nitrate remediation. In the present study, batch tests are conducted to evaluate three common solid organic carbons and their combination with ZVI for nitrate removal from water. The results show that the combined system achieves better denitrification efficiency than that measured with sawdust or cotton alone. However, no obvious difference is noted between the cornstalk alone and its mixture with ZVI treatment. When complete nitrate removal is achieved in the system that combined ZVI with sawdust or cotton, only 72 and 62.6 % of nitrate removal, respectively, are obtained in which the carbon (C) source is used alone. The results indicate that there are synergistic effects in the combined denitrification system, and the effects depend on the type of carbon material used. Sawdust is an alternative carbon source for nitrate removal in a C-ZVI-combined system. In a sawdust-ZVI system, the accumulation of nitrite and ammonium is affected greatly by nitrate concentration, C/N ratio, and Fe/N ratio.

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Section: Evolution Of Nitrogen Compounds In Various Systemsmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

Nitrate-Contaminated Water Remediation Supported by Solid Organic Carbon and ZVI-Combined System

Wang

et al. 2015

Water Air Soil Pollut

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“…The improved removal efficiency at high levels of sulfate should be ascribed to the fact that sulfate could accelerate electron generation as a corrosion promoter [27], thus created more reactive sites on the iron surface. Iron corrosion and electron release were the prerequisites of pollutant degradation [32]. And it has been suggested that sulfate promotes the corrosion of Fe 0 through destabilizing the passivation layers on the iron surface [33].…”

Section: Effects Of Ha and Co-existing Ionsmentioning

confidence: 99%

Comprehensive study on the removal of chromate from aqueous solution by synthesized kaolin supported nanoscale zero-valent iron

Wang

Zhen

Ding

et al. 2015

Desalination and Water Treatment

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A removal mechanism of chromate (Cr) by synthesized kaolin supported nanoscale zerovalent iron (K-nZVI) from aqueous solution is demonstrated. Parameters which potentially influenced the functioning of K-nZVI have been investigated as well. Based on the scanning electron microscopy, Fourier transform infrared spectroscopes, X-ray crystal powder diffraction and X-ray photoelectron spectroscopy identifications, we confirm that amorphous Fe 0 core/Fe x O y shell nZVI can be successfully loaded into the pores and cracks, and onto the surface of kaolin. Removal efficiency of Cr by K-nZVI decreased with increasing initial pH and Cr(VI) concentration, but increased while K-nZVI dosage increased. Humic acid and phosphate had similar dual impacts on chromium removal by K-nZVI, and the inhibitory effect was obvious at high concentrations in spite of their different reaction mechanisms. In contrast, high concentrations of sulfate and nitrate could advance the chromium removal. Adsorption isotherms indicate that the removal processes are endothermic. The data obtained can be better explained with Langmuir than Freundlich model. At the conditions of 318 K and optimized pH 4.0, the maximum adsorption capacity was 33.39 mg g −1 illustrating that K-nZVI was effective for the removal of total Cr. The removal mechanism is proposed to divide into four phases, including: (1) aqueous Cr(VI) ions are captured on the surface of K-nZVI; (2) the captured Cr(VI) are partly reduced to Cr(III) accompanied by Fe 0 oxidizing to Fe 2+ ; (3) part of oxidized Fe 2+ continues to reduce Cr(VI); and (4) produced Cr(III), Fe 2+ , and Fe 3+ are formed passivation layers on the K-nZVI surface which prevent further removal of chromium and result in redundant Fe 0 .

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“…[1][2][3][4] Numerous studies [5][6][7][8][9][10][11][12][13] have shown that nZVI can effectively degrade chlorinated solvents, organo-chlorine pesticides, organic dyes, and inorganic pollutants, such as perchlorate, nitrate, and heavy metal ions. However, high reactivity is not the only decisive factor that makes nZVI an excellent in situ remediation agent; the transport and delivery properties of nZVI in porous media are other crucial elements in the successful remediation of contaminated sites using nZVI technology.…”

Section: Transport Characteristics Of Nanoscale Zero-valent Iron Carrmentioning

confidence: 99%

Transport characteristics of nanoscale zero-valent iron carried by three different “vehicles” in porous media

Zhao

et al. 2014

Journal of Environmental Science and Health, Part A

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This study investigated the transport properties of nanoscale zero-valent iron (Fe(0)) (nZVI) carried by three vehicles: water, sodium dodecyl sulfate (SDS) solution, and SDS foam. Batch experiments were conducted to assess the sedimentation capability of nZVI particles in these three vehicles. Column experiments were conducted to investigate the transport properties of nZVI in porous media formed with different sizes of sand (0.25 mm to 0.5 mm, 0.5 mm to 0.9 mm, and 0.9 mm to 1.4 mm). Three main results were obtained. First, the batch experiments revealed that the stabilities of nZVI particles in SDS solution and SDS foam were improved, compared with that of nZVI particles in water. Moreover, the sedimentation of nZVI in foam was closely associated with the foam drainage volume. The nZVI content in foam was similar to that in the original foaming suspension, and the nZVI particle distribution in foam became significantly more uniform at a stirring speed of 3000 r/min. Second, the transport of nZVI was enhanced by foam compared with water and SDS solution for 0.25 mm to 0.5 mm diameter sand. For sand with diameters of 0.5 mm to 0.9 mm and 0.9 mm to 1.4 mm, the mobility of nZVI carried by SDS solution was optimal, followed by that of nZVI carried by foam and water. Thus, the mobility of nZVI in finer sand was significantly enhanced by foam, compared with that in coarse sand. In contrast, compared with the bare nZVI suspension and nZVI-laden foam, the spatial distribution of nZVI particles carried by SDS solution was significantly uniform along the column length. Third, the SDS concentration significantly influenced the migration of nZVI in porous media. The enhancement in the migration of nZVI carried by SDS solution was greater at an SDS dose of 0.25% compared with that at the other three doses (0.2%, 0.5%, and 1%) for sand with a 0.25 mm to 0.5 mm diameter. Increased SDS concentrations positively affected the transport of nZVI by foam for sand with a 0.25 mm to 0.5 mm diameter, and the SDS concentrations for enhancing the mobility of nZVI carried by SDS foam satisfied the following order: 1% > 0.5% > 0.25% > 0.2%. Thus, SDS solution and SDS foam were better vehicles than water for delivering nZVI particles to porous media for contamination remediation.

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Effect of common ions on nitrate removal by zero-valent iron from alkaline soil

Cited by 54 publications

References 39 publications

Nitrate-Contaminated Water Remediation Supported by Solid Organic Carbon and ZVI-Combined System

Nitrate-Contaminated Water Remediation Supported by Solid Organic Carbon and ZVI-Combined System

Comprehensive study on the removal of chromate from aqueous solution by synthesized kaolin supported nanoscale zero-valent iron

Transport characteristics of nanoscale zero-valent iron carried by three different “vehicles” in porous media

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