Sulfidation of nanoscale zerovalent iron in the presence of two organic macromolecules and its effects on trichloroethene degradation

Bhattacharjee, Sourjya; Ghoshal, Subhasis

doi:10.1039/c7en01205e

Cited by 24 publications

(22 citation statements)

References 42 publications

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“…Anionic polyelectrolytes are preferred because they provide both electrostatic and steric interparticle repulsion, as well as lower deposition on subsurface collector surfaces which tend to be negatively charged. , Therefore, the high molecular weight and high densities of charged functional groups make polymers like CMC ideal . The stabilizing agent can be applied by introducing the polymer before the reducing agent is added (presynthesis stabilization) or by physical adsorption to the existing nZVI particles (postsynthesis stabilization). , This distinction is important as the mode of application will affect the stability and reactivity. ,, …”

Section: Synthesis Methods and Its Impacts On S-nzvi Composition And ...mentioning

confidence: 99%

“…The S to Fe ratio associated with the particle (i.e., [S/Fe] particle ), has been recognized to be more closely related to the reactivity of S-(n)ZVI for TCE than the dosed value during synthesis (i.e., [S/Fe] dosed ), although limited data is available. , For example, the reactivity of S-nZVI synthesized using the two-step method with Na 2 S to TCE only increases with [S/Fe] dosed to a certain point, because incorporation of FeS on nZVI surface becomes difficult at higher [S/Fe] dosed . ,,, In comparison, Bhattacharjee and Ghoshal reported that the reactivity of S-nZVI to TCE increases with [S/Fe] particle from 0.035 to 0.4, where the nanoparticles were synthesized using the one-step method with Na 2 S and the [S/Fe] dosed equals [S/Fe] particle . This may explain the lack of correlation of R with the optimal [S/Fe] dosed of S-(n)ZVI obtained from the two-step method where relatively limited sulfur loading on the particle is achievable, but significant correlation of R with the optimal [S/Fe] dosed is found for those from one-step synthesis using Na 2 S 2 O 4 ( p < 0.05) where higher extent of sulfur loading is observed (SI Figure S2).…”

Section: Contaminant Transformationmentioning

confidence: 99%

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Recent Advances in Sulfidated Zerovalent Iron for Contaminant Transformation

Garcia

Zhang

Ghoshal

et al. 2021

Environ. Sci. Technol.

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169

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2021 marks 10 years since controlled abiotic synthesis of sulfidated nanoscale zerovalent iron (S-nZVI) for use in site remediation and water treatment emerged as an area of active research. It was then expanded to sulfidated microscale ZVI (S-mZVI) and together with S-nZVI, they are collectively referred to as S-(n)ZVI. Heightened interest in S-(n)ZVI stemmed from its significantly higher reactivity to chlorinated solvents and heavy metals. The extremely promising research outcomes during the initial period (2011−2017) led to renewed interest in (n)ZVI-based technologies for water treatment, with an explosion in new research in the last four years (2018−2021) that is building an understanding of the novel and complex role of iron sulfides in enhancing reactivity of (n)ZVI. Numerous studies have focused on exploring different S-(n)ZVI synthesis approaches, and its colloidal, surface, and reactivity (electrochemistry, contaminant selectivity, and corrosion) properties. This review provides a critical overview of the recent milestones in S-(n)ZVI technology development: (i) clear insights into the role of iron sulfides in contaminant transformation and long-term aging, (ii) impact of sulfidation methods and particle characteristics on reactivity, (iii) broader range of treatable contaminants, (iv) synthesis for complete decontamination, (v) ecotoxicity, and (vi) field implementation. In addition, this review discusses major knowledge gaps and future avenues for research opportunities.

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Section: Synthesis Methods and Its Impacts On S-nzvi Composition And ...mentioning

confidence: 99%

Section: Contaminant Transformationmentioning

confidence: 99%

Recent Advances in Sulfidated Zerovalent Iron for Contaminant Transformation

Garcia

Zhang

Ghoshal

et al. 2021

Environ. Sci. Technol.

Self Cite

169

View full text Add to dashboard Cite

show abstract

“…Doong and Lai (2006) have also studied the effect of metal ions in the absence and the presence of humic acid, with a decrease of constant rates in the presence of humic acid (Table 6.17). Generally, the presence of macromolecules, which are abundant in the subsurface, results in a decrease in iron reactivity due to the blocking of reactive site through adsorption, complexation or a combination of both (Bhattacharjee et al 2016;Bhattacharjee and Ghoshal 2018b).…”

Section: Medium Compositionmentioning

confidence: 99%

In Situ Chemical Reduction of Chlorinated Organic Compounds

Rodrigues

Betelu

Colombano

et al. 2020

Applied Environmental Science and Engineering for a Sustainable Future

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Chlorinated organic compounds (COCs) are common anthropogenic contaminants of soil and groundwater. COCs were industrially produced for different applications, such as dry cleaning, degreasing, or as pesticides. The presence of COCs in the environment is a major concern because of their toxicity and persistence.The most widely used method for their remediation is the conventional pump-and-treat system. However, this technology can hardly achieve a complete remediation because of geological characteristics and the presence of pore space pollution/adsorbed pollution, leading to a residual saturation. Hence, in addition to the improvement of pump-and-treat systems, in situ chemical processes have been largely developed. These chemical processes involve the injection of chemical reagents for the removal of residual source pollution and/or the treatment of plume contamination. Chemical degradation of COCs can be achieved by oxidative or reductive processes. If chemical oxidation has been first developed for in situ application, chemical reduction is one of the most important emerging remediation techniques for COCs treatment. Due to the electronegative character of chlorine substituents, COCs can effectively be transformed via reductive pathways. Moreover, reductive dechlorination has shown higher efficiency on highly chlorinated compounds. This chapter focuses on the presentation of the chemical reduction of the most common COCs pollutants, followed by kinetic and mechanistic approaches related to the use of iron-based particles. Developments on in situ chemical reduction technologies in order to enhance remediation rates are also exposed. Influence of environmental conditions for in situ applications is then developed. Finally, a case study is presented.

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“…In recent years, the removal of chlorinated organic solvents, which can deeply penetrate aquifers, accumulating in the sub-surface as lenses of highly hazardous and toxic pollutants [1,2] from groundwater and soil, has become a major problem. Many laboratory-as well as field-scale studies exist considering different reaction pathways between reactants and the target contaminant, such as immobilization of contaminants [3][4][5][6][7][8][9] or in situ degradation of target contaminants into less hazardous or even non-hazardous substances [10][11][12][13][14][15][16][17][18]. Thereby, a major difficulty is the monitoring of reactants during the injection and after secondary mobilisation by groundwater flow.…”

Section: Introductionmentioning

confidence: 99%

Fluorescing Layered Double Hydroxides as Tracer Materials for Particle Injection during Subsurface Water Remediation

et al. 2020

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Nowadays, the contamination of groundwater and soils by highly hazardous and toxic chlorinated solvents is a global issue. Over the past years, different remediation strategies have been developed, involving injection of reactive solutions and/or particles. However, a major difficulty is the monitoring of injected particles during the injection and after secondary mobilisation by groundwater flow. This study is focussed on the development of directly traceable particles by combining fluorescein with Layered Double Hydroxides (LDHs). We present here the facile and easily tuneable synthesis of fluorescing LDHs (Fluo-LDH) via co-precipitation under supersaturation conditions. Their ability to mimic particle sizes of previously studied reactive LDHs, which proved to be able to adsorb or degrade chlorinated organic solvents from aqueous solutions, was investigated as well. Tests using a novel Optical Image Profiler (OIP) confirmed that the fluorescent LDHs can be easily detected with this tool. Even LDHs with the lowest amount of fluorescent dye were detectable. Together with the use of an OIP, which is capable of exciting the fluorescent material and collecting real-time pictures, this can provide a new, efficient, and cost-effective method for in situ tracing of injected particles in the subsurface.

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Sulfidation of nanoscale zerovalent iron in the presence of two organic macromolecules and its effects on trichloroethene degradation

Abstract: Sulfidation of nanoscale zerovalent iron (NZVI) enhances its reactivity to chlorinated organic contaminants such as trichloroethene (TCE).

Cited by 24 publications

References 42 publications

Recent Advances in Sulfidated Zerovalent Iron for Contaminant Transformation

Recent Advances in Sulfidated Zerovalent Iron for Contaminant Transformation

In Situ Chemical Reduction of Chlorinated Organic Compounds

Fluorescing Layered Double Hydroxides as Tracer Materials for Particle Injection during Subsurface Water Remediation

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