Reduction of nitrate by bimetallic Fe/Ni nanoparticles

Abstract

Bimetallic Fe/Ni nanoparticles were synthesized and their nitrate reduction capacity was studied. Nitrate (354 mg L(-1), equal to 5.71 mmol L(-1)) reduction was performed using Fe/Ni nanoparticles with various Ni contents (1.0, 5.0, 10 and 20%) in an unbuffered condition. Optimum nitrate reduction rate (1.03 +/- 0.087 x 10(-4) mol x min(-1) x greduc(-1)) was obtained with 5.0% nano-scale Fe/Ni, while only 25% nitrate (1.05 +/- 0.091 x 10(-5) mol x min(-1) x greduc(-1)) was transformed by nano-scale Fe(0) within the same reaction time, which means that these bimetallic nanoparticles are obviously more reactive than monometallic nano-scale Fe(0). For this bimetallic system a near-neutral initial pH (6.5) is more favourable than an acidic condition (2.0 and 4.0). Relatively air-stable nano-scale Fe/Ni particles were developed by slowly aging them for 22 h and exhibited similar reactivity to freshly synthesized nano-scale Fe(0). Although undesirable transformation of nitrate (91.0 +/- 0.37%) to ammonium was observed in this study, Fe/Ni particles showed a much higher nitrate reduction rate and an optimum reduction rate at near-neutral pH, which may have important implications for nitrate-contaminated site remediation.

Nitrate reduction by chelating resin‐supported Fe and Fe/Ni nanoparticles: comparison of reactivity and effect of co‐existing inorganic anion

“…. For DOW 3N–Fe, weak signals of the iron oxide shell (peaks at 35° and 61° for Fe 3 O 4 ) was observed, but there was almost no signal of iron, possibly due to its poor crystallinity . In contrast, the peak in the X‐ray diffraction pattern of DOW 3N–Fe/Ni showed evidence of iron, nickel or nickel–iron alloy (Fe, 2 θ = 44.9°; Ni, 2 θ = 44.5°); but there were no peaks for oxide phase, indicating that the presence of Ni prevented the oxidising of iron particles by O 2 and improved the air stability of nanoscale Fe 0 particles …”

Nanosized iron based permeable reactive barriers for nitrate removal – Systematic review

“…Jiang et al (2011) tested two types of polystyrene resins as support for NZVI e porous polystyrene resins functionalized with eCH 2 Cl to encapsulate NZVI (Cl-S-ZVI) and eCH 2 N þ (CH 3 ) 3 (N-S-ZVI) e N-S-ZVI proved to be more effective in reducing nitrate; the use of both materials yielded ammonia and nitrite. Kang et al (2012) used bimetallic Fe/Ni nanoparticles to reduce nitrate. As reduction products ammonium was produced, and possibly some dinitrogen gas.…”

Removal of Crystal Violet by Using Reduced-Graphene-Oxide-Supported Bimetallic Fe/Ni Nanoparticles (rGO/Fe/Ni): Application of Artificial Intelligence Modeling for the Optimization Process

“…The rGO/Fe/Ni composites were synthesized by the co-precipitation method [ 31 ]. FeSO 4 ·7H 2 O solution and NiCl·6H 2 O solution were added into GO solution using ultrasonication for about 2 h. The mixture was then stirred for 12 h. After this, 5.2 g NaBH 4 dissolved in 50 mL of deionized water was added to the mixture.…”