Reactive NO absorption in aqueous FeII(EDTA) solutions in the presence of denitrifying micro-organisms

Abstract

Reactive NO absorption in aqueous FeII(EDTA) solutions in the presence of denitrifying micro-organisms Gambardella, F.; Galán Sánchez, L.M.; Ganzeveld, K.J.; Winkelman, J.G.M.; Heeres, H.J. Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum. AbstractThe effect of the presence of denitrifying biomass on the reactive absorption of NO in aqueous Fe II (EDTA) solutions has been investigated (T = 303, 325 K, C Fe II (EDTA) = 30-35 mol/m 3 , C total solids = 0-7.5 kg/m 3 , C suspended solids = 0-1.2 kg/m 3 , C NO in = 250 vppm). The absorption rate of NO is affected by the presence of the biomass sludge and high sludge loadings resulted in reductions in the NO absorption rates. The decrease is likely due to partial blockage of the gas-liquid interface by inorganic and organic suspended solids and to a lesser extent to changes in the physical properties of the liquid. For one of the samples, an enhancement of the NO absorption rate was observed, presumably as a result of a shuttling effect due to the presence of small, adsorptive particles. A semi-empirical engineering model was developed based on the theory of mass transfer in combination with solid particles. The model includes both possible enhancement of mass transfer due to the presence of small adsorptive particles as well as reduction of the mass transfer rate due to the presence of particles adhering to the gas-liquid interface. The experimental profiles were modeled successfully using this approach.

Adsorption of EDTA on activated carbon from aqueous solutions

“…Although Fe II -EDTA can obtain a high NO removal efficiency, it is easily oxidized to Fe III -EDTA that is not capable of binding NO [6,7]. Many methods [8][9][10][11] have been put forward to regenerate Fe II -EDTA to sustain the NO removal efficiency. The authors [12] put forward to utilize activated carbon as a catalyst to speed up the regeneration of iron(II)(EDTA).…”

Evaluation of a newly isolated Klebsiella sp. DL-1 and its interaction with Klebsiella sp. FD-3 in regenerating nitrogen oxide scrubbing liquor using ethylenediaminetetraacetic acid iron(II) as absorbent

“…The absorbing solution in the system contains Fe(II)EDTA, Fe(II)EDTA-NO and Fe(III)EDTA , Lin et al, 2014and Zhou et al, 2013a. Because this process depends on the chelating reagent of Fe(II)EDTA to absorb NO, the reduction efficiencies, i.e., Fe(II)EDTA-NO reduction by the denitrifying bacteria and Fe(III)EDTA reduction by the iron-reducing bacteria, are significant factors for NO x removal (Gambardella et al, 2006, Lu et al, 2011and Xia et al, 2013.…”

Adsorption characteristics of [Fe(III)–EDTA]− on granular activated carbon from aqueous solutions

“…[Fe(II)–EDTA] 2− can combine with NO quickly, but it is liable to lose its capability of binding NO because of its fast oxidation to [Fe(III)–EDTA] − . Many measures have been tried to regenerate [Fe(II)–EDTA] 2− to sustain the NO removal efficiency. Zhu et al .…”

“…[Fe(II)-EDTA] 22 can combine with NO quickly, but it is liable to lose its capability of binding NO because of its fast oxidation to [Fe(III)-EDTA] 2 [6,7]. Many measures [8][9][10][11] have been tried to regenerate [Fe(II)-EDTA] 22 to sustain the NO removal efficiency. Zhu et al [12] put forward to apply activated carbon as a catalyst to accelerate the reduction of [Fe(III)-EDTA] 2 by sulfite so as to maintain the capability of removing NO from gas streams.…”