Reduction of Fe(III) chelated with citrate in an NOx scrubber solution by Enterococcus sp. FR-3.
Biological reduction of Fe(III) to Fe(II) is a key step in nitrogen oxide (NO(x)) removal by the integrated chemical absorption-biological reduction process. NO(x) removal efficiency strongly depends on the concentration of Fe(II) in the scrubbing liquid. In this study, a newly isolated strain, Enterococcus sp. FR-3, was used to reduce Fe(III) chelated with citrate to Fe(II). Strain FR-3 reduced citrate-chelated Fe(III) with an efficiency of up to 86.9% and an average reduction rate of 0.21 mM h(-1). SO(4)(2-) was not inhibitory whereas NO(2)(-) and SO(3)(2-) inhibited cell growth and thus affected Fe(III) reduction. Models based on the Logistic equation were used to describe the relationship between growth and Fe(III) reduction. These findings provide some useful data for Fe(III) reduction, scrubber solution regeneration and NO(x) removal process design.
Department of Environmental Engineering, Zhejiang University (Yuquan Campus), Hangzhou, China. w_li@zju.edu.cn
Wei
W
Li
Nan
N
Liu
Ling-Lin
LL
Cai
Jin-Lin
JL
Jiang
Jian-Meng
JM
Chen
D002614:Chelating Agents / Q000737:chemistry; D019343:Citric Acid / Q000737:chemistry*; D016983:Enterococcus / Q000378:metabolism*; D007501:Iron / Q000737:chemistry*; D009569:Nitric Oxide / Q000737:chemistry* / Q000302:isolation & purification*; D010084:Oxidation-Reduction; D012996:Solutions
D002614:Chelating Agents; D012996:Solutions; D019343:Citric Acid; D009569:Nitric Oxide; D007501:Iron