Microbial mediated iron redox cycling in Fe (hydr)oxides for nitrite removal.
Nitrite, at an environmentally relevant concentration, was significantly reduced with iron (hydr)oxides mediated by Shewanella oneidensis MR-1. The average nitrite removal rates of 1.28±0.08 and 0.65±0.02(mgL-1)h-1were achieved with ferrihydrite and magnetite, respectively. The results showed that nitrite removal was able to undergo multiple redox cycles with iron (hydr)oxides mediated by Shewanella oneidensis MR-1. During the bioreduction of the following cycles, biogenic Fe(II) was subsequently chemically oxidized to Fe(III), which is associated with nitrite reduction. There was 11.18±1.26mgL-1of NH4+-N generated in the process of redox cycling of ferrihydrite. Additionally, results obtained by using X-ray diffraction showed that ferrihydrite and magnetite remained mainly stable in the system. This study indicated that redox cycling of Fe in iron (hydr)oxides was a potential process associated with NO2--N removal from solution, and reduced most nitrite abiotically to gaseous nitrogen species.
School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Rd., Shanghai 200444, PR China.
Yongsheng
Y
Lu
School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Rd., Shanghai 200444, PR China.
Lu
L
Xu
School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Rd., Shanghai 200444, PR China.
Weikang
W
Shu
School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Rd., Shanghai 200444, PR China.
Jizhi
J
Zhou
School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Rd., Shanghai 200444, PR China. Electronic address: xpchen@shu.edu.cn.
Xueping
X
Chen
School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Rd., Shanghai 200444, PR China.
Yunfeng
Y
Xu
School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Rd., Shanghai 200444, PR China.
Guangren
G
Qian
D005290:Ferric Compounds / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D007501:Iron / Q000737:chemistry / Q000378:metabolism*; D009573:Nitrites / Q000032:analysis / Q000737:chemistry*; D010084:Oxidation-Reduction; D020592:Shewanella / Q000378:metabolism*; D018508:Water Purification / Q000379:methods; D014961:X-Ray Diffraction
D005290:Ferric Compounds; D009573:Nitrites; C092844:ferric oxyhydroxide; D007501:Iron
Iron (hydr)oxide; Microbial reduction; Nitrite removal; Redox cycling