A pilot study on the regeneration of ferrous chelate complex in NOx scrubber solution by a biofilm electrode reactor.

Institute of Environmental Engineering, Zhejiang University (Yuquan Campus), Hangzhou, China.
Bioresource Technology (Impact Factor: 5.04). 10/2010; 102(3):2605-9. DOI: 10.1016/j.biortech.2010.10.012
Source: PubMed

ABSTRACT A chemical absorption-biological reduction integrated process has been proposed for the removal of nitrogen oxides (NO(x)) from flue gases. In this study, we report a new approach using biofilm electrode reactor (BER) to regenerate Fe(II)EDTA via simultaneously reducing Fe(II)EDTA-NO and Fe(III)EDTA in NO(x) scrubber solution. Biofilm formed on the surface of the cathode was confirmed by Environmental Scan Electro-Microscope. Experimental results demonstrated that it was effective and feasible to utilize the BER to promote the reduction of Fe(II)EDTA-NO and Fe(III)EDTA simultaneously. The reduction efficiency of Fe(II)EDTA-NO and Fe(III)EDTA was up to 85% and 78%, respectively when the BER was continuously operated with electricity current at 30 mA. The absence of electricity induced an immediate decrease in reduction efficiency, indicating that the bio-regeneration of ferrous chelate complex was electrochemically accelerated. The present approach is considered advantageous for the enhanced bio-reduction in the NO(x) scrubber solution.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Nitrogen monoxide (NO), a major air pollutant, can be directly used as a precursor for nitrogen fertilizer production as long as it is collected in a pure form. In this study, an innovative dual fuel cell system was designed for the efficient capture and collection of pure NOX from industrial flue gases as well as for electricity generation. The system consisted of a methanol/ferric-EDTA fuel cell for NOX capture and a ferrous-EDTA–NO/air fuel cell for captured NOX collection. In a separation operation, the maximum power densities, which were obtained at pH 2 and 20 °C, were 785 and 1,840 mW m−2 in FC1 and FC2, respectively, and increased with temperature. The highest overall outputs from FC1 and FC2 were measured at pH 2, a result that is possibly attributable to the redox potential difference between the anolyte and catholyte in the fuel cells. In the combined operation, ferrous-EDTA–NO prepared in the cathode compartment of FC1 was successfully and efficiently converted to ferric-EDTA and NO in the anode compartment of FC2. The present approach was considered advantageous for advanced NOX reuse technology in the respect that valuable products, such as fertilizer, could be produced.
    Journal of Applied Electrochemistry · 1.84 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: An enriched biomass was developed from municipal sewage sludge consisting of three dominant bacteria, representing the genera of Enterobacter, Citrobacter and Streptomyces. The biomass was used in a series of batch experiments in order to determine kinetic constants associated with biomass growth and NOx reduction in aqueous Ferrous EDTA/NTA solutions and Ferric EDTA/NTA solutions using ethanol as organic electron donor. The maximum specific reduction rates of NOx in Ferrous EDTA and Ferrous NTA solutions were 0.037 and 0.047mMolesL(-1)d(-1)mg(-1) biomass, respectively while in Ferric EDTA and Ferric NTA solutions were 0.022 and 0.024mMolesL(-1)d(-1)mg(-1) biomass, respectively. In case of Ferric EDTA/NTA solution, the kinetic constants associated with reduction of Ferric EDTA/NTA to Ferrous EDTA/NTA were also evaluated simultaneously. The maximum specific reduction rates of Ferric EDTA and Ferric NTA were 0.0021 and 0.0026mMolesL(-1)d(-1)mg(-1) biomass. The significance of these observations are presented and discussed in this paper.
    Bioresource Technology 12/2012; 130C:644-651. · 5.04 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Anthropogenic nitrogen oxides (NO x ) emitted from the fossil-fuel-fired power plants cause adverse environmental issues such as acid rain, urban ozone smoke, and photochemical smog. A novel chemical absorption-biological reduction (CABR) integrated process under development is regarded as a promising alternative to the conventional selective catalytic reduction processes for NO x removal from the flue gas because it is economic and environmentally friendly. CABR process employs ferrous ethylenediaminetetraacetate [Fe(II)EDTA] as a solvent to absorb the NO x following microbial denitrification of NO x to harmless nitrogen gas. Meanwhile, the absorbent Fe(II)EDTA is biologically regenerated to sustain the adequate NO x removal. Compared with conventional denitrification process, CABR not only enhances the mass transfer of NO from gas to liquid phase but also minimize the impact of oxygen on the microorganisms. This review provides the current advances of the development of the CABR process for NO x removal from the flue gas.
    Applied microbiology and biotechnology. 08/2014;