title: Generation, utilization, and transformation of cathode electrons for bioreduction of Fe(III)EDTA in a biofilm electrode reactor related to NOx removal from flue gas.
abstract: A chemical absorption-biological reduction (CABR) integrated system, which employs iron chelate as a solvent, is under development for NOx removal from flue gas. Biofilm electrode reactor (BER) is deemed as a promising bioreactor to regenerate the iron chelate. Although it has been proved that BER can significantly enhance the bioreduction of Fe(III)EDTA, the bioelectrochemistry mechanism involved in the bioreduction of Fe(III)EDTA remains unknown. This work aims to explore this mechanism via the analysis of the generation, utilization, and transformation of cathode electrons in the BER. The results indicate that the generation of cathode electrons follows Faraday's law. The generated cathode electrons were used to produce H2 and directly reduce Fe(III)EDTA in the BER. Meanwhile, the produced H2 served as an electron donor for bioreduction of Fe(III)EDTA. The excess H2 product was transformed to simple organics, e.g., methanol by the hydrogen autotrophy of Pseudomonas under the inorganic and anaerobic conditions. Overall, this work revealed that the reduction of Fe(III)EDTA in the BER was enhanced by both direct electrochemical reduction and indirect bioreduction using H2 as an intermediate. It is also interesting that the excess H2 product was transformed to methanol for microbial metabolism and energy storage in the BER.
authors: †Key Laboratory of Biomass Chemical Engineering of Ministry of Education, Institute of Industrial Ecology and Environment, College of Chemical and Biological Engineering, Zhejiang University (Yuquan Campus), Hangzhou, 310027, China.|‡Institute of Environmental Engineering, Zhejiang University (Zijingang Campus), Hangzhou, 310058, China.
authors: Wei
authors: W
authors: Li
authors: †Key Laboratory of Biomass Chemical Engineering of Ministry of Education, Institute of Industrial Ecology and Environment, College of Chemical and Biological Engineering, Zhejiang University (Yuquan Campus), Hangzhou, 310027, China.|‡Institute of Environmental Engineering, Zhejiang University (Zijingang Campus), Hangzhou, 310058, China.
authors: Yinfeng
authors: Y
authors: Xia
authors: †Key Laboratory of Biomass Chemical Engineering of Ministry of Education, Institute of Industrial Ecology and Environment, College of Chemical and Biological Engineering, Zhejiang University (Yuquan Campus), Hangzhou, 310027, China.
authors: Jingkai
authors: J
authors: Zhao
authors: †Key Laboratory of Biomass Chemical Engineering of Ministry of Education, Institute of Industrial Ecology and Environment, College of Chemical and Biological Engineering, Zhejiang University (Yuquan Campus), Hangzhou, 310027, China.
authors: Nan
authors: N
authors: Liu
authors: †Key Laboratory of Biomass Chemical Engineering of Ministry of Education, Institute of Industrial Ecology and Environment, College of Chemical and Biological Engineering, Zhejiang University (Yuquan Campus), Hangzhou, 310027, China.
authors: Sujing
authors: S
authors: Li
authors: †Key Laboratory of Biomass Chemical Engineering of Ministry of Education, Institute of Industrial Ecology and Environment, College of Chemical and Biological Engineering, Zhejiang University (Yuquan Campus), Hangzhou, 310027, China.
authors: Shihan
authors: S
authors: Zhang
mesh_terms: D000393:Air Pollutants / Q000378:metabolism*; D018407:Bacterial Physiological Phenomena; D018441:Biofilms; D019149:Bioreactors; D004492:Edetic Acid / Q000378:metabolism*; D004566:Electrodes; D005290:Ferric Compounds / Q000378:metabolism*; D009589:Nitrogen Oxides / Q000378:metabolism*; D010084:Oxidation-Reduction
chemical_list: D000393:Air Pollutants; D005290:Ferric Compounds; D009589:Nitrogen Oxides; D004492:Edetic Acid