Enhancing bio-cathodic nitrate removal through anode-cathode polarity inversion together with regulating the anode electroactivity
| Autor: | Shaoan Cheng, Zhufan Lin, Yi Sun, Haobin Huang, Zhen Yu, Jiawei Yang |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Environmental Engineering
010504 meteorology & atmospheric sciences Biomass 010501 environmental sciences 01 natural sciences law.invention Catalysis chemistry.chemical_compound Nitrate law RNA Ribosomal 16S Environmental Chemistry Autotroph Electrodes Waste Management and Disposal 0105 earth and related environmental sciences Pollutant Autotrophic Processes Nitrates Biofilm Pollution Cathode Anode chemistry Chemical engineering Nitrogen Oxides Oxidation-Reduction |
| Zdroj: | Science of The Total Environment. 764:142809 |
| ISSN: | 0048-9697 |
| Popis: | Bio-cathodic nitrate removal uses autotrophic nitrate-reducing bacteria as catalysts to realize the nitrate removal process and has been considered as a cost-effective way to remove nitrate contamination. However, the present bio-cathodic nitrate removal process has problems with long start-up time and low performance, which are urgently required to improve for its application. In this study, we investigated an anode-cathode polarity inversion method for rapidly cultivating high-performance nitrate-reducing bio-cathode by regulating bio-anodic bio-oxidation electroactivities under different external resistances and explored at the first time the correlation between the oxidation performance and the reduction performance of one mixed-bacteria bioelectrode. A high bio-electrochemical nitrate removal rate of 2.74 ± 0.03 gNO3−-N m−2 d−1 was obtained at the bioelectrode with high bio-anodic bio-oxidation electroactivity, which was 4.0 times that of 0.69 ± 0.03 gNO3−-N m−2 d−1 at the bioelectrode with low bio-oxidation electroactivity, and which was 1.3–7.9 times that of reported (0.35–2.04 gNO3−-N m−2 d−1). 16S rRNA gene sequences and bacterial biomass analysis showed higher bio-cathodic nitrate removal came from higher bacterial biomass of electrogenic bacteria and nitrate-reducing bacteria. A good linear correlation between the bio-cathodic nitrate removal performance and the reversed bio-anodic bio-oxidation electroactivity was presented and likely implied that electrogenic biofilm had either action as autotrophic nitrate reduction or promotion to the development of autotrophic nitrate removal system. This study provided a novel strategy not only to rapidly cultivate high-performance bio-cathode but also to possibly develop the bio-cathode with specific functions for substance synthesis and pollutant detection. |
| Databáze: | OpenAIRE |
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