Biological Reduction of Nitric Oxide for Efficient Recovery of Nitrous Oxide as an Energy Source

Abstract

Chemical absorption–biological reduction based on Fe­(II)­EDTA is a promising technology to remove nitric oxide (NO) from flue gases. However, limited effort has been made to enable direct energy recovery from NO through production of nitrous oxide (N2O) as a potential renewable energy rather than greenhouse gas. In this work, the enhanced energy recovery in the form of N2O via biological NO reduction was investigated by conducting short-term and long-term experiments at different Fe­(II)­EDTA–NO and organic carbon levels. The results showed both NO reductase and N2O reductase were inhibited at Fe­(II)­EDTA–NO concentration up to 20 mM, with the latter being inhibited more significantly, thus facilitating N2O accumulation. Furthermore, N2O accumulation was enhanced under carbon-limiting conditions because of electron competition during short-term experiments. Up to 47.5% of NO–N could be converted to gaseous N2O–N, representing efficient N2O recovery. Fe­(II)­EDTA–NO reduced microbial diversity and altered the community structure toward Fe­(II)­EDTA–NO-reducing bacteria-dominated culture during long-term experiments. The most abundant bacterial genus Pseudomonas, which was able to resist the toxicity of Fe­(II)­EDTA–NO, was significantly enriched, with its relative abundance increased from 1.0 to 70.3%, suggesting Pseudomonas could be the typical microbe for the energy recovery technology in NO-based denitrification.

The photocatalytic NO-removal activity of g-C3N4 significantly enhanced by the synergistic effect of Pd0 nanoparticles and N vacancies

“…In the atmosphere, 95% of NOx is NO, which originates from the incomplete combustion of fuel and emissions of flue gas from factories and vehicle exhaust. [3][4][5][6][7] The released NO can cause many health problems, such as pinkeye, respiratory diseases, and lung cancer. 7,8 Besides the harm to human health, NO is also harmful to the environment because it can cause acid rain, photochemical smog, and tropospheric ozone.…”

Sulfur‐driven autotrophic denitrification of nitric oxide for efficient nitrous oxide recovery

“…Previously, N 2 O has been demonstrated to be a potential energy source and able to accumulate efficiently during Fe(II)EDTA‐NO‐based denitrification process (S. S. Wang, Cheng, et al, 2021; Yu et al, 2019). The results from L. K. Wang, Cheng, et al (2021) suggested that the nitrogen converting efficiency from Fe(II)EDTA‐NO to gaseous N 2 O could reach up to 30.8% under the condition with 20 mM Fe(II)EDTA‐NO and sufficient supply of sodium acetate. Compared with an organic electron donor, S 0 has been proposed as an ideal electron donor alternative due to lower cost and biomass yield, and thus used for water treatment processes like nitrate‐contaminated groundwater disposing (Di Capua et al, 2015; Hu et al, 2020; Y. Liu, Ngo, et al,; Tian & Yu, 2020).…”

“…The nitric oxide (NO) released from coal combustion has become one of the main gas pollutants as it poses serious threats to both environment and people's health (van Durme et al, 2008; Gomez‐Garcia et al, 2005; Harding et al, 1996). A two‐step system based on complex absorption and biological reduction was recently developed to mitigate the emission of this nitrogen oxide (L. K. Wang, Cheng, et al, 2021; Yu et al, 2019; Zhou et al, 2013). Such integrated method usually uses Fe(II)EDTA to absorb gaseous NO in an attempt to facilitate the solubility of NO in water and enhance its availability to microorganisms thereafter (van der Maas et al, 2003; Sharif et al, 2019).…”

“…NO‐based denitrification has the potential of inducing more N 2 O accumulation than denitrification based on nitrate (NO 3 − ) or nitrite (NO 2 − ) owning to the inhibitory effect of NO on N 2 O reductase (N 2 OR) activity and electron transfer compounds such as cytochrome c oxidase (CCO) (L. K. Wang, Cheng, et al, 2021; Yu et al, 2019). In terms of the potential of recovering N 2 O from sulfur‐based denitrification, recent studies have revealed that N 2 O can accumulate significantly via the said process after converting NO 3 − ‐ or NO 2 − (Park et al, 2002; Zhang, Zhang, Hu, Liu, & Bai, 2015; Zhu et al, 2019).…”

Efficient electrocatalytic nitric oxide reduction to ammonia using manganese spinel oxides

“…Nitrogen oxides (NO x ) are typically atmospheric pollutants, of which nitric oxide (NO) accounts for up to 95%. 1 Artificial sources mainly include stationary sources (for example, coal-fired power plants, waste incineration, chemical plants, etc. ) and mobility sources dominated by automobiles.…”