Redox Structures of Humic Acids Derived From Different Sediments and Their Effects on Microbial Reduction Reactions

Insight to Microbial Fe(III) Reduction Mediated by Redox-Active Humic Acids with Varied Redox Potentials

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18136807 ◽

2021 ◽

Vol 18 (13) ◽

pp. 6807

Author(s):

Jingtao Duan ◽

Zhiyuan Xu ◽

Zhen Yang ◽

Jie Jiang

Keyword(s):

Molecular Weight ◽

Electron Transfer ◽

Humic Acids ◽

Weight Fraction ◽

Electrochemical Analysis ◽

Microbial Reduction ◽

Redox Potentials ◽

Groundwater Environment ◽

Redox Active ◽

Different Molecular Weight

Redox-active humic acids (HA) are ubiquitous in terrestrial and aquatic systems and are involved in numerous electron transfer reactions affecting biogeochemical processes and fates of pollutants in soil environments. Redox-active contaminants are trapped in soil micropores (<2 nm) that have limited access to microbes and HA. Therefore, the contaminants whose molecular structure and properties are not damaged accumulate in the soil micropores and become potential pollution sources. Electron transfer capacities (ETC) of HA reflecting redox activities of low molecular weight fraction (LMWF, <2.5) HA can be detected by an electrochemical method, which is related to redox potentials (Eh) in soil and aquatic environments. Nevertheless, electron accepting capacities (EAC) and electron donating capacities (EDC) of these LMWF HA at different Eh are still unknown. EDC and EAC of different molecular weight HA at different Eh were analyzed using electrochemical methods. EAC of LMWF at −0.59 V was 12 times higher than that at −0.49 V, while EAC increased to 2.6 times when the Eh decreased from −0.59 V to −0.69 V. Afterward, LMWF can act as a shuttle to stimulate microbial Fe(III) reduction processes in microbial reduction experiments. Additionally, EAC by electrochemical analysis at a range of −0.49–−0.59 V was comparable to total calculated ETC of different molecular weight fractions of HA by microbial reduction. Therefore, it is indicated that redox-active functional groups that can be reduced at Eh range of −0.49–−0.59 are available to microbial reduction. This finding contributes to a novel perspective in the protection and remediation of the groundwater environment in the biogeochemistry process.

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Microbial reduction of Fe(III)-bearing clay minerals in the presence of humic acids

Scientific Reports ◽

10.1038/srep45354 ◽

2017 ◽

Vol 7 (1) ◽

Cited By ~ 13

Author(s):

Guangfei Liu ◽

Shuang Qiu ◽

Baiqing Liu ◽

Yiying Pu ◽

Zhanming Gao ◽

...

Keyword(s):

Clay Minerals ◽

Humic Acids ◽

Microbial Reduction

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Humin as an electron donor for enhancement of multiple microbial reduction reactions with different redox potentials in a consortium

Journal of Bioscience and Bioengineering ◽

10.1016/j.jbiosc.2014.07.010 ◽

2015 ◽

Vol 119 (2) ◽

pp. 188-194 ◽

Cited By ~ 25

Author(s):

Dongdong Zhang ◽

Chunfang Zhang ◽

Zhixing Xiao ◽

Daisuke Suzuki ◽

Arata Katayama

Keyword(s):

Electron Donor ◽

Microbial Reduction ◽

Redox Potentials ◽

Reduction Reactions

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Humic acids facilitated microbial reduction of polymeric Pu(IV) under anaerobic conditions

The Science of The Total Environment ◽

10.1016/j.scitotenv.2017.08.184 ◽

2018 ◽

Vol 610-611 ◽

pp. 1321-1328 ◽

Cited By ~ 7

Author(s):

Jinchuan Xie ◽

Wei Liang ◽

Jianfeng Lin ◽

Xiaohua Zhou ◽

Mei Li

Keyword(s):

Humic Acids ◽

Microbial Reduction ◽

Anaerobic Conditions

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Rational prediction of multifunctional bilayer single atom catalysts for the hydrogen evolution, oxygen evolution and oxygen reduction reactions

Nanoscale ◽

10.1039/d0nr05202g ◽

2020 ◽

Vol 12 (39) ◽

pp. 20413-20424

Author(s):

Riming Hu ◽

Yongcheng Li ◽

Fuhe Wang ◽

Jiaxiang Shang

Keyword(s):

Oxygen Reduction ◽

Hydrogen Evolution ◽

Oxygen Evolution ◽

Single Atom ◽

Reduction Reactions ◽

Oxygen Reduction Reactions

Bilayer single atom catalysts can serve as promising multifunctional electrocatalysts for the HER, ORR, and OER.

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ROLE OF ADDED PHOSPHOGYPSUM AND HUMIC ACIDS IN THE KINETIC RELEASE OF SALT FROM SALT AFFECTED SOIL (SALINE – SODIC)

Anbar Journal of Agricultural Sciences ◽

10.32649/ajas/2020/2 ◽

2020 ◽

pp. 15-27

Keyword(s):

Electrical Conductivity ◽

Humic Acids ◽

Release Rate ◽

Release Kinetics ◽

Sodium Adsorption Ratio ◽

Salt Affected Soil ◽

Two Factors ◽

Dissolved Ions ◽

Kinetic Release

In order to study the effect of phosphogypsum and humic acids in the kinetic release of salt from salt-affected soil, a laboratory experiment was conducted in which columns made from solid polyethylene were 60.0 cm high and 7.1 cm in diameter. The columns were filled with soil so that the depth of the soil was 30 cm inside the column, the experiment included two factors, the first factor was phosphogypsum and was added at levels 0, 5, 10 and 15 tons ha-1 and the second-factor humic acids were added at levels 0, 50, 100 and 150 kg ha-1 by mixing them with the first 5 cm of column soil and one repeater per treatment. The continuous leaching method was used by using an electrolytic well water 2.72 dS m-1. Collect the leachate daily and continue the leaching process until the arrival of the electrical conductivity of the filtration of leaching up to 3-5 dS m-1. The electrical conductivity and the concentration of positive dissolved ions (Ca, Mg, Na) were estimated in leachate and the sodium adsorption ratio (SAR) was calculated. The results showed that the best equation for describing release kinetics of the salts and sodium adsorption ratio in soil over time is the diffusion equation. Increasing the level of addition of phosphogypsum and humic acids increased the constant release velocity (K) of salts and the sodium adsorption ratio. The interaction between phosphogypsum and humic acids was also affected by the constant release velocity of salts and the sodium adsorption ratio. The constant release velocity (K) of the salts and the sodium adsorption ratio at any level of addition of phosphogypsum increased with the addition of humic acids. The highest salts release rate was 216.57 in PG3HA3, while the lowest rate was 149.48 in PG0HA0. The highest release rate of sodium adsorption ratio was 206.09 in PG3HA3, while the lowest rate was 117.23 in PG0HA0.

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