CN-122017114-A - Method for measuring oxidation-reduction potential of soluble black carbon

Abstract

The invention provides a method for measuring the oxidation-reduction potential of soluble black carbon, and belongs to the technical field of environmental analysis. The method comprises the steps of reducing soluble black carbon by quinone reducing bacteria under anaerobic conditions, sterilizing, adding ferrihydrite, enabling the reduced soluble black carbon to react with the ferrihydrite, measuring the total amount of Fe (II), and calculating the oxidation-reduction potential of the soluble black carbon by taking the electronic equivalent of a standard substance AQDS as a reference. The method adopts the microbial reduction process to simulate the electron transfer of the soluble black carbon in the natural environment, the result is closer to the real environment, the operation is simple and convenient, the repeatability is good, and the method is suitable for evaluating the electron shuttling capability of the soluble black carbon in the environment.

Inventors

• LI QINGSHAN
• BU QINGWEI
• LIU HAOZHE
• QIN WENXIN
• WEI DAPENG
• ZHANG XIAOFAN
• JIANG HAO
• ZHOU XINYU

Assignees

• 山东农业工程学院
• 中国矿业大学(北京)
• 枣庄矿业(集团)济宁七五煤业有限公司

Dates

Publication Date

20260512

Application Date

20260213

Claims (10)

1. 1. A method for determining the redox potential of a soluble black carbon comprising: under anaerobic conditions, uniformly mixing the soluble black carbon and quinone reducing bacteria in a culture medium, reacting, and sterilizing after the reaction is finished to obtain a mixed system; adding ferrihydrite into the mixed system for reaction, and measuring the total amount of Fe (II) in the liquid phase and the solid phase after the reaction is completed; And calculating the oxidation-reduction potential of the soluble black carbon by taking the AQDS as a reference to obtain the catalyst.
2. 2. The method for measuring the oxidation-reduction potential of the soluble black carbon according to claim 1, wherein the preparation method of the soluble black carbon comprises the steps of mixing biochar with water, oscillating, ultrasonic treating, filtering, and desalting by resin to obtain a soluble black carbon solution; Or the mass ratio of the biochar to the water is 1:100-120; or, the oscillation time is 24-32 h; Or, the ultrasonic time is 30-40 min; Alternatively, the pore size of the filtration membrane is 0.45. Mu.m.
3. 3. The method for determining the redox potential of soluble black carbon according to claim 1, wherein the mixing ratio of the soluble black carbon and the quinone-reducing bacteria is 100-120 mg c:1.6x10 9 -2×10 9 cells.
4. 4. The method for determining the redox potential of soluble black carbon according to claim 1, wherein the reaction condition of the soluble black carbon and the quinone-reducing bacteria is anaerobic light-shielding reaction for 30-32 days under the conditions of 35-37 ℃ and 150-160 r/min.
5. 5. The method for measuring the redox potential of soluble black carbon according to claim 1, wherein a microorganism community having a quinone reducing function is cultured and domesticated to obtain a quinone reducing bacterium; expanding culture of quinone reducing bacteria to logarithmic phase, and centrifuging to obtain thallus suspension.
6. 6. The method for determining the redox potential of soluble black carbon according to claim 5, wherein the acclimation medium is a mineral salt medium, the acclimation temperature is 35-37 ℃, and the acclimation period is 2-3 weeks.
7. 7. The method for measuring the redox potential of soluble black carbon according to claim 5, wherein the concentration of the quinone-reducing microorganism inoculum is 5X 10 7 -1×10 8 cells/mL, the time of the expansion culture is 28-35 days, and the temperature of the expansion culture is 35-37 ℃.
8. 8. The method for determining the redox potential of soluble black carbon according to claim 1, wherein the ferrihydrite is added at a concentration of 2-3 mM and the reaction time is 72-76 h.
9. 9. The method for determining the redox potential of a soluble black carbon according to claim 1, wherein the redox potential calculation formula is: 。
10. 10. A system for measuring the redox potential of soluble black carbon is characterized by comprising quinone reducing bacteria, a culture medium, ferrihydrite, a container and an ultraviolet-visible spectrophotometer.

Description

Method for measuring oxidation-reduction potential of soluble black carbon Technical Field The invention belongs to the technical field of environmental analysis, and relates to a method for determining the oxidation-reduction potential of soluble black carbon. Background The disclosure of this background section is only intended to increase the understanding of the general background of the invention and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art already known to those of ordinary skill in the art. The soluble black carbon contains rich quinolyl and phenolic functional groups, has electron shuttle capability, participates in microbial metabolism and pollutant conversion processes in anaerobic environments such as soil, sediment and the like, and for example, research discloses the influence research of the soluble black carbon on Geobacter sulfurreducensPCA reduction of Fe (III). The redox potential of the material is measured by an electrochemical method at present, for example, research discloses a quantitative prediction method of the electron transfer capability of soluble black carbon, and the electron transfer capability of the material is detected by adopting the electrochemical method. However, this method usually overestimates the electron transfer capability of the soluble black carbon in the actual environment and does not truly reflect the microorganism-driven redox process. In particular, for measuring the redox potential of DBC in anaerobic environments such as soil and sediment, it is highly desirable to develop a measurement method capable of accurately quantifying the redox potential of soluble black carbon by simulating the anaerobic environment. Disclosure of Invention In order to solve the problems, the invention provides an accurate and environment-simulative method for measuring the oxidation-reduction potential of soluble black carbon, which can more accurately measure the oxidation-reduction potential of DBC in anaerobic environments such as soil, sediment and the like. In order to achieve the above purpose, the present invention adopts the following technical scheme: in a first aspect of the invention, there is provided a method of determining the redox potential of a soluble black carbon comprising: under anaerobic conditions, uniformly mixing the soluble black carbon and quinone reducing bacteria in a culture medium, reacting, and sterilizing after the reaction is finished to obtain a mixed system; adding ferrihydrite into the mixed system for reaction, and measuring the total amount of Fe (II) in the liquid phase and the solid phase after the reaction is completed; And calculating the oxidation-reduction potential of the soluble black carbon by taking the AQDS as a reference to obtain the catalyst. The research shows that under anaerobic environment such as soil, sediment and the like, the main active group in DBC participating in the redox process of natural environment is a quinone group, so that the quinone reducing bacteria are selected to reduce DBC so as to more accurately simulate the redox process of DBC under the anaerobic environment and more accurately measure the redox potential of DBC under the condition. In a second aspect of the invention, a system for determining the redox potential of soluble black carbon is provided, comprising a quinone reducing bacteria, a culture medium, ferrihydrite, a container, and an ultraviolet-visible spectrophotometer. The beneficial effects of the invention are that (1) The invention adopts microorganisms to simulate DBC to participate in the redox process of natural environment under the anaerobic environment such as soil, sediment and the like, is more close to the real environment, can more accurately measure the redox potential of DBC under the anaerobic environment such as soil, sediment and the like, and can be used for evaluating the environmental behaviors of soluble black carbon with different sources. (2) The invention has simple operation and stable and reliable result. Drawings The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention. FIG. 1 is a schematic diagram showing electron transfer efficiency of 300DBC in example 1; FIG. 2 is a schematic diagram showing electron transfer efficiency of 500DBC in example 2; FIG. 3 is a graph showing electron transfer efficiency of 700DBC in example 3. Detailed Description It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the invention. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Unless