Measuring method of biochemical oxygen demand and BOD sensor and applications

Abstract

The invention discloses a measuring method of biochemical oxygen demand and a BOD sensor and applications. The measuring method comprises the following steps of: constructing a unilocular air cathode no-amboceptor microbial fuel cell, adding a sample into the microbial fuel cell; measuring output voltage generated by the microbial fuel cell and calculating electrical quantity value; and substituting the electrical quantity value into a liner equation and calculating the BOD value and the like. The invention provides the specific BOD sensor and applications thereof for implementing the method; the lowest detection limit of the measuring method is 0.2mg / L, the measuring range of BOD is 5 to 50mg / L, and the relative error with the detection result of a culture method at the temperature of 20 plus or minus 1 DEG C for 5 days is less than 4.0%. The invention has simple and programmable operation process, stable and fast measuring process, can realize online detection, has low cost and is suitable for promotion and application commonly.

Description

technical field [0001] The invention belongs to the technical field of environmental detection, and in particular relates to a method for measuring biochemical oxygen demand (BOD), a BOD sensor and a use method for realizing the method. Background technique [0002] Biochemical oxygen demand (BOD) is a comprehensive index to characterize the degree of organic pollution. The detection of BOD plays a very important role in environmental testing and water treatment engineering, and is widely used in water body monitoring and sewage treatment plant operation. Control, the meaning of BOD is: the mass of dissolved oxygen consumed by the oxidation of organic matter in a unit volume of water sample under the action of microorganisms. [0003] At present, BOD is mainly used at home and abroad 5 Determination method, after cultivating the sample at 20±1°C for 5 days, measure the dissolved oxygen before and after the culture of the sample, and the difference between the two is the bio...

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Problems solved by technology

However, the proton exchange membrane used in this MFC is expensive, especially the aeration of the cathode chamber is required, and the operation is more complicated

In addition, metal platinum (Pt) is generally used as the cathode catalyst of MFC at present, and Pt is expensive, which limits the popularization and application of MFC BOD sensors.

The Chinese patent application with the publication number CN01315347 discloses a device for on-line determination of the biochemical oxygen demand of a sample. An upflow microbial fuel cell is used to measure the biochemical oxygen demand of a sample. The structure of the battery includes a shell, an anode, a cathode, an anode The electrode chamber between the cathode and the cathode, the anode and the cathode are made of platinum, graphite, graphite felt and other materials, the water sample passes through the anode, the electrode chamber, and the cathode from bottom to top, and flows out from the water sample outlet of the battery; the battery with this structure can Realize the biochemical oxygen demand of continuous on-line measurement water sample, but there are following defects in this invention: 1) in order to prevent clogging, it has adopted filter treatment to remove particulate matter and microbial thalline in water sample, and this will cause detection result to be on the low side, because Particles and microbial cells in water samples are also part of BOD; 2) It adopts a membraneless upflow battery structure, the anode and cathode are placed in an electrode chamber at the same time, and there is no diaphragm in the middle to separate them, so that the electricity-producing microorganisms in the anolyte The organic matter (fuel) will directly pass through to the cathode, causing cathode pollution, resulting in a decrease in the cathode oxygen reduction efficiency and worse battery performance, which will affect the stability of the test results, and the internal resistance of the microbial fuel cell of this configuration is relatively high. Large, low output power, thereby reducing the accuracy of BOD detection; 3) The invention does not optimize the design of the detection conditions to obtain better detection results

However, according to the retrieval, the BOD sensor using the single-chamber microbial fuel cell as the core component has not been reported yet.

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