Biochemical oxygen demand bod on-line measuring instrument and its detection method

Abstract

The invention relates to a biochemical oxygen demand BOD online measuring instrument and a detection method thereof. The sewage pump, dilution water pump, air pump and buffer pump are connected to the aeration tank, the aeration tank is connected to the reactor, the reactor is connected to the controller, the connecting pipe and the connecting wire are equipped with dissolved oxygen electrodes, and the controller is connected to the sewage pump, dilution water pump. When the sewage to be tested passes through the sewage pump, the dilution water passes through the dilution water pump, and the air is pumped to the aeration tank through the air pump to aerate and reach dissolved oxygen saturation, after passing through the porous ceramic of the reactor, measure the change of dissolved oxygen concentration before and after passing through the porous ceramic material . The dissolved oxygen concentration of the effluent sewage after the reaction is continuously monitored by the dissolved oxygen sensor. The controller controls the input flow rate of the sample to keep the change of the dissolved oxygen concentration constant, and calculates the BOD value according to the flow rate of the sample to be tested under the condition that the dissolved oxygen concentration reaches the same constant value after the reaction and the input flow rate of the standard sample. The measurement process of the present invention is fully automated, can monitor continuously in real time, and display the dynamic BOD value of the water body at any time.

Description

technical field [0001] The invention relates to a measuring instrument for continuously and uninterruptedly measuring BOD in a water body and a detecting method. Background technique [0002] Biochemical oxygen demand (BOD) refers to the dissolved oxygen consumed by microorganisms to decompose some oxidizable substances in water under specified conditions, especially the biochemical process of decomposing organic matter. BOD is one of the most important indicators to detect the degree of water pollution. When domestic sewage or industrial sewage is discharged into rivers, rivers or lakes, the aerobic microorganisms in the water will decompose the components in the sewage, so the dissolved oxygen in the water will be consumed in large quantities, making some organisms that need a lot of oxygen to survive, such as fish Difficult to survive. On the other hand, in order to reduce the pollution of the environment, the sewage will be treated before it is discharged into the natu...

AI Technical Summary

Problems solved by technology

Although this method is very simple and rapid, it also has considerable problems: First, since the activity of microorganisms immobilized on the dissolved oxygen electrode membrane will change over time, it requires frequent calibration of equipment

Second, due to the limited variety of microorganisms immobilized on the membrane, it is easy to encounter organic components beyond the ability of the immobilized microorganisms to decompose in practical applications, resulting in the problem of low test results

Third, when the concentration of organic matter in the sample exceeds a certain range, the oxygen consumption rate of the fixed microorganisms on the membrane will no longer increase and reach saturation, making the measurement range limited

Fifth, since the biofilm needs to be replaced frequently, continuous online monitoring of BOD cannot be achieved

[0005] The limitations of existing methods lead to the fact that the current BOD rapid detection equipment cannot really provide fast and accurate water parameters, which greatly limits the application of BOD in environmental monitoring

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