Detection device for monitoring water quality on line and water quality on-line monitoring method

Abstract

The invention provides a detection device for monitoring water quality on line. The detection device comprises a sampling device, a microorganism fixing device, and an electrochemical detection device wherein a sample inlet of the microorganism fixing device is connected with a sample outlet of the sampling device; the microorganism fixing device is a microbial film reactor; the microbial film reactor comprises a container and a microbial film arranged in the container; the microbial film comprises a microbial carrier and a microorganism attached to the microbial carrier; the microbial film reactor is placed in a thermostat; a sample inlet of the electrochemical detection device is connected with a sample outlet of the microbial film reactor; the electrochemical detection device comprises a detection pool, an electrode system, an electrochemical work station and a program control device; the electrode system is arranged in the detection pool; the electrochemical work station is connected with the electrode system; and the program control device is used for controlling the electrochemical work station. The invention further provides a water quality on-line monitoring method. When the on-line monitoring device detects the biochemical oxygen demand and the toxicity of the water sample, the result is accurate.

Description

technical field [0001] The invention relates to the technical field of environmental monitoring, in particular to a detection device for online monitoring of water quality and a method for online monitoring of water quality. Background technique [0002] The impact of water security on human beings is multifaceted, involving all aspects of nature, society and humanity. Therefore, water quality monitoring has attracted extensive attention from domestic and foreign experts, governments and international organizations. [0003] Biochemical oxygen demand (BOD) is an important indicator of water quality monitoring. The international standard is the 5-day BOD method, but its operation is cumbersome, time-consuming, requires skilled technology, and cannot reflect water quality changes in time (Liu et al. al., Biosens. Bioelectron., Vol. 20, 562 (2004)). The rapid measurement of BOD developed in recent years is based on the principle that microorganisms assimilate organic matter a...

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Problems solved by technology

At present, organisms such as frogs, fish, mice, plankton, and seaweed have been used to detect water toxicity. However, the above-mentioned organisms have disadvantages such as long test cycle, high cost, and complicated operation, which are not only difficult to popularize. , and cannot meet the needs of on-site rapid detection

The existing international standard ISO11348-3 stipulates that the deep-sea luminescent bacteria V. fischeri is used as the test organism, which realizes the need for rapid detection, but there are still many shortcomings: first, in order to balance the osmotic pressure, the test must be carried out under high salinity conditions, It may cause changes in the properties of some chemicals in the sample, and salinity correction will lead to false negative results; secondly, for some samples with low solubility, false positive results will be caused by the precipitation of toxic substances; thirdly, this method uses Fluorescence detection, the detection signal is easily affected by the turbidity and color of the water; finally, luminescent bacteria are not ubiquitous microorganisms in nature, it is difficult to obtain and preserve, and the price of commercial luminescent bacteria is relatively expensive, resulting in higher detection costs

Accordingly, water quality monitoring methods based on microorganisms using artificial media as detection probes have been gradually developed. For example, European Patent Publication No. WO 023770 discloses a method for detecting biochemical oxygen demand and toxicity of water bodies using electronic media. In this method, microorganisms are cultivated and directly added to the water sample to be tested to degrade the organic matter in the water sample, so as to obtain the detection results of biochemical oxygen demand and toxicity of the water body. However, this method uses free microorganisms, and each Microbial cultivation, centrifugation, cleaning and other processes are required before each test, which consumes time and cost, and online monitoring of water quality cannot be carried out

Pasco et al. introduced potassium ferricyanide into the Micredox system, and confirmed that the system can be used for water toxicity detection by measuring the influence of different toxic substances on microbial respiration, resulting in changes in the electron transfer rate of potassium ferricyanide, but it also uses free microorganisms , unable to realize online monitoring

[0006] Morris et al. disclose a method for monitoring water quality by embedding immobilized microorganisms, which embed the microorganisms in embedding materials to obtain immobilized microorganisms, and then use the immobilized microorganisms to detect biochemical oxygen demand and Toxicity. Although this method can realize online monitoring of water quality, it uses embedding to immobilize microorganisms. Microbes are embedded in embedding materials, which will affect mass transfer and microbial activity, thereby affecting the effect of microorganisms on water samples. The degradation of organic matter in the medium will ultimately affect the accuracy of the test results

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