Method for detecting trace amounts in sewage

Abstract

The application provides a trace substance detection method in sewage, comprising a sampling stage and a detection stage; the sampling stage comprises the following steps: (S1) switching of a flow path switching module, pumping, sewage sequentially passing through a sampling tube, the flow path switching module and the pump, and entering a temporary storage container; (S2) real-time monitoring of the sewage volume in the temporary storage container, and after the sewage volume reaches a first set volume, entering the next step; (S3) switching of the flow path switching module, closing the valve between the communication pipeline and the sampling bottle, adjusting the working parameters of the pump, and the sewage in the temporary storage container sequentially passing through the pump and the flow path switching module and entering the communication pipeline; (S4) real-time monitoring of the sewage volume in the communication pipeline, and after the sewage volume reaches a second set volume, entering the next step; (S5) respectively and sequentially opening the valves between the communication pipeline and the sampling bottles, and equally injecting the sewage in the temporary storage container into each sampling bottle by the pump. The application has the advantages of high sampling precision.

Description

TECHNICAL FIELD

[0001] The present application relates to sewage monitoring, in particular to a method for detecting trace substances in sewage. BACKGROUND

[0002] The concept of sewage epidemiology was first proposed in 2001, which is based on the principle that after a certain drug is taken by the body, a part of the unabsorbed and metabolites of the active ingredients will enter the sewage with urine and feces. Sewage epidemiology was first applied to the evaluation of cocaine abuse in 2005. Subsequently, sewage epidemiology analysis method was gradually applied to the monitoring of drug abuse, including the abuse monitoring of cocaine, heroin, methamphetamine and marijuana.

[0003] In recent years, many cities in China have carried out drug situation monitoring methods based on sewage epidemiology. This method mainly determines the concentration of drugs and their metabolite target substances (DTR) in municipal sewage inflow and outflow. Through sewage drug situation monitoring, data support can be provided for formulating drug control policies and then implementing precise crackdown on drug violations and criminal activities.

[0004] The current sewage drug testing sampling mostly uses manual sampling. This method has many shortcomings, such as:

[0005] 1. High labor cost;

[0006] 2. Poor precision of manual sampling, large deviation of sewage volume in sampling bottle. SUMMARY

[0007] To solve the above-mentioned deficiencies in the prior art, the present application provides a method for detecting trace substances in sewage.

[0008] The purpose of the present application is achieved by the following technical solutions:

[0009] A method for detecting trace substances in sewage, comprising a sampling stage and a detection stage; the sampling stage comprises the following steps:

[0010] (S1) Switching of flow switching module, pump working, sewage passing through sampling pipe, flow switching module and pump in turn, and entering temporary storage container;

[0011] (S2) Real-time monitoring of the volume of sewage in the temporary storage container, and after the volume of sewage reaches a first set volume, proceeding to the next step;

[0012] (S3) Switching of the flow switching module, closing the valve between the communication pipeline and the sampling bottle, adjusting the working parameters of the pump, and the sewage in the temporary storage container passing through the pump and the flow switching module in turn, and entering the communication pipeline;

[0013] (S4) Real-time monitoring of the sewage volume in the communication pipeline, and when the sewage volume reaches a second set volume, entering the next step;

[0014] (S5) Opening the valves between the communication pipeline and the sampling bottles in sequence, and injecting the sewage in the temporary storage container into each sampling bottle by the pump.

[0015] Compared with the prior art, the present application has the beneficial effects of:

[0016] 1. Automatic sampling;

[0017] Without human intervention, all-weather automatic sampling is realized, and the detection personnel take the sampling bottles back to the laboratory regularly;

[0018] 2. High sampling precision;

[0019] Real-time monitoring of whether the flow channel is abnormal, cleaning the flow channel when abnormal, and improving the subsequent sampling precision;

[0020] Real-time monitoring of whether the communication pipeline is full, and injecting the sewage into each sampling bottle when full, thereby improving the sampling precision. BRIEF DESCRIPTION OF DRAWINGS

[0021] The disclosure of the present application will become more apparent with reference to the drawings. It is easy for those skilled in the art to understand that these drawings are only used to illustrate the technical solutions of the present application, and are not intended to limit the protection scope of the present application. In the drawings:

[0022] Figure 1 is a flow chart of the method for detecting trace substances in sewage according to the embodiment of the present application. DETAILED DESCRIPTION

[0023] Figure 1 The following description describes optional specific embodiments of the present application to teach those skilled in the art how to implement and reproduce the present application. Some conventional aspects have been simplified or omitted in order to teach the technical solutions of the present application. Those skilled in the art should understand that variations or substitutions derived from these specific embodiments will be within the scope of the present application. Those skilled in the art should understand that the following features can be combined in various ways to form multiple variations of the present application. Therefore, the present application is not limited to the following optional specific embodiments, but is only limited by the claims and their equivalents.

[0024] Example 1

[0025] The method for detecting trace substances in sewage according to the embodiment 1 of the present application includes a sampling stage and a detection stage; as shown in the figure, the sampling stage includes the following steps: Figure 1

[0026] ​(S1) The flow path switching module is switched, the pump is operated, and the sewage sequentially (forwardly) passes through the sampling tube, the flow path switching module and the pump, and enters the temporary storage container (i.e. the transfer position);

[0027] (S2) The volume of the sewage in the temporary storage container is monitored in real time, and after the volume of the sewage reaches a first set volume, the next step is entered;

[0028] (S3) The flow path switching module is switched, the valve between the communication pipeline and the sampling bottle is closed, the working parameters of the pump are adjusted, and the sewage in the temporary storage container sequentially passes through the pump and the flow path switching module, and enters the communication pipeline (i.e. the main liquid path);

[0029] (S4) The volume of the sewage in the communication pipeline is monitored in real time, and after the volume of the sewage reaches a second set volume, the next step is entered;

[0030] (S5) The valves between the communication pipeline and the sampling bottles are sequentially opened, and the pump is used to inject the sewage in the temporary storage container into each sampling bottle in equal amounts.

[0031] In order to identify flow path abnormalities such as blockage in a timely manner, further, in step (S2), if the volume of the sewage in the temporary storage container does not reach the first set volume within a first set time, the working parameters of the pump are adjusted to make the sewage flow reversely in the sampling tube, the pump is used to discharge the sewage from the sampling tube to dredge the pipeline, and then the process returns to step (S1).

[0032] In order to make sampling proceed normally, further, after returning to step (S1) and within a second set time, if the volume of the sewage in the temporary storage container still does not reach the first set volume, the sampling is terminated, and the process directly enters step (S3).

[0033] In order to improve the precision of the amount of sewage entering the sampling bottles, further, in step (S4), if the volume of the sewage in the communication pipeline does not reach the second set volume within a set time, the valves between the communication pipeline and the sampling bottles are sequentially opened, and the pump is used to inject the sewage in the temporary storage container into each sampling bottle in equal amounts.

[0034] In order to reduce the requirements for the pump, further, in step (S1), the pump is rotated forward, and in steps (S3) and (S5), the pump is rotated reversely.

[0035] Example 2

[0036] The application example of the method for detecting trace substances in sewage according to the method for detecting trace substances in sewage in Example 1 in the detection of drugs and metabolites in sewage.

[0037] In this application example, as shown in FIG. 1, the method for detecting trace substances in sewage includes the following steps: Figure 1 ​

[0038] (S1) Switching of flow switching module (two-position electromagnetic three-way valve), forward rotation of pump, sewage sequentially passing through sampling tube, flow switching module and pump, and entering temporary storage container;

[0039] (S2) Real-time monitoring of overflow of temporary storage container, by setting liquid detection module downstream of overflow port of temporary storage container, when liquid is detected to flow through, indicating overflow of temporary storage container, sewage in temporary storage container reaching first set volume (i.e. volume of temporary storage container).

[0040] After the sewage volume reaches the first set volume, the next step is entered;

[0041] If the sewage volume in the temporary storage container does not reach the first set volume within the first set time, the pump is reversed, so that the sewage flows reversely in the sampling tube, and the sewage is discharged from the sampling tube by the pump to dredge the pipeline, and then returns to step (S1).

[0042] If the sewage volume in the temporary storage container still does not reach the first set volume within the second set time after returning to step (S1) in the judgment of step (S2), the sampling is terminated, and step (S3) is directly entered, at this time, the first set volume may not be detected due to sensor failure, but it does not affect the subsequent liquid separation process, and can continue.

[0043] (S3) Switching of flow switching module, closing of valve between connecting pipeline and sampling bottle, and reverse rotation of pump, sewage in temporary storage container sequentially passing through pump and flow switching module, and entering connecting pipeline;

[0044] The connecting pipeline has multiple outlets, each outlet sequentially connecting valve and sampling bottle;

[0045] (S4) Real-time monitoring of sewage volume in connecting pipeline, by setting sewage detection module downstream of overflow port of connecting pipeline, when sewage is detected by the detection module, indicating overflow of connecting pipeline, sewage in connecting pipeline reaching second set volume (i.e. volume of connecting pipeline), and entering next step (S5);

[0046] If the sewage volume in the connecting pipeline does not reach the second set volume within the set time, the valves between the connecting pipeline and the sampling bottles are sequentially opened, and the sewage in the temporary storage container is injected into each sampling bottle by the pump.

[0047] (S5) Sequentially opening of valves between connecting pipeline and sampling bottles, and injection of equal amount of sewage in temporary storage container into each sampling bottle.

[0048] The experimental results show that the sampling accuracy is maintained at ±5%.

[0049] In the detection stage, the staff will take the sampling bottle on site back to the laboratory for analysis, so as to obtain the content of the drug and its metabolites in the sewage in the sampling bottle, and according to the sampling time and sampling place corresponding to the sampling bottle, the content of the drug and its metabolites in the sewage upstream and downstream of the sampling point is obtained, and the area where the drug user is located is obtained.

Claims

1. A method for detecting trace substances in sewage, comprising a sampling stage and a detection stage; characterized in that, The sampling stage comprises the following steps: (S1) switching of the flow switching module, operation of the pump, sewage sequentially passing through the sampling tube, the flow switching module and the pump, and entering the temporary storage container; (S2) real-time monitoring of the sewage volume in the temporary storage container, and after the sewage volume reaches a first set volume, entering (S3); If the sewage volume in the temporary storage container does not reach the first set volume within a first set time, adjusting the working parameters of the pump so that the sewage flows reversely, and the sewage is discharged from the sampling tube to the dredging pipeline through the pump, and then returning to step (S1); If the sewage volume in the temporary storage container still does not reach the first set volume within a second set time after returning to step (S1), terminating the sampling, and directly entering step (S3); (S3) switching of the flow switching module, closing the valve between the connecting pipeline and the sampling bottle, adjusting the working parameters of the pump, and the sewage in the temporary storage container sequentially passing through the pump and the flow switching module, and entering the connecting pipeline; (S4) real-time monitoring of the sewage volume in the connecting pipeline, and after the sewage volume reaches a second set volume, entering the next step; (S5) respectively and sequentially opening the valves between the connecting pipeline and the sampling bottles, and equally injecting the sewage in the temporary storage container into each sampling bottle through the pump.

2. The method of claim 1, wherein, In step (S4), if the sewage volume in the connecting pipeline does not reach the second set volume within a set time, the valves between the connecting pipeline and the sampling bottles are sequentially opened, and the sewage in the temporary storage container is equally injected into each sampling bottle through the pump.

3. The method of claim 1, wherein, The method for judging whether the set volume is reached is: detecting whether there is overflow, if there is overflow, the set volume is reached, and if there is no overflow, the set volume is not reached.

4. The method of claim 1, wherein, The trace substance is a drug or a metabolite thereof.

5. The method of claim 1, wherein, In step (S1), the pump is rotated forward, and in steps (S3) and (S5), the pump is rotated reversely.

6. The method of claim 1, wherein, The connecting pipeline has a plurality of outlets, and each outlet is connected with a valve and a sampling bottle.

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