On-site sampling is required for acceptance monitoring, sewage permit requirement monitoring and supervisory monitoring of new and expanded plant areas. Sampling is the basic work in the whole monitoring and also plays an important role in the follow-up work. This paper mainly analyzes the details of environmental monitoring field sampling for reference.
Keywords: environmental monitoring; On-site sampling; Influencing factors; Sample preservation
With the rapid development of China's economy and the deepening of industrialization, environmental pollution has become increasingly serious. Hazy weather and groundwater pollution have led to the collective appearance of cancer villages, and effective measures must be taken to protect it. Environmental monitoring is an effective means of environmental protection, but the effect of environmental monitoring is easily affected by many factors, such as sampling location, frequency and natural factors in the monitoring process. Therefore, in the usual monitoring process, only by figuring out the factors that affect the monitoring effect can we get the ideal monitoring results better.
1 analysis of influencing factors of field sampling in environmental monitoring
(1) Natural factors: Natural factors affect the ambient temperature, pressure, wind speed, humidity, etc. In the process of noise monitoring, wind speed and rainy days have great influence on it, and it is strictly forbidden to detect it under strong wind and lightning. In the process of surface water monitoring, because the river bank environment will have an impact on the detection of water quality, it is necessary to avoid detecting on the river bank when monitoring and sampling surface water.
(2) Sampling frequency and sampling location: master the sampling frequency and sample at equal intervals when the enterprise reaches normal and stable production conditions, so as to collect representative samples. For the sampling site, it is arranged in strict accordance with the technical specifications, and the sampling results obtained with a slight deviation may have a large deviation.
(3) Container factor: After the sample collection process, the selection of sampling container also has a very critical impact on the sampling effect. In container selection, try to buy some enterprises with strong strength and reliable quality. In the process of sampling, appropriate containers should be selected to hold the collected samples. If an inappropriate container is selected, the detection factor will react with the container, thus making the collected samples seriously inconsistent with the reality.
2 Environmental monitoring site need to pay attention to the details
(1) Atmospheric sampling: In the daily monitoring process, monitoring instruments are generally used. Because of its high detection limit, some low-concentration gases cannot be effectively detected. In this case, the chemical analysis method can take samples. The detection limit of chemical analysis method is not very high, and the detection of low concentration gas is reliable. Absorption liquid and sample collection: after the sample is collected with absorption liquid, it should be sealed at low temperature and protected from light. This is because the stability of the absorption liquid is not very high and it is easily influenced by many factors.
(2) Water quality sampling: In order to improve the accuracy of test results, the detection limit [1] which is 20% lower than the implementation standard must be selected. In the sampling process, different sampling factors use different sampling containers to avoid the inaccurate detection results caused by the reaction between the sampling factors to be measured and the containers. Water quality fixative should be added immediately after sampling is completed, and it should be stored away from light if necessary.
(3) Check the sampling container: When the concentration of the samples we collected is relatively high, we can choose the direct sampling method. Commonly used containers are: vacuum bottles, plastic airbags, syringes. These containers must be monitored for air tightness before use, so as to avoid air leakage during use and affect sample collection [2].
(4) Sampling of solid waste and soil: Selection of sampling instruments: It is forbidden to react with sampling instruments, which makes the data and facts of monitored solid waste and soil inaccurate. At the same time, in the process of soil sampling, different sampling units should be divided according to soil texture and fertility for unified sampling [2].
(5) Noise detection: Noise monitoring related work is mainly to monitor environmental sensitive noise and industrial enterprise noise [3]. When detecting the noise at the boundary of an enterprise, the quantity and distribution of production equipment should be investigated in detail, whether the production equipment works normally and whether the production load meets the monitoring requirements. Noise monitoring needs to be carried out under the conditions of no wind, no rain, no lightning and the wind speed is less than 5m.
3 Conclusion
Environmental monitoring is the most basic work in environmental protection, but it plays an important role in the follow-up work. Only by doing a good job of on-site sampling can we ensure the reliability of the collected samples and better carry out environmental protection work.
refer to
[1] Six flavors. Quality control in sampling process of environmental monitoring [J]. Commodity and quality, 20 1 1, S3:112.
[2] Zhu Zhu. On quality control measures of field sampling in environmental monitoring [J]. Environmental Research and Environmental Protection, 20 13, 0 1: 26 ~ 27+ 18.
[3] Hu Ruifeng. Analysis of sampling problems and matters needing attention in environmental monitoring [J]. Resource conservation and environmental protection, 20 16, 05: 97.
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