What are the types of water samples sampled? Methods of sampling water

Hello landlord. In addition to instantaneous water samples, mixed water samples, and comprehensive water samples, there are also the following types of water samples: (1) Periodic samples are collected at fixed time intervals (depending on the time) Samples are automatically started and stopped at specified time intervals through a timing device.

Samples are usually drawn over a fixed period of time and a certain volume of sample is injected into each vessel. When collecting samples manually, cycle samples are collected according to the above requirements. (2) Cycle samples are collected at a fixed discharge interval (depending on volume) When the water quality parameters change, the sampling method is not affected by the discharge flow rate, and such samples are classified as flow proportional samples.

For example, the unit volume of liquid flow.

e.g. 10,000 L), the amount of sample taken is fixed and not time-dependent. (3) Collect serial samples at a fixed flow rate (depending on the timing or time average.

Continuous samples taken at a fixed flow rate can measure all the components present during sampling, but do not provide changes in the concentrations of individual parameters during sampling. For details, please refer to the National Reference Materials Network.

4) Continuous samples collected at variable flow rates (depending on or proportional to flow rate) Collected flow-proportional samples represent the overall quality of water. Even though the flow rate and composition are changing, the flow ratio sample can reveal these changes that would not be observable with the instantaneous sample. Therefore, for flowing water with significant changes in flow rate and pollutant concentration to be measured, collecting a flow-proportional sample is an accurate sampling method.

Type of water sample and container.

Rigid glass bottles or polyethylene plastic bottles are used for raw water samples and acidified water samples, and polyethylene plastic bottles are used for alkalized water samples.

Sampling of various water sources.

1. Open-air water source, the bottle mouth is 10-30cm below the water surface, so that the water can flow into the balance slowly to prevent impurities from entering.

2. Sampling in swamps, deep and hidden places.

3. Pumping, first remove the water in the pipe, then rinse 2-3 times, and take samples.

4. In the well or shaft, make sure that it is not stagnant water, and it is not a direct sampling, if it is, first extract 1-2 times the volume of water column and then excite for sampling.

5. Take samples in special boreholes, pump water first, and wait for the water level and chemical composition of the water to stabilize before taking it.

If you don't understand, you can ask again, or you can check the field work manual yourself.

Summary. Hello, the difference between water quality collection and gas sample collection is that gas sample collection is often spread out to distant and high places, whereas gas sample collection is three-dimensional; Although water quality samples are usually located in a designated body of water, if the water depth is not taken into account, the number of samples is 2. Size.

Water quality sampling varies with the purpose of monitoring and the object of monitoring.

Hello, the difference between water quality collection and gas sample collection is that gas sample collection is often scattered to distant late and high places, whereas gas sample collection is three-dimensional; Although water quality samples are usually located in a designated body of water, if the water depth is not taken into account, the number of samples is 2. Size. Water quality sampling varies with the purpose of monitoring and the purity of the monitoring object.

Among them: different water samples, different collection methods. Generally, water samples are collected in polyethylene bottles or split macro glass bottles, and should be analyzed as soon as possible. If it needs to be preserved, sulfuric acid should be added to acidify the water sample to a pH <2,2 5 and it can be stored for 7 days.

Summary. What are the types of drinking water samples, and how to choose sampling points?

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At present, there are three types of bottled drinking water, including purified water, mineral water, and natural water.

Drinking water samples.

For example, water samples are divided into surface water, lake dust and reservoir water, sewage (domestic sewage and industrial wastewater), groundwater, seawater, and drinking water.

That is true. Sampling point selection.

The selection of sampling points should meet the requirements of the Xiazenxin lead column: the setting of sampling points should be Tanchang representative, and should be set up at the water intake, the outlet of the centralized water supply unit and the frequent water use point of Hehao residents.

1. The water samples at each sampling point should be analyzed, and no mixed samples should be taken.

2: When it is necessary to mix the water quality of the process section, the water samples on each perpendicular line in each sampling section in the section should be mixed into a water sample each time; In other cases, only one mixed water sample is taken at a time for each sampling section, that is, the water samples taken from various places on the section are mixed into one water sample.

Three: In principle, only the cross-section mixed water sample is taken.

The difference between water quality sampling and atmospheric sampling is that atmospheric samples are often diffused to great distances and high places, and atmospheric auspiciousness is three-dimensional; However, the water quality sample is often in the specified water body, and if the water depth is not considered, the sampling is two-dimensional. Water quality sampling varies depending on the purpose of monitoring and the object of monitoring.

1) Sampling of factory drains. Sampling at the outfall of the factory is selected at the outfall or other places with the same water quality as the outlet. The amount of samples collected, the full analysis of water quality is 2-5L, and the single analysis is 100-1000ml.

In general, industrial wastewater is sampled and filled in polyethylene plastic containers or colorless glass containers with grinding plugs. The sampling time is generally not less than 24 hours.

2) River sampling. The river is usually divided into several river sections, such as upstream, middle and downstream, and each section needs to be sampled separately on the left and right banks, the central axis of the river, and the upper, middle and lower layers. The interval of sampling time should be 1 5-2h, and the continuous sampling time is 24-48h.

3) Lake sampling. The water of the lake is collected from the surrounding small rivers. In order to collect representative water quality samples, water samples can be collected at the inlets of rivers around the lake, in the center of the lake, and at overflows. In terms of time, sampling should be carried out at least twice a year in summer and winter.

4) Sea area sampling. When collecting water auspiciousness in the sea area, samples should be taken regularly according to the law of high tide and low tide. In the case of marine pollution surveys, samples should be taken in a specific way. Since the water quality of the sea varies greatly throughout the year, it is appropriate to take samples more than 4 times within one year.