Field groundwater filtering and sampling and moving-water flow index measuring device and method

Patent metadata

Field	Value
Publication number	US-11225422-B2
Application number	US-202016887556-A
Country	US
Kind code	B2
Filing date	May 29, 2020
Priority date	May 30, 2019
Publication date	Jan 18, 2022
Grant date	Jan 18, 2022

Abstract

A field groundwater filtering sampling and moving-water flow index measuring device comprises a precipitation tank, an electrode measuring column of moving-water flow, a suction filter unit and a control unit; also provided is a measuring method by adopting the index measuring device. Sample filtering and electrode measuring work in the field groundwater sampling process can be integrally solved, sampling time point selection after well washing is scientifically and automatically achieved, and the sample filtering and collecting efficiency is remarkably improved; and meanwhile, the accuracy of testing various in-situ indexes such as pH value, oxidation reduction potential and the like in groundwater is remarkably improved in the design of moving-water flow electrode measurement. The method has good application prospect and value for carrying out groundwater monitoring and evaluation, remediation and governance, and the like.

First claim

The invention claimed is:

1. A field groundwater filtering, sampling, and moving-water flow index measuring device comprising:
a precipitation tank configured to preprocess the groundwater continuously extracted through a pipeline from a monitoring well;
a moving-water flow column comprising a water inlet connected with a first water outlet of the precipitation tank, the moving-water flow column configured to receive the groundwater from the precipitation tank via the water inlet;
a measuring electrode housed in the moving-water flow column at a first end of the moving-water flow column and configured to measure physical and chemical indexes of dynamic moving-water flow in the moving-water flow column;
a suction filter unit connected at a second end of the moving-water flow column opposite the first end and configured to form a moving-water flow channel between the measuring electrode in the moving-water flow column and the suction filter unit via a filtering membrane unit, wherein the suction filter unit is configured to collect a groundwater sample while the measuring electrode measures the physical and chemical indexes of the dynamic moving-water flow; and
a control unit configured to monitor the measurements by the measuring electrode and the suction filter unit to accurately determine and control collection time of the groundwater sample.

2. The index measuring device according to claim 1 , wherein the precipitation tank comprises a brown or dark and transparent design, and is made of PP or PET.

3. The index measuring device according to claim 1 , wherein the moving-water flow column is a cylindrical structure, the water inlet located at a side of the cylindrical structure proximal to the second end, a second water outlet provided proximal to the first end at a side circumferentially opposite to the water inlet, and the second water outlet of the moving-water flow column is externally connected to a drainage pipeline;
an upper sealing cover is arranged at the first end of the move-water flow column, and a plurality of electrode sockets are arranged on the sealing cover, wherein the measuring electrode comprises one or more electrodes inserted into the electrode sockets and selected from a pH electrode, an oxidation-reduction potential (ORP) electrode, and an electrical conductivity (Ec) electrode;
the electrode sockets on the upper sealing cover each comprising a waterproof gasket suitable for internal connection of electrodes with different diameters, and a fixing cap cover that blocks a respective electrode socket when a measuring electrode is not inserted into the respective electrode socket;
wherein the upper sealing cover is a cylindrical porous protective cover, and comprises a fixed cap with a caliber that is larger than the first end of the moving-water flow column; and
wherein the second end of the moving-water flow column is provided with a lower sealing cover, and the sealing cover has a hollow design.

4. The device according to claim 1 , wherein the suction filter unit comprises a suction filter container, a suction pipeline and a vacuum pump, wherein the suction filter container is a suction flask, comprises a brown or dark and transparent design, and is made of glass or plastic; and the vacuum pump is configured to provide power for water to flow through a membrane during the vacuumizing.

5. The device according to claim 1 , wherein the second end of the moving-water flow column is connected with a first end of the suction flask, and both of the second end of the moving-water flow column and the first end of the suction flask are connected by a fixing clip; and the suction flask comprises a mouth having a porous medium design, and the filter membrane unit is configured to receive filtering membranes of different pore diameters placed on the first end of the suction flask.

6. The index measuring device according to claim 1 , further comprising a sampling unit connected to a third water outlet of the suction flask, wherein the sampling unit comprises an airtight control valve connected to the third water outlet, a water passing pipeline, and a sampling bottle configured to receive the collected groundwater sample, and, wherein the sample bottle is used for sending the collected groundwater sample to a laboratory for detection.

7. A moving-water flow index measuring method comprising:
providing groundwater to a moving-water flow column, the groundwater extracted through a pipeline from a monitoring well via a submersible pump;
measuring, using a measuring electrode, indexes of dynamic moving-water flow in the moving-water flow column, the measuring electrode provided at a first end of the moving-water flow column opposite a suction filter unit connected to a second end of the moving-water flow column;
when well washing by the groundwater is completed, determining that the indexes of the dynamic moving-water low has stabilized for an amount of time, the amount of time selected from a plurality of amounts of time according to requirements of a different sampling situations, automatically starting, by a control unit, a vacuum pump of the suction filter unit in response to determining that the indexes are stabilized; and
closing an airtight control valve of the sampling unit while the vacuum pump of the suction filter unit operates so as to ensure stable operation of the suction filter unit;
after a suction flask of the suction filter unit reaches ⅔ full of groundwater, closing the suction filter unit, by the control unit, and opening the airtight control valve and a plurality valves for sample collection into a sampling bottle, wherein the suction filter unit and the sampling unit are opened and closed cyclically according to a collection amount of the sample of the groundwater; and
determining a sample collection time for collection of the amount of the sample of the groundwater.

8. The measuring method according to claim 7 , wherein a flow speed of groundwater by the submersible pump into the moving-water flow column is 30-50% higher than a suction filtration speed of the groundwater by the vacuum pump such that water flows in a direction toward the measuring electrode in the moving-water flow column, which provides for measuring the indexes of the dynamic moving-water by the measuring electrode.

Assignees

• Chinese Res Acad Env Sciences

Inventors

• Jiang Yonghai
• Jia Yongfeng
• Xi Beidou
• Lian Xinying
• Yang Yu
• Xu Xiangjian
• Feng Fan

Classifications

• C02F2209/04

  Oxidation reduction potential [ORP] · CPC title

• C02F2209/06

  pH · CPC title

• C02F1/001

  Processes for the treatment of water whereby the filtration technique is of importance (C02F1/44 takes precedence; construction of filters in general B01D24/00 - B01D41/00) · CPC title

• C02F2209/05

  Conductivity or salinity · CPC title

• G01N27/4168

  Oxidation-reduction potential, e.g. for chlorination of water (water analysis G01N33/18) · CPC title