AU2021100221A4

AU2021100221A4 - A High-Resolution Sampler for Interstitial Water at Sediment Interface

Info

Publication number: AU2021100221A4
Application number: AU2021100221A
Authority: AU
Inventors: Ruilin WANG; Xinyu Wang
Original assignee: Chengdu Univeristy of Technology
Current assignee: Chengdu Univeristy of Technology
Priority date: 2021-01-14
Filing date: 2021-01-14
Publication date: 2021-04-08
Anticipated expiration: 2029-01-14

Abstract

The invention provides a high-resolution sampler for interstitial water at sediment interface, which comprises a sampling plate with a hand-held part arranged at the top. Further, the sampling plate is sequentially provided with a first horizontal batten mounting groove, a first sampling area for collecting overlying water and overlying water-sediment interface, a second sampling area for collecting sediment and a second horizontal batten mounting groove. The invention designs a hand-held handle, therefore, in addition to the rope used for deep lake sedimentation collection based on the weight of sampling plat, the portable method can be used to collect sediment interstitial water and overlying water in floodplain and other water bodies, effectively increasing the applicable water types of the sampler. The invention encrypts the overlying water-sediment interface and other sensitive areas to realize high-resolution acquisition at the water-sediment sensitive interface, which greatly improves the amount of single-layer collected samples as well as the analysis and test range and the number of testable indexes. -1/1 2 Figure 1 Figure 2 10' Figure 3

Description

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Figure 1

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A High-Resolution Sampler for Interstitial Water at Sediment Interface

TECHNICAL FIELD

The invention relates to the technical field of analysis of pollutants in sediment and

overlying water at sediment interface, in particular to a high-resolution sampler for

interstitial water at sediment interface.

BACKGROUND

At present, shallow lakes in China are seriously polluted, and sediments are an important

source of pollution. Especially, with the urbanization process and the development of

industry and agriculture along the basin, excessive pollutants accumulate in the

sediments. Under certain conditions, a large number of pollutants accumulated in the

sediments will seriously affect the quality of overlying water in lakes through

morphological changes, interface characteristics changes and releases, resulting in

continuous high pollution of lakes. Sediment-water interface is an important link and

interface of material circulation in lake ecosystem, especially the change of interface pH,

redox potential and biological composition, which has a very important influence on lake

water environment quality and ecosystem. Therefore, the sediment-water interface has

always been the focus and research focus of limnologists all over the world. Accurate

acquisition of water samples at in-situ sediment-water interface and interstitial water

samples at different depths is the key to quantitatively study sediment pollution flux,

evaluate sediment pollution characteristics and study micro-environment characteristics

of lake sediment-water interface.

In the study of sediment-water interface process, sediments are usually taken out from

lakes through samplers, and the obtained interstitial water samples and overlying water

samples are used to study the sediment-water interface process.

However, the traditional sampler has the following defects. 1. The traditional sampler

can't be inserted into sediment smoothly in flood plain, sand and gravel areas. 2. The

design of the sampler is mainly to observe the change of elements in the abrupt change

area of elements such as water-sediment interface. However, the traditional sampler has a

single resolution, which is the same for sensitive areas such as overlying water-sediment

and other areas. While, due to the sudden change of chemical conditions and

composition, the natural water body at the water-sediment interface is a sudden change

area of element transformation; therefore, the traditional sampler is not enough to collect

and test important areas with meticulous and high resolution. 3. The traditional sampler

design has only two columns or one column, and the total amount is only 4000

microliters. Therefore, the sample size is only enough to complete the microanalysis of

some elements. Therefore, how to provide a sampler with wider use of water body, high

resolution collection, large number of samples collected in a single layer, large analysis

and test range and large number of testable indexes is an urgent problem to be solved by

technicians in this field.

In view of this, the present invention has been proposed.

SUMMARY

The present invention aims at solving one of the technical problems in related

technologies to at least a certain extent.

Specifically, the first object of the present invention is to provide a high-resolution

sampler for interstitial water at sediment interface. The specific technical scheme is as

follows.

A high-resolution sampler for interstitial water at sediment interface is composed of a

sampling plate, wherein a hand-held part is arranged at the top of the sampling plate; a

first horizontal batten mounting groove, a first sampling area for collecting overlying

water and overlying water-sediment interface, a second sampling area for collecting

sediment and a second horizontal batten mounting groove are sequentially arranged on

the sampling plate from top to bottom. Specifically, the first sampling area is provided

with multiple rows and columns of first horizontal grooves from top to bottom, and the

second sampling area is provided with multiple rows and columns of second horizontal

grooves. Further, the column number of the first horizontal groove and the second

horizontal groove is at least three. Deionized water is added into the first horizontal

grooves and the second horizontal grooves. The first horizontal grooves and the second

horizontal grooves form a semi closed state by pressing the permeable membrane of the

first sampling area and the second sampling area. The first horizontal groove has the

same horizontal length as the second horizontal groove, the vertical width of the first

horizontal groove is less than the second horizontal groove, and the depth of the first

horizontal groove is greater than the second horizontal groove. The first horizontal

groove and the second horizontal groove in each adjacent row are provided with a

vertical batten mounting groove, and the first horizontal batten mounting groove, the

second horizontal batten mounting groove and the vertical batten mounting groove are

provided with battens for fixing the permeable membrane.

The invention provides a sediment interface interstitial water high-resolution sampler,

which is designed with a hand handle, therefore, in addition to the rope used for deep lake

sedimentation collection based on the weight of sampling plat, the portable method can

be used to collect sediment interstitial water and overlying water in floodplain and other

water bodies, effectively increasing the applicable water types of the sampler. The

invention encrypts the overlying water-sediment interface and other sensitive areas to

realize high-resolution acquisition at the water-sediment sensitive interface, which greatly

improves the amount of single-layer collected samples as well as the analysis and test

range and the number of testable indexes.

In addition, the sediment interface interstitial water high-resolution sampler provided by

the invention also has the following additional technical features.

According to one embodiment of the present invention, the horizontal length x vertical

width x depth of the first horizontal groove is 55x3.5x10 mm, and the interval of each

column is 1.5 mm, with 4 columns and 10 rows in total. The horizontal length x vertical

width x depth of the second horizontal groove is 55x8x6 mm, and the interval of each

column is 2 mm, with 4 columns and 20 rows in total.

According to one embodiment of the present invention, the sampling plate, the first

horizontal groove and the second horizontal groove are made of polyethylene.

According to one embodiment of the present invention, the material of the batten is

polypropylene.

According to one embodiment of the present invention, the lower part of the sampling

plate is provided with a triangular prism insertion end which is convenient for the

sampling plate to be inserted into the sediment.

According to one embodiment of the present invention, a resistance sensor is installed at

the inclined surface of the triangular prism insertion end, and the resistance sensor is

connected with an external terminal. The resistance sensor detects the obstructed data

information of the inclined plane in real time and transmits the data information to the

external terminal. The external terminal is provided with a resistance pre-set value. When

the obstructed data information detected by the resistance sensor is greater than the

resistance pre-set value, the external terminal will give an alarm.

According to one embodiment of the present invention, the hand-held part is provided

with an opening and the bottom of the hand-held part is hinged with the top end of the

sampling plate. The hand-held part is provided with at least one vertical first threaded

hole through the hand-held part and the top of the sampling plate is provided with a

second threaded hole matched with the first threaded hole. A screw connected with the

second threaded hole is installed in the first threaded hole, and the top of the screw is

provided with a knob.

Additional aspects and advantages of the invention will be given in the following

description, some of which will become apparent or will be learned from the practice of

the invention.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 is a schematic structural diagram of the high-resolution sampler for interstitial

water in sediments interface of this embodiment.

Figure 2 is a side view of the high-resolution sampler for interstitial water in sediments

interface of this embodiment.

Figure 3 is a schematic diagram of the hand-held part of the high-resolution sampler for

interstitial water in sediments interface of this embodiment.

DESCRIPTION OF THE INVENTION

Embodiments of the present invention are described in detail below. Embodiments are

shown with the accompanying figures, in which identical or similar reference numerals

denote identical or similar elements or elements having identical or similar functions

throughout. The embodiments described below by referring to the figures are exemplary

and are intended to explain the present invention but cannot be understood as limiting the

present invention.

Next, a high-resolution sampler for interstitial water in sediment interface according to

the present invention will be described in detail with reference to the figures.

As shown in figs. 1-3, this embodiment provides a high-resolution sampler for interstitial

water in sediment interface, which includes a sampling plate (1), the top of which is

provided with a hand-held part (2). Traditionally, it is mainly used for collecting

interstitial water and overlying water in lake sediments, but in floodplain with large

particle size sand and gravel, the traditional sampler cannot be successfully inserted into

sediment. Therefore, the applicant improved the structure of the sampler and designed the

hand-held part (2). In addition to the rope used for deep lake sedimentation collection

based on the weight of sampling plat, the hand-held part (2) can be used to collect

sediment interstitial water and overlying water in floodplain and other water bodies,

effectively increasing the applicable water types of the sampler.

In this embodiment, a first horizontal batten mounting groove (3), a first sampling area

for collecting overlying water and overlying water-sediment interface, a second sampling

area for collecting sediment and a second horizontal batten mounting groove (4) are

sequentially arranged on the sampling plate (1) from top to bottom. Specifically, the first

sampling area is provided with multiple rows and columns of first horizontal grooves (5)

from top to bottom, and the second sampling area is provided with multiple rows and

columns of second horizontal grooves (6). Further, the column number of the first

horizontal groove (5) and the second horizontal groove (6) is four. Deionized water is

added into the first horizontal grooves and the second horizontal grooves. The first

horizontal grooves and the second horizontal grooves form a semi closed state by

pressing the permeable membrane of the first sampling area and the second sampling

area. The size of the first horizontal groove (5) is 55 x 3.5 x 10 mm, with an interval of

1.5 mm in each row, a total of 4 x 10 grids and 7700 [L; the size of the second horizontal

groove (6) is 55 x 8 x 6 mm, with an interval of 2 mm in each row, a total of 4 x 20 grids

and 1,0560 [L. The first horizontal groove (5) and the second horizontal groove (6) in

each adjacent row are provided with a vertical batten mounting groove (), and the first

horizontal batten mounting groove, the second horizontal batten mounting groove and the

vertical batten mounting groove are provided with battens for fixing the permeable

membrane (not shown).

Specifically, the sampling plate of this embodiment is divided into three parts. The upper

part is isosceles trapezoid, with an upper bottom of 92 mm, a lower bottom of 292 mm

and a height of 98 mm, grooveless distribution and it is provided with the hand-held part

(2). The handle of the hand-held part (2) is a hollow ellipse with a circular arc radius of mm, a total length of 122 mm and a width of 30 mm. The middle part is distributed with groove (that is, the first horizontal groove and the second horizontal groove), which is a rectangular square frame with a size of 286x292x15 mm, and the grooves are 13.5 mm away from the upper edge of the middle part, 24 mm away from the lower edge and

12 mm away from both side edges. There are through square-shaped circular-arc grooves

of compacted permeable membrane around the frame, which are 3 mm away from the

two side edges, 0 mm away from the upper edge and 15 mm away from the lower edge,

with an arc radius of 3 mm and a groove depth of 6 mm. There are three columns of

vertical grooves with the same specification and function inside the frame, which are

communicated with the grooves around the frame. The lower insertion end (8) is a

triangular column, and the side surface is a right triangle, with a size of 50x15 mm, so

that the sampling plate can be easily inserted into the sediment.

Specifically, the specification of the permeable membrane in this embodiment is 0.45 mi,

and it is compacted with a batten made of polypropylene to be tightly attached to the

sampling plate. The permeable membrane can selectively permeate through interstitial

water by using the principle of balanced permeation. The polypropylene batten in this

embodiment is used to compact the 0.45 m permeable membrane, which is closely

attached to the sampling plate, so that each cell forms a relatively independent

environment, preventing mutual jumping and interference between samples, and thus

providing better spatial position information of ions in interstitial water.

In addition, during the test, the applicant found that it is often difficult to pull out when

the insertion end (8) is inserted into the sticky sediment, and the fixed hand-held part is

not only unfavourable to pull out, but also easy to damage the device during the process of pulling out by using machinery and ropes. Therefore, the applicant improved the hand held part, as shown in Fig. 3, the bottom of the hand-held part (2) is hinged with the top end of the sampling plate (1), and the hand-held part (2) is provided with at least one vertical first threaded hole (201) penetrating through the hand-held part. The top end of the sampling plate (1) is provided with a second threaded hole (101) matched with the first threaded hole (201), in which a screw rod (9) connected with the second threaded hole (101) is installed, and the top end of the screw rod (9) is provided with a knob (100, so that the angle of the hand-held part can be adjusted when the sampling plate needs to be pulled out, which is convenient for pulling out the sampling plate. It is not only labour-saving, but also will not damage the structure of osmotic membrane.

More advantageously, the applicant has also improved the above-mentioned insertion end

(8), because the applicant found that when the sampling plate is inserted by mechanical

equipment, it is easy to cause damage to the device, which is caused by not knowing the

structure of the lower deposited layer and forcibly inserting the sampling plate because

the mechanical equipment cannot recognize the relatively hard structure. Therefore, the

applicant installed a resistance sensor (not shown) at the inclined surface of the triangular

columnar insertion end (8). The resistance sensor is connected with an external terminal,

which detects the blocked data information of the inclined plane in real time and

transmits the data information to the external terminal. A resistance pre-set value is set in

the external terminal, and when the blocked data information detected by the resistance

sensor is greater than the resistance pre-set value, the external terminal gives an alarm.

The external terminal can be an electronic device such as a mobile phone.

The following description will be made in connection with the specific preparation and

use method of high-resolution sampler for interstitial water in sediment interface of this

embodiment.

Pre-preparation. Cut the 0.45 m permeable membrane into a strip that can cover all

grooves, with the edge around it more than 0.6 cm, and soak it in HNO3 solution, wash it

with deionized water, and then store it in deionized water; further, the sampling plate is

soaked in HNO3, washed with deionized water and dried.

Device assembly. Place the sampling plate horizontally in the groove filled with

deionized water and cover the permeable membrane on the surface of the main body after

removing bubbles, ensuring that the permeable membrane is closely attached to the

surface of the main body. And then press a batten to fix the permeable membrane and the

main body.

Nitrogen filling of the device. Put the assembled device into deionized water and fill the

water with nitrogen to remove oxygen from the device.

Placement of the device. For floodplain, the device can be vertically inserted into the

sediment with a hand-held handle; for lake sediment collection, the device can be inserted

into the sediment by using the gravity sinking of the sampling plate. Keep it 2-4 cm

above the sediment-water interface, and keep it for more than 24 h, preferably 48-72 h, so

that the ions in the water body and the sediment interstitial water in sampling cells can

diffuse and reach equilibrium.

Device recovery. Take out the device, judge and record the sediment-water interface

position according to the sediment mark on the device.

Freeze of the interstitial water sample. After cleaning the sampler, quickly put the

sampler into a clean sealed bag, contact the sealed bag with the permeable membrane and

stick it tightly, press a stainless steel sheet to cover all sampling cells, and isolate the

interstitial water sample in the sampling cells from the air. Spray dry ice cooling agent on

the surface of the steel sheet until the interstitial water sample in the sampling cell is

frozen into ice, and then store the sampling device at a temperature lower than -10 C.

Sampling of interstitial water sample. After taking out the sampling device, remove the

steel sheet and sealing pocket, clean the sediment particles left on the surface of the

permeable membrane, then cover the surface of the permeable membrane with plastic

film, and press the plastic film to isolate the interstitial water sample in the sampling cell

from the air. After the air is isolated, the sampling device thaws at room temperature, and

then uncover the plastic film, pierce the permeable membrane, and sequentially suck the

interstitial water samples in the sampling cell for analysis.

To sum up, the high-resolution sampler for interstitial water in sediment interfacial

provided in this embodiment has the following beneficial effects.

1. The applicable water body is wider. The traditional method is mainly used for

collecting interstitial water and overlying water in lake sediments, but in floodplain, the

sand and gravel have a large particle size, so the traditional sampler can't be inserted into

sediments smoothly. Therefore, the invention improves the sampler and design a hand

held handle, which can not only be used for deep lake sedimentation collection depending

on the weight of sampling plate by tying ropes, but also be held in floodplain and other

water bodies to collect interstitial water and overlying water in sediments, effectively

increasing the applicable water body types of the sampler.

2. High-resolution collection at water-sediment sensitive interface. The collector is

mainly designed to observe the changes of elements in the abrupt change areas of

elements such as water-sediment interface. Traditional sampler has a single resolution,

that is, it has the same resolution for sensitive areas such as overlying water-sediment and

other areas. However, the traditional sampler has a single resolution, which is the same

for sensitive areas such as overlying water-sediment and other areas. While, due to the

sudden change of chemical conditions and composition, the natural water body at the

water-sediment interface is a sudden change area of element transformation; therefore,

the traditional sampler is not enough to collect and test important areas with meticulous

and high resolution. In view of this, encryption design is adopted in the overlying water

sediment sensitive area, for a higher resolution acquisition of sensitive area water and a

resolution adjustment of the other area water. Under the condition of not increasing the

burden of analysis and test, the invention can carry out high-resolution acquisition for key

areas, and moderately reduce the resolution for other areas, so the design is more

reasonable and more in line with the purpose of research.

3. The sample quantity collected by single layer has been greatly improved, and the

analysis test range and the number of testable indexes has been greatly improved. The

traditional sampler design has only two columns or one column, and the total amount is

only 4,000 microliters, so the sample quantity is only enough to complete the micro

analysis of some elements, while the volume of high-resolution area of our improved

sampler can reach 7,700 microliters. Further, the volume of other grooves reaches 10,560

microliters, and the water sample quantity of single layer has been greatly increased. It

not only meets the test requirements of ICP-MS for trace element analysis, but also can be used for ion chromatography and ICP-OES, and simultaneously, meets the traditional analysis methods that require a large amount of samples, such as spectrophotometric analysis (3,000-4,000 microliters) and volumetric analysis (3,000-4,000 microliters).

Moreover, the general pH-Eh meter can be used to determine the pH and Eh of interstitial

water and overlying water without special devices such as microelectrodes

4. The sampling device has high strength and is not easy to be damaged. This device is

made of polyethylene, and its specifications are much larger than the previous sampler

specifications, which improves its strength so that it is not easy to be damaged and can be

reused for many times.

5. The triangular prism structure at the bottom facilitates the insertion of the sampling

plate into the sediment. Because the device is longer horizontally, and in order to improve

its strength, the sampling plate is thickened, thus increasing the resistance of inserting the

sampling plate into the sediment. Therefore, the bottom of the device is designed as a

triangular prism structure, which can reduce the resistance and facilitate the insertion of

the sampling plate into the sediment.

In the description of the present invention, it should be understood that the terms

"center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower",

"front", "rear", "left", "right", "vertical", "horizontal" and so on are only for the

convenience of describing the present invention and simplifying the description, and do

not indicate or imply that the referred device or element must have a specific orientation,

be constructed and operated in a specific orientation, so they cannot be understood as

limiting the present invention.

In the present invention, unless otherwise specified and limited, the terms "installed",

"linked", "connected" and "fixed" should be understood in a broad sense, for example, it

can be fixed connection, detachable connection or integrated; it can be mechanically

connected or electrically connected; it can be directly connected or indirectly connected

through an intermediate medium, and it can be the internal communication of two

elements or the interaction between two elements. For those of ordinary skill in the art,

the specific meanings of the above terms in the present invention can be understood

according to specific conditions.

In the present invention, unless otherwise specified and defined, the first feature "up" or

"down" in the second feature can be the direct contact between the first and second

features, or the indirect contact between the first and second features through an

intermediate medium. Moreover, the first feature is "above", "over" and "up" the second

feature can mean that the first feature is directly above or obliquely above the second

feature, or only indicates that the horizontal height of the first feature is higher than that

of the second feature. The first feature "below", "under" and "down" of the second

feature can be that the first feature is directly below or obliquely below the second

feature, or only that the horizontal height of the first feature is less than that of the second

feature.

In the description of this specification, reference to the description of the terms "one

embodiment", "some embodiments", "examples", "specific examples", or "some

examples" mean that a specific feature, structure, material, or feature described in

connection with the embodiment or example is included in at least one embodiment or

example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradicting each other.

Although the embodiments of the present invention have been shown and described

above, it can be understood that the above-mentioned embodiments are exemplary and

cannot be understood as limiting the present invention, and those of ordinary skilled in

the art can make changes, modifications, substitutions and variations to the above

mentioned embodiments within the scope of the present invention.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A high-resolution sampler for interstitial water at sediment interface, comprising a

provided with battens for fixing the permeable membrane.

2. The high-resolution sampler for interstitial water at sediment interface, according to

claim 1, characterized in that the horizontal length x vertical width x depth of the first horizontal groove is 55x3.5xl0 mm, and the interval of each column is 1.5 mm, with 4 columns and 10 rows in total. The horizontal length x vertical width x depth of the second horizontal groove is 55x8x6 mm, and the interval of each column is 2 mm, with 4 columns and 20 rows in total.

3. The high-resolution sampler for interstitial water at sediment interface, according to

claim 1, characterized in that the sampling plate, the first horizontal groove and the

second horizontal groove are made of polyethylene.

4. The high-resolution sampler for interstitial water at sediment interface, according to

claim 1, characterized in that the material of the batten is polypropylene.

5. The high-resolution sampler for interstitial water at sediment interface, according to

claim 1, characterized in that the lower part of the sampling plate is provided with a

triangular prism insertion end which is convenient for the sampling plate to be inserted

into the sediment.

6. The high-resolution sampler for interstitial water at sediment interface, according to

claim 5, characterized in that a resistance sensor is installed at the inclined surface of the

triangular prism insertion end, and the resistance sensor is connected with an external

terminal. The resistance sensor detects the obstructed data information of the inclined

plane in real time and transmits the data information to the external terminal. The external

terminal is provided with a resistance pre-set value. When the obstructed data information

detected by the resistance sensor is greater than the resistance pre-set value, the external

terminal will give an alarm.

7. The high-resolution sampler for interstitial water at sediment interface, according to

claim 1, characterized in that the hand-held part is provided with an opening and the bottom of the hand-held part is hinged with the top end of the sampling plate. The hand held part is provided with at least one vertical first threaded hole through the hand-held part and the top of the sampling plate is provided with a second threaded hole matched with the first threaded hole. A screw connected with the second threaded hole is installed in the first threaded hole, and the top of the screw is provided with a knob.

-1/1- 14 Jan 2021 2021100221

Figure 1

Figure 2

Figure 3