RU2762631C1 - Method for sampling bottom sediments for environmental studies and a device for its implementation - Google Patents

Abstract

FIELD: environmental protection.

SUBSTANCE: inventions group relates to the field of environmental protection, namely to the selection of bottom sediments when monitoring the state of the environment. A method for sampling bottom sediments for environmental studies using a sampler is disclosed, which includes lowering the sampler with a waterproofing valve to the bottom sediment, pushing the sampler into the bottom with filling the sampler with sediment, then closing the check valve, lifting the sampler and retrieving samples. At the same time, at the stage of sample extraction, the sample receiver is divided or cut into selected intervals, followed by hermetic packing of the open holes of the sample receiver parts with plugs with O-rings. Also disclosed is a device for implementing the specified method.

EFFECT: inventions group makes it possible to increase the sample volume, expand the granulometric range of bottom sediments, increase the operational capabilities of the sampler due to more reliable extraction of samples from the device, storage and transportation of samples.

4 cl, 3 dwg

Description

Technology area

The invention relates to the field of environmental protection, namely to the selection of bottom sediments when monitoring the state of the environment, the implementation of work to assess the accumulated environmental damage of various waste disposal facilities and water bodies in order to analyze the pollution of bottom sediments with a layer of a covering liquid phase up to 3 m and power precipitation up to 10 m, including the period of negative temperatures.

State of the art

When studying bottom sediments of shallow water bodies and technogenic objects, there is a problem of sampling sediments with the preservation of their structure and material composition, including the pore solution and the weakly consolidated upper part of the sediment, which demonstrates fresh pollution.

A way to solve this problem is to use piston tubes that are lowered to the bottom using a cable or rods (Blomqvist S. Quantitative sampling of soft-bottom sediments: problems and solutions // Marine Ecology Progress Series. 1991. V.72. P / 295- 304; Glew JR, Smol JP Last WM Sediment Core Collection and Extrusion // Tracking Environmental Change Using Lake Sediments. Developments in Paleoenvironmental Research. Dordrecht: Springer, 2001. V.1 P.73-105). The tubes are made of transparent polymeric materials and act as a sampler, which, under load, penetrates into the sediment, while the piston is located above the bottom. The water-saturated sludge is held in the pipe by the vacuum pressure under the piston. Already on the surface, sediment sampling is carried out by portionwise extrusion of the sampled core with a piston.

A variant of the sampling method with preserving the structure and material composition of sediments are systems using a lock-valve, which is controlled from the surface with a cable (Remberg I. The HON-Kajak sediment corer // J. of Paleolimnology. 1991. V. 6 (2). P. 167-170), techniques using freezing sediment with refrigerants (liquid nitrogen, dry ice) (Kilbe T., Niederreiter R. Freeze coring of soft surface sediments at a water depth of several hundred meters // J. Of Paleolimnology. 2003 V. 29. P. 257-263; Remberg I., Hansson H. Freeze corer No. 3 for lake sediments // J. of Paleolimnology. 2010. V. 44 (2). P. 731-736).

The above methods have a common disadvantage associated with the complexity of manufacturing devices for sampling, high cost in the presence of these devices on sale, special skills in sampling.

The most widely presented device on the market for sampling bottom sediments of water bodies is the Biker sampler, which allows sampling of bottom sediments of undisturbed stratification with a sediment thickness of 1 and 1.5 m (https://econix.com/files/el/katalog_eijkelkamp.pdf, pages 10, 11). The standard set of the specified device includes: a stainless steel sampler, transparent tubes for a sample of 1 and 1.5 m in length, a piston and a pressure and vacuum pumps with chargers, stackable rods, a T-shaped handle, a handle with an impact head, a hammer, stretch ropes, cleaning brush, etc. The set is placed in an aluminum container for transportation and storage.

The Beeker sampler allows sampling of bottom sediments of a relatively undisturbed structure with a thickness of up to 1.5 m by immersion in the thickness of sediments, the samples are placed in special containers made of stainless steel or bags, assembly-disassembly of the structure for the next sampling is not required, the body of the structure made of stainless steel can considered as an inert material, excluding sample contamination.

The disadvantage of using the Biker sampler for sampling sediments for environmental studies is the high cost of equipment, its significant weight and dimensions, the limitation on the thickness of bottom sediments (up to 1.5 m), the presence of metal parts, which limits its use at low temperatures due to freezing of water on the structure of the device.

Close in technical essence and the achieved result to the proposed method and device is the description of sampling bottom sediments using a plastic sampler with the ability to take samples with different thickness of bottom sediments (from 0.5 to 5 m), without damaging the structure of the sample, from different depths and the possibility of stratification (Patent RU 126464 U1, published 03/27/2013 Bul. No. 9). In the technical solution - the prototype, the sampling is carried out by vertical immersion of the sampler and bottom sediments to the set depth.

The design of the sampler consists of a set of cylindrical pipes 1 and 2 m long, a cutting head with a built-in valve, a piston with a handle, made in the form of a pipe made of a material with a volumetric heat capacity of no more than 3.54 MJ / (m ³ ⋅K) and a thermal conductivity of no more than 45 , 4 W / (m⋅K) (for example, polyester), the weight of the device is about 1 kg with a total length of 4 m. The sampler allows taking samples of bottom sediments from a depth of 12 m and can be used in the cold season.

The disadvantage of the device under consideration is its small diameter (from 50 to 60 mm), which makes it possible to select an insignificant amount of a substance and creates restrictions for the integration of methods for analytical study of complex systems of bottom sediments of waste disposal facilities (clause 1.3 of the PND F 12.1: 2: 2.2: 2.3: 3.2-03), small diameter creates technical problems when working with fine and viscous sediments; the design of the device does not limit the possibility of mixing the upper layer of bottom sediments with the bottom layer of water when the column is raised, the loss of pore solution due to the compaction of the sediment with a layer of overlying water.

For the tasks of environmental studies of bottom sediments of waste disposal facilities (settling ponds, sludge and tailing dumps, etc.), representing complex non-equilibrium physicochemical systems "solid phase ↔ pore solution", often viscous and finely dispersed, a device for sampling with preservation stratification and pore solution, the ability to work in the cold season, which for waste disposal facilities is considered the most favorable and safe period for sampling bottom sediments and is carried out from the ice.

Disclosure of the essence of the invention

The task of creating inventions is to develop a method for the selection of bottom sediments for environmental research and a device for its implementation, free from the shortcomings of the prototype

The problem is solved by the proposed technical solution with the help of essential features specified in the 1st paragraph of the claims, such as a method of sampling bottom sediments for environmental studies using a sampler, including lowering the sampler with a waterproofing valve to the bottom sediment, pressing the sampler into the bottom with filling the sampler with sediment, then the check valve is closed, the sample receiver is lifted and the samples are extracted, characterized in that at the stage of sample extraction, the sample receiver is divided (cut) into selected intervals, followed by hermetic packing of the open holes of the sample receiver parts with plugs with O-rings.

The above set of essential features allows to obtain the following technical result - to increase the sample volume, expand the granulometric range of bottom sediments, and increase the operational capabilities of the sampler due to more reliable extraction of samples from the device, storage and transportation of samples.

To achieve the named technical result, according to claim 2 of the claims, a device is proposed for implementing the method according to claim 1, made in the form of a sampler for bottom sediments, containing a connected cutting crown with a check valve, a sample receiver made of tightly connected pipes, a lifting cable, mounted on the check valve body, a waterproofing valve with an O-ring and a measuring rod, placed in the sample receiver, and the sample receiver pipes are equipped with plugs with O-rings if they can be used as containers for transporting and storing samples.

According to claim 3 of the claims, the sample receiver tubes preferably have a length of 0.5-2.0 m and a diameter of 110 mm.

According to paragraph 4. of the claims, the sample receiver is made of unmodified polyvinyl chloride.

Thus, the above described technical solutions belong to the group of inventions since one of them is intended for the implementation of the other.

The proposed inventions are illustrated by drawings, where:

in FIG. 1 shows a diagram of the sampler; in FIG. 2 stages of the sampling process; in FIG. 3 plug with O-ring and sample.

The proposed method is carried out in the following sequence (Fig. 2):

1. Perform reconnaissance work using a measuring rod, mark points for testing and determining the depth of the reservoir.

2. Assemble the structure of the Bottom Sediment Sampler for Environmental Research (hereinafter PDOE) of the required length. All connections are checked for tightness.

3. At the intended sampling point, a sampler with a waterproofing valve is lowered to the bottom sediment (perpendicular to the bottom of the reservoir), (a) After passing through the thickness of the liquid phase, the thickness of the bottom sediment is measured using a measuring rod.

4. Pressing the sampler into the bottom (b), by pressing on the body, filling the sampler with sediment, then close the check valve, control the depth with a measuring rod.

5. The sample receiver is lifted. The PDOE is removed using a lifting cable (c).

6. At the stage of sample extraction, the sample receiver is divided (cut) into selected intervals, followed by hermetic packing of the open holes of the sample receiver parts with plugs with O-rings, i.e. the structure is disassembled into selected sampling intervals (for example, 1.0 m) or layers are cut with a sharp tool of a different power), followed by isolation of the open holes with plugs; part of the structure in this case is containers for transporting or storing samples; 2) Either the bottom sediment is carefully removed under its own weight to a prepared site for its description, photo documentation and sampling.

After carrying out all the stages of work, an external examination of the PDOE is performed for the presence of mechanical damage, the surface of the sampler is cleaned for subsequent use. One-time use of the sampler is recommended to avoid contamination of the extracted samples.

FIG. 2 positions indicate: 9 ice (floating craft); 10 - water; 11 - bottom sediment; 12 sample.

The proposed device (Fig. 1) is made in the form of a sampler for bottom sediments, containing interconnected cutting crown (1) with a check valve (2), a sample receiver (3) - made of hermetically connected pipes by the funnel method, a lifting cable (4) mounted on the check valve body (2), a waterproofing valve with an O-ring (5) and a measuring rod (6), located in the sample receiver (3). Sample receiver tubes (3) are equipped with plugs (7) with O-rings (8) when used as containers for transporting and storing samples. (Fig. 3) The tubes from the sample receiver set (3) preferably have a length of 0.5-2.0 m and a diameter of 110 mm. Sample receiver (3) is made of unmodified polyvinyl chloride.

The crown (1) acts as a cutting element for better penetration of bottom sediments. The check valve (2) is designed to retain bottom sediments in the sample receiver (3) and their subsequent extraction. The entire structure is lifted from the bottom using a lifting rope (4) fixed at the end of the sampler. A waterproofing valve with an O-ring (5), located in the check valve (2), during the immersion of the sampler to the bottom sediment, serves to isolate from the overlying water column. The measuring rod (6) is designed to accurately determine the thickness of the layer of the selected substance. Insulating plugs (7) with an O-ring (8) are designed to close the openings of the sample receiver when used as a container for transporting and storing samples.

The sample receiver consists of a set of cylindrical pipes with a diameter of 110 mm made of unmodified polyvinyl chloride (specific heat 1.0 J / g, thermal conductivity 0.15 W / m), which are mainly used for the installation of outdoor sewerage, are resistant to corrosion and the effects of chemical elements, are easy to processing, can be operated at temperatures from -15 to +60 degrees, are widely represented in the retail market, affordable. The specified pipe diameter allows to select a sufficient amount of the substance, works in a wide granulometric range of bottom sediments (from sands to clays). At the base of the column, the length, which is determined by the layer of water (liquid phase of waste) and the thickness of bottom sediments, is a check valve. A waterproofing valve is installed inside the sample receiver, designed to isolate the upper layer of the liquid phase from the bulk of bottom sediments and facilitate the extraction of the undisturbed substance while preserving the pore solution.

The device works as follows. The length of the assembled structure was 8.00 m. The body of the sample receiver (3) is made of PVC-U, the diameter is 110 mm, the wall thickness is 3 mm. A check valve (2) and a crown (1) are mounted in the lower part of the PDOE; a waterproofing valve (5) is located inside the structure. A lifting rope (4) is attached to the check valve body. The principle of operation of the check valve is as follows: with sufficient pressure created when lowering the sampler, the shutter rises up, opening the hole, allowing bottom sediments to pass through itself and enter the sample receiver (3). Having reached the intended depth of bottom sediments with the help of a lifting rope (4), the entire structure begins to rise. At this moment, the shutter of the check valve (2) closes. The rise is carried out evenly and smoothly in order to preserve the physical and chemical properties of the selected substance. The next step is to divide the sample receiver into selected intervals and seal the open holes with plugs (7) with an O-ring (8). The resulting plastic containers are labeled and transported to the laboratory.

If necessary, all the selected material can be removed to a previously prepared site for description, photographic documentation and sampling from the designated layers (Fig. 2).

The advantages of the proposed invention in comparison with those used in practice are as follows:

1) sampling of bottom sediments is carried out when the thickness of bottom sediments is from 0.5 to 10 m with a layer of the covering liquid phase up to 5 m, including during the period of negative ambient temperatures;

2) sampling of bottom sediments is carried out with the preservation of stratification and pore solution, which is important for research with separate analysis of solid and liquid phases of sediments;

3) parts of the sampler structure, combined with open hole plugs, can be used as a container for storing and transporting samples;

4) the structure consists of parts widely available in the retail market and at an affordable price, with a low weight.

Although the preferred embodiments of the inventions have been described, it is clear that changes and additions can be made therein by those skilled in the art, which, however, do not go beyond the scope of the following claims.

Claims (4)

1. A method of sampling bottom sediments for environmental studies using a sampler, including lowering the sampler with a waterproofing valve to the bottom sediment, pushing the sampler into the bottom with filling the sampler with sediment, then closing the check valve, lifting the sampler and extracting samples, characterized in that at the extraction stage samples are divided or the sample receiver is cut into selected intervals, followed by hermetic packing of the open holes of the sample receiver parts with plugs with O-rings. 2. A device for implementing the method according to claim 1, made in the form of a sampler for bottom sediments, containing an interconnected cutting crown (1) with a check valve (2), a sample receiver (3) of hermetically connected pipes, a lifting cable (4 ), fixed to the check valve body (2), a waterproofing valve with an O-ring (5) and a measuring rod (6), located in the sample receiver 3, and the sample receiver pipes (3) are equipped with plugs (7) with O-rings 8 when used as containers for transportation and storage of samples. 3. A device according to claim 2, characterized in that the tubes of the sample receiver (3) preferably have a length of 0.5-2.0 m and a diameter of 110 mm. 4. The device according to claim 2, characterized in that the sample receiver 3 is made of unmodified polyvinyl chloride.

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