Multi-section sediment pore water sampler

The present invention discloses a multi-section sediment pore water sampler, which comprises a plurality of sampling units arranged coaxially and separated with each other; this arrangement ensures no water exchange occurred between two adjacent sampling units, collection of the sediment pore water samples from different depths of a same position is realized, whereby to facilitate organic pollutant sampling in sediment pore water at different depths according to different time resolutions. Furthermore, as the heights of the sampling units as well as the clearances between two neighboring sampling units may be various, in use users can configure the sampler according to the actual condition of the time resolution required, thus this sampler can also help improve the time resolution of water sampling.

FIELD OF THE INVENTION

The present invention relates to a water sampler, and more particularly to a multi-section sediment pore water sampler.

BACKGROUND OF THE INVENTION

Persistent organic pollutants (POPs) refer to the highly toxic and hydrophobic organic compounds left and migrated in the environment and bio-accumulated in human and animal tissue. POPs in the environment mainly occur in the organic phase of sediment, having higher concentrations in pore water (water filling the spaces between grains of sediment). The hydrophobic organic compounds dissolved in natural water, including the water located in sediment pores, are cycled in ecosystems through evaporation, dissolution, adsorption and biological absorption processes. As the hydrophobic organic compounds have potential significant impacts on human health and the environment, it is important to accurately evaluate the density and biological effectiveness of the hydrophobic organic compounds dissolved in water, thus as a major carrier the sediment pore water sampling is necessary and important for water quality supervision against the persistent and hydrophobic organic pollutants.

Approaches for water sampling can be divided into two groups: passive and active approaches. As one of the most common active approaches, centrifugation may lead to the analysis results on the high side as its samples isolated by possibly excessive centrifugal speeds contain the pollutants dissolved in the inner water of the sediment particles. On the contrary, the passive approaches collect high-distribution-coefficient extraction medium rich samples; no additional power is required, thus applicable for uses in wild environment monitoring. The existing passive sediment pore water sampling mainly include two types of approaches: in-situ solid-phase micro-extraction and low-density polyethylene membrane extraction.

The in-situ solid phase micro-extraction instruments use high polymer coatings as adsorption medium, protecting the micro-extraction membranes as well as filtering out particles through using porous copper tubes and glass fiber membranes, however the adsorption membrane used herein are relatively expensive and easy to get damaged as well, because of this, it is inapplicable in field uses. The low density polyethylene membrane micro-extraction techniques use polyethylene membranes as adsorption medium, as in use the adsorption membranes are in direct contact with sediments, the particles adhered to the membranes may interference the determination results.

The abovementioned two types of water sampling approaches even have a drawback in common, which is difficult to collect water samples from different depths of a same position, and thus the water sampled cannot reflect the concentration changes over time.

SUMMARY OF THE INVENTION

In order to solve abovementioned problems, the present invention provides a multi-section sediment pore water sampler capable to collect water samples from different depths at a same position.

The multi-section sediment pore water sampler disclosed by the present invention comprises a plurality of sampling units arranged along the axis thereof in a straight line and separated with each other; the heights of the sampling units as well as the clearances between two adjacent sampling units may be various.

Furthermore, the sampling units are mounted in order on a main spindle which has, on one end thereof a pyramid with a stopping tray thereon, on the middle thereof a shaft, and on the other end thereof a threaded rod; the sampler further comprises a ring and a locking nut mounted on the threaded rod.

As another aspect of the present invention, each sampling unit comprises a center ring, which is sheathed by an adsorption film, a filtering membrane and a porous protection pipe from inside to outside, the center ring is provided with a separation tray, a pipe protection tray, a column, a positioning groove on the side of the separation tray, a positioning ring on the opposite side matched with the positioning groove, and a nozzle therein.

In another aspect of the present invention, the pyramid is a square pyramid.

The advantages of the present invention are as follows:

The multi-section sediment pore water sampler disclosed by the present invention has a plurality of sampling units arranged coaxially in a straight line and separated with each other, within this arrangement no water exchange is permitted between two adjacent sampling units. The sampler enables water sampling at different depths at the same position and so that the samples collected by different sampling units can reflect the historical pollution data for a position. Furthermore, as the heights of the sampling units as well as the clearances between two neighboring sampling units may be various, in use users can configure the sampler according to the actual condition of the time resolution required, thus this sampler can also help improve the time resolution of water sampling.

DETAILED DESCRIPTION

As shown byFIG. 1, the multi-section sediment pore water sampler disclosed by the present invention comprises several sampler units1arranged along the axis thereof in a straight line, the sampler units1are fixed coaxially and separated with each other, the heights of the sampling units1as well as the clearances between two neighboring sampling units1may be various.

From above description, it is known that the sampler units1are arranged in a straight line and separated with each other, thus, no water exchange between two sampling units1is permitted and therefore the sampler can be used in sampling the organic pollutants dissolved in the sediment pore water at different depths at a same position. Furthermore, as the heights of the sampling units1as well as the clearances between two sampling units1may be various, users can configure the sampling units according to the actually required time resolution for more accurate results.

As a preferred embodiment for the present invention, as shown byFIG. 2, the sampling units1are fixed in order through a main spindle2, the main spindle2has a pyramid3on one end thereof, a shaft21on the middle thereof and a threaded rod22on the other end thereof, wherein the pyramid3has a stopping tray31on the top thereof. Correspondingly, the sampler further comprises a ring5and a locking nut4mounted on the threaded rod22for securing the sampling unites1mounted.

In assembly the sampling units1are one by one sheathed on the shaft21of the main spindle2in series, the ring5and locking nut4is then screwed on the threaded rod22, thus the sampling units1are so fixed between the stopping tray31and the tightened locking nut4. In use the arrangement described above can prevent the sampler from rotation by water flow when the sampler is stabbed into the settled layer through the pyramid3.

As shown byFIGS. 3 and 4, in the preferred embodiment, within a sampling unit1, the adsorption film7, the filtering membrane8and the porous protection pipe9are sheathed on the center ring6from inside to outside. The center ring6has a separation tray61, a pipe protection tray62, a column63, a positioning groove64on the side thereof where the unit separation tray61is located, and a positioning ring65on the other side thereof engaged with the positioning groove64of an adjacent sampling unit, the center ring6further has a nozzle66in the center thereof

The porous protection pipe9is secured on the center ring6through the pipe protection tray62, said porous protection pipe9is provided with a plurality of small through holes used for filtering the large particles and protecting the filtering membrane8as well, thereby ensuring only water can go into the sampling units1.

Each sampling unit1is sheathed on the main spindle2in series through the nozzle66in the center of the center ring6; the positioning ring65of one sampling unit1is spliced into the positioning groove64of an adjacent sampling unit1, thereby effectively preventing the relative displacement between two adjacent sampling units2. The unit separation tray61on the center ring6can effectively eliminate the possibility of water exchange between two adjacent sampling units1, so as to improve the time resolutions for the pore water sampling.

The adsorption film7is adhered to the outer wall of the column63, and the filtering membrane8is adhered on the adsorption film7.

In addition, as a preferred embodiment, the pyramid3is a square pyramid.