A METHOD AND A DEVICE FOR PURIFYING WATER

Abstract: The invention is related to a method and a device for purifying rain or ground water contaminated with liquid organic compounds. The invention is characterised in that the contaminated water mixture is discharged to a purifying container (7) comprising a number of plate-shaped bodies (4) containing an absorbent, such as peat, which are placed onto each other and separated by layers (bottoms) (5) or plastics, such as HDPE, which are perforated over the cross section in order to spread the fluid to be purified over the complete absorbent/peat surface (5), wherein said fluid organic compounds are absorbed and the rain/ground water is led further.

Description: A METHOD AND A DEVICE FOR PURIFYING WATER FIELD OF THE INVENTION The present invention is related to a method for purifying rain or ground water contaminated with liquid organic compounds and a device for executing this method. PRIOR ART Different devices for purifying rain or ground water contaminated with liquid organic compounds are known and it is well known that discharge of such non-purified water is hazardous for the environment. It is known to pass such contaminated water through an absorbent, in which diesel oil, etc. is absorbed, but the known methods are relatively uneconomical due to the fact that only small amounts of the absorbent is utilised , and the known methods are often too complicated. THE INVENTION The purpose of the invention is to solve these and other closely related problems. According to an embodiment of the inventive method, the water mixture is discharged from a collecting vessel to a purifying container comprising a number of plate-shaped bodies, which comprise an absorbent, for example peat, said bodies being located on top of each other and separated by layers (bottoms) of plastic, such as HDPE, perforated over the cross-section, in order to spread the fluid to be purified over the entire absorbent/peat surface, wherein a diesel/organic dissolvent is absorbed and the rain/ground water is led further. This method is easy and very effective. The absorbent in each layer is effectively utilised by spreading the fluid, and an effective 100 % purifying is effected in an environmentally good way by choosing several layers separated by these spreading members. The invention also comprises a device for executing this method. The device comprises a collecting vessel for the contaminated water, which is connected to a purifying arrangement comprising a number of layers containing an absorbent, for example peat, which are located on top of each other and sepa- rated by bottoms of plastic, such as HDPE or a similar material, which are perforated over the cross-section in order to spread the passing fluid, wherein diesel or the organic dissolvent is absorbed and the fluid mainly comprises water after passage. Such a device is easy to mount, takes up little space, and the layers with the absorbent may easily be changed after the used absorbent is fully contaminated with diesel oil, etc. According to a preferred embodiment, the side-walls of the pu- rifying layers are formed by non-perforated plastic, such as HDPE, which side-walls are joined with the perforated bottoms to a container for each purifying layer. The side-walls are continuous. Such absorbent containers are open upwards. A plurality of such absorbent containers, or bowls, are piled on top of each other. According to a preferred embodiment, a purifying unit comprising a plurality of such piled absorbent containers is arranged in a container member, such as a sack, preferably formed by a textile material, which is insertable into and ex- ertable out of a larger, upright container. The sack is exerted out of the upright container when the absorbent is saturated with diesel oil, etc. , and a new such sack comprising a purifying unit with an unsaturated absorbent is inserted into the container. Such filled sacks may easily be put in order and transported, if needed. THE DRAWINGS The invention is exemplified in the attached drawings. Fig. 1 illustrates a device according to the invention, and fig. 2 is a more detailed figure of the device according to the invention. EMBODIMENT EXAMPLES Figure 1 shows a collecting vessel 1 for rain or ground water contaminated with liquid organic compounds, which vessel is connected to the purifying device 3 with a tube 2. The term organic liquid compounds comprises dispersed and/or dissolved organic compounds. The term organic compounds comprises hydrocarbons in the form of different types of oils, such as diesel, petrol, and organic dissolvents. The collecting vessel 1 is formed as a trough, which has a surface large enough for collecting the actual contaminated water. Figure 2 illustrates the same collecting vessel 1 in a side-view, and its tube connection 2 to the purifying device 3. The purifying device 3 comprises an outer vessel 7 of plastic or metal. A number of layers 4 comprising an absorbent, such as peat, are inserted into the outer vessel. The contaminants, such as diesel oil, or organic dissolvents, are absorbed in this material (the filter mass). The material is usable for all different types of such dissolvents, wherein the absorption will be completed after passage of the purifying arrangement. The mass (absorb- ent) may be formed by pressed and heated peat, preferably in the form of granulates. The different layers are separated by plastic, such as HDPE, perforated over the entire cross-section. These bottoms with perforations 5 serve as spreading members in order to distribute the fluid over the entire absorbent cross-section and thus effectively utilise the entire absorbent mass. This purifying or filtering device may be comprised by any number of separate layers. Side-walls to the layers may be formed by plastic, which will not let water through, such as HDPE. These side-walls may be joined with each of the perforated bottoms 5 to containers, or bowls, each of which encloses the absorbent and forms a layer 4. A purifying unit comprising a plurality of such piled layers 4, may easily be placed down into the outer container 7. A purifying unit comprising four layers 4 is shown in figure 2, but the number of layers may be determined by the need. The effectively purified water is discharged in the bottom of the purifier at 6. The aim of the method according to the invention is to collect contaminated water, for instance comprising diesel oil or organic dissolvents, in the collecting vessel, and thereafter discharge the water through the tube 2 to the purifying (filter) device 3 with its four layers 4 with absorbents, which are located on top of each other. Substantially all present dissolvent will be absorbed in the device. The fluid is spread over the entire absorbent cross-section through the bottoms and the absorbent mass is effectively utilised. The purified water is drinkable. The invention may be varied within the scope of the claims be- low. Thus, the contaminated water is moved downwards through the absorbent layers by means of the gravity force.

Claims: Claims 1 . A method for purifying rain or ground water contaminated with liquid organic compounds, characterised in that the con- taminated water mixture is discharged from a collecting vessel (1 ) to a purifying container (7) comprising a number of plate- shaped bodies (4), which comprise an absorbent, said bodies being located on top of each other and separated by layers (bottoms) (5), which are perforated over the cross-section in or- der to spread the fluid to be purified over the entire absorbent surface (5), wherein said liquid organic compounds are absorbed and the rain/ground water is led further. 2. A method according to claim 1 , characterised in that peat is selected as said absorbent. 3. A method according to claim 1 or 2, characterised in that rain or ground water contaminated with diesel is purified. 4. A device for purifying rain or ground water contaminated with liquid organic compounds, characterised in that the device comprises a collecting vessel (1 ) for contaminated water, which vessel is connected to a purifying arrangement (3) comprising layers (4), which comprise an absorbent, said layers being lo- cated on top of each other and separated by bottoms (5), which are perforated over the cross-section in order to spread the passing fluid, wherein said liquid organic compounds are absorbed, and the fluid mainly comprises water after passage. 5. A device according to claim 4, characterised in that each of the perforated bottoms (5) is joined with side-walls to an absorbent receptacle for each layer (4). 6. A device according to any of the claims 4 and 5, character- ised in that the purifying device comprises an upright container (7), in which layers of the absorbent are located on top of each other and separated from each other. 7. A device according to claim 6, characterised in that it com- prises a container member, which comprises at least the absorbent layers (4) and the bottoms (5), and that the container member is arranged in the upright container (7). 8. A device according to claim 6 or 7, characterised in that the upright container (7) comprises an inlet for insertion of the contaminated rain or ground water at an upper end of the container, and an outlet for discharge of purified rain or ground water at a lower end of the container. 9. A device according to any of the claims 6-8, characterised in that the purifying container (7) is formed by a plastic or metal container containing the absorbent layers enclosed in plastic. 10. A device according to any of the claims 4-9, characterised in that it is intended for purifying rain or ground water contaminated with diesel. 1 1 . A device according to any of the claims 4-10, characterised in . that the perforated bottoms comprise a polymer material, such as HDPE. 12. A device according to any of the claims 4-1 1 , characterised in that the absorbent is peat.

Inventors: AXELSSON PER, AXELSSON, PER
Applicants: AXELSSON PER, AXELSSON, PER
Application year: 1999
Main classification: C02F1
IPC codes: B01D17, C02F1