METHOD AND APPARATUS FOR WATER TREATMENT

Abstract: Apparatus for water treatment comprising a water treatment container (2) having an inlet and an outlet for ingress and egress of water from and to the body of water to be treated, comprises a porous or screening solids collection bag (10) associated with the inlet (6), to remove the larger particles of solid matter from the water before further filtration by finer filters. The receptable comprises by-pass or over-flow means to provide an alternative flow route for the water, if the pores, or screening surface, of the collecition bag become blocked.

Description: METHOD AND APPARATUS FOR WATER TREATMENT This invention relates to a method and apparatus for water treatment. The invention is particularly, but not exclusively, applicable to the treatment of water used in ponds, aquaria and fish farming. Certain prior proposals in relation to water treatment have included the use of open polymeric material such as open-cell foam, open-fibre matting and the like. Such materials serve as both a mechanical and a biological filter. In one example of a filtration unit, pond water is pumped into a moulded container having an inlet positioned in the top of the container. The water is subsequently directed over, or delivered to, one or more layers of foam and subsequently through a further filtration process comprising plastic media, which acts as a further biological filter. The filtered water is then delivered to the pond through an outlet positioned in the base of the unit. One of the main problems arising from this prior art system is that due to their relatively small size (50 micrometres to 2.5 millimetres) , the pores within the material can quickly become blocked by the growth of the microorganisms which arise from the purification process, and also by solids contained in the liquid being treated. As a result, the flow of liquid through the open-cell material is subjected to rapidly increasing resistance, and in due course the water treatment material becomes blocked, and treatment ceases. The cleaning of the foam cartridges represents a high proportion of the maintenance of the water treatment apparatus. A need exists for a method and apparatus for water treatment which requires reduced routine maintenance. One know way to achieve this aim is to first pass the water through a sedimentation tank. This reduces the amount of solids in the water and thus eases the load on the subsequent filtration stages. However, the inclusion of a sedimentation tank increases both the space occupied by the water treatment system, and the initial cost. Additionally, drainage pipework must be provided to remove the sediment from the sedimentation tank. Accordingly it is an object of the present invention to provide a method and apparatus for water treatment which provides improved filtration of water and/or which attempts to reduce the maintenance of the system and/or provides improvements in relation to one or more matters discussed herein, or generally. According to the invention there is provided apparatus for water treatment comprising a water treatment container having an inlet and an outlet for ingress and egress of water from and to the body of water to be treated, for example a pond or aquarium, and characterised by a porous or screening solids collection receptacle, or screen, associated with the inlet. By providing the water inlet with an associated porous solids collection receptacle, the larger solid particles in the water entering the apparatus through the inlet are screened and retained within the receptacle, whilst the water and the smaller particles may readily escape through the pores. This serves to reduce the load on any subsequent filtration stages, and thereby increase the overall efficiency of the apparatus. Preferably, the collection receptacle is removably mounted within the apparatus to assist in routine maintenance of the apparatus. The receptacle may be disposable, and simply discarded and replaced, once it becomes full of matter. Alternatively the receptacle may be re-usable, requiring its contents to be routinely emptied, the receptacle rinsed and then replaced in situ in the apparatus. In an embodiment the receptacle comprises by-pass, or over-flow means to provide an alternative flow route for the water, if the pores, or screening surface, of the collection receptacle become so blocked with matter that water cannot escape through the side walls of the receptacle in the usual way. In this way, problems such as undue back pressure on the pump are limited, and continuity of circulation within the system is maintained. In an embodiment, the over-flow or by-pass means comprises the inlet aperture of the receptacle, with the inlet aperture of the receptacle and the inlet of the apparatus being spaced from one another to define the alternative flow path for the water. Surprisingly, it has been found that during normal use, gravity and/or the momentum of the inflowing water, is sufficient to carry the majority of the larger solid matter into the receptacle. Only in the event of the pores of the receptacle becoming blocked does the flow of water adopt the alternative route out of the inlet aperture and through the space, or gap, onto the next stage of water treatment. In this way a simple, yet effective, by-pass or over-flow system is provided. An automatic switch over from screening is thus provided in the event of inadequate maintenance. In an alternative embodiment, the over-flow or by-pass means comprises one or more apertures or slots formed in the collection receptacle in the region in which it abuts the water inlet. Although it is envisaged that in many applications water treatment apparatus according to the present invention obviates the need for a sedimentation tank, it has been found that it may also be beneficial to combine the apparatus of the present invention with a sedimentation tank. A sedimentation tank is only effective in removing solid matter which is amenable to settling. Certain solids, notably filamental solids such as blanket weed, are not removed by a sedimentation tank, and quickly block filtration material such as open-cell foam cartridges. In contrast, the type of matter removed by a solids collection receptacle according to the present invention is determined solely by the pore size. It is envisaged that the water to be treated will first pass through a sedimentation tank to remove the settleable solids, and then passed through the inlet of apparatus according to the invention. In an embodiment, the receptacle comprises an elongate bag, or sack. Such a receptacle is particularly suitable where the inlet of the water treatment container is in the form of an inlet pipe. Alternatively, the receptacle may be in the form of a trough. Such a receptacle is particularly suitable where the inlet of the water treatment container is in the form of a spray bar. The collection receptacle may be manufactured from a woven polymeric mesh material. The pore size, or mesh size, may be optimised according to the conditions in the pond or aquarium, such as volume, location, climate and level of stocking. The pore size is preferably in the range of 2mm to 10mm, and more particularly in the range of 3mm to 5mm. In a further aspect of the invention there is provided a solids collection receptacle comprising a porous, or screening, material for use in water treatment apparatus. In yet a further aspect of the invention there is provided a method of water treatment comprising the step of passing water to be treated through a solids collection receptacle comprising a porous, or screening, material. Embodiments of the invention will now be described by way of example only with reference to the following illustrative drawings in which: Figure 1 shows a plan view of apparatus according to one embodiment of the present invention; and Figure 2 shows a section view of apparatus according to a further embodiment of the invention. As seen in Figure 1, water treatment apparatus according to the present invention comprises a water- tight container (2) having side wall (4) and a closure lid (not shown) . The container (2) comprises an upper chamber and a downwardly tapering lower chamber. Water to be treated enters the apparatus through inlet pipe (6) provided in the side wall (4) of the upper chamber. Mounted adjacent the mouth (8) of the inlet pipe (6) is an elongate solids collection bag (10) . The inlet aperture (12) is maintained in an open position by, for example, an 0-ring located in a hem provided around the aperture (12) . The collection bag is manufactured from a woven polymeric material. The inlet aperture (12) of the collection bag (10) is spaced from the mouth (8) of the inlet pipe (6) by spacer elements (14) to leave a gap (15) . Also mounted within the upper chamber of the container two spaced rows of brush filters (16) , and adjacent these, one or more rows of open-cell foam filter elements (18) . The lower chamber of the container is filled with plastics bio media, which acts as a biological filter. In use, water enters the container (2) through the inlet pipe (6) . The momentum of the inflowing water is sufficient to carry the majority of the larger solid matter contained within the water into the bag (10) for screening. Those particles which are larger that the pore or mesh size of the material of the bag (10) (us- ally between 2mm a d 10mm) , and including bl -sket wee . are retained w :hin the bag (10) , whils the remaining smaller particles and the water pass out εhe side walls of the bag (10) for subsequent treatment by the brushes (16) , the foam cartridges (18) and the plastic bio media. Because the filamentous algae and larger solid particles have been retained within the bag (10) , the efficiency of the subsequent filter media is increased, and maintenance is reduced. Eventually, if the collection bag (10) is not removed and cleaned, the pores of the material become blocked. In this event, water and the smaller particles can no longer pass through the side walls of the bag (10), and the flow (F) is able to by-pass the collection bag (10) and instead flow through the gap (15) onto the subsequent filtration stages before being returned to the pond. In an alternative embodiment, shown in Figure 2, the inlet of the apparatus (20) is in the form of a spray bar (26) . In this embodiment, the water to be treated is sprayed into porous screening trough (28) to screen out, or collect, the larger solid matter in the water. In normal use, the screened water passes out through the pores in the side walls (30) of the trough (28) , and is then further treated by filtration brushes (32) and foam cartridges (34). However, in the event of inadequate maintenance and cleaning of the trough (28) , the water is able to adopt the alternative flow path (F) , and continuity of circulation is maintained.

Claims: CLAIMS l. Apparatus for water treatment comprising a water treatment container having an inlet and an outlet for ingress and egress of water from and to the body of water to be treated, and characterised by a porous or screening solids collection receptacle, or screen, associated with the inlet . 2. Apparatus for water treatment according to claim 1 wherein the receptacle comprises by-pass or over-flow means to provide an alternative flow route for the water, if the pores, or screening surface, of the collection receptacle become blocked. 3. Apparatus for water treatment according to claim 2 wherein the over-flow or by-pass means comprises the inlet aperture of the receptacle, with the inlet aperture of the receptacle and the inlet of the apparatus being spaced from one another to define the alternative flow path for the water. 4. Apparatus for water treatment according to claim 2 wherein the over-flow or by-pass means comprises one or more apertures or slots formed in the collection receptacle in the region in which it abuts the water inlet. 5. Apparatus for water treatment according to any one of the preceding claims wherein the receptacle comprises an elongate bag, or sack. 6. Apparatus for water treatment according to claim 5 wherein the collection receptacle is manufactured from a woven polymeric mesh material . 7. Apparatus for water treatment according to any one of the preceding claims 1 to 4 wherein the receptacle is in the form of a trough. 8. Apparatus for water treatment according to any one of the preceding claims wherein the collection receptacle is removably mounted within the apparatus. 9. A solids collection receptacle comprising a porous, or screening, material for use in water treatment apparatus. 10. A method of water treatment comprising the step of passing water to be treated through a solids collection receptacle comprising a porous, or screening, material. 11. Apparatus for water treatment substantially as herein described with reference to the accompanying drawings .

Inventors: GOODSON MALCOLM GRAHAM, GOODSON, MALCOLM, GRAHAM
Applicants: CYPRIO LIMITED, GOODSON MALCOLM GRAHAM, GOODSON, MALCOLM, GRAHAM
Application year: 1997
Main classification: C02F1
IPC codes: A01K63