SK283567B6 - Waste water treatment plant - Google Patents

Abstract

A waste water treatment plant, especially for small outlying settlements, with a pre-treatment or settlement device (1), behind which are arranged a biological purification stage (13) followed by a soakaway (17). To permit simple construction, the upper region of the biological purification stage (13) has an inlet pipe (6) from the pre-treatment or settlement device (1), beneath which are fitted several superimposed non-woven fibre filters (25, 26, 27, 28), behind which there is an active charcoal filter (42) over a sand bed (29, 30) in front of which there is a run-off (15) leading to the soakaway (15), where the topmost filter (25) is covered in the region beneath the opening of the inlet pipe (6) by a baffle (35) preferably made of concrete, and the spaces (39) between the individual filters (25, 26, 27, 28) are ventilated.

Description

The invention relates to a cleaning device according to the preamble of the first claim.

BACKGROUND OF THE INVENTION

When disposing of wastewater, especially from decentralized detached houses or semi-detached houses or smallest housing estates with mostly less than ten single-family houses, the problem usually arises that connection to a central sewage treatment plant is possible only with very long sewage pipes with corresponding high costs. Frequently used infiltration pits, in which the untreated waste water can be infiltrated, on the other hand, represent a significant environmental burden and are no longer permitted.

Insulated sludge collecting tanks, which are often built for such smallest housing estates or family houses, often have the problem that they must be emptied at appropriate intervals and the contents must be transported and processed, which entails considerable costs. In addition, there is a risk that the sludge collector tank will leak.

FR-A-2 518 523 discloses a cleaning device of the type described in which foam plastic filters are arranged one above the other on the water-permeable supports. The filter supports are stacked one above the other while leaving the ventilated intermediate space.

In this known solution, however, the problem arises that, in order to replace the filters which hold the supports apart, the filters must be replaced and placed on top of each other. In practice, it is only possible to replace all filters at the same time.

Furthermore, a cleaning device is known from AT-B-391 125, in which the supporting sections are stacked with a water-permeable bottom and at least a partially raised edge. These support sections are coated with a plastic blank and a layer of gravel or sand deposited thereon, which together form a filter.

There is also the problem that, when replacing the filter, the support sections must also be separated from each other, and the layers constituting each filter must be removed and renewed, and a new filter must be arranged on each support section.

In both cases, such a filter change entails considerable costs.

SUMMARY OF THE INVENTION

It is an object of the invention to overcome these disadvantages and to propose a cleaning device of the kind mentioned at the outset, which is characterized by simple construction and operation.

According to the invention, this is achieved in an apparatus of the foregoing kind by the features of the characterizing part of the first claim.

The proposed measures make it easy to replace the filter. Just wind up and remove the filter. This also gives the advantage that water is forced out of the filter during winding. Because the filters are made of glass or mineral wool, they are easy to handle. When inserting new filters, which are preferably formed as rectangles, they can be simply spread on the support section. In addition, the proposed filter materials provide very good living conditions for the microorganisms necessary for the degradation of harmful substances in waste water.

By means of the features of claim 2 a very simple construction is obtained. It is also possible to replace only individual filters. In addition, the design of the filter support sections required for the known solutions is also saved.

By means of the features of claim 3, a very compact construction of the cleaning device is obtained.

By means of the features proposed in claim 4, the filters obtain high mechanical strength and can receive a relatively large volume of air.

By means of the features of claim 5, a high degree of water purity is ensured which enters the infiltration shaft.

By means of the features of claim 6, a particularly high degree of purification of the treated waste water can be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows schematically a cleaning device, FIG. 2 schematically shows a section through the pretreatment and settling device along line II-II in FIG. 1, FIG. 3 schematically a longitudinal section through the biological purification stage; and FIG. 4 is a cross-sectional view of the biological purification step.

DETAILED DESCRIPTION OF THE INVENTION

The cleaning apparatus of FIG. 1 has a pre-cleaning and settling device 1 embedded in the ground into which the inlet 2 flows. The pre-cleaning and settling device 1 has basically three chambers 3, 4 and 5, the last of which is a drain pipe 6 provided with a ventilation sleeve 7.

The individual chambers 3, 4 and 5 are divided by a wall 8 which extends substantially along the web of the substantially cylindrical pretreatment and settling device 1 and a wall 9 which extends substantially perpendicular to the wall 8. In the region of the chamber 4, the wall 8 has apertures 10 through which waste water 9, free of coarser solids, can flow into chamber 4. Coarser solids are retained in chamber 3 where they can fall out and settle as sludge.

In the chamber 4 finer solids can settle so that the waste water, substantially free of solids, can flow through the openings 11 arranged in the highest region of the wall 9 into the chamber 5.

Since the pre-cleaning and settling device 1 has a vent 12, enough air and hence oxygen is available for the rotting processes. In this case, a corresponding drop in the water level at each waste water inlet is ensured by the drop height between the inlet of the inlet 2 and the water level in the chamber, which is determined by the location of the suction opening of the outlet pipe 6, thereby improving the aeration of the waste water.

The purified waste water, free of solids, discharged from the chamber 5 of the pretreatment and settling device 1, enters a biological treatment stage 13 provided with two ventilations 14, which will be explained in more detail with reference to FIG. 3 and 4. From the biological purification stage 13, the purified water enters through the exhaust duct 15 provided with venting sleeves 16, into the infiltration shaft 17, which is also provided with venting

18th

In this case, an activated carbon filter 19 is provided in the region of the mouth of the exhaust pipe 15.

The infiltration shaft 17 stands on an approximately 40 cm thick layer 20 of washed sand having a grain size of 30 to 100 mm and has a sand bed 21 having a thickness of about 20 cm with a grain size of up to 4 mm. The sand bed 21 is protected by a reflecting plate 22 made of concrete in the area below the mouth of the withdrawal pipe 15.

As can be seen from FIG. 3, the biological cleaning stage 13 has a wall 23 extending in its longitudinal direction which is provided with apertures 24. This wall 23 divides the area in which the filters 25, 26, 27, 28 are arranged from the area in which the sand is arranged bed 29.30.

As can be seen from FIG. 4, the filters 25, 26, 27, 28 are connected at their underside to the plastic web 31, 32, wherein the bottom web 31 of the uppermost filter 25 is substantially thicker than the web layers 32 of the other three filters 26, 27, 28 and a thickness of about 9 mm, while the webs 32 have a thickness of about 1 mm.

The filters 25, 26, 27, 28 are mounted on gratings 33 supported by profiles 33 which are fixed on the inside of the biological treatment stage 13 and on the wall 23.

The uppermost filter 25 is connected at its upper side to another layer of plastic fiber web 34. In addition, a reflection plate 35 made of concrete is provided in the area immediately below the mouth of the drain pipe 6.

Below the four filters 25, 26, 27, 28 is arranged a concrete layer 36, the surface of which is inclined, with a flow pipe 37 passing through the wall 23 in the region of the deepest point of the concrete layer 36. 30, which is protected by a reflector plate 38 in the region of the mouth of the flow tube 37.

The wastewater treatment in the biological treatment stage 13 is carried out under aerobic conditions, the necessary air being available both from the air present in the filters 25, 26, 27, 28 made of mineral or glass wool and by venting the interspaces 39 between the filters through the apertures 24 in the wall 23.

In addition, by striking water on the baffle plate 35, there is considerable aeration of the water so that sufficient air is available for the aerobic degradation process.

The filters 25, 26, 27, 28 are clogged starting from the area surrounding the reflector plate 35 to the filter edges, thereby reducing the height of the filters 25, 26, 27, 28 and mixing the air present in the filters with purified water.

As shown in FIG. 3, a winding device 40 is provided, which for the sake of clarity is only shown in FIG. 3. It consists essentially of four removably mounted winches 41 to which the filters 25, 26, 27, 28 can be wound. The water displaced by the filter winding always flows onto the lower filter or the concrete layer 36 and the sand bed 29, 30.

When replacing the filters 25, 26, 27, 28, the used filters can be easily wound up and removed together with the winches. After the new reels 41 have been wound with the fresh filters wound, the filters are pulled out and spread out on the grate 33.

The water exiting the sand bed 29, 30 enters the activated carbon filter 42 upstream of the inlet duct 15.

This ensures that the waste water enters the infiltration shaft 17, through which it is discharged into the environment, to a large extent purified.

PATENT CLAIMS

Claims (6)

1. Wastewater treatment plant, in particular at the decentralized smallest housing estates, with a pre-treatment or settling plant (1) followed by a biological treatment stage (13) followed by a seepage shaft (7), the biological treatment foam ( 13) has in its upper part an inlet pipe (6) led from a pre-cleaning or settling device (1) under which a plurality of superimposed filters (25, 26, 27, 28) are arranged on the water-permeable supports, the interspaces they are ventilated between the filters, characterized in that the filters (25, 26, 27, 28) formed from the fiber web are made of mineral or glass wool and a winding device is provided for each filter (25, 26, 27, 28) (40). Cleaning device according to claim 1, characterized in that the winding device (40) comprises a winch (41) which can be attached to the holders which are associated with a partition wall (23) projecting from the bottom of the shaft and extending over part of its height and opposite a shaft wall supporting the filter supports (25, 26, 27, 28). A cleaning device according to claim 1 or 2, characterized in that a concrete layer (36) having a slope is arranged below the filters (25, 26, 27, 28), from which the flow pipe (37) runs from the deepest point. 1), passing through the separation wall (23) of the shaft, to a sand bed (29, 30) arranged in the same shaft which is covered in the area below the mouth of the flow pipe (37) with a reflecting plate (38) preferably made of concrete. A cleaning device according to any one of claims 1 to 4 3, characterized in that the filters (25, 26, 27, 28) are connected at their underside to the synthetic fiber web (31, 32), the highest positioned filter (25) being connected to the synthetic fiber web (34). The fiber layers also on their upper side and the nonwoven layers (31, 34) of the uppermost filter (25) are preferably thicker than that of the other filters (26, 27, 28). A cleaning device according to any one of claims 1 to 5 4, characterized in that the sand bed is formed of a roughly 10 cm thick gravel layer (30) having a grain size of 4 to 8 mm and a roughly 20 cm thick layer of washed sand (29) having a grain size of 0 to 4 mm. Cleaning device according to any one of claims 1 to 6 5, characterized in that an activated carbon filter (42) is arranged downstream of the sand bed (29, 30), upstream of the outlet (15), which leads into the infiltration shaft (17).