AT403473B - FLOORED DRAINAGE BODY FOR BIOLOGICAL CLEANING OF MECHANICALLY TREATED WATER - Google Patents

Abstract

A description is given of a multistage trickling filter according to Fig. 1 for the biological purification of mechanically clarified wastewaters which consists of liquid-impermeable trays 1 which are disposed in a plurality of stages horizontally one above the other with an air intermediate space, each having high rims 2, 3 on three sides and being covered with surface-area-enlarging and pore-forming filler 4. These trays are each twisted in the horizontal plane by 180 degree about the longitudinal axis of the trickling filter and if appropriate are offset horizontally in the longitudinal direction. The multistage trickling filter is impinged with wastewater at the end of the top stage via a feed 5, which wastewater runs through the trickling filter from stage to stage in opposite direction of flow and exits via the outlet 6 at the end of the bottom stage. <IMAGE>

Description

ΑΤ 403 473 Β

The invention relates to a floor trickling filter for the biological purification of mechanically clarified wastewater, consisting of liquid-impermeable floors, horizontally one above the other, provided with air gaps, on which surface-enlarging filler material made of sand, plastic foam chips, geotextiles, or other pore formers rests, and a feed on the first floor, which intermittently applies waste water to the filling material, and a drain through which the biologically cleaned waste water emerges.

According to the state of the art, there are numerous biological wastewater treatment options, whereby a distinction must first be made between anaerobic and aerobic processes.

The subject invention is to be assigned to the aerobic processes in which the biological degradation of the waste water constituents takes place by bacteria, which in this case consume oxygen.

To be classified in this group is e.g. the activated sludge process, in which finely divided oxygen is blown from below into the sludge-containing wastewater in the sludge activation tank; the Trofkörpen / experience in which mechanically cleaned wastewater is sprinkled with rotary sprinklers or other suitable distribution devices intermittently over filling materials made of mineral lumps, slag, plastics and the like; the immersion trickling filter process, in which porous plastic disks, which are parallel and spaced apart, rotate slowly around a horizontal drive axis, the lower part always immersing them in mechanically cleaned waste water; and the bottom body filter method, in which mechanically cleaned waste water is intermittently trickled over layers of sand or other suitable materials.

All of these processes have the purpose of supplying the bacteria with sufficient oxygen for their own use and for the breakdown of the organic substance.

They also have to provide the bacteria with the necessary living and growth space.

In the activated sludge process, the bacteria are in the sludge-containing wastewater.

In the other processes described above, the wastewater has already been mechanically treated, that is, it is sludge-free.

It is therefore necessary to provide the bacteria with sufficient growth areas, i.e. large surfaces.

Intermittent exposure to mechanically cleaned waste water is therefore necessary in order to alternately bring the bacteria into contact with water and atmospheric oxygen.

The problem here is to apply sewage to all surfaces as evenly as possible, i.e. to achieve optimal water distribution. While this is technically solved in larger systems, the water distribution in small systems, apart from the technically relatively complex immersion trickling filter systems, is usually a very unsatisfactory matter.

Ultimately, it must also be ensured that the supplied wastewater can drain off as completely as possible in order to supply the bacteria with sufficient atmospheric oxygen in the non-exposure intervals.

The aim of the invention is to provide a solution for small systems in which the tasks described are solved with the least space and construction effort and with the simplest mechanical equipment.

In addition, such systems should have low investment costs and a low energy requirement, as well as being easy to use and low-maintenance.

According to the invention, these objects are achieved by the measure that the bottoms have raised edges on three sides and are rotated in the horizontal plane by 180 * around the longitudinal axis of the trickling filter and are optionally offset horizontally in the longitudinal direction.

Conceptually, the floor-level tropic body according to the invention represents a long cascade-shaped channel which is filled with surface-enlarging and pore-forming material and in which the intermittently supplied wastewater can drip from one to the next floor.

In order to save space, the floors are pushed together in a suitable manner.

As a result, the wastewater supplied at one end of the first floor flows in the opposite direction on the next floor.

On the basis of the drawing, an embodiment of the invention is illustrated schematically and without a housing.

The longitudinal section shown in FIG. 1 shows the floors 1 arranged one above the other with the raised front edges 2, the longitudinal edges 3, the filling material 4 and the feed 5 and the drain 6.

In Fig. 2 the superimposed floors 1 with the end edges 2 on every second floor and the two longitudinal edges 3 on each floor, the filler 4 and the drain 6 can be seen. 2nd

Claims (3)

AT 403 473 B Fig. 3 is a horizontal section through the floor trickling filter and shows the opposite end edges 2 of two superposed floors, the two longitudinal edges 3 with the filling material 4 of a floor and the drain 6. From the above explanations it can be seen that the proposed construction is very simple and can be produced from a wide variety of building materials. If the floors are covered with plate-shaped filling materials, these can be easily replaced if necessary by pulling out and pushing in at the front. Since the intermittent loading of the first floor with clarified waste water is advantageously carried out by means of a tipping channel, the mechanical effort is also minimal. The effectiveness of the system can be increased by introducing hot air into the air space on the lowest floors in the drainage area and heating the floor trickling filter from below in counterflow to the outflowing sewage water when flowing through all the air spaces. In order not to lose the heat supplied through the drain, a liquid countercurrent heat exchanger can also be arranged, which returns the heat of the flowing water to preheat the inflowing waste water. 1. Floor trickling filter for the biological purification of mechanically clarified wastewater, consisting of liquid-impermeable floors, horizontally one above the other, provided with air gaps, on which surface-filling material made of sand, plastic foams, chips, geotextiles, or other pore formers rests, and a feed on the first floor, which intermittently applies waste water to the filling material and a drain through which the biologically purified water emerges, characterized in that the bottoms (1) have raised edges (2, 3) on three sides and each in the horizontal plane are rotated by 180 * around the longitudinal axis of the trickling filter and are optionally offset horizontally in the longitudinal direction. 2. Floor trickling filter according to claim 1, characterized in that a blower is provided in order to blow warm air into the air space in the bottom floor of the drainage area, so that the floor trickling filter is heated from below in countercurrent to the outflowing sewage water. 3. Floor trickling filter according to claim 1 or 2, characterized in that a countercurrent heat exchanger is provided to use the heated water emerging from the drain (6) for preheating incoming cold wastewater. With 1 sheet of drawings 3