Bio-filter for waste water digestion

Abstract

The present disclosure relates to a biofilter for wastewater digestion, in which a high degree of contaminant removal is obtained with a single device. In order for these levels to be achieved, the following are essential: the shape of the biofilter, the supply/discharge ratio of the biofilter, the position and height of each of the components and, finally, the combination of two packed zones, namely: a random zone, and a zone arranged in the form of ringed or corrugated tube bundles.

Claims

1. A bio-filter for the digestion of waste water which comprises a tank with an upper first section which is vaulted or shaped like a frustum and delimited by a mouth, wherein the mouth is closed by a lid; a second intermediate section which is a right cylinder; and a third section in the lower part of the tank, wherein the lower part is shaped as an inverted cone and which also has a cylindrical section at the bottom; the bio-filter also has a horizontal feeding duct which reaches towards the upper first section of the tank to the center of the tank passing through an inner upper container with the shape of an inverted bucket closed on its upper and lower faces, with openings placed along the perimeter at a height lower than the feeding duct, which give the treated water access into the inner upper container; the bio-filter also includes a discharge duct whose diameter is smaller than the diameter of the feeding duct, and which is placed at a lower height than that of the feeding duct, the discharge duct is connected to the inner upper container, so the treated water collected by the inner upper container can be discharged through the discharge duct; the feeding duct in turn has a “T” shaped shunt in a horizontal position, the shunt having an upper arm and a lower arm, wherein the upper arm of the “T” extends to the lid of the tank and the lower arm of the “T” extends downwards to the third section of the tank having a lower conical section, the lower arm also going through a lower inner container where the feeding discharge is poured, the lower inner container is an object with the shape of an inverted bucket or inverted frustum, wherein the upper part of the lower inner container is closed, allowing only the lower arm of the “T” to pass, wherein the lower inner container has upper openings along the perimeter of its upper wall to allow water to exit as well as lower openings along the perimeter of the lower part of its wall so that entering water touches and then breaks up sludge at the bottom of the lower inner container, wherein the lower openings allow the exchange of sludge to the outer part of the lower inner container, causing fragmentation and bio-feeding of the sludge; wherein the bio-filter has two packing bed sections: a lower section with the packing bed distributed at random and an upper section formed by tubular bundles with corrugated surfaces; and wherein the bio-filter also has a gas exit situated in the upper first section of the tank.

2. The bio-filter of claim 1, wherein the No-filter has a self-cleaning system consisting of a maintenance duct which is an inclined duct that reaches from the upper first section of the tank to the lower cylindrical section, the maintenance duct has a horizontal shunt which is below the level of both the feeding duct and the discharge duct, the diameter of the horizontal shunt is smaller than the diameter of the feeding duct, the maintenance duct transports the sludge from the bottom of the bio-filter, expelling it through the horizontal shunt which has a valve or a stopper in its outer extreme.

3. The bio-filter of claim 1, wherein the inner upper container is fixed to the mouth of the tank.

4. The bio-filter of claim 1, wherein the upper first section of the tank has projections shaped like right triangular prisms in opposing points and distributed symmetrically around the tank, one acute angle of these projections protrudes from the center of the tank, the hypotenuse joins the vaulted or frustum-shaped upper first section of the tank.

5. The bio-filter of claim 1, wherein the discharge duct is placed in a position opposite to that of the feeding duct.

Description

DESCRIPTION OF THE FIGURES

(1) FIG. 1 is a diagram of the bio-filter for the digestion of waste water.

(2) FIG. 2 is a bundle of tubes utilized as contact material.

(3) FIG. 3 is a detail of the walls of the contact material.

(4) FIG. 4 is a graph of the concentration of fecal coliforms; the right column shows the concentration in the output and the left column shows the concentration in the input. This nomenclature will be used in all subsequent figures.

(5) FIG. 5 is a graph of the biochemical demand of oxygen after five days of starting the process.

(6) FIG. 6 is a graph of the chemical demand of oxygen during the process.

(7) FIG. 7 is a graph which shows the behavior of the process in relation to the concentration of total phosphorus.

(8) FIG. 8 is a graph which shows the concentrations of grease and oil in the input and output of the process.

(9) FIG. 9 is a graph of the behavior of total suspended solids.

(10) FIG. 10 shows the total concentration of nitrogen in the input and output of the process.

(11) FIG. 11 shows the efficiency of the equipment in reducing the concentration of sedimentable solids.

(12) These data were obtained from a pilot test in which livestock waste water was treated.

DETAILED DESCRIPTION OF THE INVENTION

(13) The bio-filter for the digestion of waste water is a tank (1) with different sections and different geometries. The upper section (2) is vaulted or has the geometry of a frustum, which has projections (3) in several opposing points distributed symmetrically around the tank (1). The purpose of these projections is to increase the mechanical resistance of the tank. Pipes can be attached to a lateral edge but preferably, the projections should be used.

(14) The second section of the tank is a straight cylinder (4), the third section of the tank is an inverted cone (5), truncated in the lower part or vaulted, and has a cylindrical section at the bottom (6).

(15) The bio-filter is fed by means of a horizontal duct (7) which reaches up to the center of the tank (1), crossing an upper inner container (8), which is closed at its base, which in turn is supported at the mouth of the tank (9) where it has a lid (10) which does not touch the pail-shaped or slightly cylindrical tank, the horizontal duct (7) which is located inside the inner tank has a “T” shaped shunt in a horizontal position (11) where the upper arm (12) reaches almost to the lid (10) of the feeding tank (1). When it is necessary, the bio-filter can be fed through the upper part by means of the upper arm (12). The lower arm of the “T” (14) extends downwards to the part of the lower conical section (5) crossing a lower inner container (15) where the feeding discharge is poured.

(16) The lower inner container (15) is a body in the shape of an inverted pail or an inverted frustum. The lower inner container (15) is closed in its upper part where only the duct (14) crosses it to the bottom; the upper and lower openings allow the flow of the liquid to the external part of the lower inner container (15). The feeding duct (14) which discharges the feeding water enters through the upper part to the center of the lower inner tank (15). The lower inner container (15) has a series of openings around the lower part of its wall which are distributed peripherally, through which the sludge is exchanged from inside the lower inner container (15), as the duct (14) feeds water to the lower inner container causing the fracturing and mixing of the sludge.

(17) Once the effluent leaves the lower container (15) through the upper openings of the lower inner tank (15), it comes in contact with the first packed material (17).

(18) The bio-filter has an inclined tube (18) for maintenance purposes which extends from the cylindrical section (6) at the bottom of the tank (1) to its upper part, where it comes out through one of the prism-shaped projections (3), where it must be placed; the inclined tube (18) has a horizontal shunt located at a lower level than the feeding duct (7) and the discharge duct (19) whose diameter is smaller than the diameter of the feeding duct (7). The horizontal shunt (20) passes through the wall of the bio-filter and discharges due to the force exerted by the hydrostatic column inside the tank (1); in the outer end of the horizontal shunt (20) there is a valve (21) to allow the cleaning of the bio-filter or to just serve as a stopper.

(19) The upper inner container (8) has a series of circular openings (22) located along the periphery of its circumference at a lower height than the feeding duct (7) and the duct that discharges treated waste water (19) and the horizontal maintenance shunt (20) in order for skimming to be achieved.

(20) The output duct (19) extends from the wall of the upper inner container (8) and has a smaller diameter than the diameter of the feeding duct (7). The maintenance duct (18) has a valve in its outer end (21) which opens to allow the evacuation of the sludge stored in the lower cylindrical section (6) of the bio-filter; in the ascending inclined projection (18) it has an upper lid (24) through which the sludge can be extracted if necessary.

(21) In the lower conical section (5) the bio-filter is filled first with contact (17) or packing material distributed at random. Above this material the bio-filter has bundles of rough or ringed tubular material which provides a greater contact surface both in the interior wall and in the interior walls of the tubes (23) which are fixed in position. The tubular material (23) is ringed, which thereby creates bundles of hollow corrugated tubes. The bio-filter has air openings (13) to prevent the accumulation of gases which can then be extracted.

(22) Process

(23) The waste water enters the bio-filter through the feeding duct (7) until it reaches the center of the bio-filter where there is a “T” shaped shunt with 2 arms (11), one of which extends to the upper part of the tank which can also be used for feeding in waste water, and a second arm (14) which discharges into the lower inner container (15) through the vertical duct (14); the lower inner container (15) has a series of openings (25) along its upper perimeter where the water to be treated is poured out by the discharge capability of the duct (14). The constant flow of the waste water coming in through the duct helps to break up the solids and get them in contact with the lower inner container (15). The liquid comes out through the openings (25) and rises to reach the contact or packing material (17) which prevents the suspended solids from rising too quickly to the second packed sections which consist of bundles of tubes. While the solids are trapped inside the lower inner container (15) and in the packed section (17), the water free of solids then goes through the second stage of the treatment, passing through the corrugated tubes (23). The liquid rises until it reaches the height of the openings (22) of the upper tank, where it comes in and floods the tank until it reaches the height of the discharge tubing (19), through which the liquid is moved and finally discharged as treated water. Additionally, the water can be given other complementary treatments such as aeration, passing it through ultra violet light or chlorination.

(24) In the lower zone of the lower inner container (15) the openings (16) have the function of sludge exchange. When the influent is discharged into the lower inner container (15) it collides with the sludge causing the bioreaction between the sludge at the bottom, which contain great quantities of microorganisms, and the influent, which contains great amounts of nutrients.

(25) We recommend the use of a decanter prior to the process to avoid stagnation.

(26) The results of a pilot test with livestock waste water which show the performance of the bio-filter are listed below:

(27) TABLE-US-00001 Analysis of the Input Output Reduction bio-filter Unit Average average (%) Fecal coliforms NMP/ 17842857.1 8735000 52 100 ml BDO mg/l 1210.3 356.4 71 QDO mg/l 3198.9 1426.6 55 Total phosphorus mg/l 83.1 30.3 64 Fat and oil mg/l 285 56.7 80 Total nitrogen mg/l 428.1 367.4 14 Total suspended solids mg/l 2415.7 339 86 Settable solids mg/l 26.2 0.9 97

(28) The above results show the capacity of the bio-filter.

(29) I consider the anaerobic bio-filter and the content of the following claims to be my property: