WO2006108956A2

WO2006108956A2 - Self-contained device for biological treatment of effluents

Info

Publication number: WO2006108956A2
Application number: PCT/FR2006/000793
Authority: WO
Inventors: René Chelle
Original assignee: Ab7 Industries
Priority date: 2005-04-12
Filing date: 2006-04-11
Publication date: 2006-10-19
Also published as: EP1868948A2; FR2884246B1; WO2006108956A3; FR2884246A1

Abstract

The invention concerns a device for eliminating through biological degradation organic matter present in circuits (100) discharging aqueous effluents, operating completely independently as it is placed directly in the circuit to be treated. It comprises: a non-immersed culture media (1) capable of being colonized by micro-organisms capable of degrading at least partly the organic matter; a tank (2) adapted to supply said culture media with nutrient medium; means (3) for maintaining said treating device within said discharge circuit. The discharged effluent constitutes the hydric source required for preparing a nutrient medium and for allowing cell multiplication of the bacteria degrading the organic matter. The use of said device is extremely simple, since it does not need to be connected to any water, power or nutrient carrier supply duct whatsoever and operates continuously without maintenance. The invention also concerns a method for biological treatment of fats and other organic matter deposited in aqueous effluent discharge conduits.

Description

AUTONOMOUS DEVICE FOR THE BIOLOGICAL TREATMENT OF EFFLUENTS

The present invention relates to the field of equipment for treating organic materials present in the aqueous effluent elimination circuits.

It relates to a device for the elimination by biological degradation of organic materials and in particular greasy deposits in the evacuation and / or treatment of domestic effluents, particularly in the collection columns of wastewater and wastewater in collective buildings, and in grease traps for kitchens and agri-food workshops. The invention also relates to a method of processing implementing the device that is the subject of the present application.

It is known that the collection and disposal of effluents are gradually fouled by the agglomeration of sludge, grease and limestone contained in the wastewater. This fouling increases with time, has the effect of reducing the passage section of the column or pipes downstream of the grease traps until clogging if we do not proceed to regular cleaning.

The cleaning of the columns of buildings is generally carried out by specialized companies, by the method of hydrocuring which consists in associating a mechanical cleaning with the help of brushes called "ferrets" and a washing with water under pressure. They require specific equipment and a lengthy intervention which, even if carried out by a competent team, is not exempt from constraints. On the one hand, the mechanical cleaning and the pressure of the water can damage the pipes, even deteriorate them when the installations are old; on the other hand, the presence of all the tenants is required during the intervention so as to take the necessary precautions to prevent upwelling in the apartments from occurring.

Disadvantages of the same order are encountered with the grease trays. These bins, placed at the outlet of the effluents coming from domestic kitchens, collective kitchens or even food manufacturing workshops, are generally very loaded with fats. The effluents cool by crossing the tank and form a layer that must be extracted regularly or the tank will no longer perform its function. Trapped fat extraction is carried out by a team of specialized emptiers, who usually send them to already saturated purification plants. In recent years, a new method of cleaning and unblocking sewage pipes has emerged, based on the degradation of organic substances by microorganisms and enzymes. This biological treatment has the essential advantage of being softer because it does not subject the pipes to the pressure of water and ferrets, and to respect the environment as long as the microorganisms are correctly chosen. It involves introducing into the conduit to be treated, almost continuously volumes of bacterial inoculants and enzymes capable of degrading grease responsible for the formation of deposits by agglomeration with sludge and limestone. The crusts formed on the walls are disintegrated by enzymatic action and gradually unhooked to be washed away in the liquid effluents.

The enzymes can be introduced directly, which is expensive, or be excreted by an inoculated bacterial population. In practice, a suspension of producing bacteria, which can be optionally supplemented by enzymatic inputs, is introduced into the pipe to be treated from a tray placed at the column head, usually in the attic of buildings. An automatic device makes it possible to send aliquots of bacterial suspension in the pipe to be treated at regular intervals of time (about 2 to 5 hours).

However, it is advantageous to obtain a constant renewal of the bacterial population by cell multiplication. Equipment for this purpose is used as above, in which the tank is replaced by a reactor associated with a water level control system. The water supply is carried out from the network via a solenoid valve, controlled by a programmer associated with a water level regulator level. A heating system regulates the temperature between 30 and 40 ⁰ C, so as to ensure active bacterial multiplication. A small booster provides oxygenation of the medium. A nutrient load adapted to the bacterial growth is introduced into the culture medium and must be renewed after a few weeks.

This method, although bringing a certain progress, is not without drawbacks. In the first place, the installation of a large reactor, generally 50 to 100 liters or more, presents difficulties because of its weight and its size, especially when it must be mounted under the roof of a building. In addition to the reactor itself, the device comprises various feed elements (water, energy, nutrient load) and control (water level, temperature) that make it complex and expensive. It is obligatory equipped with a device for oxygenating the culture medium. The device, whose operation requires regular maintenance, must also be easily accessible.

The biological treatment device effluent discharge circuits, object of the present invention, overcomes these disadvantages by providing a non immersed cell culture and multiplication device and operating completely independently thanks to the fact that it is placed directly in the circuit to be treated. To be more explicit, this device comprises a cell culture support associated with a nutrient solution reservoir, both of which are placed in the evacuation circuit to be treated. The effluent discharged is the water source necessary to prepare a nutrient medium and to allow cell multiplication of bacteria degrading organic matter. The implementation of this device is excessively simple, since it does not need to be connected to any water supply conduit, energy or nutrient load and it operates continuously without maintenance. The treatment device according to the invention thus consists of a single unit operating autonomously during the period necessary for the treatment.

More specifically, the subject of the present invention is a biological degradation treatment device for organic materials present in the effluent discharge circuits comprising:

a non-submerged culture support capable of being colonized by microorganisms capable of degrading at least partially the organic materials,

a reservoir able to supply said culture medium in a nutrient medium,

means for maintaining said treatment device inside said evacuation circuit.

In the device according to the invention, the reservoir comprises a receptacle of any shape, the function of which is to contain a nutrient medium which must feed the culture medium, or more exactly the bacterial cells which have colonized it. This reservoir is conveniently provided with fixing means for maintaining the treatment device inside said evacuation circuit.

According to an advantageous embodiment of the treatment device according to the invention, the tank has side walls, a bottom and an upper opening capable of collecting a fraction of the evacuated effluents. Thus, when effluents are discharged above the installation point of the treatment device according to the invention, a part of these effluents enters the reservoir and dissolves a dissolving nutritional load previously placed in the reservoir, to form a nutrient medium that will feed the culture medium not immersed in water and nutrients to ensure bacterial growth. The reservoir has an opening diameter generally between 50 and 70% of the diameter of the duct in which it is installed.

According to a particular embodiment, the walls of at least said reservoir are made of filtering material. As a result, the effluent collected in the tank and loaded with mineral elements, gradually passes through the wall and flows gradually and continuously on the culture medium which is thus permanently impregnated with water. It may for example be made of synthetic fibers such as polyester or polypropylene, or natural fibers such as cotton or wool. The pores have a dimension such that they can filter water and particles of 5 microns, or even 10 microns.

Those skilled in the art are familiar with various techniques for preparing a nutrient medium of desired composition and concentration for use in bacterial cultures. One method is to introduce into an aqueous medium, a permeable bag, sometimes called "sock", containing an inorganic and organic nutrient load in solid form. The nutrients dissolve gradually and diffuse through the bag, so that the nutrients are constantly renewed which allows for continuous nutrient supply downstream. The nutrient load is calculated as a function of the dissolution rate and the nutrient requirements of the bacterial culture on the porous fibers, so as to obtain sufficient bacterial growth for an effective permanent seeding of the effluent discharge conduit to be treated. Alternatively, the nutrient load may further contain lipolytic enzymes, supplementing the action of bacterial secretions.

The immersed culture support may be formed of any material capable of being colonized by microorganisms. It must be placed in line with the tank, in contact with or at a distance from it, so that the nutrient medium flowing from the tank reaches it.

Advantageously, the non-submerged culture support is essentially formed of a porous support attached to the walls of said reservoir. The fastening means can be of any kind, such as hooks, ties, seam, that the skilled person will choose and achieve without difficulty. The porous support may be attached to any height on the walls of the reservoir, it being understood that it is necessary for the nutrient medium to feed the porous support while flowing.

The main purpose of porosity is to allow good bacterial anchoring and to offer a high specific surface area allowing the development of a large quantity of cells. Such materials are numerous and may be implemented by those skilled in the art with the necessary adaptations. A preferred embodiment is to use flexible porous fibers because of their strength and ease of use. It is possible to use natural fibers such as flax fibers, or synthetic fibers, for example Rilsan tortilla bouffant. The latter material indeed has excellent water absorption capacity and a high porosity that can accommodate a large bacterial population. The fibers are fixed at one end and can be left free in their length or woven more or less loosely, forming panels that can be cut to the desired size.

As already indicated, it is important that the substrate remains wet at all times. For this it is preferable that the porous fibers are in contact with each other so as to better retain the nutrient medium and to limit evaporation. Therefore, when formed of flexible fibers, the porous support preferably comprises a bond surrounding the fibers to gather them into a bundle. This link can be placed in the lower part of the fibers. This further allows to keep them in contact with the walls of the tank, in the case where the fibers are attached to the upper part of the tank.

The microorganisms are chosen according to the enzymatic functions secreted, preferably from the lipolytically active enzyme producing bacteria, such as certain bacilli, for example Bacillus circulons, Bacillus magaterium, Bacillus Subtilis; lactobacilli such as Lactobacillus cellobiotus, Lactobacillus pentosus; or Pseudomonas cepacia or species belonging to the genus Acinetobacter. Other microorganisms may also be used depending on the particular application that is made of the non-submerged culture device and the type of treatment to be performed. Preferably, a mixture of different microorganisms associated in the form of "cocktail" that the skilled person knows how to choose and implement.

The device according to the invention has the advantage of allowing easy seeding of the porous support from the reservoir. Indeed, it is convenient to introduce a bacterial inoculum into the reservoir also containing the liquid nutrient medium necessary for cell multiplication. Whenever the reservoir receives a new quantity of effluent, there is an overflow of nutrient medium loaded with bacterial cells which, associated with the filtration through the walls, will flow on the porous support and colonize it.

Once the bacteria are installed in the porosity of the culture medium, they develop and form cellular clusters that detach, fall into the duct and become deposit on organic deposits to be eliminated. This phenomenon is accentuated each time effluents are evacuated and come to lick the porous fibers in the passage.

Thus, during the establishment of the device according to the invention, the bulk of the bacterial population comes from the reservoir, and as time passes, a cell dilution occurs, but it is offset by the production installed on the culture medium. .

The means for holding the treatment device in the evacuation circuit are suitable means chosen by those skilled in the art from the numerous existing systems. For example, one can resort to suspension means supporting the weight of the device. A simple and safe way is for example a bracket equipped with a hook, which must of course be accessible from a look made in the exhaust duct. It is possible to position the culture device at different levels by providing several means of suspension, depending on the areas whose treatment needs are most acute, to ensure a complete treatment over the entire length of the conduit to degrease.

The operating temperature of the device is advantageously between 25 ° C and 35 ° C, temperature reached through wastewater which are largely warm or warm water from bathrooms, kitchens and laundries. The air circulating in the column is used for the natural oxygenation of the culture. This air can have a temperature of 10 ° C to 20 ^° C depending on the season.

As understood in the light of the foregoing description, the present processing device is both simple and efficient. In particular it occupies a small volume - at least ten times smaller than conventional devices. It eliminates the equipment for its supply of fluids (water, energy) and the electromechanical control and sequential transfer of bacterial suspension fractions. It operates without forced oxygenation system and without heating, the conditions of temperature and aeration prevailing in the columns of sewage evacuation and in the ducts of evacuations of the kitchens suitable for the bacterial development. In addition, no equipment is visible outside the column which limits the risk of accidental or malicious damage. The device must simply be introduced into the column to be treated by a simple opening giving access to a very simple fastening system. It is therefore a complete, simple and autonomous device.

The present invention also relates to a degradation treatment method organic material present in the aqueous effluent discharge circuits using a device as described above, comprising the steps of: a) - fixing in said evacuation circuit a treatment device comprising :

a non-submerged culture support capable of being colonized by microorganisms capable of degrading at least partially the organic materials, and

a reservoir capable of supplying said culture medium in a nutrient medium, b) forming a nutrient medium in the reservoir, c) seeding the non-submerged culture support with the aid of microorganisms capable of degrading at least partially the organic materials. , d) - feeding the non immersed culture medium in a nutrient medium from the reservoir, so as to ensure microbial multiplication. e) - leave said treatment device in place until disappearance of organic matter to be eliminated.

According to a preferred feature of the method according to the invention, the treatment device is placed in the evacuation circuit so as to collect a fraction of the effluents discharged through an opening in the upper part of the reservoir. It is thus the evacuated effluent which constitutes the essential source of water allowing the preparation of a nutritive medium and the hydration of the bacteria.

Many aspects and advantages of the present method have been explained above to describe the operation of the treatment device according to the invention and also apply here. Rather than repeat ourselves, we will detail some particular characteristics.

When the effluent is discharged into the conduit, a fraction is collected in the tank. Another fraction passes near the reservoir, with or without contact with the culture device. In doing so, at each passage of the effluent bacteria are torn off the device and are driven and even projected on the walls to which they can attach and continue to proliferate or react. They thus ensure a biological cleaning by progressive degradation and liquefaction of the organic matter of the fouled parts.

According to a preferred implementation of the method, the nutrient medium is formed by gradually dissolving a dry nutrient in the effluent fraction collected in the reservoir.

According to another preferred embodiment of the method, a tank is placed in the tank. inoculum of microorganisms capable of at least partially degrading organic matter. As already indicated, the bacteria develop in this nutrient medium and are carried away when the tank overflows with each effluent evacuation.

According to another particularly preferred embodiment of the process according to the invention, the inoculation of the non immersed culture medium by the microorganisms is carried out from the reservoir by the flow of the nutritive medium containing said microorganisms. These are transported by the medium to the porous support where they are implanted. This supply can be repeated from time to time to renew and reactivate the bacterial colonies, which is particularly useful when the treatment device is intended to operate over long periods, as is the case in the kitchen grease trays. According to a characteristic of the present process, the feeding of said non-submerged culture medium in a nutrient medium is carried out at least in part by the continuous flow of the nutrient medium from the reservoir.

Advantageously, the non-submerged culture support is a porous support, preferably consisting of free or woven porous fibers, attached to the walls of the reservoir.

According to an advantageous variant, the porous fibers are gathered in a bundle to maintain a high porous support moisture content.

According to another advantageous variant of the process according to the invention, there are further provided in the reservoir enzymes capable of degrading at least partially the organic materials. This enzyme supply can advantageously be carried out at the beginning of the treatment, when the bacterial colonization is still insufficient to accelerate the start of treatment of the evacuation circuit. This option is advantageously chosen during a treatment of fixed duration and which must be repeated after a few months or a few years, such as the cleaning of the domestic effluent columns.

In a particular embodiment of the method, the non-submerged culture device is placed in a wastewater collection column of a building. It can be placed first in the lower part of said column and then moved progressively towards its upper part. This can be achieved by fixing the treatment device to fixing systems provided in the column at different points, or by means of a sliding suspension system in the conduit.

According to another characteristic of the method according to the invention, the treatment device is placed in the drain of a kitchen sink. It can be placed under the grate of the drain of said sink. In this case, it will be necessary to adapt the diameter of the exhaust duct at the siphon, which does not constitute a serious obstacle to the implementation of the method according to the invention. It can also be installed in the wastewater discharge pipe from a food processing plant, especially in the vertical part of the pipe leading to the grease trap.

Of course, the present processing device and its method of implementation are not limited as regards their applications or the embodiments which have just been described. Other variants can be designed easily while applying the principle described here.

In general, the biological treatment device according to the invention, which has the particularity of being a non-immersed cell culture system operating completely autonomously, can be used for any application in which it is desired to be rid of solid substances or soluble substances that can be digested or degraded by microorganisms. It is particularly well suited to the treatment of fatty deposits in pipes.

Other advantages and interesting properties will become more apparent in the light of the following examples given for illustrative purposes.

Figure 1 shows a treatment device with porous support consisting of a free porous fiber bundle attached to a conical tank, installed in a collection column of wastewater of a multi-family building.

FIG. 2 illustrates the treatment method according to the invention, carried out using a treatment device with porous support consisting of a bundle of free porous fibers attached to a frustoconical tank.

EXAMPLE 1

The device according to the invention can be produced as illustrated by FIG. 1. In this example, the treatment device 101 by biological degradation of the organic materials is intended for the treatment of a wastewater discharge column 100, such as it is found in apartment buildings. It comprises: the non-submerged culture support 1 capable of being colonized by microorganisms capable of degrading at least partially the organic materials,

the reservoir 2 capable of supplying said culture medium in a nutrient medium,

the means 3 for holding the treatment device in the evacuation circuit 100.

The tank 2 comprises a receptacle of conical shape, having the side walls 4, the bottom 5 (here confused with the walls) and the upper opening 6 which collects a fraction of the evacuated effluents. The side walls 4 are in polyester whose mesh is 5 microns. The reservoir 2 contains a sock containing the progressive dissolving nutritive load (not shown) to form the nutrient medium which feeds the culture support 1, or more exactly the bacterial cells which colonized it. A handle 10 makes it possible to hook the treatment device 101 to the bracket 11 fixed inside the evacuation circuit 100.

The non-submerged culture support 1 is formed essentially of the porous support 7 colonized by a cocktail of commercial microorganisms. It consists of rilsan fibers of about 1.5 meters, clustered together, connected at one end and left free in their length. The porous support 7 is fixed to the walls 4 of the tank 2 by a seam approximately one-third of the height of the tank 2.

The culture support 1 is fed in a nutrient medium by flow through the wall 4 of the reservoir 2. The nutrient medium which flows on the fibers 8 makes it possible to restore the bacterial density on the lower part of the fibers which are shed from the cell masses

EXAMPLE 2

FIG. 2 illustrates an embodiment of the treatment method by biological degradation of the organic materials present in the effluent discharge circuits according to the invention. It is implemented here using a treatment device similar to that just described in Example 1, with a few details: the tank 2 is of frustoconical shape. The porous support 7 is fixed at the opening 6 of the reservoir 2 via the metal hoop 12 at the same time stiffening the opening 6 of the reservoir 2. It comprises a link 9 surrounding the porous fibers 8 to collect them together. a beam enveloping the tank 2.

The first step consists in fixing in an evacuation circuit the treatment device 101 comprising:

the non-submerged culture support 1 likely to be colonized by microorganisms capable of degrading at least partially the organic materials, and - the tank 2 able to supply said culture medium in a nutrient medium.

The gaze 103 allows the introduction of the device in the column 100. Care is taken to place at the bottom of the tank 2 a sock (not shown) containing the slow dissolving nutrient load and a quantity of a cocktail of inactivated microorganisms with lipolytic activity .

The upper opening 6 of the tank 2 collects a fraction of the evacuated effluents. This causes, on the one hand, the progressive dissolution of the nutritive load, thus forming the nutritive medium which will supply the non-submerged culture medium 1 with liquid and nutrients. On the other hand, the inoculum in aqueous medium is reactivated and the cell population increases. Bacteria are progressively transported to the culture support 1 either by filtration through the walls 4 of the reservoir 2, or by overflow when the filtration rate is lower than the water inlet into the reservoir 2.

Once the bacteria are installed in the porosity of the culture support 1, they develop and form cellular clusters which become detached, fall into the conduit 100 and deposit on the organic deposits 102 to be eliminated. The bacteria and enzymes that they secrete digest fats that break up and are washed away. This phenomenon is accentuated each time effluents are evacuated and lick the porous fibers in the passage.

The formation of the nutrient medium in the tank 2 therefore begins as soon as the nutrients are in solution and continues without interruption until the load is exhausted, this being calculated for the total duration of a treatment. A nutrient load of 1 to 3 kg is sufficient for a treatment of 3 to 4 weeks. Initial seeding of the immersed culture medium 1 with the cocktail of microorganisms occurs in the first hours of operation of the device. The nutrient feed of this cell culture is continuously from the reservoir.

The arrows represent the flow of fluids. The long arrows represent wastewater discharged without direct contact with the treatment device 101. The short arrows represent the effluent flowing after having loaded with nutrients and bacterial cells.

Fibers with a capacity of 10 ⁹ to 101 ° bacteria per meter in monolayer, support from 1 to 10 mg of living matter. In multiplication mode, each fiber will produce this amount of material in one hour. It is thus recommended to use for the treatment of a building column a bundle of 100 fibers 1 m long.

The system operates unattended, except for the possible replacement of the nutrient load. It is left in place until the organic matter to be eliminated disappears.

Claims

1- Device for treatment by biological degradation of organic materials present in an evacuation circuit (100) of aqueous effluents characterized in that it comprises:

- a non-immersed culture support (1) capable of being colonized by microorganisms capable of at least partially degrading organic matter,

- a tank (2) having side walls

(4), a bottom

(5) and a top opening

(6) in which a nutrient load is placed, said reservoir being capable of collecting a fraction of the evacuated effluents and supplying said culture support with a nutrient medium,

- means (3) for maintaining said treatment device inside said evacuation circuit.

2- Treatment device according to claim 1 characterized in that the walls (4) at least of the tank (2) are made of filtering material.

3- Treatment device according to one of claims 1 or 2 characterized in that the non-immersed culture support (1) is formed essentially of a porous support

(7) fixed to the walls (4) of the tank (2).

4- Treatment device according to claim 3, characterized in that the porous support (7) consists of free or woven porous fibers (8).

5- Treatment device according to claim 4, characterized in that the porous support (7) comprises a link (9) surrounding the porous fibers (8) to bring them together into a bundle.

6- Process for treating organic matter by biological degradation present in the evacuation circuits (100) of aqueous effluents, characterized in that it comprises the steps consisting of: a) - fixing a device in said evacuation circuit treatment (101) comprising:

- a non-immersed culture support (1) capable of being colonized by microorganisms capable of at least partially degrading organic matter, and

- a reservoir (2) having side walls (4), a bottom (5) and an upper opening (6) in which a nutrient load is placed, said reservoir being capable of supplying said culture support with nutrient medium, b) - form a nutrient medium in said reservoir, c) - seed said non-immersed culture support with microorganisms capable of at least partially degrading organic matter, d) - supply said non-immersed culture support with a nutrient medium from said reservoir, so as to ensure microbial multiplication. e) - leave said treatment device in place until the organic matter to be eliminated disappears.

7- Method according to claim 6, characterized in that the treatment device (101) is placed in the evacuation circuit (100) so as to collect a fraction of the effluents evacuated through the upper opening (6).

8- Method according to claim 7, characterized in that the nutrient medium is formed by progressive dissolution of a dry nutrient load in the fraction of effluents collected in the tank (2).

9- Method according to one of claims 6 to 8, characterized in that an inoculum of microorganisms capable of at least partially degrading the organic materials is placed in the reservoir (2).

10- Method according to claim 9, characterized in that the seeding of the non-immersed culture support by said microorganisms is carried out by the flow of the nutrient medium from the reservoir.

11- Method according to one of claims 6 to 10, characterized in that the supply of said non-immersed culture support (1) with nutrient medium is carried out at least in part by the continuous flow of the nutrient medium from the reservoir (2).

12- Method according to one of claims 6 to 11, characterized in that the non-immersed culture support (1) is a porous support (7), preferably consisting of porous fibers (9) free or woven, fixed to the walls (4) of the tank (2).

13- Method according to claim 12, characterized in that the porous fibers (9) are gathered into a bundle to maintain a high humidity level of the porous support (7).

14- Method according to one of claims 6 to 13, characterized in that one also brings into the reservoir (2) enzymes capable of at least partially degrading organic matter.

15- Method according to one of claims 6 to 14, characterized in that the treatment device (101) is placed in a wastewater collection column of a building, first in the lower part of said column, then gradually moved towards its upper part.

16- Method according to one of claims 6 to 14, characterized in that the treatment device (101) is placed in the discharge pipe of a kitchen sink or a food workshop.