RU2313497C2 - Conditioning agent for treatment of sewage water or contaminated air, method for producing and using the same - Google Patents

Abstract

FIELD: treatment of sewage water or air.

SUBSTANCE: conditioning agent contains polymers enabling coagulation or settling, and mixed microbial culture containing in biological solution microorganisms capable of photosynthesis and luminescent bacteria. Conditioning agent is used for biological purification of sewage water or contaminated air, or for purifying of gases contaminated with hazardous substance particles. Method involves producing polymer or mixture of polymers acting as coagulating or settling agent; producing mixed microbial culture containing microorganisms in biological solution; mixing said mixed culture with polymer or mixture of polymers.

EFFECT: increased efficiency in purification of sewage water as well as contaminated air.

15 cl, 2 dwg, 1 ex

Description

The invention relates to a method and conditioning agent for treating wastewater and polluted air.

In the biological treatment of industrial waste or wastewater, microorganisms turn the organically utilized components of the prepared wastewater into a cellular substance or into gases, for example, CO ₂ , methane, hydrogen sulfide and others. Depending on the implementation option, aerobic and anaerobic methods are distinguished, while municipal treatment facilities, as a rule, use better-mastered aerobic methods. In such facilities, for the wastewater treatment after the mechanical treatment stage, biological decomposition is used in the activated sludge pool, which contains the biological treatment medium, i.e. microorganism activated sludge. Air is supplied to these activated sludge pools, thereby ensuring the presence of oxygen necessary for biological conversion. With such aeration of wastewater in the pool with activated sludge or in the so-called aeration tank, mucous, macroscopically distinguishable flakes are formed, which, upon completion of aeration, settle to the bottom in the form of sediment.

In wastewater treatment technology, it is well known that soluble polymers, in particular polyelectrolytes (polysilicic acid, polyacrylamide, etc.), which are widely used in the preparation of water for industrial and domestic needs, mineral processing, in paper production, in rural production, are effective flocculants. agriculture (to improve the structure of soils), in the processes of the separation of valuable products from industrial waste, the neutralization of industrial wastewater. In water treatment, polymer flocculants are usually used at a concentration of 0.1 = 5 mg / l (See: L. Kulsky Theoretical Foundations and Water Conditioning Technology, 2nd ed., K., 1971, p.138; S. Vojutsky. The course of colloid chemistry, 2nd ed., M., 1975; Weizer Yu.I., Mints D.M. High-molecular flocculants in water purification processes, M., 1975).

It is known that to increase the efficiency of biological wastewater treatment, organic or inorganic polymers are used that support the growth of flakes. The polymers are structured to promote the formation of flakes having the greatest possible compactness and density and slight surface heterogeneity, with the possibility of subsequent combination into relatively large aggregates that are insensitive to the action of shear forces caused by wastewater flows (see, for example, RF patent 2081856 , 06/20/1997, according to which the flocculant is used in combination with biological wastewater treatment, while the flocculant is the product of the interaction of latex polymethylvinylpyridine and with benzyl chloride, which is fed into wastewater), publication www.unipotsdamm.de/u/putz/oktober 1996 / 30.htm or RF patent 2121982, according to which biological treatment of domestic and industrial wastewater is carried out in combination with the use of cationic and anionic flocculants).

Such auxiliary coagulating agents are polymers that, depending on the formulation of the problem, have different charge density, charge distribution, and molecule size. They are used to isolate solid materials from suspensions with organic or inorganic particles, which can be distributed up to a colloidal consistency. Due to the high adsorption potential, auxiliary coagulating agents act as a connecting link between solid particles and micro flakes that are formed as a result of the use of coagulants, and they are combined into larger aggregates (flocculation). Along with polymers acting as auxiliary coagulating agents, the conditioning agent may contain precipitating agents and coagulants. For wastewater treatment, aluminum or iron salts are often used, which in certain pH areas form flocculent sediments with a very high surface area. Heavy metals or other undesirable wastewater components can be adsorbed on these flakes. Monomeric salts, for example aluminum, calcium, iron and magnesium, or polymer compounds of aluminum or iron, are used for wastewater treatment.

The closest analogue of the claimed invention is a conditioning agent according to WO 93/25480 of 12/23/1993, which is a mixture of water-absorbing clay with amine compounds and microorganisms that are capable of decomposing oil, and is intended to clean natural water tanks from pollution by oil spills.

Despite significant progress in polymer chemistry, known conditioning agents can only be designed for the average composition of the treated wastewater, while the biological conversion does not meet the requirements put forward, especially in the case of fluctuations in the biosphere, i.e. organic fractions in the treated wastewater, or, conversely, are intended for the treatment of wastewater contaminated with a particular pollutant, such as oil, and is not suitable for the treatment of waters having a different composition of pollutants and biological substances.

Therefore, an object of the present invention is a conditioning agent, as well as a method for treating wastewater and polluted air, which provides a wastewater treatment substantially independent of the biosphere contained in the wastewater.

This problem is solved by the conditioning agent according to claim 1, the method with the features according to claim 10, as well as the use of a conditioning agent according to claim 15.

The conditioning agent according to the invention has a predetermined content of microorganisms, therefore the biological activity is largely determined by the content in the conditioning agent of mixed cultures of microbial origin and practically does not depend on the random content of microorganisms in wastewater or in the air. As described in more detail below, with the introduction of a conditioning agent containing polymers and microorganisms, a stable biofilm appears on the surface of the flakes formed on the polymers, which does not break even with high wastewater turbulence. This ensures the immobilization of microorganisms on the flakes and creates almost ideal conditions for biological transformation.

It was unexpectedly found that the specified conditioning agent can also be used to clean gases contaminated with particles of harmful substances.

In one of the most preferred embodiments, the conditioning agent contains a mixed culture of microbial origin, which in one biological solution contains a certain proportion of microorganisms that provide photosynthesis, and a certain proportion of luminescent bacteria.

As indicated above, biopolymers and other organic or inorganic polymers are used as flocculating agents. Recently, so-called “conjugated polymers,” i.e. conjugated polymers that emit radiation when interacting with certain substances. Conjugated polymers are semiconductor materials and have been used so far for physicotechnical purposes, for example, for solar cells or for flat screens. The luminescence of these semiconductor polymers can be used to completely or partially replace luminescent bacteria of a mixed culture of microbial origin.

The work with the conditioning agent and its storage are especially simplified if the microorganisms are subjected to deep cooling or freezing before storage, and the cooling conditions must be selected so as to exclude harm to microorganisms.

As an example of the composition of a mixed culture of microbial origin, you can use a culture that contains the proportion of photosynthetically active organisms and the proportion of luminous microorganisms, for example, as described in patent application DE 10062812 published previously by the applicant, the contents of which should be considered fully incorporated into the description of this patent application.

Other advantages of the invention are the subject of other claims.

Preferred embodiments of the invention are described below with reference to the accompanying schematic figures, in which:

figure 1 is a flowchart of a biological wastewater treatment method;

figure 2 is a schematic diagram of the formation of flakes according to the invention.

Below, with reference to figure 1, a description is given of a method for biological treatment of wastewater (municipal and industrial effluents), according to which, to improve the growth of flakes, a conditioning agent is added to the wastewater containing a certain proportion of flocculant and / or precipitant, as well as agents that contribute to sedimentation, for example, organic or inorganic, as well as conjugated polymers. Such flocculating and precipitating agents are substances that cause agglomeration of dispersed particles in the wastewater due to the increase in particle size and providing rapid separation of solid and liquid phases. The specified conditioning agent along with the polymers may contain additional components, for example metals and other constituent elements that contribute to the formation of flakes. The conditioning agent according to the invention contains mixed cultures of microbial origin, which have a given composition, which largely determines the course of metabolic reactions in flakes.

According to the attached scheme of the method, a mixed culture of microbial origin (microbiological composition) in a preferred embodiment of the invention contains a fraction of microorganisms 1 that provide photosynthesis, and a fraction of microorganisms 2, which are luminescent bacteria or similarly functioning light-emitting microorganisms, which are solubilized in a biological solution 4, characterized by a wide emission band. As indicated above, part of the light-emitting microorganisms can be replaced by conjugated polymers that emit light in the presence of certain biomolecules in the microbiological composition.

As a result of the interaction of photosynthetically active microorganisms with light-emitting bacteria or conjugated polymers, the emitted light induces photosynthetically active microorganisms to photosynthesis. Under the action of microorganisms, photosynthesis occurs with hydrogen sulfide and water as an educt and the release of sulfur or oxygen, respectively. Further, microorganisms can bind nitrogen and phosphate and decompose organic as well as inorganic matter.

In the microbiological composition according to the invention, preferably microorganisms providing photosynthesis are used, which are optionally phototropic. The term “optionally phototropic” means that these microorganisms can grow under both anaerobic conditions in light and under aerobic conditions in the dark.

Photosynthetically active bacteria include gram-negative aerobic rod-shaped and circular bacteria, as well as gram-positive circular bacteria. They may have endospores or be without spores. These include, for example, actinomycetes and related bacteria.

This composition may also contain nitrogen-binding organisms. These include, for example, algae, in particular Anabena Nostoc in symbiosis with Azola. In addition, you can specify actinomycetes, for example Frankia, in symbiosis with alder, and bacteria, for example Rhizobium, in symbiosis with legumes.

In addition, aerobic algae, azotobacter, methane-oxidizing bacteria and sulfur bacteria can be used. These also include green sulfur bacteria and brown-green photosynthetic bacteria. Non-violet sulfur bacteria and violet sulfur bacteria can also be indicated.

It is also preferable that the microbiological composition according to the invention as optional phototropic microorganisms contain prochlorophytes, cyanobacteria, green sulfur bacteria, purple bacteria, forms similar to Chloroflexus, and forms similar to heliobacteria and heliobacilli. The above optional phototropic microorganisms can be used in the form of mixtures of two or more microorganisms. In a particularly exceptional embodiment, a mixture containing all six of these microorganisms is used.

The light that drives the photosynthesis mechanism is emitted by luminescent bacteria, which are the second important component of the microbiological composition according to the present invention. These luminescent bacteria have luminosity, i.e. they can emit light quanta. They are a system of enzymatic action. An example is the luciferin-luciferase system.

In one preferred embodiment, the mixture according to the invention contains Photobacterium phosphoreum, Vibrio fischeri, Vibrio harveyi, Pseudomonas lucifera or Beneckea as luminescent bacteria. It is also possible to use a mixture containing at least two of these bacteria.

To optimize the microbiological composition according to the invention, additional components can be added to it. Such additional components are preferably plant extracts, enzymes, trace elements, polysaccharides, alginic derivatives, as well as other microorganisms mentioned above. Additional components can be added to the composition according to the invention separately or in combination. Plant extracts may contain, for example, plantain extract.

As a liquid nutrient medium for the microbiological composition according to the invention, a solution is used that allows microorganisms to live. An important factor is the full realization of the variable action of photosynthesis bacteria and luminescent bacteria. A suitable nutrient medium turned out to be molasses, the main component of which is molasses, in particular molasses from raw sugar or sugar beet.

The ratio of microorganisms providing photosynthesis and luminescent bacteria in the microbiological composition according to the invention usually lies in the range from 1:10 to 1: 500. The preferred ratio is 1: 100.

When implementing the method according to the invention, the above-described components are homogenized, thus obtaining a microbial culture 6 as the first intermediate product, while the concentrations of the components are determined depending on the wastewater to be treated.

In the next step 8, the mixture is deeply cooled and subjected to freeze-drying in such a way that the solvent, in this case, for example, water particles, evaporates in a frozen state (freeze-drying). Such dehydration is a widespread method of gentle drying and preservation of sensitive materials. Drying parameters are adjusted so as not to harm microorganisms. Preliminary experiments have shown that a cooling rate of more than 30 ° C per minute, preferably about 40 ° C per minute or more, is optimal in order to prevent damage to microorganisms. In this case, the final temperature of the mixed culture is up to minus 50 ° C.

As a result of this drying operation, extracellular polymeric substances (IPN) surrounding microbial cells are dehydrated, while the IPN mucous layer thickens and forms a protective barrier that protects microorganisms during freezing.

After that, the obtained dehydrated product 9 goes to the mixing operation 12, where it is mixed with a coagulating or precipitating agent, and the resulting mixture with a predetermined concentration is fed to the aeration tank 14 containing waste water. Before mixing with the coagulating or precipitating agent, the dried / frozen material is thawed and stored under reduced pressure, with the first preliminary experiments showing that a reduced pressure of 0.01 mbar is preferred.

Oxygen is injected into the aeration tank, and in the course of this technological process, the problem of oxygen distribution with the greatest possible uniformity and maintaining the formed flakes in suspension is solved in order to obtain the largest and most evenly distributed mass transfer surface and provide a sufficient amount of oxygen for biological conversion.

The polymers introduced into the wastewater form long chains with a positive surface charge, on which solid particles of suspended material are deposited, containing organics and, as a rule, have a negative surface charge, resulting in flake nuclei, the growth of which depends, in particular, on type of coagulating agent, the activity of microorganisms and the composition of wastewater.

The conditioning agent according to the invention acts as a coagulant that allows the removal of materials dissolved or suspended in wastewater or in gases by the formation of flakes. The main mechanism for the formation of flakes is shown in Figure 2. Filamentous cationic polyelectrolytes are formed, for example, by the Archaea bacterium, which releases protons, and by an added charge carrier, while anionic polyelectrolytes are formed by bacteria that release ions, in addition, there is a negative wastewater field or polluted air. Microorganisms contained in the mixture and emitting protons are located on sewage sludge. Then, as shown in FIG. 2, these colloidal particles are interposed between cationic and anionic polyelectrolytes and agglomerate into macro flakes. These flakes formed serve as carriers of microorganisms that are located inside and on the surface of the flakes, as well as on colloidal particles. At the same time, nutrients are bound that provide the growth of microorganisms inside and on the surface of the flakes. In certain applications, it may be preferred if the polymers and / or microorganisms are added continuously.

In the implementation example shown in FIG. 1, a conditioning agent was used to treat wastewater.

Example 1. For wastewater treatment in the process described above in detail with reference to the schemes in figures 1 and 2a, b, a conditioning agent was used containing:

as photosynthetic microorganisms, the following optional phototropic microorganisms:

- prochlorophytes, cyanobacteria, green sulfur bacteria, purple bacteria, forms similar to Chloroflexus, and forms similar to heliobacteria and heliobacilli;

as luminescent bacteria: Photobacterium phosphoreum and Vibrio fischeri;

- as an additional component of the mixture: plantain plantain extract, and

- as a nutrient medium: molasses from raw sugar.

In this case, the ratio of photosynthetic bacteria and luminescent bacteria was 1: 100.

The biological polymer chitosan was added to the mixture, while the molar weight of the component of the charge carrier, which is chitin, was about 100,000 gm / mol.

The conditioning agent contained one volume part of chitosan as a coagulation promoting agent per ten volume parts of a mixed culture (microorganisms plus nutrient solution).

Mikrobioticheskuyu mixed culture was used in an amount of from 60 to 100 ml per m ³ wastewater.

This mixed culture was used with great success for the treatment of municipal and industrial wastewater, as well as for the disposal of structures contaminated with oil residues.

Another field of application of the conditioning agent according to the invention is the purification of air or other gases contaminated with particles of harmful substances. The solution to this problem is illustrated below with a specific example.

For laying cork slabs at construction sites until the 60s, usually used resin adhesives, which were made on the basis of coal tar pitch or bitumen. When laying cork slabs, such hot adhesives were applied directly to the cork slabs, which were then pressed to the walls, ceiling or floor. Similarly, when laying wooden sidewalks in industrial and commercial areas, resin or bitumen substances are still used.

Since the mid-70s, these resinous substances are no longer produced in Germany, so for these purposes they have to be imported from foreign countries. The cessation of the production of resin adhesives in Germany was carried out voluntarily, as technologically more advanced, harmless substitutes appeared.

When dismantling or rebuilding buildings in which glued materials were treated with resin adhesives, the health of the personnel performing such work is in great danger, since resin adhesives have an extremely high content of polycyclic aromatic hydrocarbons (PAHs). To ensure work safety, appropriate precautions must be taken to avoid damage to health due to dust and direct skin contact. This means that the implementation of such work should be done only by specialized companies, and the technological process should include operations with the minimum possible emission of dust with its effective removal. In order to minimize the formation of dust during the dismantling of contaminated elements of building structures, a sufficient amount of liquid should be sprayed (moistened). It turned out unexpectedly that when the conditioning agent according to the invention is added to the humidifying medium (water), the concentration of PAHs in air can be significantly reduced compared to the use of conventional solutions, while the health hazard during the dismantling of such contaminated buildings can be reduced at a relatively low cost. The cationic polyelectrolytes of the conditioning agent according to the invention convert the released PAH particles into peculiar flakes and bind them to the starting material.

As indicated above, in the conditioning agent according to the invention, instead of synthetic polymers, microbial biopolymers can be used. For example, by adding chitin, which, along with cellulose, is the most common natural biopolymer, a sharp increase in the effectiveness of the product is achieved. In this case, as a result of microbial biochemical decomposition of chitin, Crustanceen (crustaceans) receive chitosan by the enzymatic method. Chitosan has a positive ionic charge and therefore can bind negatively charged particles contained in wastewater or in exhaust air. The biopolymers used in the conditioning agent may be a mixture that can be obtained from sugar production wastes. The biopolymer is easily soluble in water and has a very high reactivity.

The microorganisms contained in the conditioning agent according to the invention are selected so that upon receipt of the flakes an extracellular polymeric mucous substance (IPN) is formed, into which a certain number of bacterial cells are introduced. Due to the formation of this mucus, especially on the surface of the flakes, a certain protective screen is created from toxic substances (for example, heavy elements), which prevents the penetration of these substances into the cells. IPN can also act as a support frame for growing filamentous bacteria. Another function of IPN is that it plays the role of a diffusion barrier, which prevents the release of substances necessary for conversion, for example, exoenzymes. In addition, when using bacteria that live in symbiosis with other species, CHD serves as an agent that allows you to maintain spatial proximity with these bacteria.

The composition of the conditioning agent is chosen so that the resulting flakes are coated with one full layer of IPN, in this case, the decomposition and transformation reactions can proceed with extremely high efficiency. Organic matter from the supplied wastewater or purified exhaust air is adsorbed from the flakes and oxidized or processed into a new cellular substance, with some of the flakes self-absorbing.

The photosynthesis process described above occurs inside flakes that act as macroscopic “photobioreactors”.

The first experiments showed good results for a mixture consisting of ten volume parts of dissolved microorganisms and one volume part of the polymer. In this case, the microbiological solution may contain about two percent of microorganisms by volume.

Another advantage of the conditioning agent according to the invention is that long polymer chains are cleaved by microorganisms, therefore, further processing of the resulting activated sludge is simplified. Long-chain polymers in known plants often create technological problems for the further processing of sludge. Thanks to the improved biological conversion, the resulting activated sludge can be decomposed in a treatment column much faster than previously known methods.

Thus, the application provides a conditioning agent for treating wastewater and polluted air, a method for producing such a conditioning agent and the use of a conditioning agent containing polymers (biopolymers, conjugated polymers, other organic or inorganic polymers), including a coagulator or precipitant, as well as microorganisms.

Claims (15)

1. A conditioning agent for treating wastewater or polluted air, containing polymers that promote coagulation or sedimentation, characterized in that it further comprises a mixed culture of microbial origin containing microorganisms capable of photosynthesis in a biological solution and luminescent bacteria. 2. The conditioning agent according to claim 1, characterized in that said mixed culture of microbial origin is in a state of deep freezing or in a state after freeze-drying. 3. The conditioning agent according to claim 1 or 2, characterized in that the mixed culture of microbial origin as microorganisms capable of photosynthesis contains prochlorophytes, cyanobacteria, green sulfur bacteria, purple bacteria, bacteria of the genus Chloroflexus Heliobacterium and Heliobacillus, as well as mixtures of the above microorganisms. 4. A conditioning agent according to any one of claims 1 to 3, characterized in that said mixed culture contains Photobacterium phosphoreum, Vibrio fischeri, Vibrio harveyi, Pseudomonas lucifera or Beneckea or a mixture thereof as luminescent bacteria. 5. The conditioning agent according to one of claims 1 to 4, characterized in that the agent additionally contains plant extracts, enzymes, trace elements, polysaccharides, alginic derivatives, as well as other microorganisms separately or in combination. 6. The conditioning agent according to any one of claims 1 to 5, characterized in that ten volume parts of the mixed culture account for one volume part of the coagulation promoting agent. 7. The conditioning agent according to any one of claims 1 to 6, characterized in that the polymer is a conjugated polymer. 8. The conditioning agent according to any one of claims 1 to 7, characterized in that the conditioning agent contains biopolymers. 9. A method of obtaining a conditioning agent according to claims 1-8 for the biological treatment of wastewater or polluted air, comprising the following operations: obtaining a polymer or a mixture of polymers acting as a coagulating or precipitating agent, obtaining a mixed culture of microbial origin containing microorganisms in biological solution, mixing said mixed culture with a polymer or mixture of polymers. 10. The method according to claim 9, characterized in that the mixed culture of microbial origin is subjected to deep cooling or freeze-drying. 11. The method according to claim 9 or 10, characterized in that the mixed culture of microbial origin is cooled to a temperature below -50 ° C. 12. The method according to claim 9 or 10, characterized in that the mixed culture of microbial origin before mixing with the polymer mixture is thawed, preferably under reduced pressure. 13. The use of a conditioning agent according to any one of claims 1 to 8 for the biological treatment of wastewater or polluted air or for the purification of gases contaminated with particles of harmful substances. 14. The application of item 13, wherein the mixed culture of microbial origin is selected so that when the specified conditioning agent is introduced into the wastewater, said mixed culture of microbial origin creates a biofilm on the surface of the flakes formed on the polymers. 15. The application of item 13, wherein the conditioning agent is added to a moisturizing agent, which is sprayed in aerosol form.

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