Biogenic treatment of mineral solids

Abstract

Process for the dissolving and / or blasting treatment of cement-bound or predominantly cement-bound solid bodies in the form of structures, buildings, parts of structures and / or building material bodies, wherein the solid body is inoculated at the place of installation and / or erection, place of manufacture or place of use with an aqueous solution containing acid-producing microorganisms (inoculation culture) to form a biofilm on and / or in the solid body, wherein microorganisms are inoculated in an amount in the range of 1 × 10 4 up to 1 × 10 12 CFU / cm 2 , based on the surface of the solid to be treated, are applied or introduced onto and / or into the solid, whereby growth-promoting environmental conditions for the microorganisms are established by (i) a targeted adjustment of the temperature and / or (ii) a targeted supply of nutrients and / or substrates for the microorganisms and / or (iii) a targeted adjustment of the humidity in the area of ​​the solid body, wherein the cement portion is at least partially decomposed and / or converted by the acid formed by the microorganisms and converted from the solid phase into a liquid, doughy and / or pasty phase, and wherein aggregates contained in the liquid, doughy and / or pasty phase and / or valuable substances formed by the treatment are separated for recovery purposes.

Description

[0001] The technical field of application of the invention lies in construction technology, especially in the field of the treatment of predominantly cement-bound solid or concrete bodies, in particular structures, buildings, parts of structures and / or building material bodies, preferably for the purposes of demolition.

[0002] Massive structures or buildings, such as bunkers, wind turbine foundations, concrete shielding for nuclear reactors, industrial chimneys, cooling towers, or bridges or bridge foundations, are typically made of cement-based materials, especially concrete, and are challenging to dismantle or demolish. These structures are often large in volume and are often difficult to access for the necessary equipment or are contaminated.

[0003] In the construction industry, demolition (also known as dismantling or demolition) refers to the complete or partial destruction and disposal of buildings or structures of all kinds. Demolition itself has generally been carried out using mechanical methods such as tearing down, removing, dismantling, breaking up (with a wrecking ball), or the use of controlled blasting.

[0004] For larger structures, such as cooling towers, chimneys, multi-story buildings, etc., blasting is preferred, provided local conditions permit. If only partial sections are to be demolished, gentler demolition equipment, such as wall saws, chisels, and core drills, is used.

[0005] In the case of contaminated structures, such as concrete shielding of nuclear reactors or other contaminated structures, dismantling is particularly difficult because appropriate safety precautions for people and the environment must be taken.

[0006] Due to their porous structure, concrete structures are generally contaminated much more deeply than metals. Contamination can penetrate to a depth of several centimeters into the structure. Due to the high material stability, rough and aggressive technologies must be used to decontaminate concrete surfaces. Current state-of-the-art methods for abrading concrete layers include concrete milling machines, concrete chisels, jackhammers, and thermal or ice blasting and laser technologies.

[0007] The aforementioned abrasion technologies make it possible to remove concrete layers even on walls and ceilings. For larger surfaces, heavy machinery is required, requiring the use of manipulators or other devices to compensate for the high weight and restoring forces. Milling machines enable the use of remote-controlled systems. In addition to purely manually operated abrasion processes, remote-controlled and fully automated technologies are also being used or developed.

[0008] The dust and aerosols released during decontamination are often highly harmful to health and require the additional use of extraction and filter systems, which entails a correspondingly high level of technical effort.

[0009] In addition to contaminated structures or buildings, structures that are difficult to access also pose a particular challenge with regard to demolition. Examples of difficult-to-access structures include underground structures, such as bunkers, or foundations embedded deep in the ground, e.g., those of wind turbines or bridges. Due to their location, such structures can only be reached with considerable technical effort by the heavy technical equipment required for demolition or dismantling. This makes dismantling challenging in terms of equipment and also involves risks for the people involved in the dismantling, especially the equipment operators.

[0010] Although DE 10 2007 008 310 A1 does not directly concern the demolition of buildings, it does describe a test procedure that can be used to determine the resistance of pipeline components to structurally damaging biogenic sulfuric acid corrosion. In this test procedure, the respective test specimen is placed in a bioreactor. A biofilm that causes biogenic sulfuric acid corrosion is then formed on the surface of the test specimen. In particular, it may be intended to create environmental conditions in the reactor that are as close as possible to those of pipeline components in use in a pipeline or sewer system. The more severe the corrosion observed or measured on the test specimen, the lower the material's resistance to biogenic sulfuric acid corrosion.

[0011] WO 2019 / 064069 A1 relates to a process for the degradation of cement- and, in particular, asbestos-containing materials ("matrix materials"). It is based on acid-based decomposition of the materials. For this purpose, a slurry or suspension is formed by contacting the matrix material to be degraded with an acidic solution. The acid-based chemical reaction in the slurry degrades the matrix material. It may also be intended to recover chemically inert secondary raw materials, such as silicates, phosphates, or metals.

[0012] Overall, the options known in the state of the art for the dismantling of cement-bound solid or concrete bodies, in particular structures, buildings, structural parts and / or building material bodies, especially if these are difficult to access, large in volume and / or contaminated, are associated with considerable disadvantages and risks.

[0013] Therefore, the object underlying the present invention is to facilitate or improve the dismantling or demolition of cement-bound solid bodies, in particular concrete bodies.

[0014] In particular, the object underlying the present invention is to provide a method which is particularly suitable for the abrasion or dismantling of hard-to-access, contaminated and / or large-volume cement-bound solids and at least reduces the disadvantages described above.

[0015] To achieve the above-mentioned object, the present invention proposes - according to a first aspect - a method for the dissolving and / or blasting treatment of cement-bound or predominantly cement-bound solid bodies in the form of structures, buildings, parts of structures and / or building material bodies, wherein the solid body is inoculated at the place of installation and / or erection, place of manufacture or place of use with an aqueous solution containing acid-producing microorganisms (inoculation culture) to form a biofilm on and / or in the solid body, wherein microorganisms are inoculated in an amount in the range of 1 × 10 4 up to 1 × 10 12 CFU / cm 2 , based on the surface of the solid to be treated, are applied or introduced onto and / or into the solid, whereby growth-promoting environmental conditions for the microorganisms are established by (i) a targeted adjustment of the temperature and / or (ii) a targeted supply of nutrients and / or substrates for the microorganisms and / or (iii) a targeted adjustment of the humidity in the area of ​​the solid body, wherein the cement portion is at least partially decomposed and / or converted by the acid formed by the microorganisms and converted from the solid phase into a liquid, doughy and / or pasty phase, and wherein aggregates contained in the liquid, doughy and / or pasty phase and / or valuable substances formed by the treatment are separated for recovery purposes.

[0016] In other words, the invention provides for treating cement-bound solid bodies, in particular concrete bodies or structures, buildings, structural parts, building material bodies, etc., by means of targeted, biogenic acid corrosion, in particular biogenic concrete and / or cement corrosion, in order to achieve complete or partial degradation of the solid body.

[0017] Preferred embodiments of the method according to the invention are described in detail below. In this context, the terms used to describe the present invention are also further explained: The term “cement-bound solid body” in the context of the present invention preferably refers to solid structures which are based on or contain cement-bound building materials or building materials with cement as a binder (cement binder), such as mortar or concrete. The cement binder or the cement portion can be supplemented or replaced by further binders, such as organic polymers, sulfur, asphalt and / or lime. The totality of all binders contained in the solid body, i.e. the cement binder and any additional binders, is referred to as the overall binder in the context of the present invention. In particular, cement-bound solid bodies in the sense of the present invention can be formed from concrete or have concrete as a building material.

[0018] Treating the solid body "on site, in particular at the site of installation and / or erection, manufacture, or use" means that the solid body is treated with the method according to the invention at the location where it was constructed, erected, or used. In particular, the invention provides that the solid body is not transported to another location or treatment site before the method is carried out. In relation to specific applications, this means that, for example, the foundation of a wind turbine is treated at the exact location where it was originally embedded in the ground. The concrete shielding of a nuclear reactor would be treated at the reactor's original site of operation or use.

[0019] The method according to the invention is particularly suitable for a dissolving or blasting treatment, in particular for the purpose of removing solid layers or for the purpose of complete dismantling of hard-to-access, particularly large-volume, and / or chemically, biologically, and / or radioactively contaminated solids. The solids to be treated with the method according to the invention can be, in particular, structures, buildings, structural components, and / or building materials. Within the scope of the present invention, a building material component is understood to mean, in particular, remnants or fragments of structures, buildings, or structural components.Examples of difficult-to-access and possibly contaminated structures for the treatment of which the method according to the invention is particularly suitable are bunkers, foundations of structures embedded in the ground, for example of wind turbines or bridges, radioactively contaminated concrete shielding of reactors in nuclear power plants, cooling towers or chimneys.

[0020] As already stated above, the treatment according to the invention is based—without wishing to be limited to this theory—on targeted biogenic corrosion or abrasion, in particular concrete or cement corrosion, of the solid body, particularly of the cement content or the total binder in the solid body. However, this can also sometimes be accompanied by attack, in particular corrosion, of other components of the solid body, such as aggregates, such as aggregates and fibers, or reinforcing bars.

[0021] For the purposes of the present invention, concrete or cement corrosion refers to changes originating from the surface of a cement-bound solid, such as a concrete body, particularly in the cement-based binder (cement binder) or the cement content in the solid. Concrete or cement corrosion can be caused, in particular, by biological, chemical, and / or weather-related attacks. Of particular importance for the present process are primarily biological and / or chemical attacks, particularly on the cement content or the entire binder, caused by acids produced by acid-producing microorganisms.

[0022] In the case of chemical and / or biogenic attacks or treatments of cement-bound solids or concrete bodies, particularly concrete and / or cement corrosion, a distinction can be made between dissolving attacks ("dissolving treatment") and blasting or driving attacks ("blasting treatment"). In addition, in the case of chemical and / or biogenic attacks or treatments of solid or concrete bodies, metal corrosion, also synonymously referred to as reinforcement corrosion, may also occur, especially when reinforcing or reinforcing bars are integrated into the solid or concrete body.

[0023] Without wishing to be limited to this theory, in the context of the present invention, the dissolving treatment is understood to mean an attack, in particular, of the cement component or the overall binder in the presence of moisture or water by inorganic and organic, preferably inorganic, acids. Both inorganic acids, such as in particular sulfuric acid, sulfurous acid, nitric acid, or nitrous acid, as well as organic acids, such as lactic, acetic, or citric acid, react with the components of the overall binder to form, among other things, soluble calcium, aluminum, and iron salts, as well as silica gel.

[0024] In addition to the dissolving treatment, the method according to the invention can also include a blasting or exploding treatment. Blasting attack, also referred to as "sulfate exploding," is triggered in particular by high sulfate concentrations, which lead to the formation of voluminous reaction products with high crystallization pressure, particularly ettringite and / or gypsum. Due to the crystallization pressure, an explosive effect is generated in the area of ​​the ettringite and / or gypsum efflorescence, which is accompanied by further destruction of the solid.

[0025] Which acids are used in the present process depends largely on the biocenosis or the acid-producing microorganisms in the biofilm on the solid. As explained below, the formation and selection of the microorganisms is controlled in particular by adjusting the environmental conditions. Within the scope of the present invention, biogenic corrosion based on sulfuric acid or through the formation of biogenic sulfuric acid is particularly preferred. Nevertheless, corrosion based on nitric acid or organic acids such as formic acid, lactic acid, citric acid, and / or acetic acid is also conceivable. Combinations of different acids can also be provided.

[0026] For the purposes of the present invention, "acid-producing microorganisms" are understood to mean bacteria, fungi, archaebacteria, and eukaryotic single-celled organisms whose energy metabolism is accompanied by or leads to the formation of acids. These acids can be inorganic acids, in particular sulfuric acid and / or nitric acid, or organic acids, such as formic acid, citric acid, lactic acid, and / or acetic acid.

[0027] In particular, the acid-producing microorganisms can be sulfuric acid-producing bacteria. Sulfuric acid-producing bacteria belong, in particular, to the thiobacteria or sulfur bacteria (also known synonymously as sulfur-oxidizing bacteria or sulfuricants) and are capable of using hydrogen sulfide and other reduced sulfur compounds as a substrate or electron donor and oxidizing them to sulfate or biogenic sulfuric acid. Sulfuric acid-producing microorganisms belong, for example, to the genera Thiobacillus, Thiomonas, Acidithiobacillus, Sulfolobus, and / or Wolinella.

[0028] Furthermore, within the scope of the present invention, it is possible to use nitric acid-producing microorganisms as acid-producing microorganisms. Nitric acid-producing microorganisms are ammonia oxidants and nitrite oxidants, which are involved in the nitrogen cycle, particularly nitrification, and oxidize nitrogen compounds, such as ammonia or ammonium ions, to nitrite (nitrous acid) and nitrate (nitric acid) in a multi-stage reaction. Nitric acid-producing microorganisms or bacteria belong in particular to the genera Nitrosomonas, Nitrosococcus and / or Nitrosospira, Nitrobacter, Nitrospina and / or Nitrococcus.

[0029] Furthermore, within the scope of the present invention, all microorganisms whose metabolism forms organic acids, such as formic acid, acetic acid, lactic acid, or citric acid, through the degradation of organic substances, in particular sugars, starch, or starch derivatives, can be used as acid-producing microorganisms. Lactic acid can be formed, for example, by so-called lactic acid bacteria or lactobacilli, which degrade carbohydrates to lactic acid. Acetic acid can be formed, among other things, by so-called acetogenic bacteria or the oxidation of sugars by bacteria of the genus Acetobacter. Citric acid can be formed, for example, by the fermentation of organic substances by fungi of the genus Aspergillus, in particular Aspergillus niger.

[0030] The above statements with regard to possible species or genera of bacteria or microorganisms which are capable of producing inorganic and / or organic acids and are suitable for the process according to the invention are not exhaustive but are to be understood as merely exemplary.

[0031] Furthermore, the term "CFU" or Colony Forming Unit is a unit commonly used in microbiology to quantify microorganisms. It involves determining the viable cell count of microorganisms in a material using cultivation methods familiar to those skilled in the art. A sample of the material whose microorganism content is to be determined is usually spread evenly, usually at a high dilution, on the surface of a selective culture medium, so that the microorganisms spread onto the culture medium are isolated and spaced apart from one another, forming visible colonies through growth and reproduction. The number of colonies, taking into account the dilution of the sample, can be used to determine the number of microorganisms originally contained in the sample.

[0032] In the context of the present invention, the term "growth-promoting environmental conditions for the microorganisms" refers to the targeted adjustment of environmental conditions within the solid body that permit microbial metabolic processes and microbial growth. In particular, the adjustment of growth-promoting environmental conditions for the microorganisms is intended to enable the formation of a stable biofilm on the solid body and the production of acids by the microorganisms.

[0033] Relevant factors for the environmental conditions include, in particular, the setting of a suitable temperature, the provision of substrates and nutrients for microbial metabolism, and the setting of a humid environment.

[0034] The present invention has numerous advantages and special features, which are described below: The method according to the invention based on biogenic abrasion can be used as a tool for abrading or removing centimeter-thick, large-area and large-volume concrete layers, which may also be contaminated, in particular radioactively contaminated.

[0035] The automated application and monitoring of an accelerated damage mechanism of biogenic corrosion, in particular biogenic sulfuric acid corrosion, can open up a completely new abrasion technology that can be used in the demolition of concrete structures and, for example, in the case of radioactive contamination, largely prevents radiation and aerosol exposure of workers.

[0036] By applying the inventive method based on chemical-microbial treatment of the solid, the surface is removed, causing the decomposed concrete residues to fall to the ground or become softened. The solid residues can then be automatically collected and disposed of.

[0037] Compared to the state of the art, biogenic abrasion is a process that operates without noise or dust.

[0038] The process is also capable of automation and contributes to the protection of the environment and workers.

[0039] Having said this, particularly preferred embodiments and variants of the method according to the invention are explained in detail below: As previously stated, the treatment of the solids according to the invention primarily results in an attack of the cement portion or the overall binder by the acid produced by the microorganisms. Therefore, the invention provides that the cement portion or the overall binder is at least partially decomposed or converted by the at least one acid produced by the microorganisms and is converted from the solid phase into a liquid, doughy and / or pasty phase, in particular a suspension or slurry. Within the scope of the present invention, the cement portion of the solid is understood to mean, in particular, the cement-based portion of the binder or overall binder, in which aggregates such as aggregates, fillers and / or fibers, or reinforcing bars and the like are embedded.

[0040] In addition, the treatment of the solids according to the invention, in particular the attack on the cement component or the entire binder, can also cause fragments to be released from the solids and fall to the ground.

[0041] According to the invention, the conversion or transformation of the cement content or total binder of the solids leads to a surface or material removal on the treated solids.

[0042] According to the invention, it can therefore be provided to determine or monitor the material or surface removal. The material or surface removal is determined using procedures or methods generally known to those skilled in the art. The selection of suitable measurement methods depends in particular on the nature, shape, and size of the solid to be treated.

[0043] A first suitable method for determining the surface or material removal compared to the original surface is the use of a mechanical caliper, whereby the average surface or material removal [in mm] is calculated based on preferably several measuring or reference points. Furthermore, the average surface or material removal [in mm] compared to the original surface can be determined based on preferably several measuring or reference points using laser rangefinders, which are generally known to those skilled in the art.

[0044] In addition, it is possible to determine the material or surface removal by determining the change in roughness compared to the surface of the solid or concrete body before treatment, preferably according to the standard EN ISO 25178. Electro-optical (profile) measuring methods are particularly suitable for measuring roughness.

[0045] In this context, it can be provided that the treatment is continued ("treatment duration") until the desired or required amount of surface or material removal is achieved. Regarding the term "treatment duration," as used here, within the scope of the present invention, this refers to the period during which the environmental conditions for the microorganisms are maintained.

[0046] The required surface or material removal can, for example, be determined by the requirements of a preferably complete mechanical demolition or dismantling of the remaining solid or concrete body following the treatment according to the invention. For this purpose, the required material or surface removal is preferably specified relative to the original surface.

[0047] According to the invention, it can be provided in this context in particular that the treatment is carried out until an average material or surface removal of at least 1 mm, in particular at least 5 mm, preferably at least 10 mm, preferably at least 15 mm, is achieved.

[0048] With the aid of the method according to the invention, in particular a surface treatment of a concrete surface or a surface attack of a concrete surface, an annual removal of the concrete surface of 2.5 mm to 25 mm, in particular 5 mm to 12.5 mm, can be achieved. The removal is preferably determined using a laser rangefinder. The above-mentioned data regarding the annual removal refer to a concrete based on Portland cement CEM I and an adjustment of the environmental conditions to an ambient temperature of 30 °C in the area of ​​the surface to be treated, a substrate input of 100 ppm H2S, and a relative humidity of 99.5%.

[0049] The conversion depth can be used as a further measure for the conversion or implementation of the cement content or total binder. The term "conversion depth" refers to the distance [in cm] between a first measuring plane on the surface of the solid before treatment and a second measuring plane through the solid at the end of treatment, whereby at least substantially complete conversion of the cement content of the solid or of the total binder content of the solid is achieved between the first and second measuring planes. For the purposes of the present invention, "at least substantially complete conversion of the cement content" means a conversion of the cement content or total binder content to at least 85 wt.%, based on the weight of the cement content or total binder in the solid.

[0050] According to the invention, it can therefore be provided in this context that the treatment is carried out until a conversion depth of at least 0.5 cm, in particular at least 1 cm, preferably at least 3 cm, preferably at least 5 cm, is reached.

[0051] As regards the conversion product, in particular the liquid, doughy and / or pasty phase or the suspension or slurry, this may in particular contain (i) water, (ii) products from the reaction of the at least one acid with the cement component or total binder of the solid, preferably calcium, aluminum and / or iron salts and / or silica gel, and / or (iii) optionally partially decomposed aggregates, in particular aggregates and / or fibers.

[0052] With a view to improving the process efficiency, it can be provided according to a preferred embodiment of the invention that the surface of the solid is mechanically enlarged before inoculation.

[0053] In this regard, it has proven particularly advantageous to create holes, notches, and / or depressions in the solid prior to inoculation, and preferably to inoculate at least directly into the area of ​​the holes, notches, and / or depressions. Enlarging the surface area through holes, notches, and depressions not only provides a larger overall area for the biofilm to spread, but also enables dissolving or blasting treatments or attacks within the solid, thus achieving a higher overall degree of transformation or destruction and thus accelerated degradation or faster abrasion or removal.

[0054] According to a further embodiment of the method according to the invention, it can also be provided that the solid is subjected to mechanical comminution prior to inoculation, preferably by blasting, drilling, impact comminution, cutting comminution, pressure comminution, and / or impact comminution. This embodiment also offers the advantage of improved process efficiency by increasing the inoculatable surface area. Furthermore, a mechanically already comminuted solid to be treated can also be easier to handle for subsequent treatment purposes.

[0055] Furthermore, it has proven advantageous within the scope of the present invention if the solid, in particular the surface of the solid to be inoculated, is dried and / or roughened prior to inoculation. Drying or roughening the solid prior to inoculation can improve the absorption capacity of the solid, in particular the surface of the solid, for the inoculation solution, the nutrient or substrate supply, and moisture, since the capillary action of the pores of the generally porous solid is enhanced.

[0056] Furthermore, as regards the inoculation process step, this is preferably carried out by spraying, sprinkling and / or soaking the solid with the inoculation culture.

[0057] In the context of the present invention, spraying the solid body means a fine distribution of liquids in the region of the solid body or on the solid body, in particular with liquid droplet sizes of less than 2 mm, preferably less than 1.5 mm, more preferably less than 1.0 mm, and particularly preferably less than 0.5 mm. According to a particularly preferred embodiment, spraying means the application of finely distributed droplets of a liquid in the form of a spray mist.

[0058] In the context of the present invention, sprinkling is understood to mean, in particular, drip wetting of the solid body with droplet sizes in the range of at least 2 mm and at most 7 mm, in particular of at least 2 mm and at most 5 mm.

[0059] In the context of the present invention, impregnation is understood to mean immersing the solid body in liquids and, if appropriate, subsequently allowing the liquid to soak in or act on it.

[0060] The above definitions of the terms “spraying”, “irrigating” and “watering” also apply to the application or introduction of all other solutions used within the scope of the present invention, in particular to the substrate solution or nutrient solution described below.

[0061] Regarding the inoculation process, the invention provides for the use of a pure culture or a mixed culture of acid-producing microorganisms as the inoculation culture. According to the invention, the inoculation culture creates the basis for the formation of the biofilm. By subsequently adjusting the environmental conditions, which will be explained below, it can be ensured that the desired biocenosis or biofilm is formed and maintained based on the microorganisms contained in the inoculation culture.

[0062] As regards the inoculation culture in particular, it can be provided according to the invention that the inoculation culture comprises (i) sulphuric acid producing microorganisms, preferably sulphur oxidizers, such as thiobacteria, and / or (ii) nitric acid producing microorganisms and / or (iii) organic acid producing microorganisms, in particular acetic acid, lactic acid and / or citric acid producing microorganisms.

[0063] For the purposes of the present invention, sulfuric acid-producing microorganisms are understood to mean, in particular, so-called thiobacteria, which can oxidize reduced or partially reduced sulfur compounds, such as hydrogen sulfide or thiosulfate, in particular to sulfate or biogenic sulfuric acid. Sulfuric acid-producing microorganisms preferably belong to the genera Thiobacillus, Thiomonas, Acidithiobacillus, Sulfolobus, and Wolinella, particularly preferably Thiobacillus, Thiomonas, and / or Acidithiobacillus.

[0064] For the purposes of the present invention, nitric acid-producing microorganisms are understood to mean, in particular, so-called nitric bacteria or nitrifying bacteria, which participate in the nitrogen cycle and catalyze the conversion, in particular the oxidation, of reduced or partially reduced nitrogen compounds, such as ammonia or ammonium ions, to nitrate or nitrite. Nitric acid-producing microorganisms or bacteria can, for example, belong to the genera Nitrosomonas, Nitrosococcus and / or Nitrosospira, Nitrobacter, Nitrospira and / or Nitrococcus.

[0065] With regard to the method according to the invention, it has proven particularly advantageous if the inoculum culture comprises sulfuric acid-producing microorganisms, preferably sulfur oxidizers and / or thiobacteria, or if sulfur oxidizers or thiobacteria are used as acid-producing microorganisms.

[0066] The use of sulfuric acid-producing microorganisms is advantageous in several respects: Firstly, the sulfuric acid produced by the microorganisms is a very strong acid, which leads to a relatively rapid conversion or decomposition of the cement component of the solids. Secondly, the high acid load generated by the sulfuric acid-producing microorganisms exerts selection pressure on other, non-acid-tolerant microorganisms that are undesirable in the biofilm.

[0067] With regard to the formation of biofilm, it has proven particularly advantageous to inoculate microorganisms in an amount in the range of 1 × 10 4 up to 1 × 10 10 CFU / cm 2 , preferably in the range of 1 × 10 5 up to 1 × 10 8 CFU / cm 2 , based on the area of ​​the solid to be treated, are applied to and / or into the solid.

[0068] Inoculation can be performed once or several times. With regard to multiple inoculations, it can be planned to repeat the inoculation at intervals of 5 hours to 15 days, in particular 1 to 14 days, preferably 2 to 12 days, more preferably 3 to 10 days, and most preferably 4 to 8 days. The frequency of inoculation and the interval are adapted to the local conditions by the expert.

[0069] In order to enable good environmental conditions for the microorganisms and, in addition, suitable reaction conditions for the dissolving or disintegrating treatment of the solid, in particular the cement component or the total binder of the solid, it is preferred according to the invention if the relative humidity or air humidity in the surrounding area of ​​the solid is adjusted by means of a measuring, control, and / or regulating device. In this context, it has proven advantageous if the surrounding area is adjusted to a relative humidity, in particular a relative air humidity, of at least 50%, in particular at least 60%, preferably at least 70%, preferably at least 80%, particularly preferably at least 90% (condensing).

[0070] With regard to adjusting the relative humidity or air humidity, the introduction of water vapor has proven particularly useful. For this purpose, conventional spray devices or spray lances are used and positioned and / or arranged according to the geometry of the solid. The positioning or arrangement is preferably carried out in such a way that, in particular, all inoculated areas of the solid to be treated are sufficiently supplied with moisture, especially water vapor.

[0071] With regard to the environmental and reaction conditions, it may further be provided that the temperature in the area surrounding the solid body is adjusted by means of a measuring, control and / or regulating device.

[0072] In this context, it is particularly preferred if the ambient temperature of the solid body is set to a temperature of less than 20 °C or a temperature in the range of 20 to 40 °C or a temperature greater than 40 °C. Preferably, the temperature or temperature range is adapted to the microbiology or microorganisms used.

[0073] The temperature can be adjusted, in particular, by supplying heat, particularly by introducing heating and / or warm air. Likewise, waste heat from other processes can be used to adjust the temperature.

[0074] Furthermore, within the scope of the present invention, it can be provided that the pH value on the surface of the solid body to be treated is controlled by means of a measuring, control, and / or regulating device. In particular, it can be provided in this context that the surface to be treated is adjusted to an acidic environment, in particular to a pH value in the range of 1.0 to 4.0, preferably 1.5 to 3.0. An acidic environment on the surface of the solid body to be treated not only improves the conversion of the cement content or the total binder of the solid body, but also prevents the biofilm from being overgrown by other microorganisms that are not desired in the biofilm.

[0075] As far as the environmental conditions or growth conditions and, furthermore, selection conditions for the microorganisms are concerned, it is preferred if the substrate for the acid-producing microorganisms is selected from (i) reduced and / or partially reduced sulfur compounds, in particular water-soluble or gaseous reduced or partially reduced sulfur compounds, preferably H2S and / or thiosulfates, and / or (ii) nitrogen compounds, in particular water-soluble nitrogen compounds, preferably ammonia, urea and / or ammonium salts, and / or (iii) carbon compounds, in particular starch and / or starch derivatives.

[0076] In the context of the present invention, the term “substrate” refers in particular to electron donors and / or carbon sources for microbial metabolism.

[0077] The substrate used in the process is tailored to the acid-producing microorganisms present in the desired solid biofilm or promotes the growth or selection of the desired biocenosis. Sulfur compounds are preferred as substrates for sulfuric acid-producing organisms. If treatment is to be carried out with nitric acid, the use of nitrogen compounds is preferred. If microorganisms that produce organic acids, such as formic acid, citric acid, lactic acid, or acetic acid, are to be established in the biofilm, carbon compounds are used as substrates.

[0078] As far as the substrate is further concerned, it can be provided according to the invention that the substrate is applied to and / or into the solid body in gaseous form and / or as an aqueous solution (substrate solution).

[0079] With regard to gaseous substrate, it has proven particularly advantageous if this, in particular in the form of H2S, is passed into the surrounding area of ​​the solid body in a concentration in the range of 1 to 3,000 ppm, in particular 2 to 2,000 ppm, preferably 3 to 1,000 ppm, more preferably 5 to 500 ppm, particularly preferably 10 to 150 ppm.

[0080] With regard to a liquid substrate solution, it has proven advantageous if the substrate solution is applied to and / or into the solid body by spraying, sprinkling or soaking.

[0081] In order to further improve the environmental conditions for the microorganisms, it may be planned to use additional nutrients for the microorganisms in the biofilm in addition to the substrate.

[0082] In this regard, it is preferred if nutrients for the acid-producing microorganisms are applied as an aqueous solution (nutrient solution) onto and / or into the solid, in particular wherein the nutrient solution can be applied onto and / or into the solid by spraying, sprinkling and / or soaking.

[0083] As regards the nutrients in particular, these are preferably selected from (i) at least one nitrogen source and / or (ii) at least one phosphate source and / or (iii) at least one potassium source and / or (iv) trace elements, in particular boron, copper, iron, manganese, molybdenum and / or zinc.

[0084] As already stated at the beginning, the method according to the invention is carried out at the place of installation or construction or at the place of manufacture or use of the solid body to be treated.

[0085] In this context, the invention may provide for the process to be carried out under ambient or atmospheric conditions, in particular without protection from weather and / or environmental influences. In other words, the invention may provide for the solid body to be exposed to all weather or environmental influences, such as rain, frost, sunlight, and wind, during the treatment.

[0086] In order to inoculate the solids, establish suitable environmental conditions for the microorganisms, and furthermore, establish suitable reaction conditions for the dissolving or disintegrating treatment of the solids, it is preferred if the inoculum and / or nutrients and / or substrate are applied to and / or into the solids and / or the humidity in the area surrounding the solids is specifically adjusted by sprinkling and / or soaking, in particular by irrigating, the solids. In this context, it can be provided that the inoculum, nutrients, substrate, and / or moisture are applied together. Separate applications can also be provided.

[0087] In order to further improve the setting of the environmental and reaction conditions, however, it is provided according to a preferred embodiment of the method according to the invention that the solid body is provided with a roof, cover or enclosure for protection against environmental and weather influences before or after inoculation, preferably before inoculation, completely or in sections, in particular in the area of ​​the surface of the solid body to be treated.

[0088] By using a roof, cover, or enclosure, the environmental and reaction conditions for the microorganisms and the dissolving or dissolving treatment can be adjusted even more precisely. In particular, weather influences such as rain, heat, drought, or cold, which are detrimental to the environmental and reaction conditions and thus also to the process efficiency, can be reduced or completely eliminated.

[0089] In this context, it has proven particularly advantageous if a material which is at least substantially impermeable to gases and / or water vapors, preferably a film which is impermeable to gases and / or water vapors, is used as roofing, covering or enclosure.

[0090] The use of foil as a roof, cover, or enclosure is a particularly practical, relatively cost-effective, and flexible technical solution and thus the preferred embodiment. Nevertheless, alternative solutions are equally possible. The primary consideration is that the desired shielding of the solid body from environmental and weather influences is achieved.

[0091] With regard to a particular embodiment, which is particularly advantageous when the solid body has been subjected to mechanical comminution prior to inoculation, it can be provided that the preferably comminuted solid body, preferably a loose bed of the comminuted solid body, is covered with a cover, in particular a gas- and / or water vapor-impermeable film. It is advantageous if the area beneath the cover is accessible for spraying devices and / or measuring, control, and / or regulating devices. In other words, according to this embodiment, it is preferred to cover a bed of the comminuted solid body with a film in order to ensure protection against weathering and drying out and, at the same time, to be able to establish suitable environmental conditions.

[0092] According to a further preferred embodiment, it can be provided that the solid body as such, i.e., in non-comminuted form, is provided, in its entirety or in sections, with a roof, cover, or enclosure. In this regard, it is preferred if the roof, cover, or enclosure, in particular the enclosure, is attached and / or arranged in such a way that a gap is formed between the enclosure and the surface of the solid body. Here, too, the gap should be accessible for spraying devices and / or measuring, control, and / or regulating devices.

[0093] To enable targeted adjustment of the environmental conditions or reaction conditions, it is preferred according to the invention if the intermediate space has a depth of at least 0.5 cm, in particular at least 1 cm, preferably at least 2.5 cm, particularly preferably at least 5 cm. Likewise, the intermediate space can have a depth of at most 1 m, in particular at most 50 cm, preferably at least 40 cm, preferably at most 30 cm, particularly preferably at most 20 cm. Furthermore, it is preferred if the roof, cover, or enclosure is adapted to the external geometry of the solid body.

[0094] In this context, the term “depth” refers to the distance between the surface of the solid and the film surrounding the solid.

[0095] With regard to this embodiment, it is further preferred if the inoculum and / or the nutrients and / or the substrate and / or water vapor for adjusting the humidity are introduced under the roofing, covering or enclosure or into the space between the roofing, covering or enclosure and the solid body, in particular by spraying.

[0096] For the introduction of the inoculum, nutrients, substrate, and / or water vapor, suitable spray devices and / or lances are used. The positioning and arrangement are determined by the expert in accordance with the dimensions and geometry of the solid body, ensuring that all areas to be treated are adequately exposed to the inoculum, nutrients, substrate, and moisture.

[0097] As stated at the beginning, the focus of treatment with the method according to the invention is on the conversion or transformation of the cement content or the total binder in the solid. In addition, treatment, in particular decomposition or (partial) removal of other components of the solid may also be provided.

[0098] According to a related embodiment of the method according to the invention, it can be provided that, in addition to the cement components of the solid body, iron or steel components, in particular reinforcing iron, present in the solid body are also treated. Preferably, the treatment is also a biogenic treatment, in particular a biogenic iron corrosion treatment.

[0099] In the context of the present invention, the term “iron corrosion”, also synonymous with reinforcement corrosion, refers to the oxidation of iron or steel in a moist environment induced by microorganisms, in particular bacteria.

[0100] In this context, it may be provided, in particular, that iron- and / or steel-containing elements contained in the solid body, in particular reinforcing iron, are partially or completely decomposed and / or corroded by iron-oxidising microorganisms, in particular microorganisms of the genera Acidithiobacillus, Thiobacillus, Sulfolobus, Gallionella and / or Ferroglobus.

[0101] To ensure the colonization of iron-oxidizing microorganisms in the biofilm, it is particularly preferred according to the invention if the inoculum contains, in addition to acid-producing microorganisms, acid-tolerant, iron-oxidizing microorganisms, such as Acidithiobacillus ferrooxidans. In this context, it is particularly preferred to use iron-oxidizing microorganisms in combination with sulfur-oxidizing microorganisms.

[0102] According to a further preferred embodiment, aggregates contained in the solid body, in particular polymer-modified aggregates such as fibers, fillers, and / or aggregates, can also be treated biogenically. In particular, the polymer components of polymer-modified fibers, fillers, or aggregates can be treated biogenically.

[0103] In this regard, it has also proven advantageous if the inoculum contains, in addition to acid-producing microorganisms, microorganisms that are capable of degrading synthetic and / or natural polymers, such as cellulose and / or epoxy resins.

[0104] In order to ensure the settlement of microorganisms for the treatment of, in particular, polymer-modified additives in the biofilm, it can be provided according to the invention that the inoculation culture contains microorganisms for the degradation of synthetic and / or natural polymers, in particular cellulose.

[0105] As already explained above, the process according to the invention may result in blasting treatment or blasting attack on the cement-bound solid. Blasting attacks may be accompanied, among other things, by the formation of gypsum and / or ettringite.

[0106] According to a particularly preferred embodiment of the method according to the invention, the substances formed during the dissolving and / or blasting treatment, in particular blasting treatment, of the cement-bound solid, preferably gypsum and / or ettringite, can therefore be recycled or recovered.

[0107] In this context, it is particularly preferred if gypsum and / or ettringite formed by the reaction of acid, preferably sulfuric acid and / or sulfate, with the overall binder or cement component is removed, preferably mechanically. In this context, the gypsum or ettringite can be removed directly from the solid.

[0108] Likewise, removal from the environment is also possible if the resulting gypsum or ettringite has already detached from the solid body.

[0109] Regarding the speed of the process according to the invention, in particular the rate of conversion of the cement component of the solid into a liquid, doughy, and / or pasty phase, this can vary widely and depends on the ambient conditions, in particular the temperature, the thickness and composition of the biofilm, and the specific composition of the cement component or binder component of the solid. Furthermore, the porosity of the solid also influences the conversion rate. The more porous the solid, the faster the biofilm and acids can generally spread within the solid.

[0110] According to the invention, however, it is preferred if, in particular by adjusting the aforementioned environmental conditions and process parameters, the conversion depth during the treatment of the solid is at least 1 cm, preferably at least 2 cm, more preferably at least 3 cm, particularly preferably at least 5 cm, with a treatment duration (as long as the environmental conditions are maintained) of at least 3 to 12 months, preferably at least 6 to 12 months, in particular at least 9 to 12 months. The aforementioned information relates in particular to environmental conditions with an ambient temperature in the range of the solid of 30 °C, a substrate input of 100 ppm H2S, and a relative humidity of > 99%.

[0111] Nevertheless, lower or higher conversion rates or conversion speeds are also possible when carrying out the process according to the invention.

[0112] With regard to the conversion rate, it can further be provided that during the treatment of the solid body, at least 30 wt.%, in particular at least 40 wt.%, preferably at least 50 wt.%, based on the weight of the cement content or total binder in the solid body before treatment, is converted over a treatment period of at least 3 to 12 months, preferably at least 6 to 12 months, in particular at least 9 to 12 months. The above information relates in particular to environmental conditions with an ambient temperature in the range of the solid body of 30 °C, a substrate input of 100 ppm H2S and a relative humidity of > 99% and molded bodies with an average material thickness of 6 cm.

[0113] Likewise, it can be provided that during the treatment of the solid body, at least 30 vol.%, in particular at least 40 vol.%, preferably at least 50 vol.%, based on the volume of the cement content or the total binder in the solid body before treatment, is converted over a treatment period of at least 3 to 12 months, preferably at least 6 to 12 months, in particular at least 9 to 12 months. The above information relates in particular to environmental conditions with an ambient temperature in the range of the solid body of 30 °C, a substrate input of 100 ppm H2S and a relative humidity of > 99%, and molded bodies with an average material thickness of 6 cm.

[0114] The degree of degradation, conversion, or transformation of the solid or the total binder to be achieved with the process according to the invention, as well as the associated treatment duration, can also vary widely. According to the invention, both a nearly complete degradation of the solid or the cement component or the total binder can be aimed for, as well as a partial conversion of the cement component or the total binder.

[0115] According to the invention, it can therefore be provided that the treatment of the solid body takes place until at least 30 wt.%, in particular at least 40 wt.%, preferably at least 50 wt.%, even more preferably at least 60 wt.%, particularly preferably at least 70 wt.%, even more preferably at least 80 wt.%, based on the weight fraction of the cement fraction or total binder in the solid body, has been converted.

[0116] Likewise, it is also possible that the treatment of the solid body is carried out until at least 30 vol.%, in particular at least 40 vol.%, preferably at least 50 vol.%, even more preferably at least 60 vol.%, particularly preferably at least 70 vol.%, even more preferably at least 80 vol.%, based on the volume fraction of the cement component or total binder in the solid body, has been converted.

[0117] The residues or fragments of the solid body remaining after completion of the treatment can be further crushed and disposed of in the usual way for construction rubble and waste.

[0118] According to a preferred embodiment of the method according to the invention, the collection and / or comminution of the residues, in particular the remaining fragments of the solid body, is carried out automatically.

[0119] A nearly complete dismantling of the solid by converting the cement content or the total binder is particularly suitable for cases where the duration or time factor of the treatment is not significant. This is often the case, for example, in the dismantling of underground bunkers, wind turbine foundations, or structures on disused industrial facilities or brownfield sites.

[0120] According to an alternative embodiment, it can also be provided that the solid body is removed only superficially by biogenic acid corrosion, particularly of the entire binder or cement content in the solid body. This embodiment has proven particularly advantageous with regard to the dismantling of chemically, biologically, and / or radioactively contaminated solid bodies. Contamination, which would lead to the release of dust, sometimes highly harmful to health, during mechanical dismantling, usually only penetrates cement-bound solid bodies relatively superficially, to a maximum depth of 7 cm.

[0121] In this context, it has proven advantageous if the solid body has a region extending from the surface to a depth of at least 1 cm, preferably at least 2 cm, more preferably at least 3 cm, particularly preferably at least 5 cm, or at most 10 cm, preferably at most 8 cm, more preferably at most 6 cm, which is chemically, radioactively, and / or biologically contaminated. The treatment of the solid body preferably takes place until the cement content or total binder content of the solid body has been at least substantially converted across the depth of the contaminated region.

[0122] In the context of the present invention, chemical contamination is understood in particular to mean contamination of the solid by pollutants or toxins. Pollutants or toxins, in the context of the present invention, are understood to be chemical elements or chemical compounds that cause functional disorders in or on a living organism even in small quantities and lead to death or mortality if a vital dose is exceeded. In particular, chemical contamination can involve contamination with contaminated sites, environmental toxins, or pesticides.

[0123] In the context of the present invention, radioactive contamination is understood to mean contamination of the solid body with radioactive materials or substances, as can occur in particular in nuclear power plants or during the final storage of radioactive waste.

[0124] For the purposes of the present invention, biological contamination is understood to mean infestation with organisms that are hazardous to the environment and / or health. In particular, biological contamination can be infestation with microorganisms, especially fungi and / or bacteria, or algae.

[0125] After the biogenic removal of the contaminated surface using the method according to the invention, the deeper, uncontaminated layers or the untreated parts of the solid body can be further demolished or dismantled using time-saving mechanical methods.

[0126] In this context, it may in particular be further provided that the untreated part of the solid body is subjected to further mechanical comminution and / or demolition, preferably by blasting, drilling, impact comminution, cutting comminution, pressure comminution and / or impact comminution.

[0127] As already stated above, it is provided within the scope of the present invention that not only a dismantling of the solid body is provided, but also a recovery or recycling of valuable substances formed by the dissolving or blasting treatment or of aggregates dissolved out of the solid body or overall binder.

[0128] In this context, it is intended that aggregates contained in the liquid, doughy, and / or pasty phase, in particular aggregates or fibers, are separated for recovery purposes. Furthermore, it may be intended that gypsum and / or ettringite contained in the liquid, doughy, and / or pasty phase be separated for recovery purposes.

[0129] With regard to recovery, it can be provided, in particular, that the liquid, doughy, and / or pasty phase, in particular the suspension or slurry, is separated, preferably by rinsing or mechanical removal. This can be done either after or after the completion of the treatment. It is equally possible to interrupt the treatment to separate the liquid, doughy, and / or pasty phase, and then reinoculate the solid and reset the environmental conditions as described above.

[0130] Given that the process according to the invention also enables the recovery or recycling of aggregates or valuable (building) materials, such as gypsum or ettringite, the process is characterized by its particular sustainability.

[0131] A possible embodiment of the method according to the invention is described below using the schematic representation in accordance with. Fig. 1. In this regard, it should be emphasized that the Fig. 1 is to be understood as an example only and for illustrative purposes and in no way restrictive: At the Fig. In the technical implementation of the method according to the invention shown in Figure 1, a solid body 1 in the form of a concrete wall of a building is eroded by biogenic acid corrosion, in particular sulfuric acid corrosion. In order to specifically adjust the environmental conditions for the acid-producing microorganisms, the surface of the solid body 1 to be treated, i.e. in this case the concrete wall, is shielded with an enclosure 2 based on a gas- and water-vapor-impermeable film stretched over a metal grid, whereby a gap is formed between the surface of the solid body and the film. In order to also show the solid body 1 to be treated, i.e. the concrete wall and fallen concrete residues or fragments 3, the enclosure 2, which actually extends over the entire concrete wall, is only shown in sections. The distance between the surface of the solid body 1 and the enclosure 2 is approximately 20 cm.The intermediate space is accessible for measuring, control and / or regulation technology as well as spraying devices for the introduction of inoculation solution, substrate, moisture or water vapor and / or nutrient solution (in . Fig. 1 not shown).

[0132] At the Fig. In the technical implementation of the process shown in Figure 1, acid-producing microorganisms are sprayed onto the surface of the solid body 1 to establish a sulfuric acid-producing biofilm beneath the enclosure 2. To create suitable environmental conditions for the microorganisms, the surface of the solid body is kept moist by introducing water vapor. Furthermore, a substrate, preferably a sulfur source, for example in the form of hydrogen sulfide, and nutrients for the microorganisms are applied to the surface or introduced into the interstitial space using appropriate spraying devices. The corrosion process induced by the microorganisms in the biofilm – targeted and accelerated by adjusting the environmental conditions – leads to the controlled erosion of the (concrete) surface.

[0133] The combined chemical-microbial degradation erodes the surface, and the decomposed concrete residues fall to the bottom as Crushed 3, or a suspension forms as a result of the conversion of the cement content or the entire binder, which also collects at the bottom. The concrete residues or Crushed 3 can then be automatically collected and disposed of.

[0134] The supply of the biofilm with a sulfur source, such as hydrogen sulfide gas, can be ensured while complying with all safety-relevant standards. In this regard, generally known safety and measurement technology for handling hydrogen sulfide can be used.

[0135] As a result, the present invention provides a method for treating cement-bound solids, in particular for the dismantling or removal of solids, which is relatively uncomplicated to handle compared to demolition or demolition methods of the prior art and is particularly suitable for the treatment of contaminated, difficult-to-access and / or large-volume cement-bound solids, in particular structures, buildings, parts of structures and / or building material bodies.

[0136] Furthermore, the present invention relates - according to a second aspect of the invention - to a method for the dissolving and / or blasting treatment of cement-bound solids, in particular of structures, buildings, parts of structures and / or building material bodies, wherein the solid body is transported from a place of installation and / or erection, production or use to a treatment site and is inoculated with an aqueous solution (inoculation culture) containing acid-producing microorganisms to form a biofilm on and / or in the solid body, wherein microorganisms are inoculated in an amount in the range of 1 × 10 4 up to 1 × 10 12 CFU / cm 2 , based on the area of ​​the solid to be treated, are applied to and / or into the solid, whereby growth-promoting environmental conditions for the microorganisms are established by (i) a targeted adjustment of the temperature and / or (ii) a targeted supply of nutrients and / or substrates for the microorganisms and / or (iii) a targeted adjustment of the humidity in the area of ​​the solid body, and wherein the cement portion or the total binder of the solid body is at least partially decomposed or converted by the acid formed by the microorganisms and is converted from the solid phase into a liquid, doughy and / or pasty phase, in particular a suspension or slurry, and wherein the treatment or conversion takes place until at least 50% by weight, based on the weight of the cement portion of the solid body, has been converted and / or until a conversion depth of at least 1 cm is reached.

[0137] In principle, the method according to the second aspect of the invention corresponds to the method according to the first aspect of the invention described above, with the only proviso that, in contrast to the method according to the first aspect of the invention, the solid body is not treated on site, i.e. not at its place of installation and / or erection, place of manufacture or place of use, but is transported to a place different from the place of installation and / or erection, place of manufacture or place of use before the treatment.

[0138] All definitions, features, and aspects described in connection with the method according to the first aspect of the invention therefore also apply equally to the second aspect of the invention. In particular, the previously described features for inoculating and comminuting the solid, for adjusting the environmental conditions, and for recovering or recycling aggregates or valuable materials apply equally to this aspect of the invention.

[0139] The method according to this second aspect of the invention is particularly suitable for the industrially designed, targeted demolition of solid bodies, in particular structures, buildings, structural components, and / or building materials. In particular, the targeted recovery of aggregates and other valuable (construction) materials, such as gypsum or ettringite, from the cement-bound solid bodies can also be a focus.

[0140] Special features of the method according to the second aspect of the invention are listed below: Regarding the specific treatment location for the procedure, this is preferably an enclosed indoor space. A closed indoor space offers the advantage of allowing for more targeted adjustment of the environmental conditions. The primary considerations for selecting the indoor space are, first and foremost, sufficient space for the treatment of the solid and, secondly, adequate shielding from the atmosphere and weather influences.

[0141] The specialist preferably selects the required size of the treatment site based on the quantity or volume of the solid to be treated.

[0142] According to a preferred embodiment, the enclosed interior space can be a hall. All types of halls are conceivable. In particular, the treatment location can also be a lightweight hall or a mobile, tent-like hall.

[0143] According to a further preferred embodiment, it can also be provided that the treatment location or interior space is formed by a cover or roof. In this context, the cover or roof can be formed from a gas- and / or water vapor-impermeable material, preferably a gas- and / or water vapor-impermeable film.

[0144] This embodiment may in particular be a type of tent in which the method according to the invention is carried out.

[0145] With a view to simplified handling, in particular with regard to transport, it can be provided according to the invention that the solid body is subjected to mechanical comminution, preferably by blasting, drilling, impact comminution, cutting comminution, pressure comminution and / or impact comminution, before transport or before inoculation.

[0146] According to a particularly preferred embodiment of the method according to this aspect of the invention, it can be provided to cover a loose bed of comminuted solid with a film for the dissolving and / or disintegrating treatment. Inoculation can take place before and / or after covering the bed with the film. The environmental conditions under the film are adjusted according to the specifications described above for the first aspect of the invention.

[0147] To ensure mass transfer within the bed of solids in the interior or beneath the cover or enclosure, it is preferable for the bed to be continuously or discontinuously re-stacked. The need for re-stacking can be monitored using measurement and control technology, if necessary. In particular, the pH value or measurements of acid concentrations can be used as indicators of intact acid metabolism in the microorganisms. If the measurements indicate that microbial acid production is declining, re-circulation should be performed.

[0148] The regulation or targeted adjustment of the temperature is also carried out as already explained for the first aspect of the invention and can be achieved in particular by supplying heat, e.g., by introducing heating and / or warm air. Furthermore, it can also be provided to use waste heat to adjust the temperature.

[0149] In the process according to the second aspect of the invention, a high degree of conversion or transformation of the cement portion or total binder in the solid is preferred. A high degree of conversion or transformation of the cement portion or total binder is particularly advantageous with regard to the recovery of aggregates. According to the invention, it can therefore be provided that the treatment of the solid takes place until at least 60 wt.%, in particular at least 70 wt.%, preferably at least 80 wt.%, even more preferably at least 90 wt.%, based on the weight fraction of the cement portion or total binder in the solid, has been converted.

[0150] Likewise, it is also possible for the treatment of the solid body to take place until at least 60 vol.%, in particular at least 70 vol.%, preferably at least 80 vol.%, even more preferably at least 90 vol.%, of the cement portion or total binder, based on the volume fraction of the cement portion or total binder in the solid body, have been converted.

[0151] Furthermore, it can also be provided in the process according to this aspect of the invention that the treatment of the solid is carried out until a conversion depth of at least 2 cm, more preferably at least 3 cm, particularly preferably at least 5 cm, is reached.

[0152] According to a particularly preferred embodiment of the method according to this aspect of the invention, valuable products from the reaction of the at least one acid with the cement component or total binder, in particular gypsum and / or ettringite, and / or aggregates dissolved out of the solid body, in particular aggregates, fibers and / or fillers, are recovered or recycled.

[0153] Recovery and / or recycling is preferably carried out by separation, in particular mechanical separation or rinsing, of the liquid, doughy and / or pasty phase.

[0154] The residues remaining after treatment and / or recovery or recycling, or the fragments of the solid body remaining after treatment, can be further crushed if necessary and disposed of in the usual way for construction rubble and waste. According to a preferred embodiment, the collection and / or crushing of the residues, in particular the remaining fragments of the solid body, is automated.

[0155] With regard to further possible embodiments of the second aspect of the invention according to the method, reference can also be made to the above statements on the first aspect of the invention, which apply equally to the second aspect of the invention.

[0156] Furthermore, the present invention relates - according to a third aspect of the invention - to the use of acid-producing microorganisms, in particular sulfuric acid and / or nitric acid-producing microorganisms and / or organic acid-producing microorganisms, in a dissolving and / or blasting treatment of cement-bound solid bodies, in particular concrete bodies in the form of structures, buildings, structural parts and / or building material bodies.

[0157] The use according to the invention is based on the methods according to the first or second aspect of the invention or is characterized by at least one feature of the previously described methods according to the invention. All features of the previously described methods thus also apply to the use according to the invention.

[0158] With regard to the use of acid-producing microorganisms for the dissolving or blasting treatment of cement-bound and possibly additionally reinforced solids, reference can also be made to the above statements in connection with the first and second aspects of the invention, which equally apply to the third aspect of the invention.

[0159] Finally, the present invention relates - according to a fourth aspect of the invention - to the use of acid-producing microorganisms, in particular sulphuric acid and / or nitric acid-producing microorganisms and / or organic acid-producing microorganisms, for the recovery of aggregates, in particular aggregates, fibres and / or fillers, and / or gypsum and / or ettringite from cement-bound solids, preferably from concrete bodies and / or preferably from solids in the form of structures, buildings, parts of structures and / or building material bodies.

[0160] The use according to the invention is based on the methods according to the first or second aspect of the invention or is characterized by at least one feature of the previously described methods according to the invention. All features of the previously described methods thus also apply to the use according to the invention.

[0161] In other words, the present invention also relates to a process for the recovery of aggregates, in particular aggregates, fibers and / or fillers, and / or gypsum and / or ettringite from cement-bound solids, preferably from concrete bodies and / or preferably from solids in the form of structures, buildings, parts of structures and / or building material bodies, characterized by the use of acid-producing microorganisms, in particular sulfuric acid- and / or nitric acid-producing microorganisms and / or organic acid-producing microorganisms and the features of the above-described processes according to the first and second aspects of the invention.

[0162] For further embodiments or embodiments with regard to the use of acid-producing microorganisms for the recovery of valuable materials from cement-bound valuable materials, reference can also be made to the above statements on the other aspects of the invention, which equally apply to the use according to the present aspect of the invention.

[0163] Preferred embodiments of the present invention are also described below on the basis of the exemplary embodiments, which, however, are also in no way to be understood as limiting. Examples of implementation:

[0164] To test the effectiveness of the method according to the invention, test specimens of cement-bound solids were used and treated with the previously described method for the dissolving and / or blasting treatment of cement-bound solids. The test specimens were cube-shaped mortar specimens with an edge length of 2 cm and cube-shaped concrete specimens with an edge length of 10 cm. The test setup and the results are described below: 1. Selection of acid-producing microorganisms. Sulfuric acid-producing bacteria were used to carry out the procedure for testing on test specimens. In particular, the bacteria used were the species Thiomonas (T.) intermedia (strain K12) and T. arsenitoxydans (DSM 22701) as exemplary representatives of weakly acidophilic, sulfur-oxidizing bacteria. Acidithiobacillus (A.) thiooxidans (strain K6 or strain K16 or DSM 9463) and A. ferrooxidans (strain R1 or strain R7 or DSM 14882) were used as representatives of strongly acidophilic, sulfur-oxidizing bacteria. 2. Cultivation of the bacteria and inoculation of the test specimens The cultivation of the above-mentioned microorganisms was carried out at a temperature of 29 °C (±1 °C) with active aeration of the cultures of 5 l each for weakly acidophilic, sulfur-oxidizing bacteria and 10 l for strongly acidophilic, sulfur-oxidizing bacteria. Cell harvesting was carried out in the logarithmic growth phase of the culture at a cell concentration of approximately 10 8 / ml using a refrigerated centrifuge at 10,000 × g and 10 °C. The cell pellet obtained by centrifugation was washed several times in mineral wash solution (nutrient medium without substrate). The cell pellet resuspended in the wash solution corresponded to a bacterial yield of approximately 5 × 10 11 up to 10 12 Cells / culture. The cell concentration of the concentrated culture was adjusted to the desired concentration using a wash solution to prepare an inoculum. The test specimens were inoculated with the inoculation culture, with approximately 5 × 10 7 up to 1 × 10 8 Cells per cm 2 The test surfaces were sprayed. The test specimens were inoculated six times each at intervals of one week. 3. Biofilm Examination The biofilm forming on the surface of the test specimens was examined as part of a process control study. For this purpose, the viable cell counts of the sulfuric acid-oxidizing bacteria were determined according to DIN EN ISO 8199:2008. Standardized, selective culture media according to the DSMZ (German Collection of Microorganisms and Cell Cultures) regulations and serial dilutions with statistical analysis using the most probable number technique were used. The cultures were incubated for a maximum of four weeks at a temperature of 29 °C (±1 °C). A result was considered positive if, after culturing a sample aliquot, evidence of substrate consumption or the accumulation of metabolites could be demonstrated in addition to the light microscopic detection of cells. Based on the relevant investigations, it was verified that sulfuric acid oxidizing bacteria had settled in the biofilm in high numbers of viable cells. 4. Environmental Conditions and Treatment Duration To nourish the biofilm of sulfuric acid-producing bacteria on the test specimens, the bacteria were supplied with hydrogen sulfide (H2S) as a sulfur source. The hydrogen sulfide was introduced into the area surrounding the test specimens at a concentration of 5 to 1,000 ppm, preferably 10 to 150 ppm. To ensure a humid environment, the relative humidity was set to at least 90% (condensing). The temperature was maintained at 30 to 35°C during the process. In addition, the bacteria were supplied with mineral nutrients at least once a week. A nitrogen-phosphate-potassium nutrient solution was used, which was also sprayed onto the test specimens. The nutrient solution contained 12 wt% total nitrogen, 4 wt% phosphate, 6 wt% potassium oxide, and the trace elements boron, copper, iron, manganese, molybdenum, and zinc. The treatment of the test specimens, in particular the maintenance of the environmental conditions, took place over a period of 12 months. 5. Results After 8 to 12 months of treatment, the sulfuric acid formed had led to significant corrosion and severe solid loss in the cement-bound solids. Due to the biological-chemical corrosion process, some of the test specimens had completely lost their strength and shape, as the sulfuric acid or biofilm had penetrated deep into the porous structure and led to a transformation of the cement content or the total binder in the test specimens into a doughy or mushy consistency. Fig. 2A and Fig. 3A each show a test specimen based on mortar ( Fig. 2A) and concrete ( Fig. 3A) in original condition. Fig. 2B and Fig. 3B show the condition of the same test specimens after a treatment period of 8 months ( Fig. 2B) or 12 months ( Fig. 3B). List of reference symbols: 1 solid body / concrete wall 2 Enclosure 3 Broken / Concrete residues

Claims

[1] Process for the dissolving and / or blasting treatment of cement-bound or predominantly cement-bound solid bodies in the form of structures, buildings, parts of structures and / or building material bodies, wherein the solid body is inoculated at the place of installation and / or erection, place of manufacture or place of use with an aqueous solution containing acid-producing microorganisms (inoculation culture) to form a biofilm on and / or in the solid body, wherein microorganisms are inoculated in an amount in the range of 1 × 10 4 up to 1 × 10 12 CFU / cm 2 , based on the surface of the solid to be treated, are applied or introduced onto and / or into the solid, whereby growth-promoting environmental conditions for the microorganisms are established by (i) a targeted adjustment of the temperature and / or (ii) a targeted supply of nutrients and / or substrates for the microorganisms and / or (iii) a targeted adjustment of the humidity in the area of ​​the solid body, wherein the cement portion is at least partially decomposed and / or converted by the acid formed by the microorganisms and converted from the solid phase into a liquid, doughy and / or pasty phase, and wherein aggregates contained in the liquid, doughy and / or pasty phase and / or valuable substances formed by the treatment are separated for the purposes of recovery. [2] Method according to claim 1, wherein the surface of the solid body is mechanically enlarged before inoculation, in particular wherein holes, notches and / or depressions are introduced into the solid body before inoculation and wherein, preferably, inoculation takes place at least directly in the region of the holes, notches and / or depressions, and / or wherein the solid body is subjected to mechanical comminution, preferably by blasting, drilling, impact comminution, cutting comminution, pressure comminution and / or impact comminution, before inoculation; and / or wherein the solid body, in particular the surface of the solid body to be inoculated, is dried and / or roughened before inoculation. [3] Method according to claim 1 or 2, wherein the inoculation is carried out by spraying, sprinkling and / or soaking the solid with the inoculation culture; and / or wherein a pure culture or a mixed culture of acid-producing microorganisms is used as the inoculum; and / or wherein the inoculum comprises (i) sulphuric acid-producing microorganisms, preferably sulphur oxidizers and / or thiobacteria, and / or (ii) nitric acid-producing microorganisms, in particular nitric bacteria and / or nitrifying bacteria, and / or (iii) organic acid-producing microorganisms, in particular acetic acid, lactic acid and / or citric acid-producing microorganisms; and / or inoculation of microorganisms in an amount in the range of 1 × 10 4 up to 1 × 10 10 CFU / cm 2 , especially in the range of 1 × 10 5 up to 1 × 10 8 CFU / cm 2 , based on the area of ​​the solid to be treated, are applied to and / or into the solid. [4] Method according to one of the preceding claims, wherein the relative humidity or air humidity in the surrounding area of ​​the solid body is adjusted by means of a measuring, control and / or regulating device, and wherein the surrounding area is adjusted to a relative humidity of at least 80%, preferably at least 90%; and / or wherein the temperature in the surrounding area of ​​the solid body is adjusted by means of a measuring, control and / or regulating device, and wherein the surrounding area is adjusted to a temperature of less than 20 °C or to a temperature in the range of 20 to 40 °C or to a temperature of greater than 40 °C. [5] Method according to one of the preceding claims, wherein the substrate for the acid-producing microorganisms is selected from (i) reduced and / or partially reduced sulfur compounds, in particular water-soluble or gaseous reduced or partially reduced sulfur compounds, preferably H2S and / or thiosulfates, and / or (ii) nitrogen compounds, in particular water-soluble nitrogen compounds, preferably ammonia, urea and / or ammonium salts, and / or (iii) carbon compounds, in particular starch and / or starch derivatives; and / or wherein the substrate is applied to and / or into the solid in gaseous form and / or as an aqueous solution (substrate solution). [6] Method according to one of the preceding claims, wherein the solid body is provided with a roof, cover or enclosure for protection against environmental and weather influences before or after inoculation, preferably before inoculation, completely or in sections, in particular in the area of ​​the surface of the solid body to be treated; and / or wherein a material which is at least substantially impermeable to gases and / or water vapour is used as roofing, covering or enclosure, preferably a gas- and / or water vapour-impermeable film; and / or wherein the roofing, covering or enclosure, in particular the enclosure, is attached and / or arranged in such a way that an intermediate space is formed between the enclosure and the surface of the solid body, in particular wherein the intermediate space is accessible for spraying devices and / or measuring, control and / or regulating devices. [7] Method according to one of the preceding claims, wherein the solid body has a region extending from the surface to a depth of at least 1 cm, preferably at least 2 cm, more preferably at least 3 cm, particularly preferably at least 5 cm, and / or at most 10 cm, preferably at most 8 cm, more preferably at most 6 cm, which is chemically, radioactively and / or biologically contaminated, and wherein the solid body is treated until the cement content of the solid body is at least substantially converted over the depth of the contaminated region; and / or wherein the untreated part of the solid body is subjected to further mechanical comminution and / or demolition, preferably by blasting, drilling, impact comminution, cutting comminution, pressure comminution and / or impact comminution. [8] Method according to one of the preceding claims, wherein in the liquid, doughy and / or pasty phase, in particular the suspension or slurry, aggregates, fibres and / or fillers, and / or gypsum and / or ettringite formed by the treatment, in particular blasting treatment, are separated for the purposes of recovery. [9] Process for the dissolving and / or blasting treatment of cement-bound solids, in particular building components and / or building material bodies, wherein the solid body is transported from a place of installation and / or erection, production or use to a treatment site and is inoculated with an aqueous solution (inoculation culture) containing acid-producing microorganisms to form a biofilm on and / or in the solid body, wherein microorganisms are inoculated in an amount in the range of 1 × 10 4 up to 1 × 10 12 CFU / cm 2, based on the area of ​​the solid to be treated, are applied to and / or into the solid, whereby growth-promoting environmental conditions for the microorganisms are established by (i) a targeted adjustment of the temperature and / or (ii) a targeted supply of nutrients and / or substrates for the microorganisms and / or (iii) a targeted adjustment of the humidity in the area of ​​the solid body, and wherein the cement portion of the solid body is at least partially decomposed or converted by the acid formed by the microorganisms and is converted from the solid phase into a liquid, doughy and / or pasty phase, in particular a suspension or slurry, and wherein the treatment or conversion takes place until at least 50% by weight, based on the weight of the cement portion of the solid body, has been converted and / or until a conversion depth of at least 1 cm is reached. [10] Use of acid-producing microorganisms, in particular sulphuric acid and / or nitric acid-producing microorganisms and / or organic acid-producing microorganisms, in a process according to one of the preceding claims for the recovery of aggregates, in particular aggregates, fibres and / or fillers, and / or gypsum and / or ettringite from cement-bound solids, preferably from concrete bodies and / or preferably from solids in the form of structures, buildings, parts of structures and / or building material bodies.

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