Biosorbents and methods for extracting metals

Abstract

The present invention provides a bio-adsorbent for extracting metals from a solution comprising metals, comprising one or more of a mycomucor fungus and a biomass prepared or processed from the mycomucor fungus; there is provided a bio-adsorbent for extracting a metal from a metal-containing solution comprising one or more of a fungus and a biomass produced from the fungus wherein the biomass is hydrophilic and has a zero charge point (pHPZC) corresponding to the pH of the metal-containing solution; and a method of extracting metal from a metal-containing solution comprising contacting the metal-containing solution with a filter comprising the bio-adsorbent of the invention.

Description

Field of the Invention

[0001] The present invention provides a biosorbent for extracting a metal from a solution containing a metal, comprising one or more of a fungus of the phylum Mucoromycota and a biomass produced from a fungus of the phylum Mucoromycota; a biosorbent for extracting a metal from a solution containing a metal, comprising one or more of a fungus and a biomass produced from a fungus, wherein the biomass is hydrophilic and has a point of zero charge (pHPZC) corresponding to the pH of the solution containing the metal; and a method of extracting a metal from a solution containing a metal, comprising contacting a solution containing a metal with a filter comprising the biosorbent of the present invention. Background of the Invention

[0003] Wastewater and industrial water often carry metals. Some of these metals are toxic (e.g., heavy metals), but others are economically valuable (e.g., critical metals). Therefore, there is a need to efficiently and continuously extract metals (especially aluminum (Al), calcium (Ca), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), nickel (Ni), zinc (Zn), and vanadium (V)) from metal-containing solutions so that the metals can be reintroduced into industrial circuits.

[0004] Current state of the art

[0005] Clean TeQ Water's so-called The technology is highly efficient in extracting and purifying a range of metals from slurries and solutions. The technology is a combination of continuous ion exchange and countercurrent ion exchange, in which the resin and slurry / solution continuously move in the system and are in direct contact with each other in a countercurrent manner. This achieves an extraction rate of metals contained in the solution that is typically greater than 98%, and provides an economically viable method for recovering and concentrating dilute streams.

[0006] CLEAN-IX metal recovery technology achieves very high eluate concentrations by providing a customized flowsheet where each ion exchange process step is performed in a dedicated vessel with specified dimensions optimized for the task.

[0007] However, such conventional systems are complex and a need remains to provide methods and means for efficient recycling in a rapid, cost-effective and more environmentally friendly manner. SUMMARY OF THE INVENTION

[0009] The present invention provides a sustainable approach based on the use of microorganism-inorganic interactions (i.e., fixation of metals in solution; a process known as biosorption). Biosorption is sustainable because it is comparable to non-biological methods such as Clean TeQ Water's Compared to other technologies, biosorption methods can advantageously provide a lower carbon footprint.

[0010] In particular, the present invention provides a biosorbent for extracting metals from a solution comprising the metals, comprising one or more of a Mucor fungus and a biomass prepared (or processed) from a Mucor fungus. In one embodiment, the Mucor fungus is Mucor moelleri, in particular The strain NEUM140 identified by ID accession number MZ374564. Other preferred examples of fungi from the phylum Mucor are Mucor hiemalis, especially strain NEUM 144 identified by ID accession number OR478153, and M. saturninus, especially by Bacterial strain NEUM 172 confirmed by ID accession number OR478154. In another embodiment, biomass is produced by culturing Mucor fungi in a culture medium comprising glucose, dextrose or glycerine, and the culture medium is a carbon source for the growth of microorganisms (or Mucor fungi). Glycerine or crude glycerine are the main byproducts when producing biodiesel, and can be used as a carbon source for the growth of Mucor fungi. Here, the metal can be one or more metals selected from aluminum (Al), calcium (Ca), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), nickel (Ni), zinc (Zn) and vanadium (V).

[0011] The present invention also provides a biosorbent for extracting metals from a solution containing metals, comprising one or more of a fungus and a biomass prepared or processed from a fungus, wherein the biomass is hydrophilic and has a point of zero charge (pH 5.0) corresponding to the pH of the solution containing the metals. PZC In one embodiment, the zero charge point (pH) corresponding to the pH of the solution comprising the metal PZC ) is pH 2 to 8. In another embodiment, the fungus is a Mucor fungus. In another embodiment, the Mucor fungus is an oospore fungus, especially composed of Other preferred examples of fungi from the phylum Mucor are the fungi Mucor spp., especially those from strain NEUM 144 identified by accession number OR478153, and Mucor saturniformis (Mucor saturniformis), especially by The strain NEUM172 confirmed by accession number OR478154. Biomass can be produced by culturing fungi in a medium comprising a carbon source such as glucose, dextrose or glycerol or crude glycerol. In addition, the metal can be one or more metals selected from aluminum (Al), calcium (Ca), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), nickel (Ni), zinc (Zn) and vanadium (V).

[0012] In addition, the present invention provides a method of extracting a metal from a solution comprising a metal, comprising contacting the solution comprising a metal with a filter comprising a biosorbent, the biosorbent comprising one or more of a Mucor fungus and a biomass prepared or processed from a Mucor fungus. In one embodiment, the filter comprises a membrane comprising the biosorbent. In another embodiment, the membrane further comprises a fabric. The membrane may be prepared from the biosorbent using electrospinning. In another embodiment, the filter is a bead or hollow spherical cavity comprising the biosorbent. In another embodiment, the filter comprises a plurality of hollow spherical cavities of 0.05-1 mm, preferably 0.1-0.5 mm, wherein the biosorbent is contained within the cavity. The hollow spherical cavities may comprise a polymeric material (e.g. polypropylene), a metallic material (based on Al), a non-metallic material (based on Si) and / or a ceramic material (silicon dioxide or aluminum oxide).

[0013] The present invention also provides a method of extracting a metal from a solution comprising the metal, comprising contacting the solution comprising the metal with a filter, beads or compact column comprising a biosorbent, the biosorbent comprising one or more of a fungus and a biomass prepared or processed from a fungus, wherein the biomass is hydrophilic and has a point of zero charge (pH 50) corresponding to the pH of the solution comprising the metal. PZC ). In one embodiment, the fungus is a fungus of the phylum Mucor. In one embodiment, the filter comprises a membrane comprising a biosorbent. In another embodiment, the membrane further comprises a fabric. In another embodiment, the filter comprises a porous material. In one embodiment, the filter comprises a porous polymer, such as polypropylene. In another embodiment, the filter comprises a porous material such as metal, ceramic. In one embodiment, the filter is a bead or compact column comprising a biosorbent. In another embodiment, the membrane is prepared from the biosorbent using electrospinning. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figures 1A, 1B and 1C show data relating to the amount of residual metal and adsorption capacity.

[0016] Figure 2 (ac) shows the pH of Mucor moelleri (NEUM140), Mucor saturnius (NEUM144) and Mucor hiemalis (NEUM172) PZC .

[0017] Figure 3 represents the results of biosorption experiments (mg vanadium / kg biomass).

[0018] Figure 4 Represents a custom built packed bed reactor with a porous filter (sponge) containing the biosorbent (Ootospores were inoculated inside the sponge).

[0019] Figure 5 Represents the different removal rates (% of metal removed by fungal biosorption over time (min)) obtained during the continuous flow experiment with Oosporium sp.

[0020] definition

[0021] Although any method or material similar or equivalent to that described herein can be used for the practice or testing of the embodiments described herein, some preferred methods, compositions, devices and materials are described herein. However, before describing the materials and methods of the present invention, it should be understood that the disclosure herein is not limited to the specific molecules, compositions, methods or models described herein, as these can vary according to routine experiments and optimizations. It should also be understood that the terms used in this specification are only for describing specific aspects or embodiments and do not limit the scope of the embodiments described herein.

[0022] Unless otherwise defined, all technical and scientific terms described herein have the same meaning as those conventionally understood by those of ordinary skill in the art to which this document belongs. However, in the event of a conflict, the contents of the present specification (including definitions) shall prevail. Therefore, the following definitions apply in the embodiments described herein.

[0023] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural forms unless expressly stated otherwise.

[0024] As used herein, the term "comprising" and its expression variants indicate the presence of the mentioned features, elements, method steps, etc., but do not exclude the presence of additional features, elements, method steps, etc. In contrast, the term "consisting of" and its expression variants indicate the presence of the mentioned features, elements, method steps, etc., and exclude any unmentioned features, elements, method steps, etc., except for conventionally related impurities. The phrase "consisting essentially of" indicates the mentioned features, elements, method steps, etc. and any additional features, elements, method steps, etc. that do not substantially affect the basic properties of the composition, system or method. Many embodiments herein are described using the open-ended term "comprising". These embodiments encompass embodiments described by multiple closed terms "consisting of" and / or "consisting essentially of", which are optionally stated or described using these terms.

[0025] As used herein, the term "biosorbent for extracting metals from solutions" refers to an agent capable of sorbing metals from solutions containing the metals and other materials, preferably as a complex.

[0026] The term "biomass prepared (or processed) from Mucor fungi" as used herein means biomass obtained by autoclaving and / or washing a liquid culture of Mucor fungi, and drying and / or grinding it to obtain a powder.

[0027] As used herein, the term "Mucocormycetes" refers to a clade or phylum within the kingdom Fungi and includes groupings of various molds. These clades include at least the oospore molds, especially those consisting of strain NEUM140 identified by accession number MZ374564; Mucor spp., especially from strain NEUM144 identified by accession number OR478153; and Mucor saturnusus, especially The strain NEUM172 was confirmed by accession number OR478154.

[0028] The term "biomass produced from a Mucor fungus (or fungi)" as used herein refers to a substance produced from a Mucor fungus (or fungi) while culturing the Mucor fungus (or fungi).

[0029] The term "hydrophilicity" as used herein refers to a physicochemical property wherein a material, in particular a fungal surface of the present invention, has an affinity for solutions whose solvent is water (H2O), as represented by a water contact angle of less than 60° or preferably less than 45°.

[0030] As used herein, the term "point of zero charge (pH) corresponding to the pH of a solution containing a metal" PZC )" refers to the pH when the net charge of the entire particle surface (i.e., the surface of the adsorbent) is zero.

[0031] The term "electrospinning" as used herein refers to a method for producing ultrafine (nanometer) fibers, in which a polymer melt or solution is charged and ejected through a spinneret under a high voltage electric field and solidified or coagulated to form filaments.

[0032] The terms "about", "approximately", "at or about", and "substantially" used herein indicate that the amount or value mentioned may be an exact value, or a value that can provide an equivalent result or effect as described in the claims or teachings herein. That is, it should be understood that these amounts, dimensions, formulas, parameters, and other quantities and features are not exact and do not need to be exact, but can be approximate and / or larger or smaller as needed, reflecting tolerances, conversion factors, rounding, detection errors, etc., as well as other factors known to those skilled in the art that can obtain equivalent results or effects. In some cases, it is not possible to reasonably determine the value that can provide an equivalent result or effect. In these cases, unless otherwise specified or implied, the "about" and "at or about" used are generally understood to represent a nominal value with a deviation of ±10%. In general, in the case where the amount, dimension, formula, parameter, or other amount or feature is "about", "approximately", "at or about", it does not matter whether it is explicitly stated. It should be understood that when "about", "approximately" or "at or about" is used before a quantitative value, unless otherwise specifically stated, the parameter also includes the specified quantitative value itself. DETAILED DESCRIPTION OF THE INVENTION

[0034] Biosorbent for extracting metals from solutions containing metals

[0035] The present invention provides a biosorbent for extracting a metal from a solution containing the metal, comprising one or more of a Mucor fungus and a biomass prepared (or processed) from a Mucor fungus. Here, the metal can be extracted (or recovered) from the solution by adsorbing the metal to the biosorbent. In one embodiment, the Mucor fungus can be an Oospore mold. Oospore mold has been isolated from a soil sample from Creux-du-Van (Neuchatel, Switzerland) at the Microbiology Laboratory of the University of Neuchatel and is included in the accession number MZ374564 on July 2, 2021. The Gene Sequence Database of the National Center for Biological Information (located at 8600 Rockville Pike, Bethesda, MD 20894, USA).

[0036] In another embodiment, the biomass is produced by culturing Mucor fungi in a culture medium comprising glycerol. In one embodiment, the prepared (or processed) biomass is produced by autoclaving and / or washing a liquid culture of Mucor fungi and drying and / or grinding it into a powder.

[0037] In another embodiment, biomass can be pre-treated (pre-adjusted) with acidic and alkaline solutions, or without these acidic and / or alkaline solution pre-treatments. In addition, the rehydration step of biomass can be carried out. But, in the claimed method, there is no such rehydration step. Here, metal can be one or more metals selected from aluminum (Al), calcium (Ca), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), nickel (Ni), zinc (Zn) and vanadium (V).

[0038] The present invention also provides a biosorbent for extracting a metal from a solution containing the metal, comprising one or more of a fungus and a biomass prepared or processed from the fungus, wherein the biomass is hydrophilic and has a zero charge point (pH 50) corresponding to the pH of the solution containing the metal. PZC Here, the zero charge point (pH) corresponding to the pH of the solution containing the metal PZC ) may be pH 2 to 8. In one embodiment, the metal concentration in the solution is about 2 to 5 mg / L. In one embodiment, the fungus is a Mucor fungus. In another embodiment, the Mucor fungus is Oospore Fungus (NEUM 140), preferably corresponding to The strain with accession number MZ374564. Another preferred example of the fungus of the phylum Mucor is Mucor terrestris (NEUM 144), preferably corresponding to strains of accession number OR478153; and Mucor saturnusus (NEUM172), preferably corresponding to The strain with accession number OR478154. The biomass may be produced by culturing the fungus in a medium comprising glycerol. In one embodiment, the biomass is produced by autoclaving and / or washing a liquid culture of a Mucor fungus and drying and / or grinding it into a powder.

[0039] In addition, the metal may be one or more metals selected from aluminum (Al), calcium (Ca), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), nickel (Ni), zinc (Zn) and vanadium (V).

[0040] Process for extracting metals from solutions containing metals

[0041] The present invention also provides a method for extracting a metal from a solution containing the metal, comprising contacting the solution containing the metal with a filter, beads or compact column containing a biosorbent, the biosorbent comprising one or more of a Mucor fungus and a biomass prepared (or processed) from a Mucor fungus. Here, the metal may be extracted (or recovered) from the solution by adsorbing the metal to the biosorbent. Contacting the solution with the filter may include any method of exposing the biosorbent to a solution containing the metal to adsorb the metal to the biosorbent. In one embodiment, this may be performed by passing the solution containing the metal through a filter, over beads or through a compact column, the filter, beads or compact column comprising the biosorbent. In one embodiment, a circulating flow may be used to expose the biosorbent to the solution containing the metal. However, the circulating flow ensures that no desorption of the metal occurs. In another embodiment, a parallel flow or a combination of multiple filters may be used to expose the biosorbent to the solution containing the metal. In this case, the filter may be a membrane filter made of or containing the biosorbent, or a membrane filter in which the biosorbent is immobilized. The membrane may further comprise a fabric. In this case, the fabric may be a waste material that serves as a physical substrate for microbial growth but does not contain any bioavailable / bioacceptable carbon for growth. In one embodiment, the membrane is prepared from a biosorbent using electrospinning. Alternatively, the filter may be a bead or compact column comprising a biosorbent. In this case, the bead or compact column may, for example, comprise the biosorbent on one or more of its surfaces. In one embodiment, the beads and compact column may be hydrophilic and / or porous. The porous compact column may comprise a polymeric material, such as a sponge comprising polypropylene. In another embodiment, the fungus of the phylum Mucor is an oospore mold, especially composed of The strain NEUM140 identified by accession number MZ374564. Another preferred example of a fungus from the phylum Mucor is Mucor terrestris (NEUM144), preferably corresponding to strains of accession number OR478153; and Mucor saturnusus (NEUM172), preferably corresponding to The strain of accession number OR478154. Biomass can be produced by culturing fungi in a culture medium comprising glucose or glycerol or crude glycerol. In one embodiment, biomass is produced by autoclaving and / or washing a liquid culture of a Mucor fungus, and drying and / or grinding it into powder. In another embodiment, biomass can be pretreated with acidic and alkaline solutions, or not pretreated. In addition, the metal can be one or more metals selected from aluminum (Al), calcium (Ca), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), nickel (Ni), zinc (Zn) and vanadium (V).

[0042] The present invention also provides a method for extracting a metal from a solution comprising the metal, comprising contacting the solution comprising the metal with a filter, beads or compact column comprising a biosorbent, the biosorbent comprising one or more of a fungus and a biomass prepared (or processed) from a fungus, wherein the biomass is hydrophilic and has a point of zero charge (pH 5.0) corresponding to the pH of the solution comprising the metal. PZC ). Here, the metal may be extracted (or recovered) from the solution by adsorbing the metal to the biosorbent. The contacting of the solution with the filter, beads or compact column may include any method of exposing the biosorbent to a solution containing the metal to adsorb the metal to the biosorbent. In one embodiment, this may be performed by flowing the solution containing the metal through a filter, over beads or through a compact column, the filter, beads or compact column containing the biosorbent. In one embodiment, a circulating flow may be used to expose the biosorbent to the solution containing the metal. In this case, the filter may be a membrane filter, which is made of or contains the biosorbent, or the biosorbent is immobilized in the membrane filter. The membrane may also contain a fabric. In this case, the fabric may be a waste material, which serves as a physical matrix for the growth of microorganisms, but does not contain any bioavailable / bioacceptable carbon for growth. In one embodiment, the membrane is prepared from the biosorbent using electrospinning. Alternatively, the filter may also be a bead or compact column containing the biosorbent. In this case, the bead or compact column may, for example, contain the biosorbent on one or more of its surfaces. In one embodiment, the beads and compact column may be hydrophilic and / or porous. The porous compact column may comprise a polymer material, such as a sponge comprising polypropylene. Here, the zero charge point (pH) corresponding to the pH of the solution comprising the metal PZC ) may be pH 2 to 8, preferably pH 2 to 5. In one embodiment, the metal concentration in the solution is about 2 to 5 mg / L. In one embodiment, the fungus is a Mucor fungus. In another embodiment, the Mucor fungus is Oospore Fungus (NEUM 140), preferably having The strain with accession number MZ374564. Another preferred example of the fungus of the phylum Mucor is Mucor terrestris (NEUM 144), preferably corresponding to strains of accession number OR478153; and Mucor saturnusus (NEUM172), preferably corresponding to The strain of accession number OR478154. Biomass can be produced by cultivating fungi in a culture medium comprising glucose or glycerol. In one embodiment, biomass is produced by autoclaving and / or washing the liquid culture of the Mucor fungus and drying and / or grinding it into powder. In addition, the metal can be one or more metals selected from aluminum (Al), calcium (Ca), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), nickel (Ni), zinc (Zn) and vanadium (V). The present invention is described below by the following examples and with reference to the accompanying drawings, which are all preferred, but do not limit the preferred embodiments of the present invention. Example

[0043] Example 1. Determination of the adsorption capacity of biosorbents for metals

[0044] Biomass synthesis / preparation

[0045] The preparation of fungal biomass is shown in Figure 1. This process is suitable for all Mucor strains used in this project (NEUM140 corresponding to M. moelleri, which is the most commonly used strain in the experiments of this project; NEUM144 corresponding to Mucor saturnalis; NEUM172 corresponding to Mucor terrestris).

[0046] First, the asexual spores of Mucor are transferred to a reactor with stirring and baffles together with the culture medium. The culture medium is composed of two main components (potato starch and D (+) -glucose- or dextrose). The ratio of potato infusion powder and glucose used is preferably 4g / L and 20g / L respectively. Glycerol can replace the glucose on the culture medium. The mixture of spores and culture medium is kept at room temperature (22-25 ° C) and stirred at 120rpm. The total residence time is 4 to 8 days, preferably 7 days. After the cultivation step is completed, the resulting biomass is transferred to the autoclave treatment step, where the mixture is heated at 121 ° C for 20 minutes.

[0047] The slurry resulting from the autoclave treatment step is then transferred to a filtration unit (preferably a disc or pressure filter) where solid-liquid separation is performed followed by a washing step. The washing step is performed using double distilled water, wherein the ratio of slurry to water is preferably 1:5. After the washing step, the remaining solid material is transferred to a drying step. Drying is performed according to conventional heating techniques to achieve less than 1% moisture. The temperature used for the drying step is 60°C and the total residence time is 4 to 48 hours, preferably 24 hours. The dried biomass is then transferred to a grinding step where the material is comminuted into a powder. Using A homogenizer performs the grinding step. The resulting biomass can then be used in the metal adsorption step.

[0048] According to a preferred embodiment, the biomass used in the biosorbent of the present invention is obtained from the fungus Oosporium (Mucor phylum) in potato-dextrose broth (20 g.l -1 D-glucose, 4 g.l -1 Potato starch) in liquid culture, the liquid culture is processed by autoclave, freeze-dried and ground to form a thin powder. Intermittent experiments are carried out in 250 ml conical bottles at room temperature on a rotary shaker (120 rpm) for 30 minutes with 100 mg of the prepared biomass. A vacuum pump is used to separate biomass from solution via a cellulose membrane of 0.1-0.5 μm (preferably 0.2-0.25 microns), the cellulose being, for example, nitrocellulose or cellulose acetate.

[0049] Contact angle measurement

[0050] Water contact angle is used to evaluate the hydrophobicity of Mucor mycelium. For this reason, asexual spores are inoculated in 20 ml malt broth (12 g / L) placed in a 50 ml Schott bottle. Cultures are cultivated on a rotary shaker (120 rpm) at room temperature and constant stirring until the presence of biomass can be seen by the naked eye. The fungi used for this study are: Aspergillus niger, oospore inoculation, frozen soil Mucor, Saturn-shaped Mucor, Beauveria bassiana, B. caledonica, B. brongniartii, Penicillium commune, P. brevicompactum and P. spinulosum.

[0051] The resulting biomass consisting of mycelial pellets was recovered through a sieve, transferred to saline (0.9% NaCl), and used The resulting suspension was centrifuged at 5000 rpm for 5 minutes and the supernatant was discarded. The mycelial pellet was washed with 5 ml of saline and centrifuged as above. Finally, the biomass was resuspended in 5 ml of saline and deposited onto a nitrocellulose filter (pore size 0.45 μm, filter diameter 2.5 mm) by vacuum filtration. ) on the surface.

[0052] Dried biomass was also evaluated. To this end, the biomass obtained from the liquid culture was sieved, autoclaved at 121°C for 20 minutes, and dried at 60°C for 48 hours. The biomass was then crushed into a powder using a mortar and pestle. The powder was then placed on a belt to measure the contact angle according to techniques known in the art.

[0053] Then, the contact angle of the biomass on the surface of a 30 μL water droplet was measured using a goniometer connected to a camera. The contact angle measured for the Mucor mycelium was less than 60°.

[0054] Zero pH (pH PZC )

[0055] The purpose of this experiment is to determine the pH at which the biomass reaches its zero charge point, in other words, the pH at which there is a perfect balance between the negative and positive charges on the biomass surface. The biosorption of favorable anions and cations is determined at specific pH values. PZC The maximum adsorption of vanadium ions was obtained at pH 4.5 in solution using the prior art described in Saudi Journal of Biological Sciences 25.8 (2018): 1664-1669.

[0056] 25 ml of 0.1 M NaCl was used and NaOH or HCl was added until the desired pH was reached, resulting in solutions of pH 2, 3, 4, 5, 6, and 8. To each of these solutions was added 0.05 g of the prepared fungal biomass and placed on a rotary shaker at 120 rpm for 24 hours. The initial and final pH were measured to calculate the pH PZC Similar to the contact angle assay, multiple fungal species were tested, including those belonging to the phylum Mucor. Two Mucor species showed pH pzc The pH values ​​of the test strains were about 4.5 (4.62 for Oospore Fungus (NEUM140) and 4.66 for Mucor sutchuenensis (NEUM144). Figure 2 (ac) shows the pH values ​​of the test strains Oospore Fungus (NEUM140), Mucor sutchuenensis (NEUM144) and Mucor sutchuenensis (NEUM 172). pzc .

[0057] Adsorption kinetics (determination of minimum contact time / extraction)

[0058] To determine the adsorption kinetics, the inventors prepared multiple batches of Mucor biomass, which had been stored at 4°C until further use. Solutions containing 1 ppm or 3.5 ppm vanadium ions (sodium orthovanadate (Na3VO4) or vanadium (III) chloride or (VCl3)) were prepared using double distilled water at a pH set to 4.5 to avoid the presence of any other metals. These solutions containing both vanadium ions were also compared with actual process water containing 3.5 ppm vanadium ions. In other words, the process water from industrial chemical synthesis had an initial vanadium concentration of 3.5 mg / L and a pH of 4.5.

[0059] Biosorption experiments

[0060] To examine the effect of time on vanadium adsorption, 0.1 g of the prepared biomass was added to 25 ml of vanadium solution and shaken at 120 rpm at room temperature for 30, 180, 360 and 480 minutes. The control was shaken for 120 minutes under the same conditions.

[0061] After the biomass was contacted with the vanadium solution for a given time, the sample was vacuumed via a 47 mm cellulose membrane to separate the biomass from the liquid phase. The metal content of both fractions was analyzed using ICP-OES. The liquid phase sample was acidified with HNO3 in advance, and the biomass sample was first mineralized to dissolve the organic material. The analysis results are shown in Figure 3.

[0062] The adsorption capacity of the resulting biosorbent (the Oospore biomass described above) was evaluated using the following vanadium-containing solutions: 1) process water from industrial chemical synthesis, which had an initial vanadium concentration of 3.5 mg / L and a pH of 4.5; and 2) a solution of Na3VO4 dissolved in double distilled water (referred to as V solution in Figures 1A, 1B and 1C), which had a vanadium concentration of 3.5 mg / L and a pH of 4.5.

[0063] As shown in Figures 1A, 1B and 1C, where "Control" refers to the experimental run without biomass and "Fungus" refers to the run containing the prepared Oospore mold, the biosorbent (Fungus) removed vanadium from both process water and Na3VO4 solution (Figure 1A), corresponding to approximately 75-78% of the vanadium in solution (Figure 1B). The adsorption capacity (mg / g) was similar to other biosorbents described in prior scientific literature (Figure 1C).

[0064] After contacting with vanadium solution (1ppm), the biomass prepared by Oospore Inoculum adsorbs vanadium ions. After contacting with this biomass for 30 minutes, the vanadium in the solution significantly reduces. On the contrary, the vanadium ion concentration in the solid biomass increases rapidly, and reaches a platform between 20mg vanadium and 25mg vanadium for 1kg biomass after 180 minutes, as shown in Figure 3c. Then, no significant changes in vanadium concentration are found in liquid or biomass fractions after 3 hours.

[0065] The adsorption capacity (Q mg / g) and adsorption rate (R%) of Oospore mold were defined using the following formulas (1) and (2):

[0066]

[0067] Where Q (mg / g) is the adsorption capacity, R (%) is the adsorption rate, v is the volume of the solution (L), M is the mass of the biosorbent (g), C0 is the V concentration before adsorption (mg / L), and C is the V concentration after adsorption (mg / L). The adsorption capacity is defined as the amount of adsorbate (vanadium or other metal ions) extracted by a unit mass of adsorbent (per gram of Oospore mold). In other words, the adsorption capacity is the amount of metal (mg) that Oospore mold (g) can adsorb.

[0068] An increased metal concentration in solution is shown by the release of metal ions from the biomass in solution, so the biomass desorbs the metal. Conversely, a decrease in metal ions in solution represents the adsorption of the metal by the biomass. A positive adsorption capacity (Q>0) represents an adsorption phenomenon; a negative adsorption capacity (Q<0) represents a desorption phenomenon. The adsorption capacity and adsorption rate are adapted to the biomass value by converting the biomass value into its inverse value.

[0069] Vanadium has been adsorbed from the solution by the solid biomass and after 3 hours 50-60% of the vanadium ions in the solution have been adsorbed at the surface of the biomass prepared by A. oosporum. In accordance with the increase of vanadium in the prepared biomass, the vanadium concentration in the solution decreases.

[0070] The adsorption capacity of Oosporium is promising: using only 0.1 g of dry biomass, more than 10% of its weight can be extracted in 30 minutes. With the removal rate showing a rapid increase towards 60% vanadium removal, longer exposure between biomass and solution can increase to 70% or more.

[0071] Example 2. Preparation of a filter containing a biosorbent

[0072] (1) Hydrophilic membrane filter containing biosorbent

[0073] A hydrophilic membrane filter (hydrophilic hyphae mat of Oospore Inonotus) was prepared by the following steps.

[0074] (i) Preparation of viscous alkaline liquid medium (VBLM): 30 g / L starch, 80

[0075] g / L syrup, 10g / l Neopeptone and 2g / l yeast extract.

[0076] (ii) Prepare small pieces of tissue or fabric in glass petri dishes and spray with VBLM until completely impregnated.

[0077] (iii) Dry it under a laminar flow hood and autoclave it.

[0078] (iv) Inoculate with an asexual spore suspension containing 103 spores / mL (try to evenly distribute the spores over the tissue surface).

[0079] (v) Incubate at room temperature (RT) in the absence of light.

[0080] (2) Membrane filter containing biosorbent in the form of electrospunned powder

[0081] A membrane filter containing the biosorbent in the form of an electrospun powder (electrospun powder of dried and dead Oosporium biomass) was prepared as follows.

[0082] Polycaprolactone (PCL) (Mw = 80,000 gmol) was purchased from Sigma-Aldrich (Switzerland). -1 ), glacial acetic acid (AA, 99%), formic acid (FA, ≥ 95%) and tetraethylammonium bromide (TEAB, 98%). Polyurethane was obtained from BASF (Germany). (Elastollan C95A55,Mw85,790g mol -1 ), and dimethylformamide (DMF, ≥99.8%) was obtained from VWR Company (France). The spinning solution of 15% w / v PCL was prepared by dissolving PCL in a mixture of AA / FA (3:1), while the spinning solution of 14.5% w / v polyurethane (PUR) was prepared by dissolving PUR in pure DMF solvent. In addition, 0.01% v / v TEAB was added to the PUR solution to improve its conductivity. To prepare melanin blend membranes (PCL / Mel and PUR / Mel), fungal melanin powder was added to the solvent and precipitated with Branson Ultrasonics. TM The ultrasonic instrument (Sonifier) ​​250 / 450 was dispersed at 83.3W and 30% amplitude for 20 minutes. The ultrasonic treatment was alternated with a 2s stop and a treatment under an ice cooling step. The polymers (PCL and PUR) were then added and kept shaking for 24 hours to obtain a homogeneous solution. The fiber membrane was prepared on a laboratory scale, and a Nanospider electrospinning instrument (NS1WS500U, Elmarco, Czech Republic) was not necessary. In this setup, the solution reservoir is continuously moved along the wire source electrode and a thin film of the solution is deposited thereon. A high electric field is applied to form multiple Taylor cones along the wire; the electrospinning jet is pulled toward the wire counter electrode, and the fibers are deposited onto a paper substrate located in front of the counter electrode.

[0083] (3) Fabric membrane filter containing biosorbent

[0084] Fabric membrane filters containing biosorbents were prepared as follows.

[0085] Waste fabric is cut into a disk with a diameter of 47mm. These fabrics are autoclaved to ensure aseptic. Then, these fabrics are placed on a 6cm petri dish containing potato dextrose agar (4g / L potato extract, 20g / L glucose, 15g / L agar). Use Pasteur (Pasteur) pipette to cut the oospore inoculation culture into small pieces (about 5-7mm diameter) and place on the fabric disk. They are left standing until colonization in the whole culture dish, especially fabric. Gently take out the fabric, and place in a glass culture dish, then autoclave. The inoculated fabric is used as a filter in the column. Use a water pump to make process water flow into the column with 1,2 or 3 layers, until the maximum amount of vanadium is removed from the process water.

[0086] (4) Beads containing biosorbent

[0087] The beads containing the biosorbent were prepared by culturing Oospore Fungus under constant stirring to induce pelletization of the biomass, whereby three-dimensional fungal growth occurred, allowing to obtain pellets of millimeter size and round shape formed by the mycelial network.

[0088] (5) Porous polypropylene sponge filter containing biosorbent

[0089] Polypropylene sponge filters containing biosorbent were prepared as follows:

[0090] Polypropylene sponges were cut into cubes of 10mm x 10mm x 10mm. The sponges were autoclaved to ensure sterility. These sponges were then placed on a 6 cm petri dish containing potato dextrose agar (4 g / L potato extract, 20 g / L glucose, 15 g / L agar) and spores at a spore concentration of 1000 spores / mL. 1 mL of spore suspension was dripped onto each sponge using a pipette. They were left to stand until colonization throughout the culture dish, especially the sponges. This process was performed for about 4 weeks. The sponges were gently removed and placed in a glass culture dish and then autoclaved. The inoculated sponges were used as filters in the column ( Figure 4 ). The process water is pumped through a column having 1, 2 or 3 layers until the maximum amount of vanadium is removed from the process water.

[0091] Example 3: Metal selectivity of Oospore Fungus

[0092] In order to detect the metal selectivity of biomass prepared by Oospore Inonotus, aluminum sulfate hexahydrate, calcium chloride dihydrate, potassium chromate, magnesium chloride hexahydrate, manganese (II) sulfate monohydrate, iron (III) chloride, cobalt (II) sulfate heptahydrate, nickel (II) sulfate hexahydrate, cupric chloride dihydrate, and zinc sulfate heptahydrate were used to prepare solutions with a pH of 4.5 containing 3.5 ppm of the following metal ions in double distilled water: Al, Ca, Cr, Mg, Mn, Fe, Co, Ni, Cu, and Zn.

[0093] The pre-adsorption conditions were 30 minutes of contact time, 100 mg of biomass in 25 mL of process water, 25 ° C, 120 rpm. 100 ml of 0.1 M raw material solution was prepared from these products. Then, dilution was performed to obtain a 200 ml solution with a metal concentration of 3.5 ppm. For each metal, three reference products (without biomass) and three treatment (containing biomass) solutions were prepared. 100 mg of the prepared biomass was added to three 200 ml "biomass" conical flasks. 25 ml of the prepared metal solution was added to all six conical flasks (200 ml) and installed on a rotary shaker under the conditions. After the contact time, these solutions were filtered through a 0.45 μm filter to recover the biomass. 10 ml of the solution was used for ICP-OES analysis. The biomass was left to dry at 60 ° C and analyzed by ICP-OES. The analysis results are shown in Table 1.

[0094] Table 1: Average adsorption capacity (Q), removal ratio of metals from solution by biomass (R).

[0095] element Q(mg / g) R(％) K Al 0.686 78.694 0.93 Ca -0.725 -108.576 - Co 0.466 54.701 0.31 Cr 0.170 20.403 0.06 Cu 0.775 98.141 13.21 Fe -0.420 -51 298.411 - Mg -0.020 -3.081 - Mn 0.262 34.875 0.14 Ni 0.533 66.481 0.50 Zn 0.739 94.748 4.54 V 0.690 80.178 1

[0096] The selectivity coefficient is defined as:

[0097]

[0098] Here, the symbol “s” represents the ion concentration on the biomass (mg / g), and aq represents the ion concentration in the solution (mg / l).

[0099] The selectivity coefficient determines the affinity of the adsorbent (biomass) for ion B relative to ion A (vanadium ion). As a result, for K>1, the resin prefers ion B, while for K<1, the resin prefers ion A. In the case of K equal to 1, the ion exchanger has no preference for ion A or ion B. Therefore, the selectivity of the Oosporium strain for these metals is: Cu>>>Zn>>V>Al>Ni>Co>Mn>Cr>Mg,Fe,Ca.

[0100] Example 4: Adsorption using Mucor species.

[0101] The purpose of this research is to detect two additional Mucor strains: frozen soil Mucor (NEUM144) and Saturn-shaped Mucor (NEUM172). The solution tested in this research is process water from Belenos, and 3.5ppm and 100ppm of artificial V solution. Fungal biomass is first grown, autoclaved, freeze-dried and ground into thin powder. Then, 100mg of fungal powder is added in a 150ml conical flask equipped with 25ml of corresponding solution. These conical flasks are stirred for 30 minutes at 120rpm, then filtered via a 0.22μm cellulose filter.

[0102] The adsorbent was placed in a 15 ml Falcon tube and placed at 60°C until completely dry. The filtered solution was separated into two 15 ml Falcon tubes: the first tube contained 10 ml of solution as a backup and the second tube contained 4 ml of solution. The latter was diluted with 8 ml of 2% HNO3. All samples were stored in a cold room until further processing.

[0103] It was demonstrated that both NEUM144 and NEUM172 had the ability to adsorb vanadium in all tested systems. Oospore mold showed the best performance in the two systems tested (3.5ppm and 100ppm vanadium), extracting 78.5% and 71.6%, respectively. When exposed to a solution containing 3.5ppm vanadium, NEUM144 showed similar adsorption performance. When exposed to a solution containing 100ppm vanadium, NEUM144 and NEUM172 had similar and poorer adsorption performance.

[0104] Example 5: Continuous flow experiment using oospore inoculation

[0105] Continuous flow experiments were conducted in a reactor using a porous polypropylene sponge filter containing a biosorbent capable of immobilizing biomass for the biosorption process to adsorb metal ions of Al, Ca, Cr, Mg, Mn, Fe, Co, Ni, Cu, Zn, and V. The flow conditions are shown in Table 2.

[0106] Table 2: Continuous reactor parameters

[0107] parameter Reactor using porous filter flow 4.2ml / min Operation time 8 hours pH 4.2 temperature 25℃ Feed Upward mobility

[0108] Figure 4 A custom-built packed bed reactor is shown with a porous filter containing the biosorbent.

[0109] The Oosporium sporogenes strain was inoculated inside the sponge and the resulting biomass was used as additional media for the continuous reactor.

[0110] The top and bottom sponges present in the reactor are denser and serve to hold the inoculated sponges in place when flow is introduced.

[0111] In this system, the input is multi-metal wastewater and the output is treated water.

[0112] from Figure 5 It can be seen that different removal rates (% of metal removed by fungal biosorption over time (min)) were obtained during this experiment: 60% to 80% removal for most metal ions (Al, Cr, Mg, Mn, Fe, Co, Ni, Cu, Zn), 40% to 60% removal for calcium ions, and about 75% removal for vanadium ions. These results indicate that these sponges act well as fixatives in continuous reactors, as they provide constant removal rates for all metals. This result is similar to the results of the batch experiment.

Claims

1. A biosorbent for extracting metals from a solution comprising the metals, comprising one or more of a Mucor fungus and a biomass prepared or processed from a Mucor fungus.

2. The biosorbent of claim 1, wherein the Mucor fungus is selected from the group consisting of Mucor spp., Mucor truncatula, Mucor saturniformis, or mixtures thereof.

3. A biosorbent as claimed in claim 1 or claim 2, wherein the biomass is produced by culturing a Mucor fungus in a medium comprising glucose, dextrose or glycerol.

4. The biosorbent according to any one of claims 1 to 3, wherein the metal is one or more metals selected from the group consisting of aluminum (Al), calcium (Ca), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), nickel (Ni), zinc (Zn) and vanadium (V).

5. A biosorbent for extracting a metal from a solution comprising the metal, comprising one or more of a fungus and a biomass prepared or processed from a fungus, wherein the biomass is hydrophilic and has a point of zero charge (pH 5.0) corresponding to the pH of the solution comprising the metal. PZC ).

6. A biosorbent as claimed in claim 5, wherein the point of zero charge (pH PZC ) is pH 2 to 8.

7. A biosorbent as claimed in claim 5 or claim 6 wherein the fungus is a Mucor fungus.

8. The biosorbent of claim 7, wherein the Mucor fungus is selected from the group consisting of Mucor spp., Mucor truncatula, Mucor saturniformis, or mixtures thereof.

9. A biosorbent according to any one of claims 5 to 8, wherein the biomass is produced by culturing fungi in a medium comprising glucose or glycerol.

10. The biosorbent according to any one of claims 5 to 9, wherein the metal is one or more metals selected from the group consisting of aluminum (Al), calcium (Ca), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), nickel (Ni), zinc (Zn) and vanadium (V).

11. A method of extracting a metal from a solution comprising the metal, comprising contacting the solution comprising the metal with a filter comprising a biosorbent according to any one of claims 1 to 10.

12. The method of claim 11, wherein the filter comprises a membrane comprising a biosorbent.

13. The method of claim 12, wherein the membrane further comprises a fabric.

14. The method of claim 11, wherein the membrane is prepared from a biosorbent using electrospinning.

15. The method of claim 11, wherein the filter is porous.

16. The method of claim 15, wherein the filter is beads comprising a biosorbent.

17. The method of claim 15, wherein the filter is a compact column comprising a biosorbent.

Images