Biological sorbents and methods for extracting metals

Abstract

The present invention provides a biological sorbent for extracting metals from a solution containing the metal, the biological sorbent comprising one or more of Mucoromycota fungi and prepared or treated biomass of said Mucoromycota fungi; a biological sorbent for extracting metals from a solution containing the metal, the biological sorbent comprising one or more of fungi and biomass produced by said fungi, the biomass being hydrophilic and having a point of zero charge (pHPZC) corresponding to the pH of the solution containing the metal; and a method for extracting metals from a solution containing the metal, the method comprising contacting the solution containing the metal with a filter comprising the biological sorbent of the present invention.

Description

[Technical Field]

[0001] Provided are a biological sorbent reagent for extracting metals from a solution containing the metal, the biological sorbent comprising one or more of Mucoromycota fungus and biomass produced by Mucoromycota fungus; a biological sorbent reagent for extracting metals from a solution containing the metal, the biological sorbent comprising one or more of fungus and biomass produced by fungus, the biomass being hydrophilic and having a point of zero charge (pHPZC) corresponding to the pH of the solution containing the metal; and a method for extracting metals from a solution containing the metal, the method comprising contacting the solution containing the metal with a filter comprising the biological sorbent of the present disclosure. [Background technology]

[0002] Background technology Wastewater and industrial water commonly contain metals. Some of these metals are toxic (e.g., heavy metals), while others are economically valuable (e.g., critical metals). Therefore, there has been a need to efficiently and sustainably 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 they can be reintroduced into industrial circuits.

[0003] Cutting edge technology (STATE OF ART) Clean TeQ Water's so-called CLEAN-IX® technology provides highly efficient extraction and purification of a wide range of metals from slurries and solutions. CLEAN-IX® combines continuous ion exchange with counter-current ion exchange, where the resin and slurry / solution move continuously through the system and directly contact each other countercurrently. This typically achieves extraction rates of over 98% of the metals contained in the solution and provides an economical method for recovery and concentration of dilute streams.

[0004] CLEAN IX metals recovery technology achieves very high elution concentrations by providing a customized flowsheet, with each ion exchange process step taking place in a dedicated vessel optimally sized for the task.

[0005] However, this conventional system is complex and there is a need to provide methods and tools that can be used for efficient recovery in a fast, cost-effective and more ecological manner. Summary of the Invention

[0006] The present disclosure provides a sustainable approach based on the use of microbe-mineral interactions (i.e., immobilization of metals in solution; a process called biosorption). Biosorption methods are sustainable because they advantageously provide a low carbon footprint compared to abiotic methods such as Clean TeQ Water's CLEAN-IX® technology.

[0007] In particular, the present disclosure provides a biological sorbent for extracting metals from a metal-containing solution, the biological sorbent comprising one or more of a Mucoromycota fungus and a prepared (or treated) biomass of a Mucoromycota fungus. In one embodiment, the Mucoromycota fungus is Mucor moelleri, particularly strain NEUM140 identified by GENBANK® ID accession number MZ374564. Other preferred examples of Mucoromycota fungi are M. hiemalis, particularly strain NEUM144 identified by GENBANK® ID accession number OR478153, and M. saturninus, particularly strain NEUM172 identified by GENBANK® ID accession number OR478154. In another embodiment, biomass is produced by culturing Mucoromycota fungi in a medium containing glucose, dextrose, or glycerol, which are carbon sources for the growth of the microorganisms (or Mucoromycota fungi). Glycerol or crude glycerol is a major by-product of biodiesel production and can be used as a carbon source for the growth of Mucoromycota fungi. Here, the metal may be one or more 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).

[0008] The present disclosure also provides a biological sorbent for extracting metals from a metal-containing solution, the biological sorbent comprising one or more of a fungus and a prepared or treated biomass of a fungus, the biomass being hydrophilic and having a point of zero charge (pH ) corresponding to the pH of the metal-containing solution. PZC In one embodiment, the biological sorbent has a point of zero charge (pH ) corresponding to the pH of the solution containing the metal. PZC) has a pH of 2 to 8. In another embodiment, the fungus is a Mucoromycota fungus. In another embodiment, the Mucoromycota fungus is Mucor moelleri, particularly the NEUM140 strain identified by GENBANK® Accession No. MZ374564. Other preferred examples of Mucoromycota fungi are M. hiemalis, particularly the NEUM144 strain identified by GENBANK® Accession No. OR478153, and M. saturninus, particularly the NEUM172 strain identified by GENBANK® Accession No. OR47815. Biomass may be produced by culturing fungi in a medium containing a carbon source such as glucose, dextrose, or glycerol or crude glycerol. The metal may also be one or more 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).

[0009] The present disclosure further provides a method for extracting metals from a metal-containing solution, comprising contacting the metal-containing solution with a filter containing a biological sorbent comprising one or more of Mucoromycota fungi and prepared or treated biomass of Mucoromycota fungi. In one embodiment, the filter comprises a membrane containing the biological sorbent. In another embodiment, the membrane further comprises fabric. The membrane may be prepared from the biological sorbent using electrospinning. In another embodiment, the filter is a bead or hollow spherical cavity containing the biological sorbent. In another embodiment, the filter comprises a plurality of hollow spherical cavities ranging from 0.05 to 1 mm, preferably 0.1 to 0.5 mm, with the biological sorbent contained within the cavities. The hollow spherical cavities may comprise a polymeric material (such as polypropylene), a metallic material (Al-based), a non-metallic material (Si-based), and / or a ceramic material (silica or alumina).

[0010] The disclosure also provides a method for extracting metals from a metal-containing solution, comprising contacting the metal-containing solution with a filter, bead, or compact column containing a biological sorbent comprising one or more of a fungus and a prepared or treated biomass of a fungus, wherein the biomass is hydrophilic and has a point of zero charge (pH ) corresponding to the pH of the metal-containing solution. PZC). In one embodiment, the fungus is a Mucoromycota fungus. In one embodiment, the filter comprises a membrane comprising a biological sorbent. 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 a metal, ceramic, or the like. In one embodiment, the filter is a bead or compact column comprising the biological sorbent. In another embodiment, the membrane is prepared from the biological sorbent using electrospinning. [Brief explanation of the drawings]

[0011] [Figure 1a] Figures 1A, 1B and 1C show data on residual metal content and adsorption capacity. [Figure 1b] Figures 1A, 1B and 1C show data on residual metal content and adsorption capacity. [Figure 1c] Figures 1A, 1B and 1C show data on residual metal content and adsorption capacity.

[0012] [Figure 2a] Figure 2(ac) shows the pHPZC of Mucor moelleri (NEUM140), Mucor saturnius (NEUM144) and Mucor hiemalis (NEUM 172). [Figure 2b] Figure 2(ac) shows the pHPZC of Mucor moelleri (NEUM140), Mucor saturnius (NEUM144) and Mucor hiemalis (NEUM 172). [Figure 2c] Figure 2(ac) shows the pHPZC of Mucor moelleri (NEUM140), Mucor saturnius (NEUM144) and Mucor hiemalis (NEUM 172).

[0013] [Figure 3a] FIG. 3 shows the results of the biosorption experiments (mg vanadium / kg biomass). [Figure 3b] Figure 3 shows the results of the biosorption experiments (mg vanadium / kg biomass). [Figure 3c] Figure 3 shows the results of the biosorption experiments (mg vanadium / kg biomass).

[0014] [Figure 4] FIG. 4 shows a custom packed bed reactor with a porous filter (sponge) containing a biological sorbent (M. moelleri inoculated within the sponge).

[0015] [Figure 5] Figure 5 presents the different removal rates (% of metal removal by fungal biosorption according to time (min)) obtained during the M. moelleri continuous flow experiments. DETAILED DESCRIPTION OF THE INVENTION

[0016] definition Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the embodiments described herein, certain preferred methods, compositions, devices, and materials are described herein. However, before the materials and methods are described, it should be understood that this disclosure is not limited to the particular molecules, compositions, methodologies, or protocols described herein, as these may vary according to routine experimentation and optimization. It should also be understood that the terminology used herein is for the purpose of describing particular versions or embodiments only, and is not intended to limit the scope of the embodiments described herein.

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. However, in case of conflict, the present specification, including definitions, controls. Therefore, in the context of the embodiments described herein, the following definitions apply.

[0018] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise.

[0019] As used herein, the term "comprise" and its linguistic variations indicate the presence of stated features, elements, method steps, etc., without excluding the presence of additional features, elements, method step(s), etc. Conversely, the term "consisting of" and its linguistic variations indicate the presence of stated features, elements, method steps, etc., and excludes unrecited features, elements, method steps, etc., except for impurities ordinarily associated therewith. The phrase "consisting essentially of" means the stated features, elements, method steps, etc., and any additional features, elements, method steps, etc. that do not materially affect the basic nature of the composition, system, or method. Many embodiments herein are described using open "comprising" language. Such embodiments encompass multiple closed "consisting of" and / or "consisting essentially of" embodiments and may alternatively be claimed or described using such language.

[0020] As used herein, the term "biological sorbent reagent for extracting a metal from a solution" means a reagent that is capable of adsorbing a metal from a solution containing the metal and other substances, preferably complexes.

[0021] As used herein, the term "prepared (or processed) biomass produced by the Mucoromycota fungus" means biomass obtained from a liquid culture of Mucoromycota fungus that has been autoclaved and / or washed and dried and / or crushed to obtain a powder.

[0022] As used herein, the term "Mucoromycota fungi" refers to a division or phylum within the kingdom of fungi, which includes a diverse group of filamentous fungi. This division includes at least Mucor moelleri, specifically strain NEUM140 identified by GenBank® Accession No. MZ374564, Mucor hiemalis, specifically strain NEUM144 identified by GenBank® Accession No. OR478153, and M. saturninus, specifically strain NEUM172 identified by GenBank® Accession No. OR478154.

[0023] As used herein, the term "biomass produced by the Mucoromycota fungus (or the fungus)" refers to material produced by the Mucoromycota fungus (or the fungus) during cultivation.

[0024] The term "hydrophilic" as used herein refers to the physicochemical property of a material, in particular the surface of the fungus of the present invention, having an affinity for solutions whose solvent is water (HO), as expressed by a water contact angle of less than 60°, or preferably less than 45°.

[0025] As used herein, the term "point of zero charge (pH )" refers to the pH of a solution containing a metal. PZC ) refers to the pH at which the net charge on all particle surfaces (i.e., the surface of the absorbent) is equal to zero.

[0026] As used herein, the term "electrospinning" refers to a method of producing ultrafine (nanometer) fibers by charging and ejecting a polymer melt or solution through a spinneret under a high-voltage electric field, which then solidifies or solidifies to form filaments.

[0027] As used herein, the terms "about," "approximate," "at or about," and "substantially" mean that the amount or value in question may be the exact value set forth in the claims or taught herein, or a value that provides an equivalent result or effect. That is, it is understood that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but can be approximated and / or increased or decreased, as desired, to reflect tolerances, conversion factors, rounding, measurement errors, etc., and other factors known to those skilled in the art to provide an equivalent result or effect. In some situations, it is not possible to reasonably determine a value that provides an equivalent result or effect. In such cases, as used herein, "about" and "at or about" are generally understood to mean the nominal value, indicating a variation of ±10%, unless otherwise indicated or inferred. In general, any amount, size, formulation, parameter, or other quantity or characteristic is "about," "approximate," "at," or about," whether or not expressly stated as such. When "about," "approximate," "at," or about" is used before a quantitative value, it is understood that the parameter also includes the particular quantitative value itself, unless specifically stated otherwise.

[0028] Detailed Description of the Invention Biological sorbents for the extraction of metals from metal-containing solutions. The present disclosure provides a biological sorbent for extracting metals from a metal-containing solution, the biological sorbent comprising one or more of Mucoromycota fungi and prepared (or treated) biomass produced by Mucoromycota fungi. Here, the metals can be extracted (or recovered) from the solution by adsorption to the biological sorbent. In one embodiment, the Mucoromycota fungus can be Mucor moelleri. Mucor moelleri was isolated from a soil sample collected in Creux-du-Van (Neuchatel, Switzerland) at the Microbiology Laboratory of the University of Neuchâtel and was deposited on July 2, 2021, in GenBank®, the National Center for Biotechnology Information Gene Sequence Database, 8600 Rockville Pike, Bethesda, MD 20894, USA, under accession number MZ374564.

[0029] In another embodiment, the biomass is produced by culturing Mucoromycota fungi in a medium containing glycerol. In one embodiment, the prepared (or treated) biomass is produced by autoclaving and / or washing a liquid culture of Mucoromycota fungi, drying and / or grinding to obtain a powder.

[0030] In another embodiment, the biomass may or may not be pretreated with an acidic and / or alkaline solution. Furthermore, a rehydration step of the biomass is also possible. However, in the claimed method, this rehydration step is not present. Here, the metal may be one or more 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).

[0031] The present disclosure also provides a biological sorbent for extracting metals from a metal-containing solution, the biological sorbent comprising one or more of a fungus and a prepared or treated biomass of a fungus, the biomass being hydrophilic and having a point of zero charge (pH) corresponding to the pH of the metal-containing solution. ZC ), where the point of zero charge (pH) corresponds to the pH of the solution containing the metal. ZC ) may have a pH of 2 to 8. In one embodiment, the concentration of the metal in the solution is approximately 2 to 5 mg / L. In one embodiment, the fungus is a Mucoromycota fungus. In another embodiment, the Mucoromycota fungus is Mucor moelleri (NEUM140), preferably a strain corresponding to GENBANK® Accession No. MZ374564. Other preferred examples of Mucoromycota fungi are M. hiemalis (NEUM144), preferably a strain corresponding to GENBANK® Accession No. OR478153, and M. saturninus (NEUM172), preferably a strain corresponding to GENBANK® Accession No. OR478154. Biomass may be produced by culturing the fungus in a medium containing glycerol. In one embodiment, biomass is produced by autoclaving and / or washing a liquid culture of a Mucoromycota fungus, drying and / or grinding it to obtain a powder.

[0032] The metal may also be one or more 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).

[0033] Method for extracting metals from solutions containing metals The present disclosure further provides a method for extracting metals from a metal-containing solution, the method comprising contacting the metal-containing solution with a filter, beads, or compact column containing a biological sorbent comprising one or more of Mucoromycota fungi and prepared (or treated) biomass of Mucoromycota fungi. Here, the metal can be extracted (or recovered) from the solution by adsorption to the biological sorbent. Contacting the solution with a filter can include any method for exposing the biological sorbent to the metal-containing solution so that the metal is adsorbed to the biological sorbent. In one embodiment, this can be done by flowing the metal-containing solution through a filter containing the biological sorbent, over beads containing the biological sorbent, or through a compact column containing the biological sorbent. In one embodiment, a circulating flow can be used to expose the biological sorbent to the metal-containing solution. However, the circulating flow ensures that desorption of the metal does not occur. In another embodiment, a parallel flow or a combination of filters can be used to expose the biological sorbent to the metal-containing solution. Here, the filter may be a membrane filter made from, containing, or having immobilized biological sorbents. The membrane may further comprise a fabric. Here, the fabric may be waste material that acts as a physical substrate for microbial growth but does not contain bioavailable / bioaccessible carbon for growth. In one embodiment, the membrane is prepared from the biological sorbent using electrospinning. Furthermore, the filter may be beads or compact columns containing the biological sorbent. Here, for example, the beads or compact columns may contain the biological sorbent on one or more of their surfaces. In one embodiment, the beads and compact columns may be hydrophilic and / or porous. The porous compact columns may comprise polymeric materials such as sponges, including polypropylene.In another embodiment, the Mucoromycota fungus is Mucor moelleri, particularly strain NEUM140, identified by GENBANK® Accession No. MZ374564. Other preferred examples of Mucoromycota fungi are M. hiemalis (NEUM144), preferably a strain corresponding to GENBANK® Accession No. OR478153, and M. saturninus (NEUM172), preferably a strain corresponding to GENBANK® Accession No. OR478154. Biomass may be produced by culturing fungi in a medium containing glucose or glycerol or crude glycerol. In one embodiment, biomass is produced by autoclaving and / or washing a liquid culture of Mucoromycota fungi, drying and / or grinding to obtain a powder. In another embodiment, the biomass may or may not be pretreated with acidic and alkaline solutions. The metal may also be one or more 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).

[0034] The present disclosure also provides a method for extracting metals from a metal-containing solution, the method comprising contacting the metal-containing solution with a filter, beads, or compact column containing a biological sorbent comprising one or more of a fungus and a prepared (or processed) biomass of a fungus, wherein the biomass is hydrophilic and has a point of zero charge (pH PZC) corresponding to the pH of the metal-containing solution. Here, the metal can be extracted (or recovered) from the solution by being absorbed by the biological sorbent. Contacting the solution with the filter, beads, or compact column can include any method for exposing the biological sorbent to the metal-containing solution so that the metal can be adsorbed to the biological sorbent. In one embodiment, this can be done by flowing the metal-containing solution through a filter, beads, or compact column containing the biological sorbent. In one embodiment, a circulating flow can be used to expose the biological sorbent to the metal-containing solution. Here, the filter can be a membrane filter made from, containing, or having an immobilized biological sorbent. The membrane can further include a fabric. Here, the fabric acts as a physical substrate for microbial growth, but may be waste material that does not contain bioavailable / bioaccessible carbon for growth. In one embodiment, the membrane is prepared from a biological sorbent using electrospinning. Furthermore, the filter may be a bead or compact column containing a biological sorbent. Here, the bead or compact column may, for example, contain a biological sorbent on one or more of its surfaces. In one embodiment, the bead or compact column may be hydrophilic and / or porous. The porous compact column may include a polymer material such as a sponge containing polypropylene. Here, the point of zero charge (pHPZC), corresponding to the pH of the solution containing the metal, may be pH 2 to 8, preferably 2 to 5. In one embodiment, the concentration of the metal in the solution is approximately 2 to 5 mg / L. In one embodiment, the fungus is a Mucoromycota fungus.In another embodiment, the Mucoromycota fungus is Mucor moelleri (NEUM140), preferably a strain with GENBANK® Accession No. MZ374564. Other preferred examples of Mucoromycota fungi are M. hiemalis (NEUM144), preferably a strain corresponding to GENBANK® Accession No. OR478153, and M. saturninus (NEUM172), preferably a strain corresponding to GENBANK® Accession No. OR478154. Biomass may be produced by culturing fungi in a medium containing glucose or glycerol. In one embodiment, biomass is produced by autoclaving and / or washing a liquid culture of Mucoromycota fungi, drying and / or grinding to obtain a powder. The metal may also be one or more 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). The present invention will now be described in detail with reference to the following examples and the accompanying drawings, both of which are presented as preferred embodiments of the present invention but are not intended to limit the preferred embodiments of the present invention. [Example]

[0035] Example 1. Confirmation of the adsorption ability of biological sorbents to metals Biomass synthesis / production Fungal biomass production is shown in Figure 1. This flowsheet applies to all Mucor strains used in this project (NEUM140 corresponding to M. moelleri, NEUM144 corresponding to M. saturninus, and NEUM172 corresponding to M. hiemalis, which were the most used strains in the project experiments).

[0036] First, asexual Mucor spores are transferred to a stirred and baffled reactor along with the culture medium. The culture medium consists of two main components: potato starch and D(+)-glucose or dextrose. The ratios of potato infusion powder and glucose used are preferably 4 g / L and 20 g / L, respectively. Glycerol can replace the glucose in the culture medium. The mixture of spores and culture medium is maintained at room temperature (22-25°C) and under 120 rpm agitation. The total residence time is 4-8 days, preferably 7 days. After the cultivation step is completed, the resulting biomass is transferred to an autoclave step, where the mixture is heated to 121°C for 20 minutes.

[0037] The slurry obtained from the autoclaving step is then transferred to a filtration unit (preferably a disc or pressure filter) where solid-liquid separation and a subsequent washing step take place. Washing is carried out using bi-distilled water, with a slurry to water ratio of preferably 1:5. After the washing step, the remaining solid material is transferred to a drying step. Drying is carried out using conventional heating techniques to achieve a moisture content of less than 1%. The temperature of the drying step is 60°C, with a total residence time of 4 to 48 hours, preferably 24 hours. The dried biomass is then sent to a grinding step where it is ground into powder. The grinding step is carried out using an Ultra-Turrax® homogenizer. The biomass can then be used for the metal adsorption step.

[0038] According to a preferred embodiment, biomass for the biological sorbent of the present invention was obtained from a liquid culture of Mucor moelleri (a Mucoromycota fungus) in potato-dextrose broth (20 g / L D-glucose, 4 g / L potato starch) that was autoclaved, freeze-dried, and ground to a thin powder. Batch experiments were performed using 100 mg of prepared biomass in a 250 mL Erlenmeyer flask at room temperature on a rotary shaker (120 rpm) for 30 minutes. The biomass was separated from the solution using a vacuum pump through a 0.1-0.5 μm (preferably 0.2-0.25 μm) cellulose membrane, such as nitrocellulose or cellulose acetate.

[0039] contact angle measurement The hydrophobicity of Mucor mycelium was evaluated using water contact angles. To do this, asexual spores were inoculated into 20 mL of malt broth (12 g / L) in a 50 mL Schott bottle. Cultures were grown at room temperature under constant agitation (120 rpm) until a visible biomass was present. The fungi used in this study were Aspergillus niger, Mucor moelleri, Mucor hiemalis, Mucor saturninus, Beauveria bassiana, B. caledonica, B. brongniartii, Penicillium commune, P. brevicompactum, and P. spinulosum.

[0040] The resulting biomass, consisting of mycelial pellets, was collected through a sieve, transferred to saline (0.9% NaCl), and homogenized using an Ultra-Turrax®. The resulting suspension was centrifuged at 5000 rpm for 5 minutes, and the supernatant was discarded. The pellet was washed with 5 mL of saline and centrifuged as before. Finally, the biomass was resuspended in 5 mL of saline and deposited on the surface of a nitrocellulose filter (0.45 μm pore size, 22 mm filter diameter) by vacuum filtration.

[0041] Dry biomass was also evaluated. For this, biomass obtained from liquid cultures was sieved, autoclaved at 121 °C for 20 min, and dried at 60 °C for 48 h. The biomass was then ground into a powder using a mortar and pestle. The powder was then placed on tape for contact angle measurements according to techniques known in the art.

[0042] The contact angle of a 30 μL drop of water was then measured using this biomass with a goniometer connected to a camera. The contact angle measured for Mucor mycelium was less than 60°.

[0043] pH at the point of zero charge (pH PZC ) The objective of this experiment is to determine the pH value at which the biomass reaches the point of zero charge, i.e., the pH value at which the negative and positive charges on the biomass surface are perfectly balanced. The preferred biosorption of anions and cations is determined by the pH PZC The maximum adsorption of vanadium ions in a solution of pH 4.5 was obtained using the latest technology described in Saudi Journal of Biological Sciences 25.8 (2018), pp. 1664-1669.

[0044] Solutions of pH 2, 3, 4, 5, 6, and 8 were obtained using 25 mL of 0.1 M NaCl and adding NaOH or HCl until the required pH was reached. 0.05 g of prepared fungal biomass was added to each solution and placed on a rotary shaker at 120 rpm for 24 hours. The initial and final pH were measured to determine the pH. PZC As with the contact angle measurements, a number of fungal species were tested, including those belonging to the Mucor group. Two of the Mucor species exhibited a pH of approximately 4.5. PZC (Mucor moelleri (NEUM140) was 4.62, and Mucor saturnius (NEUM144) was 4.66). Figure 2(ac) shows the pH of the tested Mucor moelleri (NEUM140), Mucor saturnius (NEUM144), and Mucor hiemalis (NEUM 172). PZC Shows.

[0045] Adsorption kinetics (determination of minimum contact time / extraction time) To determine adsorption kinetics, we prepared several batches of Mucor biomass and stored them at 4°C until further use. Solutions containing vanadium ions (sodium orthovanadate (NaVO) or vanadium(III) chloride (VCl)) at 1 ppm or 3.5 ppm, pH set at 4.5, were prepared using bidistilled water to avoid the presence of other metals. These two vanadium ion-containing solutions were compared with actual processed water containing 3.5 ppm vanadium ions. Meanwhile, treated water from an industrial chemical synthesis had an initial vanadium concentration of 3.5 mg / L and a pH of 4.5.

[0046] Biosorption experiment To investigate 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 min. A control was shaken under the same conditions for 120 min.

[0047] After allowing the biomass and vanadium solution to contact for a period of time, the sample was passed through a 47 mm cellulose membrane under vacuum, and the biomass was separated from the liquid phase. The metal content of both fractions was analyzed by ICP-OES. The liquid phase sample was previously acidified with HNO3, and the biomass sample was mineralized to dissolve the organic matter. The analytical results are shown in Figure 3.

[0048] The adsorption capacity of the resulting biological sorbent (M. moelleri biomass as described above) was evaluated in vanadium-containing solutions: 1) treated water from an industrial chemical synthesis with an initial vanadium concentration of 3.5 mg / L and a pH of 4.5; and 2) a solution of NA3VO4 dissolved in bidistilled water with a vanadium concentration of 3.5 mg / L and a pH of 4.5 (referred to as V solution in Figures 1A, 1B, and 1C).

[0049] In Figures 1A, 1B, and 1C, "Control" represents an experiment without biomass, and "Fungus" represents an experiment with prepared M. moelleri biomass. As shown in Figures 1A, 1B, and 1C, the biological sorbent (Fungus) removed vanadium from both the treated water and the Na3VO4 solution (Figure 1A), representing approximately 75–78% of the vanadium in the solution (Figure 1B). The adsorption capacity (mg / g) is comparable to that of other biological sorbents reported in the scientific literature (Figure 1C).

[0050] After contact with a vanadium solution (1 ppm), the prepared biomass of M. moelleri adsorbed vanadium ions. The vanadium in the solution significantly decreased after 30 min of contact with the biomass. Meanwhile, the vanadium ion concentration in the solid biomass rapidly increased, reaching a plateau of between 20 mg and 25 mg vanadium per kg biomass after 180 min, as shown in Figure 3c. Thereafter, no significant changes were observed in the vanadium concentrations in the liquid and biomass fractions after 3 h.

[0051] The adsorption capacity (Qmg / g) and adsorption rate (R%) of M. moelleri were defined using the following equations (1) and (2).

number

number

[0052] 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), C is the V concentration before adsorption (mg / L), and C is the V concentration after adsorption (mg / L). Adsorption capacity is the amount of adsorbate (vanadium or other metal ions) taken up per unit mass of adsorbent (per gram of M. moelleri). In other words, adsorption capacity is the amount of metal (mg) that can be adsorbed by M. moelleri (g).

[0053] An increase in metal concentration in solution indicates that the biomass releases metal ions from the solution, and therefore the biomass desorbs the metal. Conversely, a decrease in metal ions in solution is synonymous with metal adsorption by biomass. A positive adsorption capacity (Q>0) indicates an adsorption phenomenon. A negative adsorption capacity (Q<0) indicates a desorption phenomenon. Adsorption capacity and adsorption rate were fitted by converting the biomass values to their reciprocal values.

[0054] Vanadium was adsorbed from solution by the solid biomass, and after 3 h, 50–60% of the vanadium ions in solution were adsorbed onto the surface of the prepared biomass of Mucor moelleri. The decrease in vanadium concentration in solution coincided with the increase in vanadium in the prepared biomass.

[0055] The adsorption capacity of M. moelleri is promising, with only 0.1 g of dry biomass able to take up more than 10% of its weight in 30 minutes. The rate increases rapidly towards a vanadium removal rate of 60%, which can increase to more than 70% with longer exposure between the biomass and the solution.

[0056] Example 2. Preparation of a filter containing a biological sorbent (1) Hydrophilic membrane filters containing biological sorbents Hydrophilic membrane filters (hydrophilic mycelial mats of Mucor moelleri) are prepared by the following steps. (i) Preparation of viscous basic liquid medium (VBLM): starch 30 g / L, molasses 80 g / L, neopeptone 10 g / L, yeast extract 2 g / L. (ii) Tissue or fabric pieces are placed in glass Petri dishes and sprayed with VBLM until completely saturated. (iii) Drying under a laminar flow hood and autoclave. (iv) Inoculate with an asexual spore suspension containing 103 spores / mL (ensuring uniform distribution of spores over the tissue surface). (v) RT, incubate without light.

[0057] (2) Electrospun membrane filters containing powdered biological sorbents A membrane filter containing electrospun powdered biological sorbent (electrospun powder of dried and killed Mucor Moelleri biomass) is prepared as follows.

[0058] Polycaprolactone (PCL) (Mw = 80,000 g mol -1 ), glacial acetic acid (AA, 99%), formic acid (FA, ≥ 95%) and tetraethylammonium bromide (TEAB, 98%) are purchased from Sigma-Aldrich (Switzerland). PUR® (Elastollan C95A55, Mw 85, 790 g mol -1) was obtained from BASF (Germany), and dimethylformamide (DMF, ≥99.8%) was obtained from VWR (France). A 15 w / v% spinning solution of PCL was prepared by dissolving PCL in an AA / FA mixture (3:1), and a 14.5 w / v% spinning solution of polyurethane (PUR) was prepared by dissolving PUR in pure DMF solvent. Additionally, 0.01 v / v% TEAB was added to the PUR solution to increase conductivity. To prepare melanin-blended membranes (PCL / Mel and PUR / Mel), fungal melanin powder was added to the solvent and dispersed for 20 minutes using a Branson Ultrasonics™ Sonifier 250 / 450 at 83.3 W and 30% amplitude. Ultrasonication was performed with alternating 2-second pauses and starts under ice cooling. The polymers (PCL and PUR) were then added, and the mixture was shaken for 24 hours to obtain a homogeneous solution. Fiber membranes are produced in a pilot-scale, water-repellent Nanospider electrospinning apparatus (NS 1WS500U, Elmarco, Czech Republic). In this setup, a solution reservoir moves continuously along a wire source electrode, depositing a thin film of solution onto it. Upon application of a high electric field, multiple Taylor cones form along the wire. The electrospinning jet is pulled towards the opposing wire electrode, and fibers are deposited onto a paper substrate placed in front of the counter electrode.

[0059] (3) Fabric membrane filters containing biological sorbents A fabric membrane filter containing a biological sorbent is prepared as follows.

[0060] Waste fabrics were cut into 47 mm diameter disks. The fabrics were autoclaved to ensure sterility. The fabrics were then placed in 6 cm Petri dishes containing potato dextrose agar (4 g / L potato extract, 20 g / L glucose, 15 g / L agar). Using a Pasteur pipette, pieces of Mucor moelleri culture were cut (approximately 5–7 mm diameter) and placed on the fabric disks. These were left to colonize the entire dish, especially the fabric. The fabrics were gently removed and placed in glass Petri dishes before autoclaving. This inoculated fabric served as a filter for the column. A water pump pumped the treated water through one, two, or three layers of the column until maximum vanadium removal was achieved.

[0061] (4) Beads containing biological sorbents The beads containing the biological sorbent are prepared by culturing Mucor moelleri under constant agitation to trigger pelleting of the biomass, which results in three-dimensional fungal growth and millimeter-sized round pellets consisting of a mycelial network.

[0062] (5) A porous polypropylene sponge filter containing a biological sorbent. A polypropylene sponge filter containing a biological sorbent is prepared as follows.

[0063] Polypropylene sponges are cut into 10 mm x 10 mm x 10 mm cubes. The sponges are autoclaved to ensure sterility. Next, the sponges are placed in 6 cm Petri dishes containing potato dextrose agar (4 g / L potato extract, 20 g / L glucose, 15 g / L agar) and a spore concentration of 1,000 spores / mL. Using a pipette, 1 mL of spore suspension is dripped onto each sponge. These are left to colonize the entire dish, especially the sponges. This process takes approximately four weeks. The sponges are gently removed and placed in glass Petri dishes before being autoclaved. This inoculated sponge is used as a column filter (Figure 4). A water pump pumps the treated water through one, two, or three layers of columns until maximum vanadium removal is achieved.

[0064] Example 3: Metal selectivity of Mucor Moelleri To test the metal selectivity of the prepared biomass of M. moelleri, 3.5 ppm solutions of Al, Ca, Cr, Mg, Mn, Fe, Co, Ni, Cu, and Zn were prepared in bidistilled water at pH 4.5 using 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, respectively.

[0065] The previous adsorption conditions were 30 min of contact time, 100 mg of biomass in 25 mL of treated water, 25 °C, and 120 rpm. From these products, 100 mL of a 0.1 M stock solution was prepared. This was then diluted to obtain 200 mL of a 3.5 ppm metal concentration solution. For each metal, three control solutions (without biomass) and three treatment solutions (with biomass) were prepared. 100 mg of the prepared biomass was added to three 200 mL "biomass" Erlenmeyer tubes. 25 mL of the prepared metal solution was added to all six Erlenmeyer tubes (200 mL) and placed on a rotary shaker under the above conditions. After the contact time, the solution was filtered through a 0.45 μm filter to recover the biomass. 10 mL of this solution was used for ICP-OES analysis. The biomass was dried at 60 °C and subjected to ICP-OES analysis. The analytical results are shown in Table 1.

[0066] [Table 1]

[0067] The selectivity coefficient is defined as:

number

[0068] The selectivity coefficient determines the affinity of the adsorbent (biomass) for ion A (vanadium ion) versus ion B. Consequently, if K > 1, the resin prefers ion B, and if K < 1, the resin prefers ion A. If K equals 1, the ion exchanger does not prefer ion A or ion B. Thus, M. moelleri strains are selective for Cu >>> Zn >>> V > Al > Ni > Co > Mn > Cr > Mg, Fe, Ca.

[0069] Example 4: Adsorption with other Mucor species The purpose of this study was to test two Mucor strains: M. hiemalis (NEUM144) and M. saturninus (NEUM172). The solutions tested in this study were treated water from Belenos and artificial V solutions at 3.5 ppm and 100 ppm. Fungal biomass was first grown, autoclaved, freeze-dried, and ground into a powder. Next, 100 mg of fungal powder was added to a 150 ml Erlenmeyer flask along with 25 ml of the corresponding solution. The flask was agitated at 120 rpm for 30 minutes and then filtered through a 0.22 μm cellulose filter.

[0070] The adsorbent was placed in a 15 ml Falcon tube and placed at 60°C until completely dry. The filtered solution was divided into two 15 ml Falcon tubes. One received 10 ml of pre-solution, and the other received 4 ml of solution. The latter was diluted with 8 ml of 2% HNO3. All samples were stored in a refrigerator until processing.

[0071] Mucor hiemalis (NEUM144) and Mucor saturninus (NEUM172) demonstrated the ability to adsorb vanadium in all systems tested. M. moelleri performed best in both systems tested (3.5 ppm and 100 ppm vanadium), with extraction rates of 78.5% and 71.6%, respectively. M. hiemalis (NEUM144) showed similar adsorption behavior when exposed to a 3.5 ppm vanadium solution. M. hiemalis (NEUM144) and M. saturninus (NEUM172) showed similar, but worse, adsorption performance when exposed to a 100 ppm vanadium solution.

[0072] Example 5: Continuous flow experiments with M. moelleri A continuous flow experiment was conducted in a reactor using a porous polypropylene sponge filter containing a biological sorbent capable of immobilizing biomass for the biosorption process of Al, Ca, Cr, Mg, Mn, Fe, Co, Ni, Cu, Zn, and V metal ions. The flow conditions are shown in Table 2.

[0073] [Table 2]

[0074] Figure 4 shows a custom-made packed bed reactor equipped with a porous filter containing a biological sorbent.

[0075] The M. moelleri strain is inoculated into a sponge and the resulting biomass is used as the attachment medium for the continuous reactor.

[0076] The upper and lower sponges present in the reactor are dense and are used to hold the inoculum sponge in place when flow is introduced.

[0077] In this system, the input is multi-metal wastewater and the output is treated water.

[0078] As can be seen in Figure 5, different removal rates (% of metal removal by fungal biosorption over time (min)) were obtained during the experiments: 60-80% for most metal ions (Al, Cr, Mg, Mn, Fe, Co, Ni, Cu, Zn), 40-60% for calcium ions, and approximately 75% for vanadium ions. This result indicates that the sponge works well as an immobilization agent in a continuous reactor, as it can provide consistent removal rates for all metals. This result is similar to the batch experiments.

Claims

1. A biological sorbent for extracting metals from a solution containing the metals, the biological sorbent comprising one or more of a Mucoromycota fungus and a prepared or treated biomass produced by the Mucoromycota fungus.

2. 2. The biological sorbent of claim 1, wherein the Mucoromycota bacterium is selected from the group consisting of Mucor moelleri, Mucor hiemalis, Mucor saturninus, or mixtures thereof.

3. 3. The biological sorbent of claim 1 or 2, wherein the biomass is produced by culturing the Mucoromycota fungus in a medium containing glucose, dextrose, or glycerol.

4. 4. The biological sorbent according to any one of claims 1 to 3, wherein the metal is one or more 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. 1. A biological sorbent for extracting metals from a solution containing the metal, the biological sorbent comprising one or more of a fungus and a prepared or treated biomass of the fungus, the biomass being hydrophilic and having a point of zero charge (pH ) corresponding to the pH of the solution containing the metal. ＰＺＣ ) a biological sorbent.

6. The point of zero charge (pH ＰＺＣ 6. The biological sorbent of claim 5, wherein the pH of the solution is between 2 and 8.

7. 7. The biological sorbent of claim 5 or 6, wherein the fungus is a Mucoromycota fungus.

8. 8. The biological sorbent of claim 7, wherein the Mucoromycota bacterium is selected from the group consisting of Mucor moelleri, Mucor hiemalis, Mucor saturninus, or mixtures thereof.

9. The biological sorbent according to any one of claims 5 to 8, wherein the biomass is produced by culturing the fungus in a medium containing glucose or glycerol.

10. 10. The biological sorbent according to any one of claims 5 to 9, wherein the metal is one or more 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. 11. A method for extracting a metal from a solution containing the metal, the method comprising contacting the solution containing the metal with a filter comprising the biological sorbent agent of any one of claims 1 to 10.

12. The method of claim 11 , wherein the filter comprises a membrane containing the biological sorbent.

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 the biological sorbent using electrospinning.

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

16. 16. The method of claim 15, wherein the filter is a bead containing the biological sorbent.

17. 16. The method of claim 15, wherein the filter is a compact column containing the biological sorbent.

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