TWI487790B - Methods for recycling valuble metal - Google Patents

Description

Valuable metal recovery method

This invention relates to a process for the recovery of valuable metals.

Geothermal energy is a clean energy source with great development potential and abundant reserves. Due to the special chemical composition of the geothermal fluid, the hydrothermal production process is prone to scale formation in the wellbore of the production well and in the reservoir fracture near the production well due to changes in temperature and pressure, for stable production of hydrothermal fluid. It is a major obstacle.

Acid treatment and chemical inhibition are geothermal well anti-scaling technologies commonly used in recent years. However, whether it is the use of acid treatment or chemical extrusion technology, although the problem of scaling can be treated/suppressed, the waste liquid generated after the application of the project has a considerable impact on the ecological environment.

In addition, the concentration of valuable metals in industrial water, geothermal water/hot springs and other water bodies is not high. If physical and chemical methods are used to extract valuable metals from the above water bodies, it is not easy to achieve the purpose of extracting low-concentration valuable metals, and it is also easy to cause Environmental pollution as described above.

Therefore, in order to reduce costs and increase the friendliness of the environment, we are gradually moving towards the development of high-efficiency green technologies with less environmental pollution.

The present disclosure provides a method for recovering valuable metals, comprising contacting an isolated extracellular protein of a thermophilic bacteria with a solution containing a metal ion to form a complex of a metal ion and a protein, and collecting the complex, wherein the step The thermophilic bacteria are deposited in the Bioresource Conservation and Research Center (BCRC) of the Republic of China Food Industry Development Institute, and registered with the number BCRC 80391, Tepidimonas fonticaldi sp. nov.

Figure 1 shows the genetic relationship of Tepidimonas fonticaldi sp. nov. established by 16S rDNA sequence similarity.

Figure 2 shows the binding ability of intracellular and extracellular proteins of Thermophilic B. thermophila to calcium ions.

Figure 3 shows the binding ability of extracellular proteins of each thermophilic bacteria to calcium ions at different temperatures.

Figure 4 shows the binding ability of extracellular proteins of each thermophilic bacteria to calcium ions under different pressures.

Figure 5 shows the binding ability of extracellular proteins of each thermophilic bacteria to calcium ions in different pH environments.

Figure 6 shows the binding ability of extracellular proteins of each thermophilic bacterium to Dy ions.

Figure 7 shows the binding ability of extracellular proteins of each thermophile to lanthanum (La) ions.

Figure 8 shows the binding ability of extracellular proteins of each thermophile to hydrazine (Nd) ions.

Figure 9 shows the binding ability of extracellular proteins of each thermophilic bacterium to sputum (Sc) ions.

Figure 10 shows the binding energy of extracellular proteins of each thermophile to strontium (Sm) ions. force.

Figure 11 shows the binding ability of the extracellular protein of each thermophilic bacterium to the ytterbium (Yb) ion.

Figure 12 shows the binding ability of extracellular proteins of each thermophilic bacterium to yttrium (Y) ions.

Figure 13 shows the binding ability of the extracellular protein of each thermophilic bacterium to barium (Ba) ions.

Figure 14 shows the binding ability of extracellular proteins of each thermophilic bacteria to calcium (Ca) ions.

Figure 15 shows the binding ability of extracellular proteins of each thermophilic bacteria to indium (In) ions.

Figure 16 shows the binding ability of extracellular proteins of each thermophilic bacteria to gold (Au) ions.

Figure 17 shows the binding ability of extracellular proteins of each thermophile to palladium (Pd) ions.

Figure 18 shows the binding ability of extracellular proteins of each thermophilic bacteria to platinum (Pt) ions.

Figure 19 shows the binding ability of extracellular proteins of each thermophile to rhodium (Rh) ions.

Figure 20 shows the binding ability of extracellular proteins and commercial proteins of thermophilic bacteria to gold (Au) and palladium (Pd) ions.

In the present disclosure, an isolated thermophilic bacterium is collected from Antong Hot Spring, Hualien County, Taiwan, and purified and separated. Thermophilic bacteria isolated by the present disclosure The 16S ribosomal DNA (16S rDNA) sequence was analyzed to show the sequence as shown in SEQ ID NO: 1. According to the sequence of the 16S rDNA, it is shown with the known Tepidimonas thermarum AA-1T (sequence similarity 97.5%), Thermomyces aquatica CLN-1T (sequence similarity 96.8) %), 16% rDNA sequences of Tepidimonas ignava SPS-1037T (sequence similarity 96.4%) and Thermomonas taiwanensis I1-1T (sequence similarity 95.8%) were similar. The relationship diagram based on the sequence similarity of 16S rDNA is shown in Fig. 1.

In one aspect, the thermophilic bacteria are hybridized with Tepidimonas thermarum AA-1T to obtain a DNA-DNA relationship of 23.9±0.2%, and the thermophilic bacteria are determined to be warm single cells. Genus ( Tepidimonas sp.).

In physiological characteristics, the thermophilic bacteria are shown to be Gram-negative aerobic strains, have unipolar flagella, are motility, and the colonies are transparent. The preferred growth temperature of the thermophilic bacteria is 35 to 60 ° C, more preferably 55 ° C, and the preferred growth salinity is 0 to 1.0% by weight of sodium chloride, more preferably 0.2% by weight of sodium chloride. The preferred pH growth conditions are pH 7.0 to 9.0, more preferably pH 7.0. The main fatty acid composition of the thermophilic bacteria includes C16:0 (40.2%), combined fatty acids (summed feature 3; including C16:1 ω7c and / or C16:1 ω6c) (20.1%) and C17:0 cyclo (11.5%) The main polar fats are phosphatidylethanolamine (PE) and phosphatidylglycerol (PG), and the total DNA in the cells has a G+C content of 70.1 mol%.

Based on the above nucleotide information and physiological characteristics, it was confirmed to be Tepidimonas fonticaldi sp. nov., deposited in the Korean Collection of Type Culture (KCTC), and deposited. The number is KCTC 23862, the registration date is January 10, 2012; and it is deposited in the Bioresource Collection and Research Center (BCRC) of the Republic of China Food Industry Development Institute. The registration number is BCRC 80391, and the registration date is November 21, 2011; and deposited in the Belgian Culture Collection Center (Laboratorium voor.Microbiologie Gent'Belgium; LMG), the registration number is LMG26746, the registration date is November 28, 2011.

The extracellular protein secreted by the Thermophilus thermophilus has excellent binding efficiency with a valuable metal under suitable environmental conditions, wherein the valuable metal comprises a rare earth metal ion and a noble metal ion. The rare earth metal ions described herein are specifically, for example, cerium (Ce), dysprosium (Dy), europium (Er), europium (Eu), strontium (Gd), strontium (Ho), lanthanum (La), lanthanum (Lu), lanthanum. (Nd), 鐠 (Pr), 钪 (Sc), 钐 (Sm), 鋱 (Tb), 钍 (Th), 銩 (Tm), uranium (U), 镱 (Yb) or 钇 (Y), but Not limited to this. The noble metal ions described herein are specifically, for example, gold (Au), silver (Ag), platinum (Pt), palladium (Pd), rhodium (Rh), iridium (Ir) or a combination thereof, but are not limited thereto.

The extracellular protein secreted by the Thermophilus thermophilum has excellent metal ion binding efficiency under suitable environmental conditions, particularly divalent or trivalent metal ions. The divalent or trivalent metal ion described herein, specifically, for example, aluminum (Al), boron (B), barium (Ba), bismuth (Bi), calcium (Ca), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), gallium (Ga), indium (In), potassium (K), lithium (Li), magnesium (Mg), manganese (Mn), sodium (Na), nickel (Ni), lead (Pb), strontium (Sr), strontium (Tl), or zinc (Zn), but is not limited thereto.

Furthermore, the extracellular protein secreted by Thermophilus thermophilus described in the present case has excellent metal ion bonding efficiency and is not affected by environmental conditions of high temperature, high pressure and pH. Specifically, in one embodiment, the extracellular protein secreted by Thermophilus thermophilum in this case has good binding efficiency with metal ions at 100 ° C and pH 7. In another embodiment, the extracellular protein secreted by Thermophilus thermophilus in the present case is at a temperature of 75 ° C, 150 ° C under a pressure of 7 atmospheres, especially at 125 to 150 ° C. In high temperature environments, the bonding efficiency with metal ions is still excellent. In another embodiment, the extracellular protein secreted by the Thermophilus thermophilum in the present case is at a pressure of 1 to 50 atm, particularly at a pressure of 30 to 50 atm, at 25 ° C and pH 7. The bonding efficiency with metal ions is still excellent. In another embodiment, the extracellular protein secreted by the Thermophilus thermophilum of the present invention is acidic at pH 2-6 or alkali at pH 7-10 at 25 ° C under atmospheric pressure. Under the condition of the bond, the bonding efficiency with the metal ion is still excellent.

The method for recovering valuable metals according to the present disclosure further includes desorbing the complex formed by the metal ions and the extracellular protein to obtain the metal ions. The desorption treatment involves the addition of a desorbent to remove metal ions from the complex formed by the extracellular protein. The desorbent can be, for example, nitrilotriacetic acid (NTA), Ethylenediamine tetraacetate (EDTA), or a combination thereof.

Due to the excellent bonding efficiency of the extracellular protein to the metal ion, it can be bonded to the metal ion in the solution to achieve the effect of adsorbing the metal ion. In particular, a small amount of metal ions remaining in high-temperature geothermal water, boiler solution, industrial wastewater or hard water is liable to cause environmental pollution and the like. Therefore, according to the disclosure The method uses an extracellular protein with excellent metal ion bonding efficiency, can effectively adsorb residual metal ions, reduces environmental pollution of the above wastewater, and can effectively recover the metal ions, and improve the medium/low metal concentration waste liquid. The concentration of valuable metals to reduce the operating costs of subsequent recovery metal projects.

The above and other objects, features, and advantages of the invention will be apparent from

[Examples]

[Example 1] Collection and identification of Thermosporum thermophilus ( Tepidimonas fonticaldi sp. nov.)

collection

In the Antong Hot Spring Area of Hualien, Taiwan, a blackened foil-coated sample bottle was used to collect a water sample with a sampling volume of 10 L at each sampling point, and the water sample was filtered with a 0.45 μm filter paper as close as possible to aseptic operation. After the filtration is completed, the filter is attached to a 1.5% solid medium (300 mL of geothermal water sample + 4.5 g of seaweed powder, sterilized at 121 ° C for 15 minutes, poured into a Petri dish for cooling), and cultured at 55 ° C. ~14 days. At the end of the culture period, single colonies with a special color or morphology were picked out with a sterile inoculating loop, and the three regions were streaked on a new medium and repeated several times until a pure strain was obtained. The purified strain was stored at 4 °C.

Bacterial DNA extraction

Scrap the appropriate amount of fresh colonies in 1 mL of sterile water with an inoculating loop and wash them with sterile water for 3 times before using the extraction kit (Blood & Tissue genomic DNA) Extraction minoprep system) The genomic DNA of the strain was extracted and stored in a refrigerator at -20 °C.

Sequencing of 16S rDNA

The genomic DNA of the strain will be extracted as a prokaryotic universal primer pair FD1 (5'-AGA GTT TGA TCC TGG CTC AG-3') and RD1 (5'-AAG GAG GTG ATC CAG CC-3'), and the following list 1. The polymerase chain reaction (PCR) reagents and conditions shown in Table 2, the 16S rDNA fragment of the strain was amplified, and then entrusted to Mingxin Biotechnology Co., Ltd. for sequencing, as shown in sequence identification number 1.

Alignment of bacterial 16S rDNA

The 16S rDNA shown in SEQ ID NO: 1 is set up at the National Center for Biotechnology Information (NCBI; www.ncbi.nlm.nih.gov) established by the National Institute for Health and Medical Research (NIH). The BLAST software in the application website compares the sequenced 16S rDNA sequence with the published sequence in the GenBank database, analyzes the sequence similarity, and completes the thermophilic thermophila ( Tepidimonas fonticaldi sp.nov). .) The strain AT-A2T is registered in the NCBI sequence database (www.ncbi.nlm.nih.gov.) under the serial number JN713899.

Construction of kinship tree

According to the above sequence similarity, the 16S rDNA gene sequence and accession number of the known model strains with higher similarity to the experimental strains were constructed using BioEdit software and CLUSTAL_X, and the homology between the strains was calculated. The relationship was plotted and a dendrogram was drawn as in Fig. 1, thereby confirming that the collected strain was novel and closely related to the known Tepidimonas thermarum AA-1T.

[Example 2] Metal ion bonding analysis of extracellular proteins

Protein collection

To validate novel proteins secreted by Tepidimonas fonticaldi sp. nov. and model strains ( Thermus aquaticus BCRC 17110) and other thermophilic strains (including intracellular and Extracellular) ability to bind to calcium ions, respectively, by inoculating the ring to scrape the pure colonies on the agar plate medium and adding 100 mL of 1/5 TSB liquid medium (formulation: trypsin-decomposed casein 1.7 g/L, enzyme) In the decomposed soybean powder 0.3 g/L, dextrose 0.25 g/L, sodium chloride 0.5 g/L, and potassium phosphite 0.25 g/L, the cells were cultured at 200 rpm and 55 ° C for 3 to 5 days.

After the completion of the proliferation culture, the cultured bacterial solution was centrifuged at 10,000 rpm for 10 minutes, and the supernatant containing the extracellular protein was concentrated by a barometric protein concentrator at a magnification of 10 times as a sample of the extracellular protein of the subsequent test. The cells after centrifugation were disrupted by an ultrasonic breaker to cause intracellular proteins to flow out as a sample of intracellular proteins for subsequent experiments.

Quantification of protein concentration

100 μL of the test protein solution was added, 400 μL of Bio-Rad protein assay solution was added, and after 15 minutes of color reaction, the absorbance was measured by a spectrophotometer under a visible light source of 595 nm, and the absorbance was substituted into the calibration line to determine the protein concentration. Assess the protein content secreted by the microorganisms.

Calcium ion binding efficiency test of intracellular and extracellular proteins

In order to investigate the binding efficiency of intracellular and extracellular proteins to metal ions, the intracellular and extracellular proteins of each of the thermophilic bacteria obtained above were subjected to a calcium ion binding efficacy test.

The above intracellular/extracellular protein solution was 50 ppm with CaCl ₂ . 2H ₂ O was formulated into a 100 ppm calcium ion stock solution and uniformly mixed 1:1, and the mixture was heated at 100 ° C for 1 hour in water. After the completion of the water-blocking heating, the mixture was filtered through an ultrafiltration system with a membrane pore size of 3 kDa to allow the protein to be trapped on the membrane, while the calcium ion filtrate not bound to the protein was diluted with deionized water. After measuring within the detection range of the instrument (0~5ppm), it is measured by inductively coupled plasma atomic emission spectrometry (ICP). Finally, the residual Ca ²⁺ concentration in the filtrate is used to estimate the bonding effect of the protein on calcium ions. The results are shown in Table 3 and Figure 2 below.

As shown in Table 3 and Figure 2 above, the calcium ion binding efficiency of extracellular proteins is much more remarkable than that of intracellular proteins. At the same time, the strain AT-A2 has the best calcium ion bonding efficiency, which is 0.327 mg per mg of protein. Ca ²⁺ ions, the other strains have a calcium ion binding efficiency lower than 0.1 mg Ca ²⁺ per milligram of protein.

Calcium ion bonding efficiency test of environmental conditions

In order to investigate the effects of environmental factors such as temperature, pressure, pH and other factors on the extracellular protein and calcium ion binding efficiency of Tepidimonas fonticaldi sp. nov., the following experiments were designed: (1) 50 ppm of the above extracellular protein sample was treated at a test pressure of 10 atm, 30 atm, 50 atm for 10 minutes at 25 ° C, pH 7, and (2) 50 ppm of the above extracellular protein sample at 25 ° C, 1 atm. Under the environment, the test pH is 2, pH 4, pH 6, pH 7, pH 8, pH 10 for 10 minutes; (3) 50 ppm of the above extracellular protein sample in the pH 7 environment to test The temperature was treated at 100 ° C, 125 ° C, and 150 ° C for 10 minutes.

After that, the above protein solution was 50 ppm with CaCl ₂ . 2H ₂ O was formulated into a 100 ppm calcium ion stock solution and uniformly mixed 1:1, and the mixed solution was further treated under the above test conditions for 10 minutes. After the test was completed, the mixture was filtered through an ultrafiltration system with a membrane pore size of 3 kDa to allow the protein to be trapped on the membrane, while the calcium ion filtrate not bound to the protein was diluted with deionized water to the instrument. After detection (0~5ppm), it was measured by inductively coupled plasma atomic emission spectrometry (ICP). Finally, the binding effect of protein on calcium ion was estimated from the residual Ca ²⁺ concentration in the filtrate.

As a result, as shown in Figs. 3 to 5, the Thermophilic Thermophilum type of the present invention has excellent binding efficiency to calcium ions under high temperature, high pressure and wide pH conditions.

Bonding efficiency of rare earth metal ions

In order to investigate the binding efficiency of the extracellular protein of Tepidimonas fonticaldi sp. nov. to rare earth metal ions, the following experiment was designed: 10 ppm of the above extracellular protein sample and containing cerium (Ce), Dy, Er, Eu, Gd, Ho, La, Lu, Nd, Pr, Sc 1:1 (Sm), 鋱 (Tb), 钍 (Th), 銩 (Tm), uranium (U), yttrium (Yb) and yttrium (Y) metal ions 10ppm standard solution 1:1 uniform mixing, at 100 ° C, The reaction was carried out for 20 minutes under the conditions of pH 2. Thereafter, the extracellular protein and the rare earth metal ions of Dy, La, Nd, Sc, Sm, Yb, Y (Y) are measured according to the aforementioned method. bonding performance, effectiveness bonded per mg of metal ions micromolar (μ mole metal / mg protein) indicates the result of 6 to 12 as shown in FIG.

Bonding effectiveness test of divalent and trivalent metal ions

The above extracellular protein sample was 10 ppm and contained aluminum (Al), boron (B), barium (Ba), bismuth (Bi), calcium (Ca), cadmium (Cd), cobalt (Co), chromium (Cr), copper. (Cu), iron (Fe), gallium (Ga), indium (In), potassium (K), lithium (Li), magnesium (Mg), manganese (Mn), sodium (Na), nickel (Ni), lead (Pb), strontium (Sr), strontium (Tl), zinc (Zn) metal ions 10ppm standard solution 1:1 uniform mixing, reaction at 100 ° C, pH 2 for 20 minutes, after which, according to the above method The binding efficiency of the extracellular protein to barium (Ba), calcium (Ca), indium (In), and metal ions, and bonding efficiency with bonding efficiency of μ mole metal/mg protein per milligram. The results are shown in Figures 13-15.

Bonding efficiency of noble metal ions

10 ppm of the above extracellular protein sample was uniformly mixed with a standard solution containing 10 ppm of gold (Au), palladium (Pd), platinum (Pt), and rhodium (Rh) metal ions, and reacted at 25 ° C and pH 2 After 20 minutes, the binding efficiency of the extracellular protein to the noble metal ion was determined by the above method, and the binding efficiency was expressed by the binding efficiency per μm of metal ion (mg). Figures 16 to 19 are shown.

As can be seen from the data of Figures 6 to 19, the extracellular protein of Thermophilus thermophilum of the present invention has excellent binding ability to a wide range of divalent or trivalent metal ions, rare earths and noble metal ions.

[Comparative Example 1] Bonding efficiency of commercial proteins to noble metal ions

50ppm commercial protein, including ovalbumin, bovine serum albumin (BSA) and lysozyme (ply) metal ion 10ppm standard solution 20:1, at 25 ° C, pH 4 conditions Reaction for 60 minutes; and 50 ppm of commercial protein, including ovalbumin and bovine serum albumin (BSA), and 100 ppm of lysozyme and gold (Au) metal ion 10 ppm standard solution at 25 ° C, pH 4 The reaction was carried out for 60 minutes. Thereafter, the binding efficiency of the above commercial protein to noble metal ions was measured by the method of Example 2. The bonding efficiency is expressed in terms of bonding efficiency per μm of metal/mg protein.

As shown in Fig. 20, the adsorption amounts of ovalbumin, bovine serum albumin and lytic enzyme on gold (Au) were 0.18, 0.20 and 0.10, respectively, and the adsorption amounts to palladium (Pd) were 0.86 and 0.98, respectively. 0.98. In contrast, the extracellular protein of Thermophilic B. thermophilum (AT-A2) in this case has an adsorption effect on gold (Au) and palladium (Pd) of 1.33 and 3.13, indicating the micro-thermophilic type B in this case. The extracellular protein of Thermomonas has a much stronger binding ability to valuable metal ions than commercial proteins.

[Example 3] Desorption of metal ions

In the reaction system containing the extracellular protein of M. thermophilum and the rare earth metal ion or noble metal ion solution in Example 2, 40 ml of a desorbent (ammonia triacetate) was added, and the solution was allowed to stand at 25 ° C. The desorption treatment was carried out for 30 minutes to obtain the metals contained in the respective reaction systems.

While the invention has been described above in terms of several preferred embodiments, it is not intended to limit the invention, and the invention may be modified and modified without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

<110> Institute of Industrial Technology

<120> Method of valuable metal recovery

<130> 0965-A24070-CIPTW

<160> 1

<170> PatentIn version 3.5

<210> 1

<211> 1276

<212> DNA

<213> Tepidimonas thermarum AA-1

<400> 1

Claims (11)

A method for recovering valuable metals, comprising: providing an isolated extracellular protein of thermophilic bacteria in contact with a solution containing metal ions to form a complex of metal ions and proteins; and collecting the complex, wherein the thermophilic bacteria are Hosted in the Center for Bioresource Conservation and Research (BCRC) of the Republic of China Food Industry Development Institute, and registered with Tepidimonas fonticaldi sp. nov. The method for recovering valuable metals according to claim 1, further comprising: desorbing the composite formed by the metal ions and the protein to obtain the metal ions. The method of recovering valuable metals according to claim 2, wherein the desorbing agent comprises nitrilotriacetic acid (NTA), Ethylenediamine tetraacetate (EDTA) or a combination thereof. The method of recovering valuable metals according to claim 1, wherein the thermophilic bacteria comprises a 16S rDNA sequence as shown in SEQ ID NO: 1. A method of recovering valuable metals as described in claim 1, wherein the metal ion comprises a rare earth metal ion or a noble metal ion. A method for recovering valuable metals as described in claim 5, wherein the rare earth metal ions include cerium (Ce), dysprosium (Dy), cerium (Er), europium (Eu), cerium (Gd), cerium (Ho). , La, Lu, Nd, Pr, Sc, Sm, Tb, Th, Tm, U , Yb, Y (Y) or a combination of the foregoing. A method for recovering valuable metals as described in claim 5, The noble metal ions include gold (Au), silver (Ag), platinum (Pt), palladium (Pd), rhodium (Rh), iridium (Ir) or a combination thereof. The method for recovering valuable metals according to claim 1, wherein the contact of the extracellular protein of the thermophilic bacteria with the solution containing the metal ions is carried out in an environment of 25 to 100 °C. The method for recovering valuable metals according to claim 1, wherein the contact of the extracellular protein of the thermophilic bacteria with the solution containing the metal ions is carried out at a pH of 2 to 6. The method for recovering valuable metals according to claim 1, wherein the metal ion-containing solution comprises geothermal water, a solution in a boiler, industrial wastewater or hard water. A method for recovering valuable metals as described in claim 1 for use in the treatment of boiler equipment, surface pipelines, geothermal production wells, industrial wastewater or hard water.