Patent Application
20250042787
This application claims the benefit of priority from Chinese Patent Application No. 202410765947.5, filed on Jun. 14, 2024. The content of the aforementioned application, including any intervening amendments made thereto, is incorporated herein by reference in its entirety.
This application relates to water environment restoration and treatment, and more particularly to a biogenic manganese oxide (BMO)@sponge biomaterial, and a preparation method and application thereof.
The rapid development of the pharmaceutical industry has greatly expanded the application of antibiotic-type antibacterial or bactericidal drugs. In China, the total consumption of veterinary antibiotics reached 33,000 t in 2020. Tetracyclines are one of the most widely used antibiotics in clinical and agricultural applications. The parent compounds of antibiotics are highly stable, and cannot be fully absorbed and utilized by human and animal bodies. Most antibiotics eventually enter the water environment and cause pollution. Some antibiotics, such as tetracycline and sulfadiazine, have been frequently detected in water bodies such as surface water, groundwater and drinking water, even reaching the mg/L levels. High concentrations of antibiotics are not only toxic to organisms, but also lead to increased drug resistance in sensitive strains and wide spread of antibiotic resistance genes. Therefore, it is of great significance to develop technologies for efficient degradation of tetracyclines.
The existing methods for treating antibiotic wastewater include biological, physical, and chemical methods. Advanced oxidation processes (AOPs) based on free radicals such as hydroxyl radicals (.OH) or sulfate radicals (SO4·−) can effectively degrade the antibiotics. Compared to hydroxyl radicals, sulfate radicals have longer half-lives, stronger oxidizing properties, and wider pH range (pH 3-9), and can degrade the organic pollutants more thoroughly. Sulfate radicals can be generated by the activation of peroxymonosulfate (PMS). The activation of PMS can be achieved by means of transition metal oxides, carbon materials, heating, ultraviolet light, etc. It has been shown that metal oxides such as iron, manganese, and cobalt can be adopted to activate PMS, thereby degrading antibiotics such as tetracycline, ofloxacin, and norfloxacin. However, the synthesis of traditional metal oxides is a complex process, which commonly requires dangerous and expensive compounds as reducing agents or stabilizers, as well as extreme conditions such as high temperature and high pressure, thereby limiting their application scope. In addition, the dissolution of metal oxides may cause the release of metal ions, which are difficult to recover and easily cause secondary pollution.
In view of the shortcomings of traditional chemical synthesis of metal oxides, biosynthesis can be used as one of the important alternatives to metal oxide catalysts. Many microorganisms (such as manganese oxidizing bacteria (MnOB)) can induce the generation of biological manganese oxides (BMOs) through biosynthesis under neutral, normal temperature, and normal pressure conditions. Compared with chemically synthesized metal Mn oxides, BMO produced by manganese oxidizing bacteria has the characteristics of weak crystallinity, high Mn valence, and multiple holes in its octahedral structure, resulting in a stronger reaction activity.
It has been shown that BMO can activate PMS or induce the generation of free radicals in a Fenton-like manner, thereby accelerating the degradation of organic pollutants. For example, biogenic MnO2 can activate PMS to produce singlet oxygen through self-decomposition and energy quenching mechanisms, which can effectively degrade organic matter. Tian et al. (Tian. N., Tian, X., Nie, Y., Yang, C., Zhou, Z., Li, Y., 2018. Biogenic manganese oxide: An efficient peroxymonosulfate activation catalyst for tetracycline and phenol degradation in water. Chemical Engineering Journal, 352:469-476) have shown that BMO has unprecedented efficiency and stability in the degradation of phenol and tetracycline by PMS activation, the reaction rate of which is three times higher than that of chemically synthesized manganese oxides. The bio-iron manganese oxide (bio-FeMnOx) prepared by Du et al. (Du, Z., Li, K., Zhou, S., Liu, X., Yu, Y., Zhang, Y., He, Y., Zhang, Y., 2020. Degradation of ofloxacin with heterogeneous photo-Fenton catalyzed by biogenic Fe-Mn oxides. Chemical Engineering Journal, 380:122427) was applied to the heterogeneous photo-Fenton method to catalyze the degradation of moxifloxacin, and with a catalytic activity of 2 times higher than that of chemically synthesized iron manganese oxide. Thongpitak et al. (Thongpitak, J., Pumas, P., Pumas, C., 2020. Paraquat degradation by biological manganese oxide (BioMnOx) catalyst generated from living microalga Pediastrum duplex AARL G060. Frontiers in Microbiology, 11:575361) used BioMnOx as a catalyst for the Fenton-like reaction to remove pollutants from real wastewater. However, it has been shown that when the synthesized BMO is directly added to the reactor for use, disadvantages such as easy agglomeration of BMO, poor mass transfer effect and limited active sites will occur, resulting in a poor pollutant removal effect.
Therefore, there is an urgent need for an antibiotic wastewater treatment method with excellent antibiotic degradation effect, low cost and no secondary pollution.
An object of the disclosure is to provide a biogenic manganese oxide (BMO)@sponge biomaterial, and a preparation method and application thereof, which has simple process, short treatment time, convenient operation, low treatment cost, wide treatment range and no secondary pollution, and can effectively degrade the antibiotics in wastewater.
In order to achieve the above object, the following technical solutions are adopted.
In a first aspect, this application provides a BMO@sponge biomaterial, wherein the BMO@sponge biomaterial is prepared by loading a manganese oxidizing bacterium and a divalent manganese ion on a sponge carrier.
In some embodiments, the manganese oxidizing bacterium is MnB 1 deposited at American Type Culture Collection (ATCC) with an accession number of ATCC 23483.
In a second aspect, this application provides a method for preparing the above BMO@sponge biomaterial, comprising:
In some embodiments, the culture medium comprises 0.15 g/L ammonium ferrous sulfate, 0.075 g/L yeast leaching powder, 0.15 g/L sodium citrate, 0.05 g/L sodium pyrophosphate and 20 mM N-2-hydroxyethylpiperazine-N-2-ethanesulfonic acid, and has a pH of 7.0-7.2.
In some embodiments, the divalent manganese ion stock solution is a MnSO4·7H2O solution, and the MnSO4·7H2O solution is added such that a final divalent manganese ion concentration in the culture medium is 5-20 mg/L.
In some embodiments, the sponge carrier has a size of 1×1×1 cm, and an addition amount of the sponge carrier is 20-40 blocks/L.
In some embodiments, the manganese oxidizing bacterium is cultured to a logarithmic phase with an optical density at 600 nm (OD600) of 0.9-1.2, and inoculated into the culture medium at an inoculum amount of 1%-5% by volume of the culture medium.
In a third aspect, this application provides a method for treating a wastewater polluted by an antibiotic, comprising:
In some embodiments, the antibiotic is selected from the group consisting of tetracycline, macrolide, aminoglycoside and a combination thereof.
In some embodiments, a dosage of the BMO@sponge biomaterial is 5-15 blocks/L with each block having a size of 1 cm×1 cm×1 cm; a dosage of the PMS is 50-400 mg/L; and the wastewater has a pH of 7-9.
Compared to the prior art, the present disclosure has the following beneficial effects.
In order to make the technical solutions of the embodiments of the present disclosure or the technical solutions in the prior art clearer, the accompanying drawings required in the description of the embodiments or prior art will be briefly described below. Obviously, presented in the drawings are merely some embodiments of the disclosure. For those of ordinary skill in the art, other drawings can be obtained based on the drawings of the disclosure without making creative efforts.
The embodiments of the present disclosure will be described in detail below. The embodiments described herein are merely illustrative of the present application, and are not intended to limit the disclosure. Unless otherwise specified, techniques or conditions can be performed in accordance with those described in the literature in the art or product instructions, and the reagents or instruments are commercially available.
A biogenic manganese oxide (BMO)@sponge biomaterial is prepared through the following steps.
A culture medium is prepared and sterilized, and sequentially added with a divalent manganese ion stock solution and a cleaned sponge carrier. A manganese oxidizing bacterium is inoculated into the culture medium followed by incubation and freeze-drying, so as to obtain the BMO@sponge biomaterial.
The BMO@sponge biomaterial can activate peroxymonosulfate (PMS) to induce the generation of active substances such as a hydroxyl radical, a sulfate radical and a singlet oxygen radical, which further trigger cause a series of physical and chemical reactions and free radical chain reactions to degrade the antibiotic in the wastewater into CO2 and water, thereby achieving the efficient removal of antibiotic pollutants.
The culture medium used herein includes 0.15 g/L ammonium ferrous sulfate, 0.075 g/L yeast leaching powder, 0.15 g/L sodium citrate, 0.05 g/L sodium pyrophosphate and 20 mM N-2-hydroxyethylpiperazine-N-2-ethanesulfonic acid (HEPES), and has a pH of 7.0.
The manganese oxidizing bacterium used herein is Pseudomonas putida strain MnB 1 deposited in American Type Culture Collection (ATCC) with an accession number of ATCC 23483.
Provided herein was a method for preparing a BMO@sponge biomaterial.
A culture medium was autoclaved at 121° C. for 15 min, and then was added with a MnSO4·7H2O solution to a concentration of 15 mg/L. A cleaned sponge carrier with a size of 1 cm (length)×1 cm (width)×1 cm (height) was added to the culture medium at an amount of 30 blocks/L. A MnB1 strain was inoculated into the culture medium at an amount of 5% by volume of the culture medium. The culture medium was cultured in an incubator at 120 rpm and 30° C. for 3 days. The sponge material was collected, washed with deionized water and 0.01 mol/L phosphate buffered saline (PBS) (pH=7.0) 5 times, and then freeze-dried at −60° C. to obtain the BMO@sponge biomaterial. The BMO@sponge biomaterial was characterized by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), and the results were shown in
Referring to the SEM image in
Provided herein was a method for preparing a BMO@sponge biomaterial.
A culture medium was autoclaved at 121° C. for 15 min, and then was added with a MnSO4·7H2O solution to a concentration to 10 mg/L. A cleaned sponge carrier with a size of 1 cm (length)×1 cm (width)×1 cm (height) was added to the culture medium at an amount of 25 blocks/L. A MnB1 strain was inoculated into the culture medium at an amount of 3% by volume of the culture medium. The culture medium was cultured in an incubator at 120 rpm and 30° C. for 2 days. The sponge material was collected, washed with deionized water and 0.01 mol/L PBS (pH=7.0) 5 times, and then freeze-dried at −60° C., so as to obtain the BMO@sponge biomaterial. The BMO@sponge biomaterial was characterized, and the result was shown in
Referring to the X-ray diffraction (XRD) pattern in
Provided herein was a method for preparing a BMO@sponge biomaterial.
A culture medium was autoclaved at 121° C. for 15 min, and then was added with a MnSO4·7H2O solution to a concentration to 20 mg/L. A cleaned sponge carrier with a size of 1 cm (length)×1 cm (width)×1 cm (height) was added to the culture medium at an amount of 20 blocks/L. A MnB1 strain was inoculated into the culture medium at an amount of 3% by volume of the culture medium. The culture medium was cultured in an incubator at 120 rpm and 30° C. for 4 days. The sponge material was collected, washed with deionized water and 0.01 mol/L PBS (pH=7.0) 5 times, and then freeze-dried at −60° C., so as to obtain the BMO@sponge biomaterial.
The oxidative degradation effect of the BMO@sponge biomaterial (prepared in Example 1)-PMS on tetracycline was verified herein.
1 L of a wastewater sample containing 15 mg/L of tetracycline was adjusted to pH 9 with a 0.1 mol/L sodium hydroxide solution, and sequentially added with PMS with a concentration of 200 mg/L and the BMO@sponge biomaterial with a dosage of 10 blocks/L. The wastewater sample was regularly monitored for a change in pH value and maintained at pH 9, and sampled at regular intervals to monitor a change in the tetracycline concentration. The results were shown in Table 1.
As shown in Table 1, the use of BMO@sponge to activate PMS to degrade tetracycline exhibited an excellent catalytic activity. The degradation efficiency for tetracycline was 68.1% at 10 min, and increased to 93.2% at 180 min, indicating that the BMO@sponge can effectively activate PMS to induce the generation of free radicals such as sulfate radicals and hydroxyl radicals, thereby accelerating the oxidative degradation of tetracycline.
The above method was adopted, and blank sponge, PMS, blank sponge+PMS, and BMO@sponge were used as controls to detect effects of using different reaction systems to activate PMS on the degradation of tetracycline. A result was shown in
As shown in
Effect of dosage of the BMO@sponge biomaterial prepared in Example 1 on the degradation of tetracycline was investigated.
1 L of a wastewater sample containing 15 mg/L of tetracycline was adjusted to pH 9 with a 0.1 mol/L sodium hydroxide solution, and sequentially added with PMS with a concentration of 200 mg/L and the BMO@sponge biomaterial with a dosage of 5, 8, 10, 12 and 15 blocks/L, respectively. The wastewater sample was regularly monitored for a change in pH value and maintained at pH 9. After reacting for 3 h, the effect of dosage of the BMO@sponge/PMS on the degradation of tetracycline in wastewater was tested. The results were shown in Table 2.
As shown in Table 2, the use of BMO@sponge at different dosages to activate PMS to degrade tetracycline exhibited an excellent catalytic activity.
The degradation efficiency for tetracycline was 88.6% at 5 blocks/L, and increased to 92.8% at 12 blocks/L.
Effect of concentration of the tetracycline in the wastewater on the degradation of tetracycline by the BMO@sponge biomaterial prepared in Example 2 was investigated.
1 L of wastewater samples containing 5, 10, 15, 20 and 25 mg/L of tetracycline, respectively, were each adjusted to pH 9 with a 0.1 mol/L sodium hydroxide solution, and sequentially added with PMS with a concentration of 200 mg/L and the BMO@sponge biomaterial with a dosage of 10 blocks/L. The wastewater sample was regularly monitored for the pH change and maintained at pH 9. After reacted for 3 h, the degradation effect of the BMO@sponge/PMS on different concentrations of tetracycline in the wastewater was analyzed. The results were shown in Table 3.
As shown in Table 3, under different tetracycline concentrations, the PMS could be activated by the BMO@sponge to catalytically degrade the tetracycline in the wastewater. The degradation efficiency reached 96.5% at a tetracycline concentration of 5 mg/L, and decreased to 89.2% when the tetracycline concentration increased to 25 mg/L.
Degradation efficiency of the BMO@sponge biomaterial prepared in Example 3 against the tetracycline under different pH conditions was investigated.
1 L of wastewater samples containing 15 mg/L were adjusted to pH 3, 5, 7 and 9 with a 0.1 mol/L sodium hydroxide solution or a 0.1 mol/L hydrochloric acid solution, respectively. The wastewater samples were each sequentially added with PMS with a concentration of 200 mg/L and the BMO@sponge biomaterial with a dosage of 15 blocks/L. The wastewater samples were each regularly monitored for a change in pH value and maintained at pH 3, 5, 7 and 9, respectively. After reacting for 3 h, the effect of pH of wastewater on the degradation of tetracycline by the BMO@sponge/PMS was tested. The results were shown in Table 4.
As shown in Table 4, the pH of the wastewater samples had a certain effect on the degradation efficiency of the BMO@sponge/PMS against tetracycline. The degradation efficiency for tetracycline was 82.0% at pH 7, and was 93.4% at pH 9. Under a strong alkaline condition (pH=9), the BMO@sponge biomaterial exhibited a higher catalytic degradation efficiency for tetracycline. This was because that under an alkaline condition, OH-can promote the decomposition of HSO5−, thereby accelerating the generation of SO4·− free radicals. In addition, the strong alkaline condition can inhibit the dissolution of the Mn element.
Effect of PMS concentration on the degradation of tetracycline in the presence of the BMO@sponge biomaterial prepared in Example 3 was investigated.
1 L of wastewater samples containing 15 mg/L of tetracycline were each adjusted to pH 9 with a 0.1 mol/L sodium hydroxide solution, and sequentially added with PMS and a BMO@sponge material with a dosage of 15 blocks/L. The PMS concentrations were 50, 100, 200 and 400 mg/L, respectively. The wastewater sample was regularly monitored for a change in pH value and maintained at pH 9. After reacting for 3 h, the effect of PMS concentration on the degradation of tetracycline by the BMO@sponge/PMS was tested. The results were shown in Table 5.
As shown in Table 5, the PMS concentration had a certain effect on the degradation of tetracycline by using the BMO@sponge biomaterial to activate the PMS. The degradation efficiency for tetracycline was merely 67.4% at a PMS concentration of 50 mg/L, and increased to 93.7% a PMS concentration of 200 mg/L. This indicated that PMS can be effectively activated by the BMO@sponge biomaterial, thereby generating more ·OH and SO4·− radicals, so as to improve the degradation efficiency for tetracycline. However, excessive concentration of PMS can cause a sharp drop in degradation efficiency for tetracycline (only 84.5%).
The reaction between the BMO@sponge biomaterial and PMS was further investigated as follows.
As shown in
As shown in
The embodiments described above are merely illustrative of the present disclosure, and are not intended to limit the patent scope of the present in disclosure. It should be understood that any improvements and modifications made by those skilled in the art without departing from the spirit of the disclosure shall fall within the scope of the disclosure defined by the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202410765947.5 | Jun 2024 | CN | national |
