Preparation method of iron and manganese modified biochar immobilized strain

Abstract

The invention discloses a preparation method of an iron and manganese modified biochar immobilized strain, and relates to a preparation method of a wastewater purification bacterial strain, the method adopts waste armeniaca sibirica shells to prepare biochar, realizes waste recycling, enriches the pore structure and functional groups on the surface of the biochar through iron and manganese modification, and improves the biochar utilization rate. Therefore, the heavy metal adsorption capacity of the biochar is improved. Then, the microbial activity and the cell density are improved through immobilization, the adaptability to environmental interference is enhanced, and the material is easier to collect and regenerate. According to the biochar immobilization method, synchronous denitrification and copper removal in a single system are successfully realized, the occupied area and energy consumption are reduced, and a new environment-friendly method is provided for treatment of composite pollutants of heavy metals and nitrogen sources.

Description

Technical Field

[0001] The invention relates to a method for preparing a wastewater purification strain, and in particular to a method for preparing an iron-manganese modified biochar immobilized strain. Background Art

[0002] With the development of electroplating, metallurgy and other industries, the treatment of complex pollutants in water bodies has become an environmental problem that needs to be solved urgently. These complex pollutants mainly include nitrogen, heavy metals and antibiotics, among which nitrogen and heavy metal pollutants are the most common. The pollution of nitrogen sources in water bodies is becoming increasingly serious, which can cause large-scale seasonal hypoxia, eutrophication and large-scale outbreaks of harmful algae and other environmental problems. At the same time, copper is a common heavy metal in industrial wastewater. Excessive copper entering the sewage biological treatment system will cause a large number of microorganisms to die, resulting in a serious decrease in denitrification efficiency or even the collapse of the system.

[0003] Immobilization technology using biochar as a carrier is a key technology to improve the effectiveness of microbial remediation. Compared with free microorganisms, biochar-immobilized microorganisms have specific advantages over free microorganisms, such as higher levels of biological activity and cell density, greater adaptability to environmental disturbances, and easier collection and regeneration. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing an iron-manganese modified biochar immobilized strain, wherein the method prepares apricot shell biochar from apricot shell, thereby realizing the resource utilization of waste. The adsorption performance of biochar for heavy metal ions is improved by iron-manganese modification. And by utilizing immobilization, biodegradation and adsorption are combined, thereby realizing the simultaneous removal of nitrogen and copper ions in a single system.

[0005] The technical method of the present invention is as follows A method for preparing an iron-manganese modified biochar immobilized strain comprises the following steps: Material preparation: Select biomass materials of appropriate thickness, cut them to appropriate size, clean them and dry them for later use.

[0006] Preparation of biochar: calcining the biomass material obtained in step (1) to obtain biochar.

[0007] Modification of biochar: The biochar prepared in step (2) is sequentially immersed in a nitric acid solution, a potassium permanganate solution, a ferrous sulfate solution and a potassium hydroxide solution to obtain iron-manganese modified biochar.

[0008] Preparation of modified biochar immobilized bacteria: The modified biochar obtained in step (3) is mixed with the bacterial suspension, cultured, and filtered to obtain a modified biochar immobilized bacteria composite material.

[0009] For the above preparation method, preferably, in step (1), the material of the biomass is apricot shell. The preparation steps mainly include selecting apricot shells with appropriate quality and thickness, cutting them into small pieces of 0.5 - 1 cm, washing the impurities on the surface with deionized water, and drying them in an oven at 80 - 100 °C.

[0010] For the above preparation method, preferably, in step (2), the calcination conditions of the biochar are as follows: using a tubular furnace, under the condition of nitrogen as an inert gas, heating at a heating rate of 5 - 8 °C / min to 500 - 600 °C, and maintaining the temperature at this level for 2 - 3 h. The prepared biochar is rinsed with pure water until neutral, dried in an oven at 80 - 100 °C, crushed and sieved through 70 - 100 meshes, and stored in a sealed bag for later use.

[0011] For the above preparation method, preferably, in step (3), the concentrations of the solutions used for impregnation are 0.5 - 1 mol / L nitric acid solution, 0.5 - 1 mol / L potassium permanganate solution, 0.3 - 1 mol / L ferrous sulfate solution, and 0.5 - 1 mol / L potassium hydroxide solution respectively, and the impregnation time is 12 - 24 h. After impregnation in the solutions in sequence, it is washed with deionized water and then dried overnight in an oven at 80 - 100 °C to obtain iron-manganese modified biochar.

[0012] For the above preparation method, preferably, in step (4), the addition amount of the modified biochar is 0.5 g - 0.8 g of biochar added to each liter of the bacterial suspension, and the bacterial genus selected for the bacterial suspension is Pseudomonas hunanensis SK-4, the OD of the bacterial suspension 600 is 1 - 1.5, and the culture time is 12 h - 24 h.

[0013] For the above preparation method, preferably, in step (4), the culture conditions of the bacterial suspension are as follows: in a constant temperature incubator, at a rotation speed of 120 - 140 rpm and a culture temperature of 28 - 32 °C, and the culture time is 12 - 16 h.

[0014] For the above preparation method, preferably, in step (4), the preparation method of the bacterial suspension includes the following steps: S1: Using an inoculation loop on the purified Pseudomonas hunanensisPick 1-3 single colonies from the SK-4 plate and inoculate them into the enrichment medium. The formula of the enrichment medium is: NH4Cl 0.36-0.4 g / L, sodium succinate 5.6-6 g / L, K2HPO4 0.8-1.2 g / L, KH2PO4 0.4-0.6 g / L, MgSO4·7H2O 0.05-0.15 g / L, FeSO4·7H2O 0.04-0.08 g / L, ZnSO4·7H2O 0.36 g / L, trace element solution 1-3 ml / L, pH 7-8; S2: The formula of the trace element solution is: EDTA-2Na 55-60 mg / L, CaCl2·2H2O 7-10 mg / L, MnCl2·4H2O 5-8 / L, FeSO4·7H2O 4-8 mg / L, CuSO4·5H2O 1-3 mg / L, COCl2 1-3 mg / L.

[0015] As a general technical concept, the present invention also provides a material of modified biochar immobilized strain prepared by the method for preparing iron and manganese modified biochar immobilized strain as described above.

[0016] As a general technical concept, the present invention also provides an application of the above-mentioned iron and manganese modified biochar immobilized strain in the remediation process of heavy metal and nitrogen compound pollutants.

[0017] The advantages of the present invention are as follows: 1. Iron and manganese modified biochar immobilized microorganisms have specific advantages superior to free microorganisms. The iron and manganese elements on the biochar surface promote higher levels of biological activity and cell density, are more adaptable to environmental interference, and are easier to collect and regenerate.

[0018] 2. Iron and manganese modified biochar immobilized microorganisms can achieve synchronous denitrification and heavy metal removal in a single system, greatly reducing the land occupation space and energy consumption.

[0019] 3. The rich functional groups on the surface of the iron and manganese modified biochar immobilized microorganism material can promote the efficient absorption of heavy metal ions, greatly improving the degradation efficiency of compound pollutants. Description of the Drawings

[0020] Figure 1 It is a graph of the removal efficiency of iron and manganese modified biochar immobilized microorganisms in copper and nitrogen compound pollutant wastewater; Figure 2 It is a SEM image of the surface of iron and manganese modified biochar immobilized microorganisms after being applied in copper and nitrogen compound pollutant wastewater. Detailed Embodiments

[0021] The present invention will be described in detail below with reference to the embodiments shown in the accompanying drawings.

[0022] The iron-manganese modified biochar-immobilized microorganisms of the present invention can maintain excellent denitrification and copper removal capabilities under the impact of high-concentration heavy metal Cu 2+ and provide a new method for the treatment of complex pollutants in water bodies, improving the treatment efficiency of composite pollutants and having broad application prospects.

[0023] Example 1: Denitrification and copper removal capabilities of iron-manganese modified biochar-immobilized microorganisms The formulation of the simulated copper-containing wastewater is as follows: NH4Cl 0.36 - 0.4 g / L, sodium succinate 5.6 - 6 g / L, K2HPO4 0.8 - 1.2 g / L, KH2PO4 0.4 - 0.6 g / L, MgSO4·7H2O 0.05 - 0.15 g / L, FeSO4·7H2O 0.04 - 0.08 g / L, ZnSO4·7H2O 0.36 g / L, CuCl2·2H2O 0.06 - 0.1 g / L, trace element solution 1 - 3 ml / L, pH 7 - 8; The formulation of the trace element solution is: EDTA-2Na 55 - 60 mg / L, CaCl2·2H2O 7 - 10 mg / L, MnCl2·4H2O 5 - 8 / L, FeSO4·7H2O 4 - 8 mg / L, CuSO4·5H2O 1 - 3 mg / L, CoCl2 1 - 3 mg / L.

[0024] The prepared iron-manganese modified biochar-immobilized microorganisms were added to 100 - 150 ml of the simulated copper-containing wastewater culture medium at a dosage of 1 - 1.5 g / L and cultured for 16 - 24 h under the conditions of 30 - 35 °C and 120 - 140 rpm. Samples were taken every 3 - 4 h, and the supernatant was obtained after centrifugation and filtration, and the ammonia nitrogen and Cu(II) contents were measured. The experimental results are as Figure 1 shown.

[0025] The prepared iron-manganese modified biochar immobilized microorganisms were added to 100-150 ml of simulated copper-containing wastewater culture medium at a dosage of 1-1.5 g / L and cultured for 24 h under the conditions of 30 °C and 120 rpm. After standing and sedimentation, the used iron-manganese modified biochar immobilized microorganisms were obtained by filtration. An appropriate amount of the material was placed in a test tube, fixed with a fixing solution and refrigerated overnight. Then the fixing solution was poured out, and the sample was rinsed three times with a 0.1-0.3 M, pH 7-8 phosphate buffer solution for 12-18 min each time. Subsequently, the cell sample was fixed with a 0.5-1% osmium tetroxide solution for 1-2 h, the osmium tetroxide waste liquid was carefully taken out, and the sample was rinsed 3-4 times with a 0.1-0.3 M phosphate buffer PB (pH 7.4) for 15-20 min each time. The sample was dehydrated with ethanol solutions of gradient concentrations (including six concentrations of 30%, 50%, 70%, 80%, 90% and 95%) for 15 min for each concentration, then treated with 100% ethanol for 20 min. Finally, new 100% ethanol was replaced, and the sample was placed in 100% ethanol. It was dried in a critical point dryer. Finally, the sample was fixed on the sample stage with conductive carbon glue, and Pt was sputtered by an ionic sputtering instrument for 115-125 s. The sample was prepared, and then the surface morphology of the material was observed under a scanning electron microscope (SEM). The surface morphology of the material was as Figure 2 shown.

[0026] The present invention includes but is not limited to the above embodiments. Technical substitution of some contents in the embodiments still falls within the technical protection scope of the present invention.

Claims

1. A preparation method of iron-manganese modified biochar immobilized strain, characterized in that, The method includes the following steps: Preparation of materials: Select biomass materials with appropriate thickness, cut them into appropriate sizes, clean them, and dry them for later use; Preparation of biochar: Calcinate the biomass materials obtained in step (1) to obtain biochar; Modification of biochar: Immerse the biochar prepared in step (2) successively in nitric acid solution, potassium permanganate solution, ferrous sulfate solution, and potassium hydroxide solution to obtain iron-manganese modified biochar; Preparation of immobilized strain with modified biochar: Mix the modified biochar obtained in step (3) with the bacterial suspension, cultivate it, and filter it to obtain a composite material of immobilized bacteria with modified biochar.

2. The preparation method of an iron and manganese modified biochar immobilized strain according to claim 1, characterized in that, The biomass material used in step (1) is Prunus armeniaca var. ansu shell. The preparation steps include selecting Prunus armeniaca var. ansu shells with appropriate quality and thickness, cutting them into small pieces of 0.5 - 1 cm, cleaning the impurities on the surface with deionized water, and drying them in an oven at 80 - 100 °C.

3. The preparation method of an iron and manganese modified biochar immobilized strain according to claim 1, characterized in that, The calcination conditions of the biochar in step (2) are as follows: Use a tube furnace. Under the condition of nitrogen as an inert gas, heat it at a heating rate of 5 - 8 °C / min to 500 - 600 °C, and keep it at this temperature for 2 - 3 h; The prepared biochar is rinsed with pure water until neutral, dried in an oven at 80 - 100 °C, crushed and sieved through 70 - 100 meshes, and stored in a sealed bag for later use.

4. The preparation method of an iron-manganese modified biochar-immobilized strain according to claim 1, characterized in that, The concentrations of the solutions used for immersion in step (3) are 0.5 - 1 mol / L nitric acid solution, 0.5 - 1 mol / L potassium permanganate solution, 0.3 - 1 mol / L ferrous sulfate solution, and 0.5 - 1 mol / L potassium hydroxide solution respectively, and the immersion time is 12 - 24 h. After successively immersing in the solutions in order, wash it with deionized water and dry it overnight in an oven at 80 - 100 °C to obtain iron-manganese modified biochar.

5. The preparation method of an iron and manganese modified biochar immobilized strain according to claim 1, characterized in that, The addition amount of the modified biochar in step (4) is 0.5 g - 0.8 g of biochar added to each liter of bacterial suspension. The bacterial genus selected for the bacterial suspension is Pseudomonas hunanensis SK-4, the OD600 of the bacterial suspension is 1 - 1.5, and the cultivation time is 12 h - 24 h.

6. The preparation method of an iron and manganese modified biochar immobilized strain according to any one of claims 1 to 5, characterized in that The cultivation conditions of the bacterial suspension in step (4) are as follows: In a constant temperature incubator, rotate at a speed of 120 - 140 rpm, at a cultivation temperature of 28 - 32 °C, and the cultivation time is 12 - 16 h.

7. The preparation method of an iron and manganese modified biochar immobilized strain according to claim 6, characterized in that, The preparation method of the bacterial suspension in step (4) includes the following steps: S1: Pick 1 - 3 single colonies on the purified Pseudomonas hunanensis SK - 4 plate with an inoculation loop and inoculate them into the enrichment medium. The formula of the enrichment medium is: NH4Cl 0.36 - 0.4 g / L, sodium succinate 5.6 - 6 g / L, K2HPO4 0.8 - 1.2 g / L, KH2PO4 0.4 - 0.6 g / L, MgSO4·7H2O 0.05 - 0.15 g / L, FeSO4·7H2O 0.04 - 0.08 g / L, ZnSO4·7H2O 0.36 g / L, trace element solution 1 - 3 ml / L, pH 7 - 8; S2: The formula of the trace element solution is: EDTA - 2Na 55 - 60 mg / L, CaCl2·2H2O 7 - 10 mg / L, MnCl2·4H2O 5 - 8 / L, FeSO4·7H2O 4 - 8 mg / L, CuSO4·5H2O 1 - 3 mg / L, COCl2 1 - 3 mg / L.

8. A preparation method of an iron and manganese modified biochar immobilized strain according to any one of claims 1 to 7, characterized in that, The immobilized strain of modified biochar prepared by the said method is used in the remediation process of heavy metal and nitrogen compound pollutants.

Images