Hexavalent-chromium reduction immobilization bacterial agent and preparing method

Abstract

The invention discloses an immobilized microbial hexavalent-chromium removing bacterial agent and a preparing method, and belongs to the technical field of chromium pollution site microbial remediation. The bacterial agent is prepared in the mode that calcium alginate serves as a carrier and is embedded with independently-separated wild bacillus. The preparing method includes the steps that an embedding agent and microbial bacterial suspension are evenly mixed according to the proportion of 1:1, the obtained thick mixed liquid is dropped into a CaCl2 solution and is dispersed into balls, coupling is carried out for a certain time, and the gel-state immobilization hexavalent-chromium removing bacterial agent can be obtained. The hexavalent-chromium reduction immobilization bacterial agent is compared with a free chromium reducing bacterium, the removing efficiency of hexavalent chromium can be remarkably improved, and the removing rate can be 100% at 96 h. According to the hexavalent-chromium reduction immobilization bacterial agent prepared with the method, the preparing method is simple and easy to operate, the reaction condition is mild, and the activity and the concentration ofmicrobial bacterial suspension can be efficiently kept; the formed bacterial agent is good in repeatability and stability, the microbial bacterial suspension is not prone to leakage, solid-liquid separation after reacting is facilitated, and the hexavalent-chromium reduction immobilization bacterial agent and the preparing method are suitable for industrial application.

Description

technical field

[0001] The invention belongs to a hexavalent chromium-contaminated site (waste water, waste residue, polluted soil, etc.) microbial remediation, reduction and immobilization bacterial agent and a preparation method thereof, in particular to a hexavalent chromium reduction and immobilization bacterial agent and a preparation method thereof. Background technique

[0002] Chromium is a widely used transition heavy metal with numerous applications in electroplating, leather tanning, wood protection, textile dyeing and metal processing industries. The most common chromium compounds in the atmosphere, soil and water exist as Cr(VI) or Cr(III). Cr(III) is an essential micronutrient element for organisms, which cannot penetrate the cell membrane and is relatively insoluble in water; compared with Cr(III), Cr(VI) has high mobility and high water solubility, and is easy for all organisms Body produces carcinogenicity, teratogenicity, mutagenicity. According to EPA an...

Examples

preparation example Construction

[0027] (1) Preparation method of microbial embedding agent: Weigh 2.0g, 3.0g, 4.0g, 5.0g, and 6.0g of sodium alginate (SA) solids respectively, dissolve them in 100mL deionized water, heat and stir to make them Dissolve, prepare sodium alginate solutions with mass concentrations of 2.0%, 3.0%, 4.0%, 5.0%, and 6.0%, and sterilize under high pressure at 121° C. for 20 minutes.

[0028] (2) Preparation method of microbial cross-linking agent: Weigh 2.0g, 3.0g, 4.0g, 5.0g CaCl respectively 2 Solid, it was dissolved in 100mL deionized water respectively, and the mass concentration was prepared as 2.0%, 3.0%, 4.0%, 5.0% CaCl 2 Solution, autoclave at 121°C for 20min.

[0029] (3) The preparation method of 0.85% normal saline: weigh 8.5 g of solid sodium chloride, dissolve it in a certain amount of deionized water, wait until it is completely dissolved, and set the volume to 1000 mL. Aliquot and autoclave at 121°C for 20 minutes.

[0030] (4) Preparation method of bacterial suspens...

Embodiment 1

[0036] The method described in this embodiment mainly proceeds according to the following steps:

[0037] 1. Prepare 100mL 2.0% SA, 100mL 3.0% SA, 100mL 4.0% SA, 100mL 5.0% SA, 100mL 6.0% SA. Prepare 100mL 2.0% CaCl 2 , 100 mL 3.0% CaCl 2 , 100mL 4.0% CaCl 2 , 100 mL 2.0% CaCl 2. Prepare 1000 mL of NaCl with a mass concentration of 0.85%, and sterilize under high pressure.

[0038] 2. Take the bacterial solution and centrifuge it at 8000-10000rpm for 10-15min, wash it with sterile water three times, mix it with sodium alginate at a ratio of 1:1, and drop the mixture into different proportions of CaCl with a syringe 2 After being fixed in the solution for a certain period of time, it is washed three times with 0.85% physiological saline to obtain a gelatinous hexavalent chromium reduction immobilized bacterial agent.

[0039] 3. Take a part of the hexavalent chromium reduction-immobilized bacterial agent prepared in different proportions for permeability testing and mecha...

Embodiment 2

[0048] The method described in this embodiment mainly proceeds according to the following steps:

[0049] 1. Prepare 100mL of 3.0% SA. Prepare 100mL 3.0% CaCl 2 . Prepare 1000 mL of NaCl with a mass concentration of 0.85%, and sterilize under high pressure.

[0050] 2. Take the bacterial solution and centrifuge it at 8000-10000rpm for 10-15min, wash it with sterile water three times, mix it with sodium alginate evenly according to the ratio of 1:1, and drop the mixture into CaCl with a syringe 2 solution, after the respective immobilization time, wash three times with 0.85% physiological saline, and obtain the hexavalent chromium reduction immobilization bacterial agent ( figure 1 ).

[0051] 3. Take a part of the prepared hexavalent chromium reduction-immobilized bacterial agent for permeability detection and mechanical strength detection.

[0052] 4. Weigh 5 g of the prepared hexavalent chromium reduction-immobilized bacterial agent, inoculate it into LB medium containi...

technical field

[0001] The invention belongs to a hexavalent chromium-contaminated site (waste water, waste residue, polluted soil, etc.) microbial remediation, reduction and immobilization bacterial agent and a preparation method thereof, in particular to a hexavalent chromium reduction and immobilization bacterial agent and a preparation method thereof. Background technique

[0002] Chromium is a widely used transition heavy metal with numerous applications in electroplating, leather tanning, wood protection, textile dyeing and metal processing industries. The most common chromium compounds in the atmosphere, soil and water exist as Cr(VI) or Cr(III). Cr(III) is an essential micronutrient element for organisms, which cannot penetrate the cell membrane and is relatively insoluble in water; compared with Cr(III), Cr(VI) has high mobility and high water solubility, and is easy for all organisms Body produces carcinogenicity, teratogenicity, mutagenicity. According to EPA an...

Examples

preparation example Construction

[0027] (1) Preparation method of microbial embedding agent: Weigh 2.0g, 3.0g, 4.0g, 5.0g, and 6.0g of sodium alginate (SA) solids respectively, dissolve them in 100mL deionized water, heat and stir to make them Dissolve, prepare sodium alginate solutions with mass concentrations of 2.0%, 3.0%, 4.0%, 5.0%, and 6.0%, and sterilize under high pressure at 121° C. for 20 minutes.

[0028] (2) Preparation method of microbial cross-linking agent: Weigh 2.0g, 3.0g, 4.0g, 5.0g CaCl respectively 2 Solid, it was dissolved in 100mL deionized water respectively, and the mass concentration was prepared as 2.0%, 3.0%, 4.0%, 5.0% CaCl 2 Solution, autoclave at 121°C for 20min.

[0029] (3) The preparation method of 0.85% normal saline: weigh 8.5 g of solid sodium chloride, dissolve it in a certain amount of deionized water, wait until it is completely dissolved, and set the volume to 1000 mL. Aliquot and autoclave at 121°C for 20 minutes.

[0030] (4) Preparation method of bacterial suspens...

Embodiment 1

[0036] The method described in this embodiment mainly proceeds according to the following steps:

[0037] 1. Prepare 100mL 2.0% SA, 100mL 3.0% SA, 100mL 4.0% SA, 100mL 5.0% SA, 100mL 6.0% SA. Prepare 100mL 2.0% CaCl 2 , 100 mL 3.0% CaCl 2 , 100mL 4.0% CaCl 2 , 100 mL 2.0% CaCl 2. Prepare 1000 mL of NaCl with a mass concentration of 0.85%, and sterilize under high pressure.

[0038] 2. Take the bacterial solution and centrifuge it at 8000-10000rpm for 10-15min, wash it with sterile water three times, mix it with sodium alginate at a ratio of 1:1, and drop the mixture into different proportions of CaCl with a syringe 2 After being fixed in the solution for a certain period of time, it is washed three times with 0.85% physiological saline to obtain a gelatinous hexavalent chromium reduction immobilized bacterial agent.

[0039] 3. Take a part of the hexavalent chromium reduction-immobilized bacterial agent prepared in different proportions for permeability testing and mecha...

Embodiment 2

[0048] The method described in this embodiment mainly proceeds according to the following steps:

[0049] 1. Prepare 100mL of 3.0% SA. Prepare 100mL 3.0% CaCl 2 . Prepare 1000 mL of NaCl with a mass concentration of 0.85%, and sterilize under high pressure.

[0050] 2. Take the bacterial solution and centrifuge it at 8000-10000rpm for 10-15min, wash it with sterile water three times, mix it with sodium alginate evenly according to the ratio of 1:1, and drop the mixture into CaCl with a syringe 2 solution, after the respective immobilization time, wash three times with 0.85% physiological saline, and obtain the hexavalent chromium reduction immobilization bacterial agent ( figure 1 ).

[0051] 3. Take a part of the prepared hexavalent chromium reduction-immobilized bacterial agent for permeability detection and mechanical strength detection.

[0052] 4. Weigh 5 g of the prepared hexavalent chromium reduction-immobilized bacterial agent, inoculate it into LB medium containi...

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