阅读说明：本技术 一种微生物固化铬渣的方法 (Method for solidifying chromium slag by microorganisms ) 是由 尹雅洁 王德强 于 2019-11-22 设计创作，主要内容包括：本发明涉及一种微生物固化铬渣的方法,属于固体废弃物处理技术领域,该方法中将铬渣球磨处理后与河砂、高岭土均匀混合,且在混合的同时喷洒菌液,获得混合物,然后将所述混合物填入快速试模,振实,最后进行养护,养护期间向固化体表面均喷含钙培养基,以刚润湿所述固化体表面为准；所述菌液为产左聚糖微杆菌菌液、巴氏生孢八叠球菌菌液或产左聚糖微杆菌和巴氏生孢八叠球菌的复合菌液。该方法中通过合理控制菌液浓度及用量,使其不仅可以较好地还原六价铬进行解毒,还能充分利用其生物矿化作用将铬进行固封,使铬无法迁移。该方法整个过程在环境温度下发生,反应温和且环保,适合扩大化应用。(The invention relates to a method for solidifying chromium slag by microorganisms, which belongs to the technical field of solid waste treatment, wherein the method comprises the steps of ball-milling chromium slag, uniformly mixing with river sand and kaolin, spraying bacterial liquid while mixing to obtain a mixture, filling the mixture into a rapid test mold, compacting, and finally maintaining, wherein a calcium-containing culture medium is sprayed on the surface of a solidified body during maintenance, and the surface of the solidified body is just moistened; the bacterial liquid is a bacterial liquid of microbacterium levanseri, a bacterial liquid of sarcina pasteurellum or a composite bacterial liquid of microbacterium levanseri and sarcina pasteurellum. In the method, the concentration and the dosage of the bacterial liquid are reasonably controlled, so that hexavalent chromium can be well reduced for detoxification, and the biological mineralization of the hexavalent chromium can be fully utilized to seal the hexavalent chromium, so that the hexavalent chromium cannot migrate. The method has the advantages that the whole process is carried out at the ambient temperature, the reaction is mild and environment-friendly, and the method is suitable for expanded application.)

1. A method for solidifying chromium slag by microorganisms is characterized by comprising the following steps:

uniformly mixing the chromium slag after ball milling treatment with river sand and kaolin, spraying bacterial liquid while mixing to obtain a mixture, filling the mixture into a rapid test mold, compacting, and finally maintaining, wherein a calcium-containing culture medium is sprayed on the surface of a solidified body during maintenance, and the surface of the solidified body is just wetted; the bacterial liquid is a bacterial liquid of microbacterium levanseri, a bacterial liquid of sarcina pasteurellum or a composite bacterial liquid of microbacterium levanseri and sarcina pasteurellum.

2. The method of claim 1, wherein the mixing is performed while mixing the mixture in a solid to liquid ratio of 3 to 7: 1, spraying a bacterium solution, wherein the unit of the solid-liquid ratio is g: mL, the concentration of bacteria in the bacterial liquid is 10⁷cfu/mL or more.

3. The method of claim 2, wherein the mixing is performed while mixing the mixture in a solid to liquid ratio of 7: 1, spraying a bacterium solution, wherein the unit of the solid-liquid ratio is g: mL, the concentration of bacteria in the bacterial liquid is 10⁹cfu/mL。

4. The method according to claim 1 or 2, wherein the mass ratio of the chromium slag, the river sand and the kaolin is 8: 1-2: 0.5-1.

5. The method of claim 4, wherein the mass ratio of the chrome slag, the river sand and the kaolin is 8: 1: 1.

6. the method of claim 1 or claim 2, wherein the chrome slag has a particle size of less than 10mm after ball milling, the river sand has a particle size of less than 2mm, and the kaolin has a particle size of less than 2 mm.

7. The method of claim 1 or 2, wherein the curing time is 28 to 60 days.

8. The method of claim 1 or 2, wherein the calcium-containing medium is sprayed onto the surface of the solidified body every 1 to 5 days during the curing period.

9. The method of claim 1 or 2, wherein the calcium-containing medium comprises the following components: 10-18g/L peptone, 2-6g/L beef extract, 3-5g/L NaCl, 20-60g/L urea and 0-0.03g/L NiCl₂、50-100g/LCaCl₂The pH value is 8-10.

10. The method of claim 9, wherein the calcium-containing medium comprises the following components: 15g/L peptone, 5g/L beef extract, 5g/L NaCl, 50g/L urea and 0.005g/L NiCl₂、92.5g/L CaCl₂The pH was 9.

Technical Field

The invention belongs to the technical field of solid waste treatment, and particularly relates to a method for solidifying chromium slag by microorganisms.

Background

The harmless treatment of the chromium slag comprises dry detoxification, wet detoxification, microwave radiation detoxification, complex process detoxification, physical solidification and microbial detoxification. The technology for detoxifying chromium pollution by microorganisms is an economic and efficient chromium slag detoxification method due to low investment and simple requirements on equipment and site, can adapt to low temperature and a wide pH value range, does not need to additionally add a large amount of chemical reagents, is green and environment-friendly, and can realize metal recovery by combining the bacterial leaching effect. Therefore, the microbial detoxification technology has application prospects in the aspects of treatment, detoxification, resource utilization and the like of the chromium slag, but the microbial detoxification method has slow effect and the phenomenon of yellowing of the chromium slag. The physical solidification method is to wrap the chromium slag (or the chromium-containing waste slag) and isolate the chromium slag (or the chromium-containing waste slag) from contacting with the outside, thereby realizing the immobilization and stabilization of the chromium slag (or the chromium-containing waste slag), but the method can not continuously detoxify and has the risk of chromium migration after the solidified body cracks for a long time. Therefore, a method for treating chromium slag, which can be used for continuously detoxifying at low cost, is urgently needed.

Disclosure of Invention

In view of the above, the present invention provides a method for solidifying chromium slag by microorganisms.

In order to achieve the purpose, the invention provides the following technical scheme:

a method for solidifying chromium slag by microorganisms comprises the following steps:

uniformly mixing the chromium slag after ball milling treatment with river sand and kaolin, spraying bacterial liquid while mixing to obtain a mixture, filling the mixture into a rapid test mold, compacting, and finally maintaining, wherein a calcium-containing culture medium is sprayed on the surface of a solidified body during maintenance, and the surface of the solidified body is just wetted; the bacterial liquid is a bacterial liquid of microbacterium levanseri, a bacterial liquid of sarcina pasteurellum or a composite bacterial liquid of microbacterium levanseri and sarcina pasteurellum.

Preferably, the solid-liquid ratio is 3-7: 1, spraying a bacterium solution, wherein the unit of the solid-liquid ratio is g: mL, the concentration of bacteria in the bacterial liquid is 10⁷cfu/mL or more.

Preferably, and while mixing, the ratio of solid to liquid is 7: 1, spraying a bacterium solution, wherein the unit of the solid-liquid ratio is g: mL, the concentration of bacteria in the bacterial liquid is 10⁹cfu/mL。

Preferably, the mass ratio of the chromium slag to the river sand to the kaolin is 8: 1-2: 0.5-1.

Preferably, the mass ratio of the chromium slag to the river sand to the kaolin is 8: 1: 1.

preferably, the particle size of the chromium slag after ball milling treatment is less than 10mm, the particle size of the river sand is less than 2mm, and the particle size of the kaolin is less than 2 mm.

Preferably, the curing time is 28-60 days.

Preferably, the calcium-containing culture medium is sprayed on the surface of the solidified body every 1 to 5 days during the curing period.

Preferably, the calcium-containing medium comprises the following components: 10-18g/L peptone, 2-6g/L beef extract, 3-5g/L NaCl, 20-60g/L urea and 0-0.03g/L NiCl₂、50-100g/L CaCl₂The pH value is 8-10.

Preferably, the calcium-containing medium comprises the following components: 15g/L peptone, 5g/L beef extract, 5g/L NaCl, 50g/L urea and 0.005g/L NiCl₂、92.5g/L CaCl₂The pH was 9.

The invention has the beneficial effects that: the invention provides a method for curing chromium slag by microorganisms, which uses a strain liquid of microbacterium laevans, a strain liquid of sarcina pasteurianum or a compound strain liquid of microbacterium laevans and sarcina pasteurianum as an adhesive for detoxifying and curing chromium slag, and reasonably controls the concentration and the dosage of the strain liquid to ensure that the strain liquid can better reduce hexavalent chromium for detoxification and can fully utilize the biological mineralization of the strain liquid to seal chromium so that the chromium cannot migrate, the reason is that the microbacterium laevans and the sarcina pasteurianum both have hexavalent chromium reducing capability and urease activity which can provide enough hexavalent chromium reductase activity and urease activity under the specific mixture ratio of culture medium components and ensure that mineralized particles formed by trivalent chromium and calcium carbonate have higher physical strength and acid resistance after the two activities reach balance, thereby achieving the best detoxification and solidification of the chromium slag. The method has the advantages that the whole process is carried out at the ambient temperature, the reaction is mild and environment-friendly, and the method is suitable for expanded application.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the means of the instrumentalities and combinations particularly pointed out hereinafter.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.