CN110713959A

CN110713959A - Microbial agent for heavy metal pollution remediation and application thereof

Info

Publication number: CN110713959A
Application number: CN201911190702.XA
Authority: CN
Inventors: 郭娜; 郭章伟; 刘涛
Original assignee: Shanghai Maritime University
Current assignee: Shanghai Maritime University
Priority date: 2019-11-28
Filing date: 2019-11-28
Publication date: 2020-01-21

Abstract

The invention discloses a microbial agent for heavy metal pollution remediation and application thereof. The raw materials of the microbial agent comprise, by weight, 1-2 parts of alkaline producing water bacteria, 1-2 parts of bacillus subtilis, 90-100 parts of peptone, 15-20 parts of yeast extract, 0.5-1 part of ferric phosphate, 30-40 parts of urea, 1000 parts of water and 0.2-0.5 part of sodium hydroxide. The microbial agent can be obtained by shaking and culturing the raw materials of the microbial agent at 37 ℃ and 120-130r/min for 18 hours. The microbial agent can be used for remediation of heavy metal pollution of soil or wastewater, a large amount of water-producing alkaline bacteria and bacillus subtilis are cultured and propagated in the soil and the wastewater, a large amount of bicarbonate radicals are generated by decomposing urea, and under the action of the bicarbonate radicals, heavy metals in the soil and the wastewater form carbonate deposits to achieve the aim of removing the heavy metals.

Description

Microbial agent for heavy metal pollution remediation and application thereof

Technical Field

The invention relates to the technical field of environmental protection, and particularly relates to a microbial agent for heavy metal pollution remediation and application thereof.

Background

The environment is the foundation for human survival and development, the good ecological environment is closely related to everyone, and the maintenance of the good ecological environment is the key for promoting ecological civilization construction and maintaining ecological safety. In the process of industrial development, the general conditions of the environment in some places are great, and heavy metal pollution is serious, wherein cadmium, lead, chromium, copper, mercury, arsenic, nickel and the like are common heavy metal pollution. The industrial development causes the pollution of soil and water to be continuously aggravated, the content of heavy metal elements in soil and water near factories such as partial electroplating and batteries exceeds standard, the toxicity is high, and the drinking water and the enrichment of a food chain cause harm to the life safety and the ecological environment of human beings. Therefore, the development of a technology for removing heavy metal elements in the environment becomes the key of ecological restoration, environmental protection and ecological safety maintenance.

At present, the remediation of heavy metal contaminated soil and water mainly comprises three methods of physical and chemical remediation, chemical remediation and biological remediation. The former two methods are more traditional treatment methods, have the defects of complex process, expensive equipment, high energy consumption, easy secondary pollution and the like, and are not beneficial to large-scale popularization and application. In recent years, the bioremediation technology for treating environmental heavy metal pollution becomes a hotspot, but the problem of low heavy metal removal rate still exists, and the current method for treating heavy metal by microorganisms becomes a hotspot as a new technology.

Recently, as a potential and promising approach, the use of microorganism-induced carbonate precipitation (MICP) to treat heavy metal contamination has been developed. Carboxyl, hydroxyl, amino groups in Extracellular Polymers (EPS) on bacterial surfaces can complex heavy metal ions and then form insoluble and stable carbonate precipitates in the environment. Among MICPs, urease-producing microorganisms are currently being studied more because they can produce a large amount of carbonate ions through hydrolysis of urea and increase of pH, promoting the formation of carbonates in the environment.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide the environment-friendly microbial agent for heavy metal pollution remediation and the application thereof.

In order to achieve the aim, the invention provides a microbial agent for heavy metal pollution remediation, which comprises the following raw materials, by weight, 1-2 parts of alkaline-producing water bacteria, 1-2 parts of bacillus subtilis, 90-100 parts of peptone, 15-20 parts of yeast extract, 0.5-1 part of ferric phosphate, 30-40 parts of urea, 1000 parts of water and 0.2-0.5 part of sodium hydroxide.

Preferably, the preparation method of the microbial agent comprises the following steps: the raw materials of the microbial agent are uniformly mixed, and the microbial agent is obtained after shaking culture for 18 hours at the temperature of 37 ℃ and at the speed of 120-130 r/min.

The microbial agent for heavy metal pollution remediation can be used for removing heavy metals in soil or wastewater.

Preferably, the microbial agent is added into soil or wastewater to be repaired, and the soil or wastewater is mixed uniformly and then fermented to remove heavy metal pollution in the soil or wastewater.

Preferably, the temperature of the fermentation is 30-37 ℃.

Preferably, the mass ratio of the added microbial agent to the soil or wastewater to be restored is (1-1.2): 1.

preferably, the fermentation time is 4 weeks when the soil is remediated.

Preferably, when the soil is repaired, urea is added to the soil to be repaired once a week in the fermentation process, and the mass ratio of the addition amount of the urea to the soil to be repaired is 0.05: 1.

preferably, the fermentation time is 4 days when the wastewater is repaired.

Preferably, when the wastewater is repaired, the wastewater is subjected to oscillation or aeration treatment after the microbial agent is added to the wastewater.

The invention has the beneficial effects that:

the microbial agent for heavy metal pollution remediation is nontoxic, harmless, pollution-free, pathogenicity-free, easy to store and transport, low in cost, simple in preparation and use methods, high in heavy metal removal rate, capable of recycling precious heavy metal resources, and suitable for large-scale popularization and application.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The microbial agent for heavy metal pollution remediation provided by the invention can be used for fundamentally removing heavy metal ions by using a biological deposition treatment method. The invention utilizes the compound microbial agent to generate adsorption or deposition to promote the transformation and precipitation of heavy metal forms in soil and wastewater, a large amount of water-producing alkaline bacteria and bacillus subtilis are cultured and propagated in the soil and the wastewater by adding the compound microbial agent and urea into the soil and the wastewater, a large amount of bicarbonate radicals are generated by decomposing the urea, and the heavy metal in the soil and the wastewater forms carbonate deposition under the action of the bicarbonate radicals to achieve the aim of removing the heavy metal. Alcaligenes aquaticus (Alcaligenes aquatilis) used in the following examples, which had a size of 0.5 to 1.2. mu.m.times.0.5 to 2.6. mu.m, was in the form of a short stick and purchased from China center for culture Collection of marine microorganisms, and had a strain number of 1A 00086. The bacteria are not pathogenic. Bacillus subtilis (Bacillus subtilis) is commercially available.

Example 1

The test soil sample (soil to be repaired) is collected from a heavy metal pollution area near a certain battery factory, and the heavy metal content in the surface soil of the area is higher than the three-level standard of soil environmental quality standard (GB 15618-2008). Repairing according to the actual condition of pollution, comprising the following steps:

(1) taking back a polluted soil sample, and detecting the content of heavy metals in the soil sample;

(2) the microbial agent for heavy metal pollution remediation of the embodiment 1 is prepared from the following raw materials in parts by weight: 1-2 parts of water-producing alkaline bacteria, 1-2 parts of bacillus subtilis, 90 parts of peptone, 15 parts of yeast extract, 0.6 part of ferric phosphate, 40 parts of urea, 1000 parts of water and 0.5 part of sodium hydroxide.

Uniformly mixing the proportioned water alcaligenes, bacillus subtilis, peptone, yeast extract, ferric phosphate, urea, water and sodium hydroxide, and obtaining a fermentation mixture after primary culture: wherein, the water content of the mixture is 98%, the primary culture time is 18 hours, the culture temperature is 37 ℃, and the rotation speed of the shaking table is 120-.

(3) The microbial agent prepared as in example 1: the mass ratio of the soil sample to be repaired is 1.2: 1, adding the mixture into a soil sample to be repaired, after uniformly mixing and naturally fermenting for 4 weeks, taking 100g of soil, adding 1kg of deionized water for soaking, then filtering to obtain a leaching solution, and detecting the content of soluble heavy metals in the repaired soil sample through ICP-MS. The results are shown in table 1:

TABLE 1 heavy metal content of soil in example 1

In example 1, the restored soil sample meets the secondary standard of soil environmental quality standard (GBl5618-2008), and the total removal rate of the heavy metals exceeds 90%.

Example 2

The test wastewater sample is collected from an electroplating factory, and the content of heavy metals in wastewater of the factory is higher than the primary standard of Integrated wastewater discharge Standard (GB 432007-432007). Repairing according to the actual condition of pollution, comprising the following steps:

(1) sampling from the wastewater of an electroplating factory, and detecting the content of heavy metals in the wastewater;

(2) the preparation method of the microbial agent for heavy metal pollution remediation in example 2 is the same as that in example 1.

(3) According to the microbial inoculum: adding the wastewater to be treated into the wastewater to be treated according to the mass ratio of 1:1.2, fully aerating, uniformly mixing, naturally fermenting, keeping the temperature at 30-37 ℃, and fermenting for 4 days. And detecting the content of heavy metal in the repaired wastewater sample. The results are shown in table 2:

TABLE 2 heavy metal content of soil after remediation in example 2

In example 2, the restored water body sample meets the primary standard of integrated wastewater discharge standard (GB8978-2007), and the removal rate of heavy metals exceeds 90%.

The soil and the wastewater repaired in the above embodiments 1 and 2 are detected, so that a good effect of removing heavy metals is obtained, the standards of the content of the relevant heavy metals are met, and the removal rate of the heavy metals is high. The heavy metal recovered from the waste water can be used as a catalyst in the catalysis industry

In conclusion, the microbial agent for heavy metal pollution remediation can effectively remove heavy metal ions in the wastewater after natural fermentation, is convenient to prepare, low in price, non-toxic and harmless, and high in heavy metal removal rate, and can recycle heavy metals removed from electroplating wastewater.

While the present invention has been described in detail with reference to the preferred embodiments, it should be understood that the above description should not be taken as limiting the invention. Various modifications and alterations to this invention will become apparent to those skilled in the art upon reading the foregoing description. Accordingly, the scope of the invention should be determined from the following claims.

Claims

1. The microbial agent for heavy metal pollution remediation is characterized by comprising the following raw materials, by weight, 1-2 parts of alkaline producing water bacteria, 1-2 parts of bacillus subtilis, 90-100 parts of peptone, 15-20 parts of yeast extract, 0.5-1 part of ferric phosphate, 30-40 parts of urea, 1000 parts of water and 0.2-0.5 part of sodium hydroxide; the microbial agent for heavy metal pollution remediation is prepared according to the following method: the raw materials of the microbial agent are uniformly mixed, and the microbial agent is obtained after shaking culture at the temperature of 30-37 ℃ and the temperature of 120-130r/min for 18-24 hours.

2. The application of the microbial agent for repairing heavy metal pollution in soil or wastewater as claimed in claim 1, wherein the microbial agent is used for removing heavy metals in the soil or wastewater.

3. The application of the microbial agent for heavy metal pollution remediation in soil or wastewater according to claim 2, wherein the microbial agent is added to the soil or wastewater to be remediated, mixed uniformly and fermented to remove heavy metal pollution in the soil or wastewater.

4. The application of the microbial agent for heavy metal pollution remediation in soil or wastewater according to claim 3, wherein the fermentation temperature is 30-37 ℃.

5. The application of the microbial agent for heavy metal pollution remediation in soil or wastewater according to claim 4, wherein the mass ratio of the added microbial agent to the soil or wastewater to be remediated is (1-1.2): 1.

6. the use of the microbial agent for remediation of heavy metal contamination of claim 5, wherein the fermentation time for remediation of soil is 4 weeks.

7. The application of the microbial agent for heavy metal pollution remediation in soil or wastewater according to claim 6, wherein during remediation of soil, urea is added to the soil to be remedied once a week in the fermentation process, and the mass ratio of the addition amount of the urea to the soil to be remedied is 0.05: 1.

8. the application of the microbial agent for remedying the heavy metal pollution in the soil or the wastewater as claimed in claim 5, wherein the fermentation time is 4 days when the wastewater is remediated.

9. The application of the microbial agent for remediating heavy metal pollution in soil or wastewater as claimed in claim 2, wherein the microbial agent is added to the wastewater during remediation of the wastewater, and then the wastewater is subjected to oscillation or aeration treatment.