CN106190871A - A kind of method that compound thread fungal organism drip leaching with straw as carbon source processes heavy-metal contaminated soil - Google Patents

Abstract

The invention discloses a strain filamentous fungal strains NAU 12, Classification And Nomenclature is letter penicillium sp (Penicillium simplicissimum), being preserved in China Committee for Culture Collection of Microorganisms's common micro-organisms center on June 25th, 2015, preserving number is CGMCC NO.10990.The invention also discloses a kind of by isopyknic letter penicillium sp NAU 12 bacterium (1 2 × 10⁸Spore/mL) and aspergillus niger A80 bacterium (1 2 × 10⁷Spore/mL) the compound thread fungal inoculant that mixes.The invention also discloses in soil growth rapidly, heavy metal resistance strong, and the straw of alkali Grape berry can be utilized as growth carbon source, the method for the compound thread fungal organism drip leaching process heavy-metal contaminated soil of the multiple small molecular organic acid of high yield.Using the inventive method to process heavy-metal contaminated soil, the removal efficiency of heavy metal is high, with low cost.

Description

A kind of compound thread fungal organism drip leaching with straw as carbon source processes heavy metal pollution The method of soil

Technical field

The invention belongs to field of environment engineering technology, relate to the drip leaching of a kind of compound thread fungal organism with straw as carbon source The method processing heavy-metal contaminated soil, specifically one utilize pH adapt to interval wide, heavy metal resistance strong, give up with agricultural Gurry straw as growth carbon source, produce the compound filamentous fungi (letter penicillium sp and aspergillus niger) of multiple small molecular organic acid efficiently, The method of the removing heavy metal in soil of low consumption.

Background technology

Industrialization, urbanization and intensive agriculture at a high speed causes heavy metal pollution of soil to be on the rise.According to the Ministry of Agriculture Measuring and calculating, current China is reached 10,000,000 hectares by the cultivated area of the heavy metal pollutions such as Pb, Cd, Cu, China Environmental Monitoring General Station Investigation is the most close to 20,000,000 hectares, and the most contaminated by heavy metals grain reaches 12,000,000 tons, and this is to agricultural product security and ecology System health constitutes threat greatly.Due to specificity and the complexity of region of heavy metal pollution of soil, it is administered not only Take effect slowly, costly, but also restricted by many factors.Therefore, administer heavy-metal contaminated soil always to study in the world Focus and difficulties, Ye Shi China agricultural sustainable development and environmental quality improve in the asking of many subject common interest Topic.

Bioleaching is a kind of new method removing heavy metal in soil risen over nearly 20 years.Its principle is: utilize certain (mainly one class is with CO for a little extreme acidophilic bacterias₂For growing carbon source, the antibacterial of obligate chemosynthetic autotroph, such as: ferrous oxide sulfur bar Bacterium Thiobacillus ferrooxidans, thiobacillus thiooxidans Thiobacillus thiooxidans, grate sulfur thiobacillus Thiobacillus thioparus) biological oxidation, acidization and the low pH that produces, promote insoluble form in solid phase of soil Heavy metal dissolve in liquid phase, after solid-liquid separation, heavy metal is removed.The method is simple, economy is high, is particularly suited for The process of compound, the serious pollution soil that detection device for multi metallic elements causes is (such as: the periphery soil of field is stacked in minery, garbage Earth), cause the great attention of scientist.Currently, this technology was in by laboratory research to the transformation stage of field conduct, The external lab scale engineering that has is reported.

From the point of view of existing research practice, based on the heavy metal-polluted soil bioleaching that acidophilia autotroph is dominant bacteria Processing the most time-consuming longer (25-30 days), effect is the most unstable, under the conditions of particularly long-term operating condition continuously, and the work of strain Property reduces sometimes.This is because: 1) growth rate of autotrophic bacteria is the slowest；2) these strains are more suitable for pH 1.0-3.0 Sour environment under grow, they are inoculated into soil (most for neutral, meta-alkali), need the growth retardation of one pH adaptation Phase；3) autotrophic bacteria has certain sensitivity to Organic substance, and Dissolved Organic Matter (Dissolved organic in soil Matters, DOM) content often can be beyond their toxic levels.

In order to improve efficiency and the stability of heavy metal-polluted soil bioleaching, in the recent period, there is researcher to propose and utilize some Fast growth, pH wide accommodation, heavy metal resistance are strong, and energy metabolism organic carbon produces small molecular organic acid (such as citric acid) Heterotroph filamentous fungi, such as: Trichoderma spp. Trichoderma sp., ankle joint mould Talaromyces sp., aspergillus niger Aspergillus niger, carries out the technical scheme of heavy metal-polluted soil bioleaching.The method can overcome to a certain extent addicted to The technological deficiency of acid autotroph bioleaching heavy metal-polluted soil.An existing relevant filamentous fungi bioleaching soil huge sum of money The research belonged to is mainly based upon with single filamentous fungi as dominant bacteria and a large amount of external source adds the commodity such as sucrose, glucose, starch Carry out under conditions of changing carbon source (soil DOM carbon content is not enough to maintain the growth demand of filamentous fungi).But, due to list The product acids type of one bacterium is the most single and maximum acid producing ability is limited (is only capable of soil pH is reduced to pH3.5 in most cases Left and right), therefore after usually cannot ensureing bioleaching process, in soil, the heavy metal of variety classes and form all can be timely, effective Remove (effective removal of such as Pb, Cd, Ni typically requires pH < 2.5).Additionally, the organic carbon source adding commercialization in a large number is also deposited In the drawback that processing cost is too high.Therefore, rational compatibility has the different filamentous fungi producing acid feature, plays compound bacteria and produces acid Pedigree width (multiple organic acid) and produce the acid high characteristic of usefulness, attempts with the high agricultural wastes of some phosphorus content (such as straw simultaneously Stalk) serve as the carbon source (substitute sucrose etc.) of growth of microorganism, then can significantly improve filamentous fungi bioleaching and process heavy metal The technology of contaminated soil and economic feasibility.

Summary of the invention

1, goal of the invention

In soil media, growth is rapidly, heavy metal resistance is strong and can utilize agriculture to it is an object of the invention to provide one Industry wastes straw, as growth carbon source, produces the compound of the multiple small molecular organic acids such as citric acid, gluconic acid, oxalic acid in a large number The method of filamentous fungi (bacterial strain NAU-12 and A80) removing heavy metal-polluted soil.

2, technical scheme

One strain filamentous fungal strains NAU-12, Classification And Nomenclature is letter penicillium sp (Penicillium simplicissimum), It is preserved in (address: court of Beijing, China Committee for Culture Collection of Microorganisms's common micro-organisms center on June 25th, 2015 North Star West Road 1 institute of sun district 3, Institute of Microorganism, Academia Sinica), preserving number is CGMCC NO.10990.Letter penicillium sp (Penicillium simplicissimum) bacterial strain NAU-12 has following biological characteristics: numerous on Rhizoma Solani tuber osi PDA plate Grow rapidly, grow 4 days at 28 DEG C, colony diameter 25mm, in the middle of bacterium colony, have projection, well-regulated radial rill；Outward appearance is ash Green, quality is velvet shape；A large amount of conidium structures, conidial head is spherical, diameter 150-300 μm；At pH 3.0- All can grow, to Zn for 8.0 times²⁺、Cu²⁺、Cd²⁺、Pb²⁺Have stronger resistance, tolerable concentration be respectively 200mg/L, 300mg/L, 100mg/L、1000mg/L；The straw that can utilize alkali Grape berry is carbon source for growth, and main malaga saccharic acid and oxalic acid (produce for 12 days Acid amount is respectively 56mM and 42mM), have a small amount of citric acid concurrently.

One strain filamentous fungal strains A80, Classification And Nomenclature was aspergillus niger (Aspergillus niger), January 10 in 2011 Day is preserved in (address: BeiChen West Road, Chaoyang District, BeiJing City 1, China Committee for Culture Collection of Microorganisms's common micro-organisms center Number institute 3, Institute of Microorganism, Academia Sinica), preserving number is CGMCC NO.4533.Aspergillus niger (Aspergillus Niger) strains A 80 has following biological characteristics: on Rhizoma Solani tuber osi PDA plate, breeding is rapidly, grows 4 days, bacterium colony at 28 DEG C Diameter 60mm, has projection, well-regulated radial rill in the middle of bacterium colony, outward appearance is brown-black, and quality is velvet shape；The most mitogenetic Spore structure, conidial head is spherical, diameter 300-500 μm；All can grow under pH 2.5-7.0, to Zn²⁺、Cu²⁺、Cd^{2 +}、Pb²⁺Having stronger resistance, tolerable concentration is respectively 300mg/L, 200mg/L, 50mg/L, 1500mg/L；Alkali heat can be utilized pre- The straw processed is carbon source for growth, mainly produces citric acid (producing acid amount for 15 days for 68mM), has a small amount of malic acid and oxalic acid concurrently.

Filamentous fungal strains NAU-12 of the present invention is processing the application of heavy-metal contaminated soil.

A kind of compound thread fungal inoculant, this microbial inoculum is by containing 1-2 × 10⁸The simple penicillium sp NAU-12 microbial inoculum of spore/mL With containing 1-2 × 10⁷The microbial inoculum that the aspergillus niger A80 microbial inoculum equal-volume of spore/mL mixes.

The preparation method of described compound thread fungal inoculant, step is as follows: picking NAU-12 thalline, accesses liquid growth Culture medium, 25-35 DEG C, shaken cultivation 5-7 days；Picking A80 thalline, access liquid growth media, 25-35 DEG C, shaken cultivation 4-6 days；After cultivation terminates, two cultures are mixed by 1:1 by volume, obtain composite bacteria agent capable.

Compound thread fungal inoculant of the present invention is in the application processing heavy-metal contaminated soil.

Compound thread fungal organism drip leaching with straw as carbon source of the present invention processes the side of heavy-metal contaminated soil Method, step is as follows:

Step (1), preparation inoculation are with being combined thread microbial inoculum: picking NAU-12 thalline, access liquid growth media, 25- 35 DEG C, shaken cultivation 5-7 days；Picking A80 thalline, access liquid growth media, 25-35 DEG C, shaken cultivation 4-6 days；Cultivate After end, two cultures are mixed by 1:1 by volume, obtain compound thread fungal inoculant；

Step (2), preparation carbon source: by crushed stalk to 1-1.5cm, be placed in the NaOH solution of 0.5-1.5%, 80-100 DEG C Lower immersion 1-2h carries out alkali Grape berry；

Step (3), process heavy-metal contaminated soil: with water by heavy metal soil dilution, make the soil of concentration of hydraulic mixture 1-5% Earth mud, puts into reactor, adds 40-80g/L through the straw of alkali Grape berry or sucrose as carbon source, adds 1-3g/L yeast Cream, is combined thread fungal inoculant, at 25-35 DEG C, aerobic, 120-150r/min rotating speed by the 5-10% inoculation processing mud volume Lower stir process 15-20 days, pumps out the Soil slurry after process；

Step (4), solid-liquid separation: the Soil slurry processed through step (3) carries out soil-water solid-liquid separation, obtains soil mud Slurry precipitation and the clear liquid containing heavy metal ion；

Step (5), neutralization precipitation: in the clear liquid containing heavy metal, add alkali make heavy metal ion precipitate；Neutralize with quick lime Soil slurry precipitates.

In step (1), described liquid growth media is: NaNO₃ 1.5g/L、K₂HPO₄0.5g/L, KCl 0.025g/L, MgSO₄0.025g/L, yeast extract 1.5g/L, sucrose, 35g/L, pH are natural, sterilizing.

The rotating speed of shaken cultivation is 120-150r/min.

In step (2), described straw is air-dried Semen Tritici aestivi or rice straw, the total solids content of straw > 90%.

In step (3), it is preferred to use through the straw of alkali Grape berry as carbon source.Interpolation through the straw of alkali Grape berry Amount is preferably 50-70g/L, and the addition of yeast extract is preferably 1-2g/L.In the present invention, addition is with straw or the matter of yeast extract Amount and the volume basis of Soil slurry, the volume of Soil slurry is equal to the volume of water.

In step (5), described basic species is magnesium oxide, quick lime or sodium hydroxide.

Heavy metal of the present invention includes Pb, Zn, Cd, Cu, Ni, Mn etc..

3, beneficial effect

The filamentous fungal strains letter penicillium sp Penicillium simplicissimumNAU-12 of the present invention and aspergillus niger The equal no pathogenicity of Aspergillus niger A80, to humans and animals safety.The present invention is used to utilize the agricultural of alkali Grape berry Wastes straw is as growth carbon source and produces the compound thread fungal organism drip leaching process of multiple small molecular organic acid with much money Belong to contaminated soil, compensate for prior art and use the deficiency that single culture removal efficiency of heavy metals is low to become with adding commercialization carbon source This high drawback.Present treatment technology is carried out at normal temperatures and pressures, and consersion unit is few, energy consumption is low, it is easy to the reality after amplification scale Application.

Accompanying drawing explanation

Fig. 1 is letter penicillium sp NAU-12 colonial morphology on PDA plate.

Fig. 2 is that letter penicillium sp NAU-12 generation of small molecular organic acid during pure culture is dynamic.

Fig. 3 is aspergillus niger A80 colonial morphology on PDA plate.

Fig. 4 is that aspergillus niger A80 generation of small molecular organic acid during pure culture is dynamic.

Biomaterial preservation information

NAU-12, Classification And Nomenclature is letter penicillium sp (Penicillium simplicissimum), protects on June 25th, 2015 It is hidden in China Committee for Culture Collection of Microorganisms's common micro-organisms center, preservation address: BeiChen West Road, Chaoyang District, BeiJing City 1 Number institute 3, Institute of Microorganism, Academia Sinica, preserving number is CGMCC NO.10990.

A80, Classification And Nomenclature is aspergillus niger (Aspergillus niger), is preserved in Chinese micro-life on January 10th, 2011 Thing culture presevation administration committee's common micro-organisms center, preservation address: Yard 1, BeiChen xi Road, Chaoyang District, Beijing City 3, China Institute of microbiology of academy of science, preserving number is CGMCC NO.4533.

Detailed description of the invention

By following example, technical scheme is described further.

Embodiment 1Penicillium simplicissimum NAU-12 and the separation of Aspergillus niger A80 With cultivation:

Weigh 10g and pick up from Tongling, Anhui Province copper mine plant area soil, pour in the triangular flask equipped with certain volume sterilized water, 28 DEG C, under 120r/min rotating speed, after shaken cultivation 1d, from triangular flask, draw 2mL bacteria suspension be coated on solid growth culture media (NaNO₃: 1.5g/L, K₂HPO₄: 0.5g/L, KCl:0.025g/L, MgSO₄: 0.025g/L, yeast extract: 1.5g/L, sucrose: 35g/L, agar: 20g/L), 28 DEG C of constant temperature culture 4 days.The doubtful bacterial strain of picking mycelia prosperity lines containing 3% bromocresol green On the solid growth culture media of (producing acid indicator), after colour developing completely, the bacterium colony that around choosing colony, yellow transparent circle is bigger, draw Line separates 2 times, obtains two strain purification bacterial strains, is respectively designated as NAU-12, A80.With reference to " Fungal identification handbook " and " China fungus Will ", Preliminary Identification bacterial strain NAU-12 and A80 is respectively Penicillium and aspergillus.Use fungal DNA test kit, extract respectively The DNA of NAU-12 and A80, PCR expand 18S rDNA-ITS sequence, by rDNA-ITS gene sequencing and and ncbi database BLAST sequence analysis, final NAU-12 and A80 of qualification is respectively letter penicillium sp and aspergillus niger.

Liquid growth media is used to be enlarged respectively bacterial strain NAU-12 and A80 cultivating:

From inclined-plane picking letter penicillium sp NAU-12 thalline, access liquid growth media, at 25-35 DEG C, 120-150r/min Shaken cultivation 5-7 days, it is thus achieved that strain density is 10⁸The NAU-12 microbial inoculum of spore/mL.Use high performance liquid chromatography to amplification culture mistake In journey, the product acids type of bacterial strain NAU-12 and product acid amount detect, such as Fig. 2, it is found that it mainly produces gluconic acid and oxalic acid (the product acid amount of 12 days is respectively 56mM and 42mM), has a small amount of citric acid (yield of 12 days is 8mM) concurrently.

From inclined-plane picking aspergillus niger A80 thalline, accessing liquid growth media, at 25-35 DEG C, 120-150r/min vibrates Cultivate 4-6 days, it is thus achieved that strain density is 10⁷The A80 microbial inoculum of spore/mL.Use high performance liquid chromatography to bacterium during amplification culture The product acids type of strain A80 and product acid amount detect, such as Fig. 4, it is found that it mainly produces citric acid, and (the product acid amount of 15 days is 68mM), a small amount of malic acid and oxalic acid (the product acid amount of 15 days is respectively 3mM and 7mM) are had concurrently.

Described liquid growth media is: NaNO₃1.5g/L, K₂HPO₄0.5g/L, KCl 0.025g/L, MgSO₄ 0.025g/L, yeast extract 1.5g/L, sucrose 35g/L, pH are natural, sterilizing.

Embodiment 2 processes single heavy metal Cu contaminated soil

The method that compound thread fungal organism drip leaching processes Cu contaminated soil, step is as follows:

Step (1), preparing microbial inoculum: as described in Example 1, obtaining strain density respectively is 10⁸The NAU-12 of spore/mL and 10⁷The A80 microbial inoculum of spore/mL, by volume 1:1 mixing, obtain the composite bacteria agent capable for inoculation；

Step (2), prepare wheat stalk carbon source: mechanical activation comminution is extremely by air-dried wheat stalk (total solids content 92.5%) 1cm, is placed in the NaOH solution of 1.5%, soaks 2h at 80 DEG C and carry out alkali Grape berry, standby；

Step (3), the biological eliminating of soil Cu: soil sample picks up from Tongling, Anhui Province Copper Mine soil, this soil sample is yellow-red soil, Soil pH value is 6.22.After testing, this soil sample is mainly polluted by single Cu, and Cu content reaches 1098mg/kg.

Taking the Cu contaminated soil of 2g, the 200mL that adds water dilutes, and puts in triangular flask by the Soil slurry made, adds 10g alkali Wheat straw (as carbon source) after Grape berry and 0.3g yeast extract, then inoculation 12mL composite bacteria agent capable.

It addition, be provided with what microbial inoculum four control treatment group: a. do not take over；The most only inoculation 12mL letter penicillium sp NAU-12 bacterium Agent；The most only inoculation 12mL aspergillus niger A80 microbial inoculum；D. inoculation 12mL is combined thread microbial inoculum but using 10g cane sugar substitution wheat straw as carbon Source.

Subsequently, above-mentioned different disposal is placed in 30 DEG C, 150r/min cyclotron oscillation device, aerobic cultivation 15d.Monitor 15d The pH value of Soil slurry, the compound thread microbial inoculum of inoculation is down to 2.46 using wheat straw as the Soil slurry pH of carbon source, is inoculated composite filament Shape microbial inoculum is down to about 2.42 using sucrose as the Soil slurry pH of carbon source, and single inoculation letter penicillium sp NAU-12 microbial inoculum or black fermented preparation The Soil slurry pH of mould A80 microbial inoculum is down to 3.52.

Step (4), will process after Soil slurry pour out, 3000r/min is centrifuged 15min, filter paper filtering, obtains containing Cu²⁺ Filtrate and Soil slurry precipitation.

Step (5), to containing Cu²⁺Filtrate puts into NaOH and regulates pH to 8.0, make Cu²⁺Transfer Cu (OH) to₂Precipitation, waste water is arranged Put；In Soil slurry precipitates, add quick lime regulation pH to 6.0, dry sample, use HCl-HNO₃-HClO₄Clear up, inductance Coupled plasma optical emission spectral detection soil sample remains the content (being shown in Table 1) of Cu.According to the difference of soil Cu content before and after processing Value, calculates the clearance of Cu.Being computed, the Cu of two groups of process (with wheat straw or using sucrose as carbon source) of inoculating compound bacterium agent goes Except rate close (82-83%), all can reach China's standard of soil environment quality (GB15618-1995), and single apparently higher than inoculation The Cu clearance that one NAU-12 or A80 processes.

The change of Cu content in soil before and after table 1 different disposal

Embodiment 3 processes Compound Heavy Metals Pb-Zn-Cd contaminated soil

The method that compound thread fungal organism drip leaching processes Compound Heavy Metals Pb-Zn-Cd contaminated soil, step is as follows:

Step (1), prepare microbial inoculum: with embodiment 2；

Step (2), prepare rice straw carbon source: mechanical activation comminution is extremely by air-dried rice straw (total solids content 90.2%) 1cm, is placed in the NaOH solution of 1%, soaks 1.5h at 100 DEG C and carry out alkali Grape berry, standby；

The biological eliminating of Zn, Pb and Cd in step (3), soil: soil sample is picked up from Jiangxi Dexing Pb-Zn deposits factory periphery and polluted Soil, this soil sample is Quaternary Red Soil, and pH value is 5.7.After testing, in this soil sample, Zn, Pb and Cd content is respectively 1520mg/ Kg, 570mg/kg and 28mg/kg, beyond country's standard of soil environment quality (GB15618-1995).

Take the Pb-Zn-Cd combined contamination soil of 250g, add the dilution of 10L water, the Soil slurry made is put into reactor In, add 700g rice straw (as carbon source) and 15g yeast extract, then, inoculating compound bacterium agent 1L.With reference to embodiment 2, arrange four What microbial inoculum matched group: a. does not take over, and b. only inoculates 1L letter penicillium sp NAU-12 microbial inoculum, and c. only inoculates 1L aspergillus niger A80 microbial inoculum, and d. connects Plant 1L and be combined thread microbial inoculum but using 700g cane sugar substitution wheat straw as carbon source.

Subsequently, by each group of reactor processed under the conditions of 30 DEG C and 150r/min, aerobic stir process 20d.Monitoring the The pH value of 20d Soil slurry, the compound thread microbial inoculum of inoculation is down to about 2.4 using wheat straw as the Soil slurry pH of carbon source, is inoculated Compound thread microbial inoculum is down to about 2.5 using sucrose as the Soil slurry pH of carbon source, and single inoculation letter penicillium sp NAU-12 bacterium The Soil slurry pH of agent or aspergillus niger A80 microbial inoculum is down to about 3.5.

Step (4), will process after Soil slurry pour out, 3000r/min is centrifuged 15min, filtration, obtains containing Zn²⁺、Pb²⁺ And Cd²⁺Filtrate and be stripped of heavy metal Soil slurry precipitation.

Step (5), to containing Zn²⁺、Pb²⁺And Cd²⁺Filtrate in add MgO regulate pH to 7.5, heavy metal is converted into hydrogen Oxide precipitation, discharge of wastewater；In Soil slurry precipitate, add quick lime regulation pH to 6.0, subsequently sample is dried, use HCl-HNO₃-HClO₄Clearing up, inductively coupled plasma atomic emission measures the content of residual Zn, Pb and Cd in soil sample and (is shown in Table 2).According to the difference of content of beary metal in soil sample before and after processing, calculate the clearance of heavy metal.It is computed, inoculating compound bacterium agent Zn, Pb and Cd clearance of two groups of process (with rice straw or using sucrose as carbon source) be more or less the same, respectively 83-85%, 40- 45% and 93-95%, all can reach China's standard of soil environment quality (GB15618-1995), and single apparently higher than inoculation The Cu clearance that NAU-12 or A80 processes.

The change of Zn, Pb and Cd content in soil before and after table 2 different disposal

Claims (10)

1. filamentous fungal strains NAU-12, Classification And Nomenclature is letter penicillium sp (Penicillium simplicissimum), in 2015 On June 25, in is preserved in China Committee for Culture Collection of Microorganisms's common micro-organisms center, and preserving number is CGMCC NO.10990。

2. the filamentous fungal strains NAU-12 described in claim 1 is processing the application of heavy-metal contaminated soil.

3. filamentous fungal strains A80, Classification And Nomenclature was aspergillus niger (Aspergillus niger), in preservation on January 10 in 2011 In China Committee for Culture Collection of Microorganisms's common micro-organisms center, preserving number is CGMCC NO.4533.

4. a compound thread fungal inoculant, it is characterised in that this composite bacteria agent capable is by containing 1-2 × 10⁸The simple penicillium sp of spore/mL NAU-12 microbial inoculum and containing 1-2 × 10⁷The microbial inoculum that the aspergillus niger A80 microbial inoculum equal-volume of spore/mL mixes.

5. the preparation method of the compound thread fungal inoculant described in claim 4, it is characterised in that step is as follows: picking NAU-12 Thalline, access liquid growth media, 25-35 DEG C, shaken cultivation 5-7 days；Picking A80 thalline, accesses liquid growth media, 25-35 DEG C, shaken cultivation 4-6 days；After cultivation terminates, two cultures are mixed by 1:1 by volume, obtain composite bacteria agent capable.

The preparation method of compound thread fungal inoculant the most according to claim 5, it is characterised in that described liquid growth Culture medium is: NaNO₃ 1.5g/L、K₂HPO₄0.5g/L, KCl 0.025g/L, MgSO₄0.025g/L, yeast extract 1.5g/L, Sucrose, 35g/L, pH are natural, sterilizing.

7. the compound thread fungal inoculant described in claim 4 is processing the application of heavy-metal contaminated soil.

8. the method that a bioleaching processes heavy-metal contaminated soil, it is characterised in that step is as follows:

Step (1), the compound thread fungal inoculant of preparation inoculation: picking NAU-12 thalline, access liquid growth media, 25-35 DEG C, shaken cultivation 5-7 days；Picking A80 thalline, access liquid growth media, 25-35 DEG C, shaken cultivation 4-6 days；Training Supporting after terminating, two cultures are mixed by 1:1 by volume, obtain compound thread fungal inoculant；

Step (2), preparation carbon source: by crushed stalk to 1-1.5cm, be placed in the NaOH solution of 0.5-1.5%, soak at 80-100 DEG C Bubble 1-2h carries out alkali Grape berry；

Step (3), process heavy-metal contaminated soil: with water by heavy metal soil dilution, make the soil mud of concentration of hydraulic mixture 1-5% Slurry, puts into reactor, adds 40-80g/L through the straw of alkali Grape berry or sucrose as carbon source, adds 1-3g/L yeast extract, By processing the 5-10% compound thread fungal inoculant of inoculation of Soil slurry volume, 25-35 DEG C, aerobic, 120-150r/min turns Lower stir process 15-20 days of speed, pumps out the Soil slurry after process；

Step (4), solid-liquid separation: the Soil slurry processed through step (3) carries out soil-water solid-liquid separation, obtain Soil slurry and sink Shallow lake and the clear liquid containing heavy metal ion；

Step (5), neutralization precipitation: in the clear liquid containing heavy metal, add alkali make heavy metal ion precipitate；Use quick lime sweetening of the soil Mud sediment.

Bioleaching the most according to claim 8 processes the method for heavy-metal contaminated soil, it is characterised in that step (1) In, described liquid growth media is: NaNO₃ 1.5g/L、K₂HPO₄0.5g/L, KCl 0.025g/L, MgSO₄0.025g/ L, yeast extract 1.5g/L, sucrose, 35g/L, pH are natural, sterilizing；

The rotating speed of shaken cultivation is 120-150r/min.

Bioleaching the most according to claim 8 processes the method for heavy-metal contaminated soil, it is characterised in that step (2) In, described straw is air-dried Semen Tritici aestivi or rice straw, the total solids content of straw > 90%；

In step (3), being 50-70g/L through the addition of the straw of alkali Grape berry, the addition of yeast extract is 1-2g/L；

In step (5), described basic species is magnesium oxide, quick lime or sodium hydroxide.