CN113714274B - Plunger pump for microbial soil layer dispersion mixing inoculation - Google Patents

Abstract

The invention discloses a regulating and controlling method for microbial soil layer dispersion mixing inoculation, which comprises inoculating one or more microorganisms to the soil layer, optionally planting plants, specifically treating soil, inoculating a first microbial inoculum, planting prosthetic plants, and mixing and inoculating a second microbial inoculum by a plunger pump. The regulation and control method and the technical equipment provided by the invention can effectively reduce heavy metals and organic pollutants in soil, realize in-situ remediation, and are safe, environment-friendly, efficient, economical and practical.

Description

Plunger pump for microbial soil layer dispersion mixing inoculation

Technical Field

The invention relates to a method for regulating and controlling soil layer dispersion mixed inoculation microorganisms and equipment used by the method, and belongs to the technical field of soil restoration and improvement.

Background

Polycyclic aromatic hydrocarbon substances (polycyclic aromatic hydrocarbons) are a type of toxic organic pollutants which are widely distributed and stably exist in natural environments and contain two or more benzene rings, and leakage of petroleum and petroleum products is one of main sources. Petroleum substances enter the soil, so that the physicochemical properties of the soil can be changed, such as blocking soil pores, changing the composition and structure of soil organic matters, causing the change of carbon-nitrogen (C/N) and carbon-phosphorus ratio (C/P) of the soil organic matters, even destroying the original ratio of carbon, nitrogen and phosphorus in the soil, and causing the change of a soil microbial community and a microbial zone system. Organic pollution easily causes soil hardening, and the pH value is changed, so that the structure and the composition of the soil are destroyed.

Heavy metals are also another pollution source of soil, and according to statistics, the area of the contaminated soil in China reaches over 5000 mu at present, various heavy metal elements in the soil have different degrees of exceeding standard conditions, and due to the characteristics of poor mobility, long residence time, difficult degradation and the like of heavy metal pollutants in the soil, the self-circulation capacity of the soil is greatly influenced, and the human health is also easily influenced through mediums such as water, plants and the like.

Many polluted soil often have organic pollution and heavy metal pollution simultaneously, and exploration of soil remediation technical methods, system equipment and the like for comprehensively regulating and controlling the organic pollution and the heavy metal pollution is an important work related to human survival. The currently adopted repairing technology mainly comprises a gas phase extraction method, a thermal desorption method, a chemical leaching method, a redox method, a biological and plant repairing method and the like, but still has the problems of low repairing efficiency, high cost, easiness in causing secondary pollution, easiness in damaging soil structures and the like.

Disclosure of Invention

In order to overcome the problems, the invention dispersedly mixes and inoculates microorganisms on the polluted soil layer, and plants proper plants, thereby comprehensively repairing the soil, efficiently, permanently and irreversibly removing heavy metal and organic pollution in the soil, and not damaging the soil structure.

Specifically, the invention provides a regulating and controlling method for microbial soil layer dispersion mixed inoculation, which comprises inoculating one or more microorganisms to the soil layer, and optionally planting plants, and specifically comprises the steps of treating the soil, inoculating a first microbial inoculum, planting a prosthetic plant, and inoculating a second microbial inoculum.

In the invention, soil treatment comprises plowing and curing a polluted soil area with generation regulation and control, the curing time is about 1 to 2 months, and the soil humidity is kept during the curing.

In the invention, the strain of the first microbial inoculum is one or more selected from saccharomycetes, photosynthetic bacteria, halomonas and pseudomonas aeruginosa, preferably the saccharomycetes, the halomonas and the pseudomonas aeruginosa are mixed according to the mass ratio of (1-6): (1-5): 1, more preferably the microbial agent is co-applied with a biomass carbon source.

In the present invention, the biomass carbon source is pyrolytic carbon, preferably mixed with inorganic pellets, and more preferably mixed in situ in the pyrolysis equipment during the preparation process.

In the invention, calcium oxide and/or calcium carbonate are added into a pyrolysis furnace simultaneously or after a plant carbon source is added and before pyrolytic carbon particles are separated, and finally, the pyrolytic carbon doped with calcium carbonate is formed and pressed for forming.

In the present invention, the first microbial inoculum is compounded with pyrolytic carbon to form a microbial inoculum complex comprising the first microbial inoculum and pyrolytic carbon, and then inoculated into a soil layer in an application amount of 1% to 5%, preferably 2% to 4%, based on the dry weight of the soil.

In the invention, the repairable plant is selected from rice, wheat, ryegrass, sorghum, corn, castor, ramie and the like, and the second microbial inoculum is inoculated into the soil layer in a dispersing and mixing way within 5-30 days after planting.

In the invention, the strain of the second microbial agent is selected from one or more of white rot fungi and/or arbuscular mycorrhizal fungi, preferably Phanerochaete chrysosporium and Young sleeve sacculus mildew, and the second microbial agent is preferably applied by a plunger pump.

In the invention, the second microbial inoculum is inoculated at a position 5-25cm, preferably 8-18cm deep from the soil surface layer in the vicinity of the plant root, and the inoculation amount is 0.8-1.5 g/m ² Preferably 0.9 to 1.2g/m ² Multiple, stratified inoculations are preferred.

The invention has the beneficial effects that:

(1) The method for regulating and controlling the microbial soil layer by dispersion mixing inoculation combines the restoration and regulation functions of various microbial agents and plants, can beautify the environment, can reduce the pollution concentration of petroleum hydrocarbon, effectively improve the soil quality of polluted soil, prevent pollutants from entering a food chain again, furthest reduce the secondary pollution of the restored soil, has low cost and small influence on the environment, can stabilize the ground surface for a long time, and eliminates the pollutants in the atmosphere and water around the polluted soil while eliminating the soil pollution, thereby being beneficial to improving the ecological environment and improving the biological diversity of the polluted soil;

(2) The regulation and control method provided by the invention can realize continuous application of the second bacterial liquid, can accurately regulate the flow and avoid bacterial liquid waste; in addition, the biological carbon source has the functions of improving the physical structure of soil and increasing the fertilizer of the soil, provides good loading and solidifying effects for the microbial inoculum, can effectively reduce the influence of petroleum pollution on plant growth, can adsorb and fix heavy metals in the soil, and provides favorable conditions for plant growth;

(3) The regulation and control method provided by the invention can realize in-situ remediation, effectively reduce heavy metal and organic pollutants in soil, and is a safe, environment-friendly, efficient, economical and practical remediation method for petroleum-heavy metal contaminated soil.

Drawings

Fig. 1 is a schematic structural view of a plunger pump employed in the present invention.

Detailed Description

The invention is further illustrated by the following preferred embodiments and examples. The features and advantages of the present invention will become more apparent from the description.

The word "exemplary" is used herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

According to the present invention there is provided a method of regulating and controlling a dispersive mixing inoculation microorganism, the method comprising inoculating contaminated soil with one or more microorganisms and optionally planting plants, in particular comprising treating the soil, inoculating a first microbial agent, planting a prosthetic plant, and inoculating a second microbial agent.

According to the method provided by the invention, in step 1, soil is treated before inoculation of the soil layer.

In step 1, soil plowing and maintenance are included, wherein the soil is polluted by heavy metals and organic matters.

In the present invention, the curing time is about 1 to 2 months, and the soil humidity is maintained during curing.

According to the method provided by the invention, in the step 2, after curing is finished, the first microbial inoculum or the compound containing the first microbial inoculum is inoculated.

According to the invention, the first microbial inoculum is one or more selected from the group consisting of yeasts, photosynthetic bacteria, halomonas and pseudomonas aeruginosa, all of which are commercially available.

The strain is activated by conventional method and then subjected to expansion culture, preferably to a bacterial concentration of 10 ⁷ ～10 ⁹ The liquid strain of each/mL is used for obtaining bacterial suspension, and then the bacterial suspension is cultured to prepare the bacterial agent.

In the invention, the microbial inoculum can be a microbial inoculum of one strain or a composite microbial inoculum of a plurality of strains, preferably, a composite microbial inoculum formed by saccharomycetes, halomonas and pseudomonas aeruginosa is used, wherein the mass ratio of each strain is (1-6): (1-5): 1, more preferably (3 to 5): (2-4) 1) when the bacterial suspension is weighed, the ratio is converted into a volume ratio.

In the invention, the composite bacterial liquid with the types and the proportions is favorable for improving the repair efficiency and the repair quality of the polycyclic aromatic hydrocarbon organic pollution soil, and simultaneously can also improve the fertility of the soil and facilitate the absorption of mineral elements by plants.

According to the invention, the microbial agent is applied together with a biomass carbon source. The biomass carbon source is preferably a solid material, and has the functions of solidification, dispersion and protection on the microbial inoculum. For this purpose, a biomass carbon source is immersed in the bacterial liquid to impart biological activity to the carbon source.

In the present invention, the biomass carbon source is preferably pyrolytic carbon, may be in the form of particles, and is preferably used in combination with other particles, such as inorganic particles. The mixing may be physical mixing of the pyrolytic carbon and the inorganic particulate material, each in the finished product, or may be in situ mixing during the preparation process.

According to the invention, the in-situ mixing is carried out in a pyrolysis device comprising a pyrolysis furnace, a plant carbon source is fed into the pyrolysis furnace together with an additive, the generated semi-coke and primary pyrolysis gas containing carbon dioxide react with calcium oxide in the additive, the final pyrolysis gas is discharged through a pipeline, calcium carbonate of a reaction product is discharged from the pyrolysis carbon and is sent to a cooling zone to be contacted with cooling gas and conduct heat exchange, and warm flue gas is converged with purge gas entering from a gas supply pipeline through a cyclone separator and returned to the pyrolysis furnace together to complete feeding, pyrolysis, discharge, conveying and cooling of the pyrolysis carbon, and closed cycle of the gas is realized.

In the present invention, the plant-based carbon source is a biomass material or material capable of providing carbon elements, and is selected from herbaceous plants or woody plants, wherein the herbaceous plants can be harvested or harvested terrestrial or aquatic crops or plants, such as rice straw, sorghum, corn stalk, wheat, ryegrass, castor bean, ramie harvests, reed or typha, and the woody plants can be forestry biomass, such as roots, branches and leaves of various trees, branches and leaves of shrubs, or other forestry waste or wood product waste. More preferably, cut or harvested prosthetic plants and waste thereof are used.

According to the present invention, the vegetable carbon source is required to be appropriately treated, including drying and pulverizing. The external moisture of the plant carbon source is removed by drying, such as by sun-drying or natural air-drying, preferably the plant carbon source is air-dried so that the water content of the plant is 10% to 20%, and then chopped. Before drying the plants, the plants are washed, preferably with deionized water, and then soaked in dilute hydrochloric acid.

In the present invention, the vegetable carbon source is pyrolyzed in a pyrolysis apparatus, such as a pyrolysis furnace, at a medium and low temperature. The plant carbon source may be pyrolyzed directly, preferably by purging with an inert gas such as nitrogen or carbon dioxide gas in advance, and then heating with an external heat source, and the temperature of the pyrolysis furnace is raised to 200 ℃ or higher, more preferably 300 to 600 ℃. Too low a temperature is detrimental to volatilization and stripping of low boiling point organics, and higher temperatures tend to result in excessive coking or complete carbonization. The process is maintained for tens of minutes to hours while maintaining a nitrogen flow to carry away gaseous products generated by pyrolysis while maintaining an anoxic environment.

The pyrolysis carried out by the invention mainly comprises three main stages of dehydration and drying, preheating and volatile component precipitation. The dehydration and drying are that the internal crystal water is removed; then entering a short preheating stage, wherein the number of active structures of the raw material molecules is continuously increased; after preheating, volatile components are gradually separated out, light hydrocarbon compounds are continuously cracked and separated out to generate carbon monoxide, methane, hydrogen, carbon dioxide and the like, and the proportion of the residual fixed carbon is gradually increased. The crystal water, the generated volatile gas and most of tar steam (collectively called pyrolysis gas) can be discharged out of the pyrolysis furnace, the pyrolysis gas can be used as heating fuel, and the volatile gas liquid can be condensed and separated out, namely pyrolysis oil.

Preferably, the calcium oxide and/or calcium carbonate is added to the pyrolysis furnace either simultaneously with or after the addition of the vegetable carbon source, prior to separation of the pyrolytic carbon particles.

The reacted material is discharged to a cooling area and can be naturally cooled, and preferably inert gas is used for directly cooling the incandescent pyrolytic carbon to obtain pyrolytic carbon particles and hot gas. The cooling gas is preferably the same inert gas as the purge gas, and may be nitrogen, carbon dioxide, or a mixture thereof, with an amount of carbon dioxide contributing to the formation of calcium carbonate upon pyrolysis.

According to the invention, the solid obtained after cooling and separation is pyrolytic carbon, in the form of granules, possibly comprising calcium carbonate in addition to pyrolytic carbon granules, in which case part of it is derived from added calcium carbonate and the other part is derived from calcium carbonate formed by calcium oxide and carbon dioxide. The addition of calcification can reduce the content of carbon dioxide in pyrolysis gas, can blend pyrolytic carbon particles with calcium carbonate, increases the density of particle materials, promotes the dispersion of pyrolytic carbon, avoids agglomeration, and is compact and porous, thus being very beneficial to the load solidification of bacterial liquid.

According to the invention, the pyrolytic carbon produced contains organic substances with a higher boiling point, has a low density and a low mechanical strength, is more fragile and consumes less energy than biomass raw materials, and for better shaping, the pyrolytic carbon is preferably crushed and can be directly pressed into a certain shape, preferably with calcium carbonate, such as microspheres, strips or rods, for example with a particle size or a cross-sectional diameter of 0.5mm to 10mm, preferably 1mm to 5mm, for example 2mm to 4mm.

In the preferred embodiment of the invention, the pyrolytic carbon and the calcium carbonate are pressed together with the pyrolytic oil, so that the pyrolytic oil can play a role of an adhesive to enable carbon powder to be easily adhered to avoid the loosening of a formed product, meanwhile, the pyrolytic oil is a pyrolysis product of the raw material, no extra material is needed to be utilized, the cost is reduced, and on the other hand, heavy carbon organic matters in the pyrolytic oil are slowly decomposed or degraded in the soil improvement process to continuously provide a carbon source or nutrient, thereby producing a fertilizer-holding slow-release effect and promoting the effective restoration of the soil.

According to the invention, in step 2, the first microbial agent is compounded with the pyrolytic carbon to form a microbial agent compound comprising the first microbial agent and the pyrolytic carbon before the soil layer is inoculated with the first microbial agent. For this purpose, the pyrolytic carbon or doped pyrolytic carbon obtained above is immersed in the bacterial liquid formed by the first bacterial agent. The soaking time may be several hours, for example, 0.5 to 5 hours, preferably 2 to 3 hours. And then taking out the soaked pyrolytic carbon, and culturing for a period of time, preferably 5-30 h, preferably 12-18 h, at a preset temperature, preferably 30-35 ℃, so as to obtain the doped pyrolytic carbon with biological activity, wherein the calcium carbonate is light calcium carbonate, and the light calcium carbonate and the pyrolytic carbon are taken as a microorganism carrier together, so that a space is provided for the adhesion of loaded microorganisms, the pyrolytic carbon can effectively improve the activity of microorganisms and regulate and control soil pollution on one hand, and can well protect strains on the other hand.

In step 2 of the invention, the prepared first microbial inoculum or the compound containing pyrolytic carbon and loaded with the first microbial inoculum is applied to the polluted soil to be regulated and controlled, and the addition amount of the first microbial inoculum is 1% -5%, preferably 2% -4%, based on the dry weight of the soil. For this purpose, the soil is deep-ploughed, for example by 10-30cm, preferably 15-25cm. Then allowed to stand for several days to several weeks, preferably for a period of one week.

According to the method provided by the invention, in step 3, a prosthetic plant is planted in the soil area, wherein the prosthetic plant can be crops, cash crops or other herbaceous plants. Preferably, according to the region, water conservancy and other conditions, rice, wheat, ryegrass, sorghum, corn, castor-oil plant, ramie and the like can be selectively planted, and ryegrass, corn, castor-oil plant and ramie are preferred.

According to the invention, in step 4, after planting the prosthetic plant for several days, other microorganisms are applied to the soil layer, preferably by dispersive mixing inoculation of the second microbial agent. Depending on the plant type and growth, it may be, for example, inoculated within 5-30 days.

In the invention, the strain of the second microbial inoculum can be selected from one or more of white rot fungi and/or arbuscular mycorrhizal fungi, wherein the white rot fungi are preferably Phanerochaete chrysosporium, have extremely strong glycolytic lignin effect, and the arbuscular mycorrhizal fungi are preferably young sleeve saccule fungi, so that the adaptability of plants to extreme environments can be improved, and the stability of an ecological system can be improved. The Phanerochaete chrysosporium and the young sleeve sacculus mildew can be purchased in the form of dry powder or spore liquid, and the respective spore suspension can be prepared from the dry powder by adopting a method commonly used in the prior art for use.

In the invention, the microbial inoculum can be applied by flow irrigation or by pumping. In order to accurately regulate the flow rate and avoid waste of bacterial liquid during continuous application, a plunger pump is preferably adopted as application equipment, and the plunger rod reciprocates in the cylinder body to change the volume of the sealed working cavity so as to realize the purposes of liquid suction and liquid discharge.

Specifically, the structure of the plunger pump used in the invention is shown in fig. 1, wherein a pump sleeve is nested in a shell, and an end cover is arranged at the upper end part of a pump body. When the bacterial liquid is applied, the plunger rod 4 which is arranged in the pump sleeve in a sliding way is pulled downwards, the bacterial liquid is pumped out from the container and is fed in from the liquid inlet 1, enters the blind hole of the end cover through the liquid guide channel 2, is communicated with the inside of the pump sleeve, then enters the liquid storage cavity 3, is formed between the upper end face of the matching part 5 on the upper part of the plunger rod and the bottom face of the blind hole, and when the bacterial liquid reaches a preset amount, the bacterial liquid accurately metered flows out from the liquid outlet 7 along with the upward movement of the plunger rod 4 and is accurately guided to the inoculation position. After the application, part of bacterial liquid is still remained in the blind hole, at the moment, the plunger pump 4 slides downwards until the matching part 5 is positioned in the area of the groove 6, the groove is axially arranged on the inner peripheral surface of the lower end part of the pump sleeve, the groove 6 is used for communicating the liquid storage cavity 3 with the outside of the plunger pump, and bacterial liquid can be completely discharged through the groove 6. The plunger pump is also convenient for cleaning the inside of the pump.

According to the invention, the location of the diffuse mixed inoculation of the second microbial inoculum in the soil layer differs depending on the plant species, for example, at a depth of 5 to 25cm, preferably 8 to 18cm, from the soil surface layer in the vicinity of the plant root. The inoculation amount of the second microbial inoculum is 0.8-1.5 g/m ² Preferably 0.9 to 1.2g/m ² Multiple inoculations, such as layering inoculations, preferably one layer per 1-2 cm thickness, can be inoculated, 2-5 layers.

Preferably, the planted prosthetic plants are subjected to normal field management, including watering, fertilizing, weeding, and harvesting on time.

Examples

The invention is further described below by means of specific examples, which are however only exemplary and do not constitute any limitation on the scope of protection of the invention.

Example 1

The corn stalk is washed by water, soaked in 0.01M dilute hydrochloric acid for 2 hours, air-dried until the water content is 15-18%, and chopped. In a pyrolysis furnace, nitrogen is introduced to purge, then straw and a calcium mixture accounting for one fifth of the weight of the straw (the weight ratio of calcium oxide to calcium carbonate is 2:1) are added through a feeding port, the temperature is raised to 450-550 ℃, the heat preservation reaction is carried out for 2 hours, and meanwhile, the circulation of nitrogen is kept.

Then cooling to room temperature to obtain pyrolytic carbon, crushing, and pressing with antipyretic oil obtained by condensing pyrolysis gas into granules with the particle size of 2-4 mm.

Expanding and culturing saccharomycetes, halomonas and pseudomonas aeruginosa to obtain a thallus concentration of 10 ⁹ And mixing liquid strains with the mass ratio of 3.2:2.5:1, soaking semicoke particles in the bacterial liquid for 4 hours, and culturing in a constant-temperature incubator at 30 ℃ for 12 hours to obtain the pyrolytic carbon-bacterial agent compound.

And (3) selecting an experimental soil area polluted by heavy metals and petroleum, dividing sample sides, wherein the length and the width are 5m, reserving ridges with the width of 0.8m between each sample side, and setting 5 sampling points according to a diagonal line principle by each sample side. Soil with the surface layer of 0-25 cm is adopted, and the soil is ventilated and dried in shade, so that impurities are removed. Soil pH7.8 was measured with a petroleum hydrocarbon content of 838.4mg/kg and heavy metals Zn, pb, cd, hg and As concentrations of 480.5, 318.3, 98.3, 14.4 and 90.3mg/kg, respectively.

Adding the soil into the polluted soil according to the addition amount of 2% of the dry weight of the soil, deep-ploughing for 22-27cm, and then standing for one week.

Then planting ramie in soil, after planting for 12 days, applying spore suspension of Phanerochaete chrysosporium and young sacculus mildew at a position 8-16cm away from the soil surface layer to obtain bacterial liquid (the concentration of the spore suspension of Phanerochaete chrysosporium is 2.8X10) ⁶ The concentration of spore suspension of the young sacculus was 3.5X10 per mL ⁶ and/mL). The inoculation amount is 1.0g/m ² The inoculation was performed in 3 times. After the ramie is ripe, the ramie is harvested.

After the soil layer of the experimental area is mixed, inoculated and regulated by the method, sampling is carried out, and the analysis and measurement results are as follows: the pH of the soil was reduced to 7.3, the petroleum hydrocarbon content was 362.4mg/kg, and the heavy metals Zn, pb, cd, hg and As concentrations were 181.5, 72.2, 0.95, 1.09 and 31.6mg/kg, respectively.

The invention has been described in detail in connection with the specific embodiments and exemplary examples thereof, but such description is not to be construed as limiting the invention. It will be understood by those skilled in the art that various equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its embodiments without departing from the spirit and scope of the present invention, and these fall within the scope of the present invention.

Claims (1)

1. A regulating and controlling method for microbial soil layer dispersion mixing inoculation is characterized in that,

washing corn stalk with water, soaking in 0.01M dilute hydrochloric acid for 2 hr, air drying to water content of 15-18%, and cutting; in a pyrolysis furnace, nitrogen is introduced to purge, and then straw and a calcium mixture accounting for one fifth of the weight of the straw are added through a feeding port, wherein the calcium mixture is a mixture of calcium oxide and calcium carbonate, and the weight ratio of the calcium oxide to the calcium carbonate is 2:1, heating to 450-550 ℃, and reacting for 2 hours while keeping the circulation of nitrogen;

then cooling to room temperature to obtain pyrolytic carbon, crushing, and pressing with antipyretic oil obtained by condensing pyrolysis gas into granules with the particle size of 2-4 mm;

expanding and culturing saccharomycetes, halomonas and pseudomonas aeruginosa to obtain a thallus concentration of 10 ⁹ Mixing liquid strains with a mass ratio of 3.2:2.5:1 of saccharomycetes, halomonas and pseudomonas aeruginosa, soaking the particles in a bacterial liquid for 4 hours, and culturing in a constant-temperature incubator at 30 ℃ for 12 hours to obtain a pyrolytic carbon-bacterial agent compound;

selecting an experimental soil area polluted by heavy metals and petroleum, dividing sample sides, wherein the length and the width are 5m, reserving a ridge with the width of 0.8m between each sample side, and setting 5 sampling points according to a diagonal line principle by each sample side; adopting soil with the surface layer of 0-25 cm in the test field, cooling in shade, ventilating and airing, and removing impurities; determining soil pH, petroleum hydrocarbon content, heavy metal Zn, pb, cd, hg and As concentration;

adding the pyrolytic carbon-microbial inoculum compound into the polluted soil according to the addition amount of the pyrolytic carbon-microbial inoculum compound accounting for 2% of the dry weight of the soil, deep-ploughing for 22-27cm, and then standing for one week;

then planting ramie in soil, after planting for 12 days, applying a bacterial liquid obtained by mixing the spore suspension of Phanerochaete chrysosporium and the spore suspension of the young sleeve sacculus mildew in a volume ratio of 1:1 at a position 8-16cm away from the surface layer of the soil, wherein the concentration of the spore suspension of the Phanerochaete chrysosporium is 2.8x10 ⁶ The concentration of spore suspension of the young sacculus was 3.5X10 per mL ⁶ The inoculation amount is 1.0g/m per mL ² Inoculating for 3 times, and harvesting the ramie after the ramie is ripe;

after the soil layer of the experimental area is mixed, inoculated and regulated by the method, sampling is carried out, and the soil pH, the petroleum hydrocarbon content and the heavy metal Zn, pb, cd, hg and As concentration are analyzed and measured.

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