CN105710121B

CN105710121B - Method for restoring petroleum hydrocarbon contaminated soil by using wild ornamental plant veronica officinalis

Info

Publication number: CN105710121B
Application number: CN201610237372.5A
Authority: CN
Inventors: 程立娟; 王亚男; 周启星
Original assignee: Nankai University
Current assignee: Nankai University
Priority date: 2016-04-15
Filing date: 2016-04-15
Publication date: 2021-04-20
Anticipated expiration: 2036-04-15
Also published as: CN105710121A

Abstract

A method for restoring petroleum hydrocarbon polluted soil by using wild ornamental plant veronica officinalis realizes the degradation of petroleum hydrocarbon in soil by using the absorption and degradation effects of plants and rhizosphere microorganisms, and comprises the following detailed steps: by adopting a method of sowing planting or soil culture seedling-seedling transplantation, the veronica officinalis is respectively planted in petroleum hydrocarbon polluted soil, the maximum water capacity of the soil is measured, and the soil is watered once a day according to 60 percent of the maximum water capacity; when the veronica is long to maturity or flowering, the whole is removed; and repeatedly planting the veronica officinalis in the soil, and continuously reducing the petroleum hydrocarbon pollution concentration in the soil until the petroleum hydrocarbon content in the soil reaches the national environmental standard or ecological safety index. The method has the advantages that: the method has the advantages of low cost, small engineering quantity, no secondary pollution to the environment and no damage to the soil structure, is an efficient and economic green restoration technology, and fully realizes the unification of ecological benefit, environmental benefit and economic benefit.

Description

Method for restoring petroleum hydrocarbon contaminated soil by using wild ornamental plant veronica officinalis

Technical Field

The invention relates to an environment restoration technology of petroleum polluted soil, in particular to a method for restoring petroleum polluted soil by using wild ornamental plant veronica officinalis.

Background

Soil is one of the most basic environmental elements on which humans rely for survival, and is also an important place of activity for microorganisms, plants, and animals. While providing a resource foundation for agricultural production and urban development of human beings, the soil has to bear various pollutants discharged by human beings (reference 1: Zhou Qixing. 2006. latest progress of research on soil environmental pollution chemistry and chemical remediation. environmental chemistry 03: 257-. According to statistics, in the past forty years, at least billions of tons of harmful substances are released into soil all over the world, and only the industrial three wastes suffered by farmlands in China have been polluted by more than 1 hundred million acres (reference 2, inspired by week, Song Yu Fang, 2001, technical connotation and prospect of plant restoration, safety and environmental statement 03: 48-53). For petroleum pollution, the pollution degree is serious, and the toxicity is also great. Benzene series (such as benzene, phenols and other pollutants), aromatic hydrocarbons and the like in the petroleum hydrocarbon component can cause physical discomfort such as headache, dizziness and nausea after being contacted and exposed for a long time by a human body, and some even have strong three-cause (carcinogenic, teratogenic and mutagenic) effects (reference 3: Bell T.H., Joly S., Pitre F.E.et al.2014.incorporated into the molecular biology efficacy and reliability using novel microorganisms for prophaces. trends in Biotechnology.32(5 271): situated 280). The petroleum hydrocarbon has stronger hydrophobicity, can damage the soil structure in the soil and poison the root system of the plant, thus reducing the diversity of microbial communities in the soil and eliminating the noise of protozoa in the soil. In the limited soil resources and the current situation of increasingly serious and generalized petroleum pollution, considerable attention has been paid to the remediation and treatment of the petroleum-polluted soil, and the remediation technology of the polluted soil is one of the increasingly active research directions in the current environmental field (reference 4: Alkorta I.and Gardisu C.2001.phyto edition of organic pollutants in resources. Bioresource technology.79: 273-.

Through continuous exploration in recent years, the restoration technology of the polluted soil is rapidly developed, and various measures such as physical restoration, chemical restoration, biological restoration and the like all play very important practical significance (reference 5: curved thriving, grandfather, Zhou Qixing. 2008. the restoration technology of the polluted soil plant and the problems yet to be solved. environmental protection, 12: 45-47). In contrast, the traditional physical and chemical remediation methods such as soil replacement, chemical leaching, solvent leaching and the like are still high in cost, are easy to cause secondary pollution, and destroy the basic physicochemical properties and relevant ecological processes of soil; the microbial remediation technology is greatly influenced by environmental factors and is not suitable for environments with high or low pollutant content, and a certain group of microbes can only remediate a certain type of pollutants and may bring biological pollution to soil and underground water (reference 6: Zhuang X., Han Z., Bai Z. et al.2010.progress in purification by biological microbial contamination in saline water and soil. environmental pollution.158(5): 1119-. The phytoremediation technology has the characteristics of low cost, no damage to the soil structure, large-area in-situ operation, no secondary pollution and the like, so that the phytoremediation technology gradually becomes one of the most effective and feasible methods for remedying the polluted soil as a green and economic remediation technology (reference 7: Miao Xin Yuan, Zhou Huan. 2015. research progress of the phytoremediation efficiency influence factors of the polluted soil. journal of ecology 03: 870-.

From the viewpoint of the restoration plants, the restoration plants commonly used include trees, grasses, crops, aquatic plants, and the like. In recent years, flower plants have begun to be applied to soil remediation and exhibit unique advantages. In the narrow-sense flower concept, "flower" refers to the reproductive organ of a plant and "flower" is a general term for herbaceous plants, so the narrow-sense flowers refer to herbaceous flowering plants and foliage plants only (reference 8: Liujia female, Zhou Hua xing, Su Jiang, etc.. 2007. study on feasibility of applying the floral plants to contaminated soil remediation. application of the ecological bulletin, 07: 1617-. The general term of flowers refers to a general term of plants with certain ornamental value, such as ornamental flowers, ornamental leaves, ornamental buds, ornamental stems, herbs, woody plants, arbors, shrubs, aquatic plants, terrestrial plants and the like, which are various and cannot win the prosperity. Compared with common plants, the application of the flower plants to soil remediation can further beautify the environment and reduce the risk of entering a food chain and causing harm to human bodies; in addition, human beings accumulate abundant experiences such as variety breeding, flower cultivation and pest control in long-term production practice, and the application of flower plants is more beneficial to engineering management and artificial maintenance. Therefore, the flower plants have huge market and potential in the remediation application of the polluted soil.

So far, many research reports of plant repairing petroleum hydrocarbon polluted soil at home and abroad exist, but most of the found efficient repairing plants are pastures and crops, and the reports of repairing petroleum polluted soil by flower plants are rare. Moreover, the plant growth is deeply influenced by climate conditions, topography, soil properties, etc. (reference 9: Li X., Feng Y. AND Sawatsky N.1997. immunity of soil-water relationships in assessing the end of biological resources: I.plant growth. PLANT growing. PLANT AND SOIL.192(2): 219) 226), the plant with good repairing effect entering into another environment does not necessarily obtain the same ideal repairing effect, so the screening of the native species better adapted to the polluted environment becomes the first choice for plant repairing. However, the research of repairing the petroleum-contaminated soil by using the wild ornamental plants is in the initial stage, and the research of repairing the wild ornamental plants under the saline-alkali stress is not reported. Therefore, there is still a need for screening of floral repair plants for petroleum hydrocarbon contaminated soils.

Disclosure of Invention

The invention aims to solve the technical analysis and problems, and provides a method for restoring petroleum hydrocarbon polluted soil by using a wild ornamental plant Veronica polita Fries, which has low cost and does not generate secondary pollution to the environment; the wild ornamental plant variety is used, the method is suitable for large-area engineering operation, the extensive management is simple, and the environment can be beautified.

The technical scheme of the invention is as follows:

a method for restoring petroleum hydrocarbon polluted soil by using wild ornamental plant veronica officinalis realizes the degradation of petroleum hydrocarbon in soil by using the absorption and degradation effects of plants and rhizosphere microorganisms, and comprises the following detailed steps:

1) by adopting a method of sowing planting or soil culture seedling-seedling transplantation, the veronica officinalis is respectively planted in petroleum hydrocarbon polluted soil with the pollution specific gravity of 1-4% w/w concentration, the maximum water capacity of the soil is measured, and the soil is watered once a day according to 60% of the maximum water capacity; when the veronica is long to maturity or flowering, the whole is removed;

2) and repeatedly planting the veronica officinalis in the soil, and continuously reducing the petroleum hydrocarbon pollution concentration in the soil until the petroleum hydrocarbon content in the soil reaches the national environmental standard or ecological safety index.

The veronica adopted by the invention belongs to the Scrophulariaceae of the order tubuliformes, is a perennial root plant from one year to two years, is generally wild in various places in China, and is convenient to manage when being widely planted. The veronica officinalis has three colors of blue, white and pink, and has good ornamental value. The plant taxonomic characteristics of veronica is as follows: the plants have short and soft hairs; the stem branches from the base and the lower part of the stem is creeping on the ground; the triangular round or nearly round leaves grow in pairs at the lower part of the stem, the upper parts of the leaves grow mutually, and the edges of the leaves are provided with round teeth; in early spring, purple red florets are opened and grow in bract armpits; the fruit period is 3-5 months. The speedwell is pleased with light and resistant to half-yin, and is contraindicated for wet waterlogging in winter. The requirements on water and fertilizer conditions in planting are not high, but the planting soil is favored to be fertile, moist and deep, and the growth is moderate at 15-25 ℃. The veronica officinalis also has good medicinal value, and comprises the following main components: ferulic acid, 3-O-acetyl oleanolic acid, 3, 4-dimethyl cinnamic acid, daucosterol, beta-sitosterol, mannitol, etc., can be used for cooling blood, stopping bleeding, regulating qi-flowing, and relieving pain, and can be used for treating hematemesis, hernia, orchitis, and leukorrhagia.

The method has the advantages that: the veronica officinalis is a wild ornamental plant which can efficiently restore petroleum hydrocarbon pollution, and has strong tolerance and certain degradation capability to low and high concentration petroleum hydrocarbon pollutants in soil. The veronica officinalis is used for repairing petroleum hydrocarbon polluted soil, so that the cost is low and the engineering quantity is small; the environment is not polluted secondarily, and the soil structure is not damaged; the wild ornamental plant variety is used, the method is suitable for large-area engineering operation, the extensive management is simple, and the environment can be beautified. When the veronica is grown to maturity or flowering period, the whole veronica can be removed and sold as ornamental flowers, namely commodities. Therefore, the method for restoring the petroleum-polluted soil by the veronica officinalis is an efficient and economic green restoration technology, and the unification of ecological benefits, environmental benefits and economic benefits is fully realized.

Drawings

FIG. 1 is a graph comparing the degradation rate of total petroleum hydrocarbons in soil for Veronica and control groups at different concentrations of petroleum hydrocarbon contamination.

Detailed Description

Example (b):

a method for restoring petroleum hydrocarbon polluted soil by using wild ornamental plant veronica officinalis realizes the petroleum hydrocarbon in the degraded soil by using the absorption and degradation effects of plants and rhizosphere microorganisms, and the greenhouse pot restoration experiment of the veronica officinalis on the petroleum hydrocarbon polluted soil is as follows:

the experimental site is carried out in a greenhouse of the Taida institute of southern university in Tianjin, is in an economic and technical development area of Tianjin, belongs to temperate semi-humid continental monsoon climate, and the annual precipitation is about 500-plus 600. The soil used in the experiment was collected from the Hongkong oil field in Tianjin.

After the petroleum-polluted soil is collected, the petroleum-polluted soil is placed in a shade place to be air-dried, and after impurities such as gravel, leaves and the like are removed, a 2mm sieve is used. And (3) determining the total petroleum hydrocarbon content of the petroleum-polluted soil, and then fully mixing the petroleum-polluted soil with clean soil according to a certain proportion to prepare the petroleum hydrocarbon-polluted soil with the required concentration gradient. The experiment was performed in 3 treatment groups, respectively: CK (clean soil), contaminated soil A-total petroleum hydrocarbon concentration is 11874mg/kg (contamination concentration is about 1%), contaminated soil B-total petroleum hydrocarbon concentration is 38986mg/kg (contamination concentration is about 4%), each treatment is set up 3 parallel groups.

The diameter of the upper opening of the flowerpot for the pot experiment is 230mm, the height is 180mm, and three jin of soil are filled in each pot. Before the experiment, the soil is drenched thoroughly, and after the balance exceeds two weeks, the seeds of the veronica officinalis are directly sown or the seedlings are transplanted into pots, wherein 3 plants are planted in each pot. The maximum water holding capacity of the soil is measured in the early stage of the experiment, and the soil is watered once at eight early points in a fixed time according to 60% of the maximum water holding capacity, so that the biomass growth is maximum, and the pollutant degradation rate is highest. The watering mode combines top spraying watering and bottom tray watering to promote the root growth of plants. When the ectopic restoration planting is adopted, the pot soil is watered thoroughly, the transplanting time is preferably in the evening, and the in-situ restoration can also be carried out by directly planting in a field.

The veronica is harvested after it grows to maturity or after flowering. The harvested plants were cleaned with tap water and then with deionized water, drained, and the fresh weight of the aerial parts and the fresh weight of the roots were weighed. And (3) drying and dehydrating the soil sample for 24 hours by using a vacuum freeze dryer, and then determining the total petroleum hydrocarbon content of the soil by using a Soxhlet method, wherein an extracting agent is analytically pure dichloromethane.

The experimental results are as follows:

when the veronica is harvested when the veronica grows to the mature period or the flowering period, the veronica is good in growth condition and free of obvious poisoning symptoms such as fallen leaves, wilting, lodging and the like. The biomass of the veronica officinalis in the petroleum-contaminated soil was inhibited, but not statistically reduced relative to the non-contaminated group.

FIG. 1 shows the degradation rate of total petroleum hydrocarbons in soil by Veronica under different concentrations of petroleum hydrocarbon contamination. The control group also has a certain removal effect on the total petroleum hydrocarbon, which indicates that certain natural degradation effects such as leaching, photolysis and volatilization exist in the soil. However, when the soil petroleum hydrocarbon concentration is 11874mg/kg (the pollution specific gravity is about 1% w/w), the total petroleum hydrocarbon degradation rate of the planting veronica group is 45.52%, which is significantly higher than that of the blank control group by 29.44%; when the total petroleum hydrocarbon concentration of the soil is 38986mg/kg (the pollution specific gravity is about 4% w/w), the total petroleum hydrocarbon degradation rate of the grandma group is 19.34%, while that of the control group is only 9.46%. That is, in the soil polluted by the petroleum hydrocarbon with low and high concentration, the total removal rate of the petroleum hydrocarbon in the soil is obviously improved relative to the control group after the veronica officinalis is planted. It can therefore be concluded that: the veronica officinalis has certain repairing effect on petroleum hydrocarbon polluted soil with low (pollution specific gravity about 1 percent, w/w) and high (pollution specific gravity about 4 percent, w/w) concentration. The veronica officinalis is repeatedly planted in the soil with different pollution specific gravities for 2-5 times, so that the petroleum hydrocarbon content in the soil can reach the national environmental standard or ecological safety index. Of course, the method of the present invention is not limited to remediation of contaminated soils outside the range of 1% to 4% total petroleum hydrocarbon concentration, and the method of the present invention also has a petroleum hydrocarbon degrading effect, but the degrading effect is optimized within the above range.

Claims

1. A method for restoring petroleum hydrocarbon polluted soil by using wild ornamental plant veronica officinalis is characterized by comprising the following steps: the method realizes the degradation of petroleum hydrocarbon in soil by utilizing the absorption and degradation effects of plants and rhizosphere microorganisms, and comprises the following steps:

1) the method of sowing seeds or cultivating seedlings by soil-seedling transplantation is adopted, the veronica is planted in the soil polluted by petroleum hydrocarbon with the pollution specific gravity of 1-4% w/w concentration, the maximum water-holding capacity of the soil is measured, the veronica is watered once a day according to 60% of the maximum water-holding capacity, and when the veronica grows to the mature period or the flowering period, the whole body is removed;

2) repeatedly planting the veronica officinalis in the soil, and continuously reducing the petroleum hydrocarbon pollution concentration in the soil until the petroleum hydrocarbon content in the soil reaches the national environmental standard or ecological safety index;

the number of times of planting the veronica in the soil in the step 2) is 2-5 times.

2. The method for remediating petroleum hydrocarbon contaminated soil using wild ornamental plant veronica as claimed in claim 1, wherein: the daily watering time is 8-9 in the morning.