CN101693252A - Application of siegesbeckia herb in remediation of soil contaminated with heavy metal cadmium - Google Patents

Abstract

The invention discloses an application of a compositae plant scutellaria in repairing soil polluted by heavy metal cadmium. The snail can only be planted in the soil polluted by heavy metal cadmium. Utilizing the enrichment characteristics of heavy metal cadmium in C. chinensis, planting it in polluted soil can absorb and accumulate heavy metal cadmium, and transfer most of it to the aboveground part, so as to achieve the purpose of remediating soil heavy metal cadmium pollution. It does not require special management during its growth process, so the cost is low and the operability is strong; moreover, the individual biomass of S. chinensis is large, which can improve the effect of remediation of heavy metals in soil per unit area, and has developed a new method for phytoremediation of heavy metal-contaminated soils. species of plant resources.

Description

The application of Xixue in remediation of heavy metal cadmium pollution in soil

technical field

The invention relates to the technical field of remediation of heavy metal pollution in the environment, in particular to the application of a plant scutellaria in remediation of heavy metal cadmium pollution in soil.

Background technique

The heavy metal cadmium (Cd) pollution in the environment has the characteristics of concealment, long-term and irreversibility. Its pollutants have poor mobility in the medium, long residence time, cannot be degraded by microorganisms, and can be transmitted through the food chain, which will eventually affect human health. have an immeasurable impact. The Japanese bone disease incident that shocked the world was caused by the pollution of cadmium in the soil. Therefore, cadmium-contaminated soil urgently needs to be treated.

Phytoremediation using heavy metal-enriched plants or hyperaccumulators is one of the research hotspots in environmental science today. It has many characteristics such as low investment, high efficiency, and no secondary pollution. shows great potential. Most of the enrichment plants or hyperaccumulation plants gather in the wild in the form of communities, mainly in mining areas, mineralization belts, and soils formed by weathering of rocks rich in metal elements. Therefore, the survey of plants growing naturally on abandoned mines or metal mine outcrops is one of the effective ways to find enriching plants or hyperaccumulating plants.

The cadmium hyperaccumulator plants discovered so far are relatively rare, including a few plants of the genus Brassica genus; the cadmium-enriching plants have been found to include vetiver, ramie, nightshade, small white wine, wolfberry, etc., which are highly resistant to cadmium. Both single and combined pollution have strong tolerance and accumulation ability. However, most of the cadmium-enriched plants found so far grow slowly, the plants are short, and the aboveground biomass is small, which are limited in practical application. Therefore, to find other cadmium-enriched plants to overcome the shortcomings of slow growth and short plants of the existing restoration plants, and to cultivate varieties with rapid growth, tall plants and large biomass is an urgent problem to be solved in the phytoremediation technology of cadmium-contaminated soil.

At the same time, with the development of industrial and agricultural production, soil cadmium pollution is increasing, especially the situation of cadmium pollution in agricultural soil is worrying. However, the plant species resources currently available for cadmium-contaminated soil remediation cannot meet the actual needs, and further research and expansion of available resources are urgently needed. In addition, there are abundant plant resources on the earth. It takes a lot of manpower, material and financial resources to determine which plants have the corresponding enrichment characteristics for cadmium. efficiency and application.

Siegesbeckia orientalis L. (Latin name Siegesbeckia orientalis L.) is a herbaceous plant of the genus Siegesbeckia in the Asteraceae family. It is mainly produced in Hunan, Fujian, Jiangsu, Zhejiang, Hubei, Sichuan and other places. Its whole plant has the effects of dispelling rheumatism, strengthening muscles and bones, clearing heat and detoxifying.

Contents of the invention

In the research work on the restoration of heavy metal pollution, the inventor discovered again after discovering heavy metal-enriching plants such as bald sore flower and chrysanthemum chrysanthemum: Siegesbeckia orientalis L. Cadmium heavy metals in the environment have significant enrichment properties. Therefore, the object of the present invention is to address the above-mentioned problem of insufficient resources of plant species that can be used for bioremediation of heavy metal pollution in soil, and to provide a new plant variety, Scutellaria chinensis, for remediation of heavy metal cadmium pollution in soil.

In order to realize the foregoing invention object, the technical scheme that the present invention adopts is as follows:

For the application of Siegesbeckia orientalis L. in remediating soil cadmium pollution, it is enough to plant Siegesbeckia orientalis L. in soil polluted by heavy metal cadmium. The Cd in the polluted soil is absorbed by the roots of C. chinensis and transferred to the above-ground organs such as stems and leaves, so as to achieve the purpose of removing the pollutant heavy metal Cd in the soil.

Seaweed has very strong vitality and is easy to survive. It can be directly transplanted or grown directly from seeds; it can survive under natural conditions and does not need special management during its entire growth process.

Periodic harvesting can be carried out when the aerial parts form a certain amount of biomass, and the heavy metal Cd will be removed in large quantities with the harvesting of the aerial parts. Its seeds naturally reproduce and grow quickly, and the stubble part can continue to grow without the need for annual planting, which can effectively reduce the content of Cd in the polluted soil, thereby remediating the polluted soil.

Siegesbeckia orientalis L. in the present invention is an annual herbaceous plant of the genus Siegesbeckia orientalis in the family Asteraceae. Experimental research has proved that it mainly has the characteristic of enriching cadmium (Cd) heavy metals. The present invention makes full use of the enrichment characteristics of Cd heavy metals of S. chinensis, transplants its seedlings or broadcasts its seeds directly into the soil polluted by heavy metal cadmium, absorbs and accumulates Cd heavy metals in the polluted soil, and transfers most of them to For the aboveground part, reduce the Cd content in the soil. When the aboveground part forms a certain amount of biomass, it can be harvested for continuous extraction, so as to achieve the purpose of reducing the Cd content in the polluted soil.

Compared with prior art, the beneficial effect of the present invention is:

The inventors have found through experimental research that the Chinese clams have significant enrichment properties for the heavy metal cadmium. The present invention just utilizes the enrichment characteristic of the heavy metal cadmium in the scutellaria, planting it in the cadmium-contaminated soil, can absorb and accumulate the heavy metal cadmium, and transfer most of it to the aboveground part, so as to achieve the purpose of repairing the polluted soil. In addition, because the vitality of Xixue is very strong and easy to survive, no special management is required during the whole growth process, so the cost is low and the operability is strong; at the same time, the individual biomass of Xixapia is large, which can increase the concentration of heavy metals in the soil per unit area. Remediation Efficiency, developed a new variety of plant resources for phytoremediation of heavy metal-contaminated soils.

Description of drawings

Fig. 1 is the above-ground biomass of C. chinensis under the treatment conditions of different Cd concentrations in the examples.

Detailed ways

The present invention will be further described in detail below in combination with specific embodiments.

However, it should not be construed that the scope of the above-mentioned subject matter of the present invention is limited to the following examples.

Example 1

The present embodiment is the application of SiCin in remediation of heavy metal cadmium pollution in soil:

The test site is located at the Soil and Fertilizer Experiment Station of the Teaching and Research Farm of Sichuan Agricultural University.

Using the method of potting to simulate soil heavy metal pollution, Siegesbeckiaorientalis L., a plant of the Asteraceae family Siegesbeckiaorientalis L., was planted in the potting soil polluted with gradient concentrations of heavy metal cadmium, and the seedlings of Siegesbeckiaorientalis were transplanted in the Growing in a potted plant; after 85 days, carry out stubble and harvest the aerial part of the plant, and measure the weight percentage content of heavy metal Cd therein.

A total of 8 treatments were set up in the experiment, namely CK (without adding Cd) and 7 experiments with different dosage concentrations, the dosage concentrations were 10mgkg ^-1 (T1), 30mg kg ^-1 (T2), 60mg kg ^-1 (T3 ), 90mg kg ^-1 (T4), 120mg kg ^-1 (T5), 150mg kg ^-1 (T6) _{, 180mg} kg ^-1 (T7). The reagent is added to the soil in solid form, mixed thoroughly, and balanced for four weeks before use.

The experiment started in spring, and the seedlings were transplanted from the transgenerational genetic seedlings collected from the southern mining area of Kangding County, Ganzi Prefecture, Sichuan Province. There were 6 plants in each pot and 3 repetitions. Cultivate in a net room, water from time to time according to the actual situation of soil moisture to ensure that the soil moisture is kept at about 80% of the field water holding capacity, and the heavy metal cadmium content is measured after the plants are mature.

The test results are as follows:

Figure 1 shows the biomass of the aboveground parts of C. chinensis under different Cd concentration treatment conditions (in Figure 1, a, b, c, and d are marked for significant differences). The significance analysis of the least significant difference method showed that there was no significant difference (P<0.05) in the aboveground biomass between the treatments with Cd concentration of 10, 30, and 60 mg kg ^-1 compared with the control (P<0.05), showing Strong patience. However, at a higher level of Cd pollution treatment, that is, after the concentration was greater than 90 mg kg ^-1 , the aboveground biomass decreased (P < 0.05), indicating that although the tolerance of Silicia chinensis is strong, it still has a certain limit. When the concentration is greater than 90mg kg ^-1 , the growth of plants will be inhibited.

The results of Cd content determination in plants are shown in the following table 1:

Table 1. The enrichment characteristics of cadmium in C. chinensis under different treatment concentrations

TF is transfer coefficient, BCF is enrichment coefficient

The results in Table 1 show that when the concentration of cadmium in the soil is between T1 and T7, the enrichment coefficients and transfer coefficients of the aboveground parts ^of C. The shoot content was greater than 100mg kg ^-1 , which reached the critical standard of hyperaccumulator plant content, and the cadmium content in the plant increased with the increase of the concentration.

Based on the tolerance and enrichment characteristics of Cd to Cd, Cicada is a hyperaccumulator of Cd, and has a strong ability to repair Cd-contaminated soil.

Claims (3)

1. The application of Xixue in remediation of heavy metal cadmium pollution in soil, characterized in that: the Xixapium is planted in the soil polluted by heavy metal cadmium. 2 . The application according to claim 1 , characterized in that: directly transplanting said Scutellaria chinensis, or directly planting seeds of Scutellaria chinensis in soil polluted by heavy metal cadmium. 3 . 3. The application according to claim 1, characterized in that: regularly harvest the above-ground parts of the plants of the planted Scutellaria chinensis.

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