What are the physical remediation technologies of contaminated soil

Physical remediation techniques for contaminated soil include the following:

1.Guest soil method: The guest soil method is an in-situ treatment technology, which mainly mixes polluted soil with guest soil (unpolluted soil) to reduce the concentration of pollutants in the mixed soil and achieve the purpose of treatment.

It is suitable for volatile and semi-volatile organic pollutants and can be used for in-situ bioremediation, such as petroleum light products (gasoline, dichlorobenzene, chloroform, etc.).

2.Thermal desorption technology: Thermal desorption technology uses physical heating to volatilize organic pollutants in the soil and collect and treat them to achieve the purpose of soil remediation. It is suitable for volatile and semi-volatile organic pollutants, such as polycyclic aromatic hydrocarbons, polychlorinated biphenyls, dioxins, etc.

3.Soil vapor phase extraction technology: Soil vapor phase extraction technology is to extract volatile organic compounds from the soil into the atmosphere through the air extraction device to achieve the purpose of removing pollutants. It is suitable for volatile and semi-volatile organic pollutants, such as benzene series, chlorinated hydrocarbons, etc.

4.Mechanical ventilation technology: Mechanical ventilation technology is to install ventilation pipes in the soil and use ventilation equipment to force air into the soil to volatilize volatile pollutants from the soil to achieve the purpose of removal.

It is suitable for volatile organic pollutants, such as benzene series, chlorinated hydrocarbons, etc.

5.Soil solidification and stabilization technology: Soil solidification and stabilization technology is to fix pollutants in the soil, making them difficult to move and volatilize, so as to reduce the toxicity and bioavailability of pollutants. Suitable for inorganic contaminants such as heavy metals and radioactive elements.

In summary, the physical remediation technologies of contaminated soil include guest soil method, thermal desorption technology, soil vapor phase extraction technology, mechanical ventilation technology and soil solidification and stabilization technology. These technologies can effectively remove contaminants from the soil for remediation purposes.

Physical remediation of contaminated soil is a technology that removes or separates pollutants, especially organic pollutants, from the soil through various physical processes. It mainly includes soil leaching, thermal adsorption, vapor extraction, microwave heating and landfill technology.

At present, commonly used contaminated soil remediation technologies include (Xuliang) and so on.

a.Physico-chemical remediation techniques.

b.Joint remediation technology.

c.Raw and bright land hosiery key transport repair technology.

d.Engineering Repair Techniques.

Correct answer: ABCD

The chemical remediation techniques for soil pollution are briefly described as follows:

Compared with physical remediation, the chemical remediation technology of contaminated soil was developed earlier, mainly including soil solidification-stabilization technology, leaching technology, redox-2 reduction technology, photocatalytic degradation technology and electrodynamic remediation.

Curing-stabilization technology.

The solidification-stabilization technology is a method for the rapid control and remediation of soil heavy metal pollution, which is a method for fixing pollutants in a polluted medium to keep them in a long-term stable state, and has obvious advantages for treating multiple heavy metal complex contaminated soils at the same time [26]. The U.S. EPA refers to solidification stabilization technology as the best technology for dealing with hazardous toxic waste.

This technology has also been used in the heavy metal-contaminated soil of some smelting enterprises in China and the contaminated soil of the stockpiles after the clean-up of chromium slag. There have been international reports on the use of cement solidification and stabilization to treat organic and inorganic contaminated soils.

According to the definition of EPA, curing and stabilization have different meanings. The immobilization technology is to encapsulate the contaminant capsule into an inert substrate, or add a low-permeability material to the outside of the contaminant, so as to limit the migration of contaminants by reducing the leaching area exposed to contaminants. Stabilization refers to the harmlessness of pollutants by transforming them into forms that are not easily soluble, migratory or less toxic through morphological transformation, so as to reduce the risk of harm to ecosystems.

The cured product can be easily transported without the need for any ancillary containers; Stabilization does not necessarily alter the physical properties of contaminated soil.

The curing technology has the advantages of simple process operation, low cost, and easy availability of curing agent, but the conventional curing technology also has the disadvantages of washing down with potatoes, such as the increase of soil volume after the curing reaction, and the poor long-term stability of the solidified body. The stabilization technology can overcome this problem, such as the chemical stabilization technology developed in recent years, which can achieve less or no increase in the capacity of the waste while realizing the harmlessness of the waste, so as to improve the overall efficiency and economy of the hazardous waste treatment and disposal system;

The chemical chelation between the chelating agent and the heavy metals and other components in the waste can also be strengthened by improving the structure and properties of the chelating agent, thereby improving the long-term stability of the stabilized product and reducing the environmental impact of the stabilized product during the final disposal process. It can be seen that stabilization technology is expected to become the main force in the field of soil heavy metal pollution remediation technology.

The remediation technologies of contaminated soil include in-situ remediation, bridge pat technology and ex-situ remediation. The details are as follows:

1. From different perspectives, soil pollution remediation technologies can be classified differently. Soil pollution remediation technologies can be divided into in-situ remediation technologies and ex-situ remediation technologies. In-situ remediation technology refers to the process of treating unexcavated soil without much disturbance to the soil.

Its advantage is that it is more economical and effective, and the degradation and attenuation of pollutants are carried out on the spot. There is no need to build expensive ground environment engineering infrastructure and long-distance transportation, and operation and maintenance are relatively simple. In addition, in-situ remediation technology can remediate deep soil pollution.

The disadvantage is that it is more difficult to control the "three wastes" generated in the process of treatment;

2. Ex-situ remediation technology refers to the process of restoring the excavated soil. Ex-situ treatment refers to the process of treating the excavated soil in situ, and off-site treatment refers to the process of transporting the excavated soil to another site for treatment. Its advantages are better control of the conditions of the treatment process and better contact with pollutants.

It is easy to control the discharge of the "three wastes" generated in the treatment process; The disadvantage is that the soil needs to be excavated and transported before treatment, which affects the reuse of the treated soil and is usually expensive.

Legal basis: Article 11 of the Law of the People's Republic of China on the Prevention and Control of Soil Pollution.

People** at the county level or above shall include efforts on the prevention and control of soil pollution in citizens' economic and social development plans and environmental protection plans.

The competent departments for ecology and the environment of local people's ** at the districted-city level or above, in conjunction with the competent departments for development and reform, agriculture and rural affairs, natural resources, housing and urban-rural construction, forestry and grassland, and so forth, shall draft a soil pollution prevention and control plan on the basis of environmental protection planning requirements, land use, soil pollution status census and monitoring results, and publish it for implementation after reporting to the people's ** at that level for approval.

What are the technologies for soil heavy metal pollution control and remediation? Please give examples of at least 3 technical principles and scope of application.

Soil heavy metal pollution control and remediation technologies include:1Bioremediation:

Use the bioadsorption and biotransformation of microorganisms to decompose or convert pollutants into harmless substances. This technology is suitable for the case of light heavy metal pollution, and the effect is better. 2.

Electrochemical remediation: The use of electrolysis technology to reduce pollutants to non-toxic substances. This technology is suitable for heavy metal pollution, but it is rarely used because it requires a high-cost power supply.

3.Soil ion exchange: a certain matrix is used to adsorb heavy metal ions, and then the matrix and heavy metal ions are removed together after combining with the matrix.

This technique is suitable for situations where heavy metal contamination is mild to moderate, but the adsorption efficiency is low.

Hello dear, I am happy to answer for you, the main engineering measures include guest soil solidification, stabilization method, electrodynamic repair method, etc., engineering measures have the advantages of stability and quick effect, but there are shortcomings such as large amount of engineering, high investment cost, secondary pollution hazards, etc., which are not suitable for the treatment of large-scale polluted soil. 2. Chemical treatment measures include leaching method, application of amendments and other methods, which can reduce the toxicity and bioavailability of heavy metals in the soil in a short period of time, because of the artificial application of chemical agents to the soil, it is easy to cause secondary pollution, and the method is an in-situ remediation of square lead method, heavy metal Cd is still in the soil, easy to reactivate and harm plants, and its potential threat has not been eliminated. The agroecological restoration measures reduced the bioavailability of CD by adjusting factors such as soil moisture, soil pH value, soil cation substitution (CEC), CaCO3 and soil redox status, as well as temperature and humidity, so as to weaken the toxic effect of heavy metals on plants.

The morphology of CD has changed, but it still exists in the soil, which is easy to reactivate and cause harm to organisms. 4. Microbial remediation: The mechanism of microbial resistance to heavy metals includes bioadsorption, extracellular precipitation, biotransformation, bioaccumulation and efflux. On the one hand, microorganisms can reduce the toxicity of heavy metals in the soil, and can adsorb and accumulate heavy metals. On the other hand, it can change the microenvironment of root biologicals, thereby improving the efficiency of heavy metal absorption, volatilization or fixation by plants.

Summary. The common denominator is in the soil remediation industry, there are more than 100 existing soil remediation technologies, and the commonly used technologies can be roughly divided into three types: physical, chemical and biological.

The common denominator is in the soil remediation industry, there are more than 100 existing soil remediation technologies, and the commonly used technologies can be roughly divided into three types: physical, chemical and biological.

Nuclear remediation refers to the technology of removing or separating pollutants, especially organic pollutants, from the soil through various physical processes. It mainly includes technologies such as soil leaching, thermal adsorption, steam extraction, microwave heating and off-site landfilling. It also includes multiphase extraction and other technologies, which have been applied to the remediation of contaminated soils such as benzene, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls.

Compared with physical remediation, Yinhong has developed chemical remediation technology for contaminated soil earlier, mainly including soil solidification-stabilization technology, leaching technology, oxidation-reduction technology, chemical improvement, photocatalytic degradation technology, electrodynamic remediation technology and organic matter improvement.

The differences include the following.

First, reduce the concentration of pollutants in the soil; secondly, through solidification or passivation, the form of polluted silver dry matter is changed, so as to reduce the migration in the environment; Third; Removed from the soil.