Commonly used contaminated site repair techniques include excavation, stabilization / curing, chemical leaching, stripping, heat treatment, bioremediation and the like. (1) excavation Refers to the mechanical, artificial and other means to make the soil from the original location of the process. Generally include the excavation process and excavation of the soil after-treatment, disposal and re-use process. Mining techniques such as site environment assessment, restoration activities, and post-assessment phases may be used in all phases of site restoration and in the implementation of various repair technologies. As a remediation technique, the recommended mining of this guideline can only be used as part of the remediation plan and can not be applied to the traditional plan of landfill technology. (2) stable / curing Refers to the solid state form of physical isolation of pollutants or pollutants into chemically inert form, reducing the hazards of pollutants can be divided into in situ and ectopic stability / cure repair technology. In-situ stabilization / curing technology is suitable for the remediation of soils contaminated with heavy metals, and generally not suitable for remediation of contaminated soils contaminated by organic pollutants. Ectopic stabilization / solidification techniques are generally applicable to the treatment of inorganic pollutants and are not applicable to semi-volatile organic compounds and pesticides Remediation of soil contaminated with insecticides. (3) chemical leaching Refers to the use of solvents that promote the dissolution or migration of contaminants in the soil environment by pushing the cleaning liquid through a hydraulic ram and injecting it into the contaminated soil and then extracting the contaminated liquid from the soil layer Separation and sewage treatment technology, can be divided into in situ and ectopic chemical leaching technology. In-situ chemical leaching is suitable for porous, permeable soils with hydraulic conductivities greater than 10-3 cm / s, such as sand, gravel, alluvial and coastal soils, not suitable for fine-grained red and yellow soils Soil; Ectopic chemical leaching is applicable to soils contaminated by heavy metals, radionuclides, petroleum hydrocarbons, volatile organic compounds, PCBs and PAHs with clay content less than 25%. (4) stripping technology Refers to the use of physical methods by reducing the vapor pressure of soil pores, soil pollutants into steam form and be removed technology can be divided into in situ soil stripping technology, heterotopic soil stripping technology and multi-phase leaching technology . Gas stripping technology is suitable for gas-bearing zones above the aquifer; multi-phase leaching technology is suitable for gas-bearing zones and underground aquifers. In situ soil stripping technology is suitable for the treatment of volatile organic compounds with a Henry's coefficient of more than 0.01 or a vapor pressure of more than 66.66 Pa, such as volatile organic or non-halogenated substances. It can also be used to remove oils, heavy metals, polycyclics Aromatics or two VA British contaminant; ectopic soil stripping technology is suitable for the repair of contaminated soil containing volatile organic halogenated substances and non-halogenated substances; multiphase leaching technology is suitable for handling medium and low permeability formations in the volatile Organics. (5) heat treatment Refers to the direct or indirect heat exchange, the contaminated medium and the organic pollutants contained in the heated to a sufficient temperature (150 ~ 540 ℃), the organic pollutants from the polluting medium or volatile process, according to the temperature can be divided into low-temperature heat treatment Technology (soil temperature of 150 ~ 315 ℃) and high temperature heat treatment (soil temperature of 315 ~ 540 ℃). Heat treatment and remediation technology is suitable for the treatment of volatile organic compounds, semi-volatile organic compounds, pesticides and high boiling point chlorinated compounds in soil. It is not suitable for the treatment of heavy metals, corrosive organic compounds, reactive oxidants and reducing agents in soils. (6) Bioremediation Bioremediation refers to bioengineering systems that use microorganisms, plants and animals to degrade, absorb or enrich hazardous contaminants in soil and groundwater. According to the treatment site is divided into in situ and ectopic bioremediation. Bioremediation technology for hydrocarbons and derivatives, such as gasoline, fuel, ethanol, ketone, ether, etc., is not suitable for the treatment of persistent organic pollutants. Printing Screen Mesh,Polyester Screen Print Mesh,Custom Polyester Screen Mesh,Bolting Cloths Mesh shaoxing gesheng wire mesh co., ltd , https://www.gscreenmesh.com