Combined chemical-phytoremediation method for fluoride compound polluted soil

Abstract

The invention discloses a chemistry-plant combined remediation method of fluoride-type combined pollution site soil. The chemistry-plant combined remediation method of fluoride-type combined pollution site soil comprises the following steps: firstly, crushing and screening pollution soil particles; then placing the soil particles into a soil multielement ex-situ remediation device, adding mixed eluant, and carrying out continuous ex-situ synergism elution by adopting the mode of ultrasonic intensification and warming treatment synchronously; then inoculating purslane for eluted soil, and applying a nutritious source buffer liquid equal to 30%-40% of soil mass; culturing and growing artificially, and completing the remediation. Perfluorinated compounds, polycyclic aromatic hydrocarbon and multiple types of heavy metals in site soil can be eluted efficiently and synchronously; purslane inoculation and outer source nutritional substance adding are beneficial to the deep degradation by combining with residual state polycyclic aromatic hydrocarbon after soil elution, and are also beneficial to the recovery of microorganism ecological function universality and stability of the pollution soil environment.

Description

technical field [0001] The invention belongs to the technical field of soil remediation of polluted sites, and in particular relates to a rapid chemical-plant combined remediation method for compound polluted site soil by perfluorinated compounds, polycyclic aromatic hydrocarbons and various heavy metals. Background technique [0002] In recent years, with the acceleration of my country's urbanization process and industrial transfer, and the implementation of national policies such as "retreating from two to three" and "retreating from cities and entering parks", a large number of coal-fired thermal power plants, heating plants, fertilizer plants and Site soils polluted by perfluorinated compounds, polycyclic aromatic hydrocarbons and heavy metals caused by the closure, relocation and irregular operation of coking plants and other enterprises. At present, most of these sites are facing the conversion and secondary development of land use functions, such as: commercial land, r...

AI Technical Summary

Problems solved by technology

However, these methods are mainly aimed at the PAH-contaminated farmland soil with low pollution concentration, and the effect is not good for the site soil with high pollution concentration; application number: 201210385520. Its method applied in the remediation of compound polluted soil, although this method can make degrading bacteria tolerate high concentrations of Cu, Zn, Cd, Ni and Pb while degrading and remediating high-concentration polycyclic aromatic hydrocarbons, but the degrading bacteria did not It shows whether it can continue to tolerate the co-toxic stress of high concentrations of Cr and perfluorinated compounds. At the same time, this restoration method has not completely removed various heavy metals from the soil, so there is still a high secondary environmental risk; application number: 200710020380.5 provides a phytoremediation method for zinc and cadmium complex pollution, but this method is often aimed at farmland soil, and the actual operation period is long, and the environmental interference factors are relatively large, so it is not the first choice to achieve the goal of rapid site soil remediation; Application number: 200710010441.X provides a heavy metal-contaminated soil washing device and its method, but this method is only aimed at the remediation of heavy metal-contaminated soil, and is less effective for complex-contaminated soil where organic pollutants and heavy metals exist simultaneously; through Relevant literature review and patent search did not find the publication and acceptance of the elution and remediation technology of perfluorinated compound compound-contaminated soil. The closest existing technology to the present invention is the surfactant elution technology, application number: 201010558286.7 provides a method for leaching and remediating organic-inorganic compound polluted soil. This method mainly uses sodium lauryl sulfate and diethylamine disuccinic acid to leaching the polluted soil, but the organic pollutants targeted by this method are mainly chlorine Benzene and trichlorethylene organic pollutants mainly target heavy metals such as copper and chromium-contaminated soil, lack of effectiveness verification for polycyclic aromatic hydrocarbons and multiple heavy metal-contaminated soil, and the chemical eluents used may affect the soil environment. It will cause the risk of secondary pollution; application number: 201210486441.8 provides a chemical-microbial joint remediation method for the soil of complex pollution sites of polycyclic aromatic hydrocarbons and heavy metals, but this method has not considered that in complex pollution sites, it also contains a large number of high-concentration The complex pollution situation of perfluorinated compounds, and after the continuous elution of this method, although the removal rate of the total PAHs is over 90%, the single eluent methyl β-cyclodextrin solution used in the continuous 3-5 After the second elution, the removal rate of Cd, Ni, Zn, Cr and Pb can be 68~93%, that is, the removal efficiency of the method for heavy metals is lower than the removal efficiency of polycyclic aromatic hydrocarbons, and through the implementation of the claims The results of Case 1 found that, using the accepted patent conditions for verification, methyl β-cyclodextrin significantly reduced the removal rate of various pollutants in the soil of the perfluorinated compound compound pollution site, and it was difficult to achieve the effect of efficient removal

Therefore, there is still a large room for improvement in the broad-spectrum synergistic removal rate of organic-inorganic pollutants.

[0004]The main defect of the existing technology is: the lack of synergistic elution technology for high-concentration perfluorinated compounds, polycyclic aromatic hydrocarbons and heavy metal compound polluted soil at the same time , There are fewer types of organic-inorganic pollutants, it is difficult to achieve simultaneous and efficient elution and removal of organic-inorganic pollutants, the selected chemical eluent is less environmentally friendly, the removal effect of pollutants is not complete, and the soil after elution The recovery effect of environmental ecological functions is not satisfactory, etc., so the market application prospect of existing technologies is not clear

[0005]The main reasons for defects are: In recent years, there have been a large number of coal-fired thermal power plants, heating plants, fertilizer plants and coking plants, etc. organic-inorganic complex polluted sites, and early scientific and technological personnel paid relatively little attention to and researched and developed such polluted soil remediation technologies; although at this stage, elution and remediation technologies for compound polluted site soils of polycyclic aromatic hydrocarbons and heavy metals have gradually emerged, However, due to the high concentration of perfluorinated compounds found in the soil of such sites in recent years, its toxic effects have gradually been recognized by humans. However, the research and development of related collaborative restoration technologies are obviously insufficient; The farmland soil with relatively low pollution concentration originally has poor remediation effect on the site soil with high pollution concentration; the existing remediation technology has little consideration for the restoration of the diversity and stability of microbial ecological functions in the remediation soil environment

Images